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1. HEADING H 1 H 2 H n PERIOD T 1 T 2 T n Here PKT_NAME is the name of the set of response operators the PERIOD option defines the periods sec and the HEADING option defines the headings deg for which drift values will be defined Once in the menu the components of the mean wave drift force for the specified headings are defined with the command M_DRIFT PER FXR 1 FXI 1 FYAWI 1 FXR n FXI n FYAWI n Here PER is the period for which this set of forces is applicable and must be one of the T i specified with the PERIOD option FXR 1 FXI 1 FYAWI 1 are the real and imaginary parts of the mean drift forces and moments per unit of wave amplitude squared bforce blength 2 for force bforce blength for moments for the heading HED 1 Likewise the values FXR 2 are for heading HED 2 etc The corrections to the mean force due to motions are a complex 6x6 matrix per wave amplitude 2 defined with the command MD_MOTION PER HED MDR 1 1 MDI 1 1 MDI 6 6 the units here are feet or meters bforce seconds and radians When all of the data has been defined the menu should be exited with a END_M_DRIFT command Rev Page 380 MOSES REFERENCE MANUAL XX THE FREQUENCY RESPONSE MENU Frequency response is a linear approximation to the equations of motion with assumed harmonic input In MOSES a menu is devoted to computing frequency response and its post processing
2. F X DISP G D X V X F Y DISP G D Y V Y F Z DISP G D Z V Z M X DISP G R X 2 OMEG X M Y DISP G R Y 2 OMEG Y M Z DISP G R Z 2 OMEG Z Where G is the gravitational constant DISP D i and R i are the quantities spec ified V i is a velocity at the point PT and OMEG i is an angular velocity in rad sec Point buoyancies can be associated with the load group by BUOY PT DISP OPTIONS and the available options are CATEGORY CAT_NAME NUM_APPLIED NUMBER TOT_WEIGHT WT Here DISP bforce is the magnitude of the buoyancy which will be applied Again this is applied at the location specified by the point PT and is applied only when this point is below the water surface Weight can also be specified with this command Rev Page 269 MOSES REFERENCE MANUAL by use of the TOT_WEIGHT option Here WT is a weight bforce which will be applied at the same point as the buoyancy The following two commands AREA and PLATE are somewhat similar in that they both define an area which attracts water and wind forces The format of the first of these is AREA PT AX AY AZ OPTIONS and the available options are CATEGORY CAT NAME NUM_APPLIED NUMBER WIND WINMUL DRAG DRGMUL AMASS AMSMUL WAVE_PM WAVMUL BUOY THICK BTHICK TOT WEIGHT WT MULT WEIGHT WMULT Here AX AY and AZ ft 2 or m 2 define the components of an area c
3. Also in STRUDL it is possible to continue a line by ending it with a MOSES will not accept this and all line ending should be changed to either a or a One thing to notice is that in STRUDL the strong axis of a beam is the Z axis while in MOSES it is the Y axis In the conversion process Y will be changed with Z The only problem we know about with local axis conversions is with a vertical member which points down where local properties will perhaps be incorrect STRUDL finite elements are handled by placing the element name class and nodes in the converted file This allows the user to build a macro to represent the element The simplest macro is shown below amp macro SBCT class nodes plate class Znodes amp endmacro Rev Page 143 MOSES REFERENCE MANUAL XII B Defaults To allow flexibility in using MOSES the user is free to set many of his own defaults When defining a model or altering its definition there are a number of things which normally have the same value In other words many things have a default value The default values used are defined with the command amp DEFAULT OPTIONS Two basic options SAVE REMEMBER allow the user to push and pop the default stack Suppose that one wishes to alter some of the defaults temporarily and then return to the initial set This can be accomplished by issuing KDEFAULT SAVE which saves the current settings on
4. DOUSIDE YES NO P_DEVICE PDVNAM LEVEL FILE FILE SINGLE YES NO Basically this command associates a true physical device with the channel CHANAM and the valid values for CHANAM are those given for LDVNAM Here the PAGE_DIMEN option defines the size of a page on the channel in points and the DOUSIDE option instructs the printer to print on both sides of the paper and currently works only on PCL devices The physical devices which can be connected to channels are defined with the P_DEVICE option Here valid values of PDVNAM are SCREEN DEFAULT POSTSCRIPT TEX PCL JPG PNG UGX DXF HTML or CSV If the physical device is PCL then LEVEL defines the PCL level for the device which must be either 3 4 or 5 Here the physical device SCREEN does double duty in that it is specified for both the LOG and graphics screen channels and the particular behavior of the SCREEN depends upon the user interface one is using Normally logical devices of the same name are associated with these channels but it is not necessary More will be said about this later Not all physical devices can be connected to all channels In particular e LOG can only be connected to DEFAULT or SCREEN physical devices e OUTPUT can only be connected to DEFAULT TEX POSTSCRIPT or PCL physical devices e SCREEN can only be connected to DEFAULT or SCREEN physical devices e GRA DEVI can only be connected to UGX POSTSCRIPT DXF JPG or PNG phy
5. One can open a flood valve and let water run into the compartment One can open the vent valves and let water run into the compartment or Fluid can be pumped directly into the compartment Any of these processes is controlled by one of two commands One of these auto matically pumps water into compartments and will be discussed below The other one is amp COMPARTMENT FLAG 1 OPTION 1 FLAG n OPTION n Now this syntax is different from the normal in that here there are two things which begin with a The basic distinction between a FLAG and an OPTION is that FLAGS specify a class of action and OPTIONS are more specific A single FLAG can apply to more than one OPTION To control accidental or intentional flooding one uses the four flags FLOOD CMP_SEL 1 CMP_SEL n NO FLOOD CMP SEL 1 CMP_SEL n OPEN_VALVE CMP SEL 1 CMP_SEL n DOWN_FLOOD CMP SEL 1 CMP_SEL n DYNAMIC CMP_SEL 1 CMP_SEL n The FLOOD flag tells MOSES that the compartments which match CMP_SEL i will be open to the sea and that they will normally be full of water up to the wa terline The NO_FLOOD flag is used to reverse the process When this is used compartments revert to being filled as before it was flooded but with the current filling type filling type is discussed below The OPEN VALVE specifies that all flood valves attached to the compartment are open Here ambient wa
6. Rev Page 204 MOSES REFERENCE MANUAL XII L 1 Defining Points To define a point one issues the command NAM X Y Z OPTIONS and the available options are REFERENCE RPA RPB RECT CYLINDER SPHERICAL LOCATION XO YO ZO RX RY RZ LOCATION XO YO ZO PT 1 PT 2 PT 3 PT 4 DEL DOF 1 DOF i JNTCLASS PRCK PRCT PRCX BBC_MUL MULT EFF CHD LEN ECHD LEN CO SCF SCF_TYPE LEN FACTOR FRACHOL MAX CHD LEN MAXCHOL CHD_FIXITY CHD_FIX MIN SCF MIN SCF where NAM is the name of the point defined and X Y Z are the coordinates feet or meters in the current point system defined by the amp DEFAULT command If the option REFERENCE is employed then the coordinates are relative to the specified points otherwise they are with respect to the part origin If one reference point is specified then X Y and Z define a vector from this reference point to point NNAM If two points are specified then X specifies the distance from the point RPA to point NNAM along a line from RPA to RPB and Y and Z are ignored If three points are specified then they will define a local coordinate system with the origin being at the first point the x axis being from point 1 to point 2 the z axis being perpendicular to the plane formed by the three points and the y axis given by the right hand rule Again X Y and Z are local coordinates in this system If four points are specified the
7. SP _HEIGHT X Y Z DT_CONVOLUTION DT_CONV WAVE _RUNUP YES NO define defaults which can be overridden with amp DESCRIBE BODY commands The options CS WIND CSW X CSW Y CSW Z CS CURRENT CSC_X CSC_Y CSC_Z AMASS AMA MULT TANAKA TANAKA FACTOR CS WIND CSW_X CSW_Y CSW Z define defaults which can be overridden with amp DESCRIBE PIECE or PGEN commands While the previous options set defaults for modeling commands those that follow set defaults for other types of options The option FILL_TYPE FTYPE defines the default type of filling for compartments Here FTYPE must be either CORRECT APPROXIMATE APP NONE APP_WORST FULL CG FCG NONE Rev Page 147 MOSES REFERENCE MANUAL or FCG_WORST The meaning of these types are discussed in the section on filling compartments The options WATER RHOWAT SPGWATER SPGWAT RAMP RAMP _TIME DEPTH WATDEP SP_TYPE TYPE W_PROFILE WP_TYPE W_PERIOD TW 1 TW 2 TW n W_DESIGN DTYPE W_SPECTRUM STYPE W_MD_CORRELATION FACTOR MD PERIOD TD 1 TD 2 TD n PROBABILITY STAT PDATA T_REINFORCE TB HEADING H 1 H 2 H n PERIOD T 1 T 2 T n define default values used by the amp ENV command and they are discussed there The last two options allow one to define the default headings and wave periods which will be used for several different commands They are discussed in det
8. The command CF MAGNITUDE CONN_SEL OPTIONS reports only the force magnitude and the magnitude divided by the breaking strength and the available options are EVENTS E_BEG EEND EINC MAG DEFINE A 1 A n The command CF _ TOTAL BODY CONN_SEL OPTIONS reports the total force on the body BODY due to the connectors selected by CONN_SEL In addition the power of these forces on the body is reported Here the body for which the results are reported is the body connected to end one of the first con nector selected The force is reported in the body system The available options are EVENTS E_BEG E END E INC MAG DEFINE A 1 A n The command FOUNDATION CONN SEL OPTIONS checks a foundation It computes four unity ratios one each for overturning slid ing and capacity or pre load Uo f Vc Vn Vn Up f Vc Vp Rev Page 427 MOSES REFERENCE MANUAL Uc f Ve Vn Us f mu He Ve Here V stands for vertical load H for horizontal load the subscript c stands for the current state the subscript n stands for the nominal state and the subscript p for the pre load state The factor f and the values for the pre load and nominal states are defined with the CONNECTOR command The coefficient of friction mu is defined with the class The available option is EVENTS E_BEG E_END E_INC Launchway connectors are not available for reporting with the above commands Inst
9. When this command is issued MOSES will compute a new set of response operators for the same frequencies and headings as those of the basic pressure data those specified on the G_LPRESSURE command unless the options HEADING or PERIOD are exercised One can obtain response operators for any one speed by including the option SPEED where VR is the speed desired in knots If either PERIOD or HEADING are used MOSES will interpolate values of the hydrodynamic forces added mass and damping from the values contained in the Rev Page 382 MOSES REFERENCE MANUAL pressure database If no data for a quadrant exists in the pressure database then MOSES will assume symmetry about the vessel centerline or about amidships when interpolating hydrodynamic results The remaining options describe how MOSES deals with viscous damping In gen eral there are three types of viscous damping which are considered empirical roll damping Morison s drag for bodies and Morison s drag for rod elements Normally MOSES will iterate up to thirty times to achieve a proper solution considering the viscous damping In some cases where there are many bodies connected by rigid connectors there is a substantial computational effort involved with this iterative solution The ITER option may be used to limit the number of iterations Here MAXIT is the maximum number of iterative steps which will be taken where 30 is the default value The SPECTRUM optio
10. aaa 86 IX E Getting User Input 2 3 6 0 6 2 ee Ba ee we ae BM 88 IX F Programming the Tool Bar o aooaa aa aaa 92 IX G Using Files sma ode e Bee ee POE BEE Be G 94 IX H Functions gosea aow aea aa a g a a e a 97 Bre ee as a a a 101 DOREEN 102 E a oreo ee 105 ge pt tee di a a a Re ee 108 X D Extremes and Statistics 0 0 000 110 X E Plotting aaa ee ee BO ee ae amp 115 eh eee ee eee ote eee ete ede bear 118 XI REPORT CONTROL amp INFORMATION 120 POOO 122 PESSORT 125 XI C Obtaining Summaries of the Model 2 130 XII THE MOSES MODEL aooaa 135 oe ee tere een A 141 XII B Defaults oa aaa 144 XILC Parameters 00 oa a a a a 149 XII D Convolutions o a a 153 XILE Curves yok a eo ek oa e a a A a E a a s A 154 XILF DHENSOFS a ak bh ee a oR ee ew ew a 156 XILG The Environment 0 000 158 XII G 1 Durations as ac r ai a EYEE ee 169 XILH Fatigue and Cycle Counting 171 soho ee ae aD Ge ee 173 STEE 176 oe 178 lt 180 XILH 5 Beam Fatigue Due to Slamming 183 XII I Forces ooa 185 e ea BSG a A ee 187 XIILK Bodies and Parts 0 0 000 191 XILL JEOMEbrY ne ee eR ee Re Ee 203 See ee ee as ee a 205 PONOSA 208 XIL M Element Classes o o a a a 000000084 211 XII M 1 Structural Classes 0a oaa 214 Dee eee ee oe E 222 XII M 3 Pile Classes 2 2 224 Sees dk oe eS 226 wee 236 ETETETT 238
11. A INERTIA This is the added inertia times the acceleration C_INERTIA This is the inertia of the contents times the acceleration FLEX_CONNECTORS This is the force due to flexible connectors RIGID_CONNECTORS This is the force due to rigid connectors TOTAL This is the sum of all of the other contributions The accuracy of the computation of forces on a plate or panel depends on the shape of the panel In particular the results for more compact panels is superior to those which are long and skinny As a guide to the badness of panels a badness measure is reported for the SUMMARIES of panels and plates Now often this Rev Page 185 MOSES REFERENCE MANUAL measure is taken as the aspect ratio of the panel i e R W H Where W is the width H is the height and W gt H This is all fine and good for rectangular plates but when these enter the water the submerged portion is rarely a rectangle To generalize this notion in MOSES we define badness as B P 2 sqrt pi A 1 Here P is the perimeter and A is the area Notice that for a circle B is zero and that for rectangular plates it increases with the increase of aspect ratio When added mass is computed for a panel or plate the results from DNV RP C205 are used In particular the force computations presented there for added mass forces are tabulated as a function of B and interpolated based on the current values of B for the submerged portion
12. CATEGORY USE NUSE and FLOOD The first three of these has been discussed with Categories and Load Types If the FLOOD option is used with a YES NO value of YES then a tubular member will be allowed to fill with water if it s below the water surface Otherwise it will be assumed to be buoyant The option STW_USE allows one to turn off the weight of stiffeners Here YES NO must be either YES in which case the weight will be used or NO where the weight will not be used The option overrides the value set via amp DEFAULT The option NUM_APPLIED allows one to have a multiplier NUMBER for a beam The results for a beam are first computed based on the specified properties and then all results are multiplied by NUMBER In particular the damping stiffness mass matrices and the force are multiplied by this number Rev Page 246 MOSES REFERENCE MANUAL XII N 3 Beams In MOSES an element is viewed as being the union of three sets of attributes its vertices its class properties and its additional attributes Defining the first two of these has already been discussed To complete the definition of a beam one uses BEAM ELE_NAME 1 CLASS 1 OPT 1 NODE 1 NODE m ELE_NAME 2 CLASS 2 OPT 2 NODE n and in addition to the available options discussed above we have CMFAC CMY CMZ KFAC KY KZ BLY BUKLENY BLZ BUKLENZ BLENG BELE NAME CFB CFSPAC HAS_P DELTA YES NO
13. EMIT PAW COMPART DESCRIPT Port Aft Fuel Tank PIECE PERM 0 98 Notice here the use of to delimit the options which are used when describing the compartment This is necessary because a is already in use to delimit the text for the DESCRIPT option Rev Page 293 MOSES REFERENCE MANUAL XII P 3 Interior Compartments As mentioned above interior compartments have attributes that exterior compart ments do not need These are specified with the options on the amp DESCRIBE COMPARTMENT command that defines the compartment The first or these options DESCRIPTION DESC allows one to specify a description for this compartment If quotes are used this description can include blanks and be up to 40 characters in length This description is simply printed with some amp STATUSes and at the top of Tank Capacity reports Sounding tubes are used to define the level of contents in a compartment and are defined with the option _S_TUBE PT PB Here PT is a point which defines the top at the deck of the tube and PB defines the other end If you do not define a sounding tube then MOSES estimates a location for you The option MINIMUM MPERC SPGC is used to define the residual water in compartments When this value is defined one cannot ballast below this level and there is no free surface correction due to the minimum amount of water The specific gravity of this residual wat
14. LIMITS 0 50 ACTION DEACTIVATE LINE1 Here MOSES would monitor the tension is connector LINE1 and when the tension exceeded 50 then the line would be deactivated Sensors can also be used statically with the amp INFO string function Here there are two types available ALARM SENSOR and VALUE_SENSOR the first of these returns TRUE or FALSE depending on the alarm setting and the second results the value of the signal itself Rev Page 157 MOSES REFERENCE MANUAL XII G The Environment The definition of the environment is a two step process First one defines any aux iliary data necessary then he defines the environment referencing the auxiliary data by name Most of the auxiliary data was discussed in the section on CURVES Here we will discuss the definition of the environment itself first and follow immediately with a definition of how to define the auxiliary data not previously discussed The environment is defined with the command amp ENV ENV NAME OPTIONS and the available options are DURATION DURATION WATER RHOWAT SPGWATER SPGWAT PROBABILITY STAT PDATA SEA SEA NAME SEA DIRECTION HS PERIOD GAMMA A_SEA SEA_NAME SEA_DIRECTION HS PERIOD GAMMA SP_TYPE TYPE SPREAD EXP S_PERIOD TW 1 TW 2 TW n MD PERIOD TD 1 TD 2 TD n TIME TOBSERV DELTA_TIME TTRA_SET NCYCLES RAMP RAMP _TIME T_REINFORCE TB WIND WIND_SPEED WIND_DIRECTION W_PROFILE WP
15. NO _STAB NO_ STRUCT DRAFT T DRAFT TRIM T TRIM BALLAST BAL SEL AMOUNT BAL_AMT CMP BAL CMP SEL EQUI DAMAGE DAM CMP S_COND C PERIOD PERIOD 1 HEADING HEADING 1 WIND W_INTACT W_DAMAGED W_VORTEX W_STRUCTURAL MO POINTS P NAMES SPEED SPEED TYPE SPECT SPECT_TYPE STEEP STEEPNESS DO FREQ DO TIME TOB TINC FLEXIBLE DURATION DUR FILE DUR_TIME DUR VELOCITY TIETEN If one does not want some of the default results they can turn them off with the NO SEAKEEPING NO VORTEX NO STAB or NO STRUCTURAL options The two options DRAFT and TRIM define the draft at the bow and the trim for the tow If these two options are not used then a trim of 57 degrees will be used and the draft will be set so that the draft amidships is half the depth A weight is then computed so that the specified condition is achieved If however the BALLAST option is used the situation is different Here the variable BAL SEL is a string containing a set of pairs of tank names and percentages full If this is specified then this ballast condition will be used and equilibrium found as the transportation condition In a similar fashion the AMOUNT option allows one Rev Page 338 MOSES REFERENCE MANUAL to specify a ballast amount in the current big force units This must also be in the form of tank name and amount pairs If the CMP_BAL option is invoked MOSES will compute the ballast amount re
16. PT1 PT2 OPTIONS where the available options are CATEGORY CAT NAME NUM_APPLIED NUMBER WIND WINMUL DRAG DRGMUL AMASS AMSMUL WAVE PM WAVMUL TOT WEIGHT WT MULT WEIGHT WMULT BUOY DIA BOD Here OD inches or mm is the diameter of the tube used to calculate environmental forces and T inches or mm it the thickness The tube is positioned between the points PT1 and PT2 The first eight options behave the same as for the AREA command and the BUOY DIA option defines the diameter used to calculate buoy ant forces for the attribute The weight computed for this element is as described about for AREA except that another weight is computed using the thickness the OD the current default density and the length of the tube Wind and current forces can be input to MOSES and then associated with a load group This is achieved with the command Rev Page 271 MOSES REFERENCE MANUAL TABLE T_NAME PNT OPTIONS Here PNT is the point of application of the force and the available options are WAVE PM WAVMUL CATEGORY CAT_NAME When computing current forces the wave particle velocity is computed a the mini mum depth of the location of PNT or the water surface The wind speed is always computed at standard anemometer height so the wind is always allied regardless of the PNT location For this command T NAME is the name of a table of user defined force coefficients for wind and current This tab
17. Rev Page 391 MOSES REFERENCE MANUAL ST_CLEARANCE PNT_SEL ENV_NAME OPTIONS where the available options are SEA SEA_NAME THET HS PERIOD GAMMA _SP_TYPE TYPE SPREAD EXP E_PERIOD EP 1 EP 2 CSTEEP YES NO The purpose of this command is to investigate the statistics of the relative motion between the points selected by PNT_SEL and the water surface Here one will receive for each point selected The mean distance above the water The statistical clearance change The difference between the mean and the statistical change The probable minimum significant wave height that will create a slam an event when the water is above the point The number of slams per hour and e The velocity the point minus the wave particle velocity in the global system Rev Page 392 MOSES REFERENCE MANUAL XX C Cargo Force Post Processing The commands discussed here apply to dynamic forces acting on pieces of cargo located at specified points These forces however are derived completely from the motion of the body and are quite useful in estimating the load which will act on any cargo Here the frequency response of the forces consist of two parts 1 The forces required to produce the given accelerations and 2 The component of weight which arises due to change in angle These forces do not contain any static contributions such as the vertical component of weight or any force on the body due t
18. STANDARD and SUMMARY is a bit different DETAIL is ignored For STANDARD one receives the total CDRs for all computed points where the maximum of the CDRs lie between L i and T G Rev Page 465 MOSES REFERENCE MANUAL XXVIII I Post Processing Joints Structural Post Processing results for joints are obtained with the command JOINT POST TYPE 1 TYPE i OPTIONS where TYPE i must be chosen from DISPLACEMENT CODE_CHECK S_FATIGUE CRUSH COUNT or FATIGUE and the available options are NODE NODE SEL 1 NODE_SEL 2 NODE_SEL 3 NODE_SEL 4 ELEMENT ELE_SEL LOAD LSEL STANDARD L 1 T 1 L n T n SUMMARY L 1 T 1 n DETAIL REPORT YES NO FILE YES NO LOCAL YES NO CLASS CLS_SEL CODE TYPE CCAT EDITION SN CURVE TYPE 1 N 1 S n N n THICK_SN TO POWER MAXCOR YES NO LIFE DLIFE WL_RANGE ELEV ELEV DURATION DURATION_SEL S_BINS S 1 S 2 n CSRV_JFAT YES NO CLS_MEAN YES NO Here joints which match NODE_SEL 1 will be considered Further if the class of the chord does not match CLS_SEL the joint will not be considered Only braces with end nodes which match both NODE_SEL 1 and NODE_SEL 2 names which match ELE_SEL and classes which match CLS_SEL will be considered Results will only be considered for cases which match LSEL which is defined with the LOAD option For FATIGUE all durations which match
19. STANDARD or SUMMARY were selected and the report limits With a STANDARD or SUMMARY report L i and T i are used to specify a range of values for which a given report will be printed The value used for determining the range is the axial load One can specify as many ranges as he desires or he can omit all data following the option If no ranges are specified one report for all ranges of axial load will be printed An option of STANDARD will result in a report of the RAOs for the maximum axial force over all selected periods and headings for each member selected If one specifies an option of SUMMARY this report will be reduced to the RAOs for only the selected element in each class which has the greatest axial force Finally if one specifies DETAIL as an option the original report will be expanded to include checks of all members for all periods and headings at all load points Notice that DETAIL STANDARD and SUMMARY may all be used on the same command to produce reports of all three types Also if no options are specified then a default of STANDARD is assumed The options REPORT and FILE are used to control whether or not the RAOs are written to a post processing file or the standard output file The default is to write them only to the output file If FILE YES is specified then the RAOs will be written to both places If FILE YES REPORT NO is specified then the RAOs will only be written to the post processing file
20. or all of the pipe is off of the bottom The assembly problem is particularly difficult with davits Here the assembly is initialized by using only the length of the first davit and the nominal pipe tension The lengths of the other davit lines are then Rev Page 317 MOSES REFERENCE MANUAL computed to conform to this estimate Rev Page 318 MOSES REFERENCE MANUAL XIII E Defining a Control Assembly A control assembly is simply a set of connectors connected to a control Such an assembly is defined by the command ASSEMBLY CONTROL CONTROL_NAME PE 1 PE i OPTIONS Here CONTROL_NAME is the name you wish to give to the control assembly and PE i are previously defined PROPULSION connector element names Here the options are either SENSORS SG 1 SEN 1 SG n SEN n Simply the control system will compute an x and y force and a yaw moment given by F i sum SG k SR k i Here SG k are the multipliers defined with the SENSORS option and SR k i is the sensor reading for the kth sensor The i is the degree of freedom for the sensor The thrust is allocated amount the thrusters based on a least squares fit Normally the sensors are VECTOR sensors where the first point of the vector is a point on the body and the second point is a point on ground The signal is the vector between the two points which we want to be zero Propulsion units with rudders are treated differently They can co
21. over loaded as long as the local variable is active In other words if one defines a local variable with the same name as a local variable in a higher macro or with the same name as a global variable the previous one will not be used so long as the new local variable remains defined The dummy variables in macros are a special case of local variables By a variable we mean a string which is stored in the database and which may be referred to by its name Before one may reference a global variable it must be defined via a amp SET command The form of this command is amp SET VAR value Notice that the equal sign must be followed by a space or comma before the value All variables including arguments are processed as string replacements In other words the above command defines a string of characters These characters will be replaced whenever the string VAR is used in an input record There are actually several ways of instructing MOSES to substitute a variable In all cases the variable must be referenced with a as the beginning character The next character may be a in which case the reference must end with a If the is omitted the reference can end with either a a comma or a blank The only real reason to enclose the name in parentheses is that MOSES will honor one level of recursive use of variables For example amp SET DOG 20 amp SET CAT DOG 2000 amp SET COW DOG HA or amp SET COW
22. BEAM defines a string of beams Here the CLASS i defines the section at tributes and NODE 1 NODE 2 NODE n is the list of connected nodes where NODE 1 connects to NODE 2 NODE 2 connects to NODE 3 and so on The locations of the command marked by OPT i are positions where one may place as many element options as desired and may be omitted if defaults are suitable for the beam in question The beams from NODE 1 to NODE m have the properties defined by CLASS 1 and OPT1 and the beams from NODE m to NODE n have properties defined by CLASS 2 and OPT 2 In other words a beam in the string has the properties defined by the last CLASS and or OPT data issued before the beam was defined Here ELE_ NAME i is a name which can be assigned to the element If it is omitted MOSES will assign a name The CLASS is a name for a set of element attributes which define the sectional properties An example of a beam definition accompanied by a sketch is shown in Figure 8 The options specified above are used when checking codes To alter the CM values for an element one can use the CMFAC option Here CMY is the factor for bending about the Y axis and CMZ is the factor for bending about the Z axis The K factors and the buckling lengths are multiplied to obtain the effective length of the element about each axis By default the buckling lengths are taken to be the element length for beams and the squa
23. BODY PART COMPARTMENT and PIECE options allow one to specify options which are emitted on the DESCRIBE command When using this capability one needs to remember to enclose the various data within or marks For complicated models with multiple pieces it can be useful to emit only the points for a piece without the associated amp DESCRIBE BODY or amp DESCRIBE PART com mands This flexibility allows the emitted points to be assigned to a previously defined body or part which facilitates automatic generation of a complete model into one post processing file To emit only points use the POINTS option The tools described here are quite powerful but as with all powerful things one must use them with care The way this operation works is that MOSES finds the part of one block inside the other and then eliminates it For this to work properly however MOSES must be able to unambiguously distinguish what is inside This Rev Page 291 MOSES REFERENCE MANUAL looks quite simple but it is not numerically Consider for example two blocks BLOCK BOX PLANE 50 50 RECT 0 10 100 END_BLOCK BLOCK HOLE PLANE 10 10 RECT 0 10 20 END_BLOCK and suppose one removes the hole from the box with DIFFERENCE BOX HOLE NEW In all likelihood this command will fail The reason is simple the top and bottom surfaces of the hole lie in the same plane as those of the box Numerics being what they are it is possible that MOS
24. Basically two types of data are used added mass and damping matrices and exciting forces MOSES always uses these properties about the vessel origin but all commands discussed here will produce data applicable to the point specified on the last FR POINT command In other words if one wants the results for the vessel origin then he should issue a FR POINT command with a point of 0 0 0 before issuing any command discussed here While commands are discussed below which give one complete control over the results he wishes to obtain a single command has been provided which produces a set of standard results which suffice in many circumstances The form of this command is EQU_SUM When this command is issued MOSES will simply generate reports of all of the equation results The Disposition Menu will not be entered Alternately one can have the option of disposing of the data for the matrices by issuing MATRICES OPTION When this command is issued the program will compute the added mass and damping matrices about the point specified on the last FR POINT command If the option FILE option is used then the matrices will also be written to the PPO file In the file the full 6x6 matrices will be written Care is needed here The results reported for damping are not the ones really used but are the maximum over all headings This is correct for a spectral linearization but not for a steepness one Also a report to paper gi
25. DO HORIZONTAL then restraints will be added to prevent lateral motion of the cargo on the barge during stages when the tiedowns are not connected A connector type of VREST works in a similar fashion Here simply specify the restraint class and support nodes and restraints will be provided at each node Command File After fixing up install dat one should turn to install cif Here one has the option to perform different installation simulations perform the structural analyses and do one comprehensive structural code check for all load cases Below we will discuss the commands to make this happen The first of these is for a structural loadout Rev Page 336 MOSES REFERENCE MANUAL analysis INST_LOADOUT OPTIONS And the available options are VERT_RST GAPDIS GAPDIS LENSKD LENSKD FXLOC FXLOC TOPLOAD PSUPNOD PNODE 1 PNODE 2 PNODE n SSUPNOD SNODE 1 SNODE 2 SNODE n NO_STRUCT It is easier to discuss these commands assuming a jacket is the structure being loaded onto a barge but this can just as easily be used for a deck loadout This command will move the structure from the land onto the barge and create a load case for structural analysis whenever a structure hard point leaves the land support Gap elements are used for the supports and a nonlinear structural solution is performed unless VERT_RST is used In this case rigid restraints would be used instead of gap elements The
26. Here S 1 ksi or mpa marks the top of the first bin S 2 the top of the second bin etc The stresses which are accumulated include the stress concentration factor but not any stress concentration due to an SN curve The final options are applicable only to a TYPE of FATIGUE Also with FA TIGUE the meaning of DETAIL STANDARD and SUMMARY is a bit different DETAIL is ignored For STANDARD one receives the total CDRs for all computed points where the maximum of the CDRs lie between L i and T i Rev Page 468 MOSES REFERENCE MANUAL Finally for SUMMARY one only receives a report of the maximum CDR for all of the computed points which lie in the specified range The CSRV_JFAT option controls the action taken with the brace chord SCFs MOSES computes CDRs at eight points around the intersection of the brace with the chord If YES NO is NO both the brace and chord side are considered and sixteen CDRs will be computed If however YES NO is YES then the maximum of the two SCF values is taken and a CDR is computed for these values of SCF at the eight points A value of YES will yield slightly conservative values and significantly reduce the computational effort The CLS MEAN option controls the manner in which the joint is classified if the previous option is not used IF YES NO is YES then the joint will be classified using the frequency mean load case otherwise MOSES will compute a new joint classification and hence
27. Here the text string defined by TXTSTR is centered between the two points defined by the current location and X2 Y2 The text is drawn with the beginning of the string toward the current location so that the bottom of the text is parallel to the line between the two points A similar command is DIMENSION X2 Y2 TXTSTR This command draws text the same way as CTEXT but it also draws dimension lines between the two points Finally if one is merging a page in UGX into other graphics generated by MOSES with figure numbers the UGX figure should also be numbered This is accomplished by issuing the command FIG NUM X Y which will place the figure number at the coordinates specified by X and Y Rev Page 46 MOSES REFERENCE MANUAL VII C The amp D_GENERATE Menu Document Formatting To allow one to fully utilize MOSES s database structure a text formatting capability is provided This formatter basically takes input text and formats it according to a set of given instructions for a specified output device To simplify matters this process occurs within an internal menu entered via the command amp D_GENERATE OPTIONS The available options are CMD CMD FILL CHAR SAVE NO_CONT The CMD option is used to alter the internal command character which will be used in this menu Normally this character is the amp The other two options control what is done with the results when the document formatter is exit
28. Mf an tea eee ty 239 XIN Structural Elements 0 20 2 02084 240 XIILN 1 Element System aaa 243 XIIL N 2 Element Options lt ooo 245 XILN 3 Beams ke we 8 he a he ee ee 247 XIILN 4 Generalized Plates 0 o a aaa 253 XILN 5 vonnecting Parts 260 XII N 6 Structural Post Processing Elements 264 ee re ee se ee 265 pee eee se ae Gece eee Eee E ee 276 XILP 1 Pieces ke ete oe Be ae ee we Re 278 eos aa 288 XILP 3 Interior Compartments 294 te eote 298 XIT Q Editing a Modell a 6 24 008684 2285 he 4 304 XIII CONNECTIONS AND RESTRAINTS 308 XIII A Defining a Pulley Assembly 311 XII B Defining a Launchway Assembly 312 XIUI C Defining a Sling Assembly 315 XII D Defining a Pipe or Riser Assembly 317 XIIE Defining a Control Assembly 319 XIIF Defining a Winch Assembly 320 E be e e oy ee ee aoe eG 321 XIV PROCESSES ic 4 4 baw POA EA eRe RRA HRS 326 XV AUTOMATIC OFFSHORE INSTALLATION 328 XVI THE CONNECTOR DESIGN MENU 345 XVI A Obtaining Connector Tables o aoa aaa aaa 346 XVI B Obtaining Connector Geometry 347 ob Habe ea eee 348 TETTETETT 349 XVLE Designing a Lifting Sling ooo aaa 350 ea 351 e e ka eee e ee ee 352 XVII THE HYDROSTATIC MENU 2 2 02 354 Ne ni e e a tee 355 Pee
29. RMS SIGNIFICANT 1 10 MAXIMUM or DURATION If MAXIMUM is selected then PDATA is used to define the number by which the root mean square RMS will be multiplied to obtain the reported maximum Here if PDATA is Rev Page 159 MOSES REFERENCE MANUAL Zv Zg Xv Xg Profile View Plan View Yg Yy 45 Deg Deg 135 Deg ENVIRONMENTAL HEADINGS FIGURE 2 Rev Page 160 MOSES REFERENCE MANUAL omitted a value of 3 72 will be used If DURATION is selected the probable maximum based on a specified duration will be reported Here one specifies the duration in seconds with PDATA To define the sea for a given environmental condition one employs SEA A SEA SPREAD SP_TYPE SPREAD TIME MD_PERIOD S_PERIOD RAMP and T_REINFORCE options In essence the first two options defines the basic sea condition and the others serve to instruct MOSES how to treat the details In MOSES one can have several different seas which will be added together to form the sea state to which the model will be subjected SEA is used to define the first sea and A_SEA is used to define subsequent ones Other than this dis tinction the two options are identical For either SEA or A_SEA SEA_NAME is the name of the sea It must be either REGULAR ISSC JONSWAP 2JON SWAP or a name defined as a curve with amp DATA CURVE P_SPECTRUM amp DATA CURVE F SPECTRUM commands in the amp DATA with GRID Here HS is the significant hei
30. Rev Page 459 MOSES REFERENCE MANUAL XXVIII G Post Processing Beams Structural Post Processing results for beams are obtained with the command BEAM POST TYPE 1 TYPE i OPTIONS where TYPE i must be chosen from LOADS CODE_CHECK H_COLLAPSE ENVELOPE STRESS COUNT NT_FATIGUE or FATIGUE and the avail able options are CLASS CLS_SEL NODE NODE SEL 1 NODE_SEL 2 NODE_SEL 3 NODE_SEL 4 ELEMENT ELE_SEL LOAD LSEL DURATION DURATION SEL CODE TYPE CCAT STANDARD L 1 T 1 L n T n SUMMARY L 1 T 1 L n T n DETAIL DOF_SEL DOF REPORT YES NO FILE YES NO B_LOAD YES NO EQUIVALENT YES NO RESIZE CONT COSTS STCOST RCOST UP_CLASS YES NO S_BINS S 1 S 2 S n SLA COEFFICIENT S_COE SLA DAF S_DAF SLA_CDAMP S CDAMP SLA _FIXITY S_FIXITY SLA MULTIPLIER S VEL 1 S MUL 1 S VEL n S MUL n Here one will only receive results for elements which match the selectors defined with the CLASS NODE and ELEMENT options as described previously and for cases which match LSEL which is defined with the LOAD option For COUNT NT FATIGUE or FATIGUE all durations which match DURATION_SEL de fined via the DURATION option will be considered If no values are given for TYPE i then results for all TYPEs will be produced Here a TYPE of Rev Page 460 MOSES REFERENCE MANUAL e LOADS will produce the internal elem
31. SPE_MULTIPLIER FACT_CONVOLUTION PERI_USE and WAVE_RUNUP on the amp DESCRIBE BODY command It also lists the current Mean Drift and Pressure names associated with each body DRAFT will produce a report of the draft readings at the defined draft marks The BMMATRIX A MATRIX and D_MATRIX actions produce reports of the weight apparent and defined weight matrices respectively The report MOTION produces the global location of the In terest Points and the motion of these points since the last time the amp DESCRIBE INTEREST was issued Environmental Information status is obtained via a REP_TYPE of ENVIRON MENT SEA SEA_SPECTRUM SEA_TSERIES or WIND_TSERIES All of these except the first two accept the PLOT option so that the data results can be plotted The first of these produces various information about the current environ ment The type SEA gives statistics and maxima information for the sea and time of the current environment This is quite useful in checking that the sea has a peak of the desired height within the time sample In addition to the raw peaks found the most probable peak for this number of cycles is reported the ratio of the peak found to that predicted and the number of cycles normally required to produce a peak of this size are reported The information available for plotting is the sea elevation as a function of time The SEA SPECTURM type reports and allows for the plotting of the frequency period an
32. The Main Workspace The Main workspace has three parts to it the command line the tabs and the data window which can be either text or graphic The command line is the standard MOSES command line and accepts standard MOSES commands The text data window shows the same MOSES output the user is accustomed to The graphical data windows can show standard MOSES pictures MOSES graphs and the new OpenGL pictures The Tab system allows the user to open and interact with multiple pictures It should be noted though that entering the MEDIT menu will cause all pictures to be closed as the model data may have changed When a tab containing a picture is in focus there will be a control panel at the bottom of the picture This panel contain from left to right a window showing the current process a button setting the speed of an animation to half the normal speed a button for playing stopping the animation a slider showing the events and a box where you can pick the view When the picture is created it will show the last event in the current process The Status Bar The Status Bar currently shows whether MOSES is Busy or Ready for another com mand as well as showing what command will actually be executed when the mouse moves over an item in the menu Window Interface The window interface presents the user with a window containing four basic areas a tool bar a display area a command line box and a scroll bar The display area is u
33. To enter the menu one inputs FREQ RESPONSE When completed the menu is exited with END FREQ RESPONSE The traditional way of obtaining frequency response is to consider a set of unit amplitude waves and to linearize the equations of motion for each wave This is exactly what is done with the RAO command Results obtained in this way can later be easily combined with different spectra to obtain approximations to the extremes in many different situations and are thus quite popular The major disadvantage of this approach is that one can only look at the response to wave frequency excitation In other words with the response operator approach one cannot investigate the effect of wind or slow drift wave excitation To cope with these other effects one can no longer look at unit amplitude waves but must consider the simultaneous effect of all environmental forces This is what is done with the SRESPONSE command The major disadvantage with spectral response is that this response is applicable to a single environment and thus the post processing options are limited Before getting into the details of these commands a few general words are in order The frequency response calculations depend not only on the sea pressures but also on the stiffness of the connectors and the mass properties of the system Instead of requiring the user to directly specify the weight and radii of gyration of the system MOSES uses those computed from the element and
34. a V then a simple vector rotation will be performed with an L a rotation and a translation will be performed and with an F a force transformation will be performed The remainder of ACTION defines the direction of the transformation The action B2G transforms a body rep resentation into a global one and G2B the inverse The action P2B transforms a part representation into a body one and B2P the inverse Rev Page 210 MOSES REFERENCE MANUAL XIIL M Element Classes Since there are many elements in a structure which have common properties MOSES allows one to associate a name with a set of properties One then associates the name of the set by specifying the name on the element definition command This name is called the class name of the properties and the elements of the set are called classes The class name must begin with a The concept of class is important in MOSES since it is used not only for defining properties but also because MOSES redesigns by class In general MOSES allows for an element to have different properties along its length To define such an element one should have a Class definition command for each segment of the element When more than one segment is defined the first set of properties are associated with the beginning or A end of the element and the last set of properties associated with the B end of the element The lengths of the segments are defined by an option LEN As mentioned above
35. and 1 for an interior compartment The OBSTACLE option provides a method for defining an obstacle in the water with which a floating body will have hydrodynamic interaction The obstacle belongs to the body defined with the last amp DESCRIBE BODY command but does not move in a simulation Multiple obstacles may be defined so that several situations Rev Page 278 MOSES REFERENCE MANUAL may be analyzed For instance three obstacles may be defined and arranged to simu late a floating body inside a dry dock A single obstacle can be arranged underneath a body to represent a sloping sea floor It is important to note that an obstacle will move only when the body it is attached to moves as a result of a positioning command such as amp INSTATE LOCATE The remaining options of the PIECE command are applicable only to exterior com partments and are used to define how forces on the piece will be computed The DIFTYPE option defines which hydrodynamic theory will be used for the piece Here TYPE must be either 3DDIF if one wishes to use Three Dimensional Diffrac tion Theory or NONE if the piece is to be ignored in computing hydrodynamic properties If one wants to use Strip Theory he must define the piece with a PGEN command which is discussed later The CS_WIND and CS CURRENT options define how the panels of the piece attract wind and current loads In general for each panel in a piece MOSES will split it into a portion abo
36. and these elements will not be used during simulations Instead their only purpose is to insure that when a stress analysis is performed the two nodes will have identical deflections One will normally use this technique to connect two nodes in different parts which have the same location in space The second method of connecting parts is with special connectors called part connec tors These elements belong to special parts which have a part type of PCONNECT These elements may be defined by standard BEAM and PLATE commands or they may be defined in the MEDIT Menu by commands which are similar to the ones used in defining tiedowns The additional commands are PCONNECT CLASS JN SEL 2 PCONNECT DX DY DZ CLASS SEL 1 SEL 2 The first format generates part connectors at a single node in one part to several nodes in the other part using beams of section CLASS Thus CLASS is the name of the class property defining the section properties of the part connector member JN is the name of the node to be tied down and SEL 2 is a selector for the nodes to which JN is connected The second format generates part connectors at several nodes where the orientation of each part connector is constant In effect DX DY and DZ define the far end of a beam element at each node which matches the selector SEL 1 This far node is then connected by a rigid link to the nearest node matching SEL 2 Here CLASS is as before and DX DY DZ
37. axial The value for DOF determines which quantity of the beam is used as the criteria for selecting the load case to report When using the STANDARD or SUMMARY options only the load case providing the highest absolute value of DOF is reported The options REPORT and FILE operate only with a TYPE of LOADS These options are used to control whether or not the results are written to a post processing file or the standard output file The default is to write them only to the output file If FILE YES is specified then the results will be written to both places If FILE YES REPORT NO is specified then the results will be written to the post processing file only The options CODE EQUIVALENT RESIZE COSTS UP_CLASS and B_LOAD are applicable only to a TYPE of CODE_CHECK The type of code which will be used depends upon the last CODE option Here TYPE may be either AISC API NORSOK or ISO The value CCAT defines the class of check for AISC or API type checks It should be omitted for ISO or NORSOK type checks and it must be either WS or LRFD for AISC or API checks If it is omitted for these checks WS will be assumed If one wishes to use an LRFD check it is his responsibility to build load cases which include the proper multipliers This option is remembered between BEAM code checks and JOINT checks Thus if one has previously used the CODE option he need not be re issued If one is checking NORSOK or ISO codes non tube
38. will become WTPF T bforce blength The buoyancy for an element is computed as the sum of that arising from a diameter and a displacement per unit length For tubular members the displacement per length is zero and the diameter is the OD For non tubular elements the diameter is zero and the displacement per unit length is the element cross sectional area times the density of water One may al ter this with the DISPLEN and BUOYDIAMETER options Here DPFT is the new displacement per unit length bforce blength and B DIAMETER is the buoyancy diameter inches or mm The wind force viscous drag and added mass are all computed based on an equivalent diameter inches or mm These can be altered via the options DRAGDIAMETER WINDDIAMETER and AMASDIAMETER Once a class has been defined it can be redefined with the command ED CLASS CLASS_NAME SEGNO _ Here CLASS_NAME and SEGNO define the class and the segment which are being edited and the remainder of the command is the same as the class command The only thing that the segment will inherit from the previous definition is the length or percent length If SEGNO is omitted the first segment will be redefined and if SEGNO is greater than the last segment defined the last segment will be modified For example ED_CLASS CLASS_NAME 1 TUBE 60 1 5 FY 42 will change the diameter thickness and yield strength of the first segment of the class Rev Page 212 MOSES
39. you wish to view Rev Page 153 MOSES REFERENCE MANUAL XII E Curves The amp DATA command is used to define curves which used in various computations Here one associates a name with a function set of data and then uses that name to refer to the function The form of this command is amp DATA CURVES TYPE NAME DATA OPTIONS Here TYPE is the type of data which is being defined NAME is the name you wish to give to the curve and DATA is the numbers used to define the curve DATA is an n tuple where normally n is two i e normally you define a curve with an indepen dent variable and a single dependent variable TYPE must be either C_LPROFILE P SPECTRUM F SPECTRUM M GROWTH W HISTORY LT MULTIPLIER CT LENGTH EFFICIENCY CS VELOCITY or AM PRESSURE The behavior of any of these can be obtained with amp STATUS CURVES NAME PLOT Where NAME is the name of the curve about which you want information The first five of these define curves which are used in defining the environment e C_PROFILE defines a current profile The DATA is Z 1 V 4 Z n V n where Z i are depths feet or meters and V i are current velocities ft sec or m sec at the corresponding depth e P_ SPECTRUM defines either a wind or wave spectrum as a function of pe riod Here DATA is P 1 S 1 P n S n P i is a period sec and S i is the spectral value Since the spectral values will later be scaled to get the prope
40. 1 CMP_SEL 2 APP_NONE CMP_SEL 1 CMP_SEL 2 APP_WORST CMP SEL 1 CMP_SEL 2 FULL_CG CMP_SEL 1 CMP_SEL 2 FCG_NONE CMP_SEL 1 CMP_SEL 2 Rev Page 299 MOSES REFERENCE MANUAL FCG_WORST CMP_SEL 1 CMP_SEL 2 INPUT AL AT Gx Gy Gz CMP_SEL 1 CMP_SEL 2 INITIAL ADDITIONAL and the options PERCENT CMP_SEL 1 PERC 1 SPGC 1 FRACTION CMP_SEL 1 FRAC 1 SPGC 1 AMOUNT CMP SEL 1 BAL 1 SPGC 1 SOUNDING CMP SEL 1 1 SPGC 1 are available In essence the flags tell MOSES how to treat the contents and the options tell the amount of contents Before this can be described intelligibly a bit of history is in order When a com partment is not filled completely its center of gravity moves about relative to the body when the body changes angle Now we simply compute the correct location of the center of gravity In the past however this was a laborious computation and several methods were developed to approximate its location i e Xg Xo Ac where Xg is the current CG location Xo is the CG location in a reference position A is a matrix with only two non zero terms of the derivative of the CG with respect to angle changes and c is the change in angle from the reference position In perhaps more familiar terms the A matrix contains all zeros except for the first and second diagonal elements and t
41. 1 SEL 2 DELETE SEL 1 SEL 2 SIGNAL S TYPE SOURCE _DESIRED S_VAL _B S N CONVOLUTION CVL_NAME DERIVATIVE YES NO LIMITS LIM_L LIM_U ACTION A_TYPE RECEIVER With the first three options one does not need a SENSOR_NAME These are used to turn on turn off or delete the sensors selected by SEL i The other options are used to define a single sensor SENSOR_NAME SIGNAL is used to define the signal which the SENSOR will monitor Here S_TYPE the type of signal and it must be chosen from TIME POINT VEC TOR C_LENGTH C_FORCE MIN_WT_DOWN MIN NWT DOWN or BODY_ANG S_SOURCE is the source of the signal For signal types of time no source is necessary For a type of POINT source is the name of the point you wish to monitor for VECTOR it is the name of the two points which define the vector for types of BODY_ANG MIN_WT_DOWN BODY_ANG and MIN_NWT_DOWN it is the name of the body to check for either C LENGTH or C_FORCE it is the name of the connector For BODY_ANG there are three nominal values a roll a pitch and a yaw These are not the three Euler angles but for small angles they are a good approximation Types of MIN WT DOWN BODY_ANG and MIN_NWT_DOWN produce the minimum of either WT or NWT downflooding points for the body specified For types of TIME MIN WT_DOWN and MIN_NWT_DOWN this is all the data you need For other types you need to define how to map the data into a
42. A of Gap node used instead Launchway of creating launchway node I I I I L J pe er JACKET BARGE LAUNCHWAY GEOMETRY FIGURE 19 class property defining the section properties of the tiedown member JN is the name of the jacket node to be tied down and SEL2 is a selector for the vessel nodes to which JN is connected The second format generates tiedowns at several jacket nodes where the orientation of each tiedown is constant In effect DX DY and DZ define the far end of a beam element at each jacket node which matches the selector SEL 1 This far node is then connected by a rigid link to the nearest node matching SEL 2 Here CLASS is as before and DX DY DZ is the distance measured from the jacket node to the body attachment point in the vessel system feet or meters The tiedown geometry is illustrated in Figure 20 Rev Page 262 MOSES REFERENCE MANUAL ZV XV YV JN _ Jacket Launch Leg BN4 BN3 BN1 BN2 Barge Tiedown Nodes JN Far End of Tiedown Member J Nearest Barge Node Rigid Link TIEDOWN GEOMETRY FIGURE 20 Rev Page 263 MOSES REFERENCE MANUAL XII N 6 Structural Post Processing Elements MOSES has a concept of pseudo elements which can be used for structural post processing The pseudo elements are called sp_beams or sp_plates and they are defined in the same manner as beams or plates except that the command BEAM is replaced with SPLBEAM or PLATE
43. AF 1 DF n SPV n AF n LEN L OPTIONS CLASS LMU LEN OD 1 OD 2 DF 1 SPV 1 AF 1 DF n SPV n AF n OPTIONS In addition to the standard class options discussed above the following are in general available SYMMETRIC YES NO IG_STIFF SEND KE 1 KE 2 CONVOLUTION CVL_NAME X PY P 1 Y 1 P 2 Y 2 P n Y n Y PY P 1 Y 1 P 2 Y 2 P n Y n Z PY P 1 Y1 P 2 Y 2 P Y n X DAMPING Co Ex Fo Y DAMPING Co Ex Fo Z DAMPING Co Ex Fo FRICTION MU Here DF i is the name of the degrees of freedom in the element system which will be restrained and must be chosen from the list X Y Z RX RY RZ By Rev Page 226 MOSES REFERENCE MANUAL default the element system is aligned with the body system of the first node defining a connection More will be said about this when defining elements are discussed SPV i is the value of the spring bforce blength for degrees of freedom X Y and Z and bforce blength radian for degrees of freedom RX RY and RZ and AF i is the allowable force in this direction For GSPRs and FOUNDATION elements SENSE defines the direction in which the element will act i e if SENSE is TENSION then the connector will have no load in any degree of freedom when the element X displacement is negative If SENSE is COMPRESSION then it will have no load when the element X displacement is positiv
44. BITALICS Here NORMAL will be standard type UNDERLINE will be underlined etc The USE option is used to create a new style based on a previously defined one OLD_NAME If used this should be the first option specified and it instructs MOSES to use the previous style as the default values for the current style The last two options are used when pictures or graphs are being produced The CSYM HEIGHT option defines the height of any centered symbols on a graph These are normally used to differentiate between two curves or to denote points The LINE_WIDTH option defines the width of any lines being drawn Rev Page 29 MOSES REFERENCE MANUAL VI C Logical Devices and Channels In MOSES the concepts of channel and logical device are quite similar A logical de vice is simply an additional layer of abstraction which allows one to achieve precisely the results he wishes We will begin with the process of defining a logical device which is accomplished by the command amp LOGDEVICE LDVNAM OPTIONS and the available options are CHANNEL CHANAM STYLE T STYLE N STYLE A STYLE MARGIN IM OM TM BM LANDSCAPE YES NO PSOURCE TRAY Here LDVNAM is the logical device name which must be either LOG OUTPUT SCREEN GRA_DEVI DOCUMENT TABLE PPOUT or MODEL These logical devices serve to provide output for screen reports hard copy reports screen graphics hard copy graphics hard copy documents stored tables po
45. Bodies Categories Classes Compartments Connectors Draft Marks Durations Active Elements Environments Grids Holes Interest Points Inactive Bodies Inactive Elements Inactive Parts Input Spectra Load Groups Load Sets Macros Load Maps Marine Growth Names Nodes Panels Active Parts Pieces Pi_views Points Processes Profiles Selection Criteria Shapes SN Curves Soils Time Variations Global Variables Structural Solution Cases Structural Report Cases Non Converged Structural Solution Cases Page 123 MOSES REFERENCE MANUAL When the amp NAMES command is issued the resulting list will be displayed at the terminal unless the option HARD is specified Also when using the string function the results will be limited to only those names which match SELECTOR Rev Page 124 MOSES REFERENCE MANUAL XI B Obtaining the Status of the System The amp STATUS command can be used to obtain a report on various quantities at the current event In some menus the current event is not completely defined until the menu is exited so amp STATUS is not always available In general these re ports can be divided into ten categories General Information System Information Connector Information Compartment Information Compartment Hole Information Load Group Information Categories and Load Sets Element Information Map In formation and Structural Solution Information The form of this command is amp STATUS REP_TY
46. CASES POST OPTIONS where the available options are DELETE CASE_SEL 1 CASE_SEL n COMBINE NEWNAME CASE 1 MULT_F 1 MULT_P 1 AMOD MULT NAME 1 NAME n NOMINAL NAME MULT PRELOAD NAME TIME ENV_NAME NEWNAME 1 T 1 NEWNAME i T i PROCESS PRC_NAME MEAN MLCNAME FATIGUE DURATION_NAME TOTTIME TOW_VEL SPECTRA ENV_NAME 1 c 0 ENV_NAME i If one has defined some cases which he no longer needs he can delete them by using the option DELETE which will delete all cases which match any of the selectors CASE_SEL i The COMBINE option is used to define a simple linear combination of previously defined cases either fundamental or combinations themselves Here NEWNAME is the name the user wishes to give to this combination CASE i is the name of the cases to be combined and MULT_F i and MULT _P i are the multiplier for this case for loads and pressure respectively One really should not have two multipliers here but some codes require multiplying the static loads by a factor If one also multiplies the pressures by the same factor one gets unreasonable code pressure checks If MULT_P is omitted then it is set to the value of MULT_F Some codes allow one to employ an allowable stress modifier This is a number which is multiplied by the allowable stress in the computation of a code check If the user takes no action these factors
47. CS 2 F 2 NORM CS NCOL RMS CS 1 CS 2 POWER P N PC CS 1 F 1 CS 2 F 2 DERIVATIVE CS 1 CS 2 INTEGRAL CS 1 CS 2 FILTER R_TYPE CS 1 CS 2 RL 1 RU 1 RL n RU n SMOOTH CS NL NR ORDER The first two options create completely new columns The COLUMN option allows the user to simply input a column of data Here the number of values input must be the same as the number of rows of the existing columns A good source of this data may be from SET_VARIABLE COLUMN On the other hand the INPUT option allows more flexibility in the number of points input Here CS is the column selector of an existing column which is like the X values For instance if the X values are times then CS should be the column selector for event number MOSES will fit a spline to the input data and then create the new column by interpolating a value from the spline for every value of CS i The remainder of the options create a column based on the values of the existing ones The COMBINE option will combine two or more columns of data using the factors specified For instance ADD_COLUMN NEW COMBINE 1 1 2 1 will make the new column the difference of columns of 1 and 2 Here CS selects the column and F is the combine factor To find the norm of two or more columns the NORM option is used CS again selects the column and NCOL is the number of Rev Page 105 MOSES REFERENCE MA
48. DOG A Rev Page 69 MOSES REFERENCE MANUAL amp TYPE COW or amp TYPE COW or amp TYPE COW will set variable DOG to 20 CAT to 20 2000 i e 40000 COW to 20A and will type 20A to the terminal For the recursive use of variables consider amp SET DOGI 20 amp SET DOG2 40 amp SET INTE 1 amp SET ANS 30 DOG INTE amp TYPE ANS will result in 30 20 being written to the terminal Here the variable INTE will be evaluated first and then the variable DOG1 will be substituted Often one wishes to have variables which are local to a given macro This can be accomplished by typing a set of variables to be local as follows amp LOCAL LVAR 1 LVAR 2 VAL When local variables are typed their values are set to blank unless one follows the variable name with a token of and another token containing the value to which the variable is to be set Once a local variable is typed it may be reset via an amp SET command and used as if it were a global variable Rev Page 70 MOSES REFERENCE MANUAL IX B Loops and IF s Two elements which must exist before a language can be useful are some means of altering execution and some method of repetition Here the execution control is offered by a standard block IF construct amp IF LPHRASE 1 amp THEN amp ELSEIF LPHRASE 2 amp THEN amp ELSE amp ENDIF Here LPHRASE 1 and LPHRASE 2 are logical phrases and if LPHRASE 1 i
49. FILE returns the file currently associated with the channel specified Program information is obtained with VERSION REVNUM HOME PGM PAT or OS_CLASS VERSION returns the general version being executed e g REV 5 10 while REVNUM returns the total revision number e g REV 5 10 010 HOME returns the path to the user s home directory PGMPAT returns the path to where the program being executed is stored e g ultra A type of OS_CLASS will return the type of operating system currently running the program For information about the current output device one should use a NAME of either TPGLEN OPGLEN FONT PWIDTH PHEIGHT IMARGIN OMAR GIN TMARGIN BMARGIN DOUSIDE LPI CPI or DEVICE The DE VICE value will return the physical device name of the current output device All dimensions here returned here are in points except for CPI and LPI which are char acters per inch and lines per inch respectively Here TPGLEN returns the length of the screen All of the others provided information about the current output channel Information about the current graphics is obtained with either FIG_NUM or PICT_TYPE FIG_NUM returns the number of the next figure plotted PICT_TYPE returns the type of data currently being used for pictures Rev Page 79 MOSES REFERENCE MANUAL IX D 2 The NUMBER String Function Perhaps one of the most useful string functions is the function amp NUMBER TYPE NUM 1 NUM 2 This function has an o
50. FVGET FUNNAM VAR amp FVPUT amp F_READ amp GET GIF amp INFO amp INSERT amp INSTATE amp LOADG amp LOCAL amp LOGDEVICE amp LOGICAL amp LOOP MACRO MENU M_ACTIVE M_CNAME M_DELETE NAMES NAMES 129 NEXT NUMBER 80 NUMVAR 98 amp PANEL amp PARAMETER 149 amp PART amp PATH amp PICTURE amp PIECE RR SL Se amp L amp amp REPORT amp REP SELECT Rev amp SELECT amp SET amp SLAM amp STATUS amp STRING amp STRING amp STYLE amp SUBELEMENT 242 amp SUBTITLE amp SUMMARY amp SURFACE amp SUSPEND 100 amp S_BACK amp TABLE amp TITLE amp TOKEN amp TYPE amp UGX amp VARIABLE amp VARIABLE amp V_EXIST amp V_TRANSF 210 amp WEIGHT 200 amp str_pst 1 49 LIST PRE TABLE U BPAGE CENTER CONTENTS EJECT EODD FOOT HEAD U Page 471 MOSES REFERENCE MANUAL PRE RPAGNUM SECTION SKIP anica SUBPART TABLE U b ADD_COLUMN 105 AGAIN ALIAS ANGLE 279 ARC ASSEMBLY CONTROL ASSEMBLY LLEG ASSEMBLY PULLEY ASSEMBLY T H_DEFINITION ASSEMBLY WINCH BBOX BEAM BEAM_POST BEAM SUM BEGIN BLOCK BMOM SHR BODY FORCE BOUNDS CONN BOX C LENGTH C SCALE C_SHIFT 101 CASES POST CATEG SUM CF MAGNITUDE 427 CF_TOTAL CFORM CL_
51. For the first of these the MAX_TORQUE will be multiplied by MULT and the winch motor will be turned on and the brake will be released For the second SMOMENT and D MOMENT will but multiplied by MULT and winch motor will be turned off and the brake will be engaged For the last action the velocity curve will be multiplied by MULT Here BOUND is a bound on the line length If MULT is greater than zero letting out line the BOUND is an upper bound on the line length If MULT is less than zero letting in line the BOUND is an lower bound on the line length Normally control assemblies are changed only in the time domain One can use the SET PROPULSION option to set the values for statics or use the option CONTROL With this option the control system will attempt to counteract the static mean wind current and wave forces Rev Page 325 MOSES REFERENCE MANUAL XIV PROCESSES One thing which is fundamental to MOSES is the concept of a process Whenever MOSES performs a simulation the results are stored in the database by the process name The name it uses is the current one or the last one which was referenced To alter the current one one should issue the following command amp DESCRIBE PROCESS PRCNAM OPTIONS and the only option is EVENTS When an amp DESCRIBE PROCESS command is encountered and the name for the specified process is not already defined in the database it will be added to the database with the n
52. IARE 40 I AREBTW IAREBTW I ARM_AR IARMARE I_AR_ RESID IARRESID I_ZCROSS IZCROSS I THETA1 ITHETA1 I RANGE IRANGE I R M_EQUI IRMEQUI FACTOR I ANG DIFF IANGDIF I DANG T1 IDANGT1 I DANG IDANG Rev Page 364 MOSES REFERENCE MANUAL I ANG MARM IANG MARM Here what follows the I is the quantity defined above and the second thing is which will be compared to the computed quantity Two of the options require a second value AR WRATIO needs MANG the nominal roll due to waves and R M_EQUI needs the FACTOR to multiply THETA1 These options will be used to check intact stability There is a second set of option which begin with D_ which are used to check damaged stability For example I_GM 5 D GM 1 will demand that the GM exceed 5 for an intact case and 1 for a damaged case STAB_OK produces the righting arm heeling arm and area ratio curves for the draft specified Since the righting arm is based on the equilibrium of the buoyancy and weight of the vessel the vessel weight must have been previously defined This can be accomplished with the stanza TMT Remar amp INSTATE CONDITION 7 Dees a ee P amp WEIGHT COMPUTE 5 32 85 85 set transit condition compute weight for condition Now stability checks with the commands of the form OPERERER EEEE EEE 2 EEEE RR EE A AACA EE check one intact hystat stab_ok 5 2 5 10 wind 100 yaw 0 GRA AA AACA ACA AAA ACA A AOR ACR CCC ACA AAA AK
53. If all of the elements are H_CATs then the computation is exact and all of the properties of each segment of each connector are properly accounted for If however one has an assembly with a B_CAT element then the idealization is exact only when the size of the wire for the H CAT element is the same as the top segment of the B_CAT Here also any additional springs on the H CAT element will be ignored These elements can be used in any way that H CAT or B_CAT connector can be used In particular the amp CONNECTOR command can be used to change the length of the first segment or the change the activity of the element Rev Page 311 MOSES REFERENCE MANUAL XITI B Defining a Launchway Assembly A launchway is a complicated set of connections which are collectively referenced within MOSES by the name amp LWAY The launchway is composed of at least two launch legs each one of which is defined via the command ASSEMBLY LLEG J 1 J 2 J n BODY_NAME 1 XB YB ZB B1 1 B1 n BODY_NAME 2 B2 1 B2 n OPTIONS and the available options are FRIC DYNFRC TPIN TPRIDEP XP YP ZP MAX_ANGLE TSECDEP DIST BEAM LENP EIP LENS EIS Here J 1 J m are the node names of the nodes along the launch cradle of the jacket in order where J 1 is the first node which will enter the water and J n is the last node which will enter the water The launch cradle is considered the part of the jacket tha
54. KG LENGTH BIL RAD PERIOD T 1 T 2 T n ANGLE AN 1 AN n The two options ROLL and PITCH are instructions to compute a set of Tanaka data and add it to what exists and one can have up to 20 different occurrences of these options The degree of freedom which will be effected by the damping is defined by the option name Here WETSURF is the total wetted surface of the body ft 2 or m 2 and one can think of each pair of ROLL and PITCH options as defining the damping for a part of the body which has a fraction FRACTION of the wetted surface All of the other variables for the option apply to the piece being defined SECTION defines the type of section and must be either BOW MIDBODY or STERN BLOCK is the block coefficient DEPKEEL is the distance from the waterline to the keel feet or meters KG is the vertical center of gravity above the keel feet or meters BEAM is the breadth of the body feet or meters LENGTH is the length of the body feet or meters and BILRAD is the bilge radius feet or meters No pitch damping is produced by default If you define no additional data on the TANAKA command you will be put into a new submenu menu Once in the submenu the equivalent linear damping coefficients are defined with the commands R_TANAKA PER VDM 1 VDM N or P_TANAKA PER VDM 1 VDM N Here PER is one of the periods specified with the PERIOD option and VDM i are the coefficient
55. LEN 500 BUOY 0 WTPL 37 51 1000 Rev Page 234 MOSES REFERENCE MANUAL EMOD 29000 0 1 CLUMP 100 WIRE B_CAT 4 625 LEN 4000 BUOY 0 WTPL 37 51 1000 EMOD 29000 0 1 WIRE B_CAT 4 375 LEN 2000 BUOY 0 WTPL 158 2 1000 EMOD 29000 0 15 WIRE B_CAT 4 625 LEN 2000 BUOY 0 WTPL 37 51 1000 EMOD 29000 0 1 DEPANCHOR 3000 Here effort is saved by using minimum uniqueness and arithmetic in the input Four line segments are described with a spring buoy at the end of the first segment The first second and fourth segments share the same material properties except for length Notice the BUOYDIA is set to zero therefore the weight per length specified is the weight in water Rev Page 235 MOSES REFERENCE MANUAL XII M 5 Rigid Connector amp Restraint Classes Rigid connector and restraint classes are defined by using one of the following CLASS FIX DF 1 DF n CLASS SPR DF 1 SPV 1 DF n SPV CLASS GAP COEF FIX and SPR classes define connections between specified degrees of freedom For these connectors it is not permitted to define offsets Instead MOSES computes an offset for the second end of the connection so that the constraint is satisfied when the connection is defined Thus one should issue an amp INSTATE command for each body prior to connection to establish the proper relative orientation The values input when defining these classes are in the body system of the body to which the fir
56. LIMITS Rev Page 238 MOSES REFERENCE MANUAL XII M 7 Tug Connector Classes In MOSES one can simulate the effect of a tug boat attached to a body Basically this is a connector that applies a force in a constant global direction When dynamic simulations are considered the force the tug applies varies with wave amplitude at the tug position A tug connector class is described using CLASS TUG_BOAT FORCE where the available options are T DYNAM PERCENT_FORCE PHASE DAMPING C Here FORCE is the force of the tug in bforce units Statically this force is simply the amount specified Dynamically the force varies according to FORCE which is the significant percentage of force change PHASE is the phase angle in degrees relative to the wave crest This data is specified using the T DYNAM option The DAMPING option defines a dashpot at the end of the tug with a constant C bforce sec ft or bforce sec meter Rev Page 239 MOSES REFERENCE MANUAL XII N Structural Elements In MOSES there are four types of structural elements beams generalized plates part connectors and structural post processing elements All of the properties of these elements are defined in terms of the element local system It is also the system in which loads and stresses will be reported With respect to local system the structural post processing elements operate exactly the same as beams and generalized plates The definition of the elemen
57. MOSES will change the body system of the jacket as described above It will also change the orientation of the barges so that their body X axis will be aligned with that of the jacket In contrast to the jacket there is no translation of the barges body system Rev Page 314 MOSES REFERENCE MANUAL XIII C Defining a Sling Assembly A sling assembly is an abstraction of the lines which a lift vessel can apply to another body Here the point at the boom where the connection begins is called the boom point This point is connected to the hook by a length of line and in turn the hook is connected to several points on the body by other lines In MOSES the hook can be connected to the body with up to four elements This set of lines is called a tip hook set and is referred to by a name given to the hook Several different tip hook sets can be defined connecting different bodies Each tip hook set is defined by a command ASSEMBLY T H_DEFINITION NAME BHE EL 1 EL 4 OPTIONS and the available options are INITIAL ORIENT VERTICAL DEACTIVATE Here NAME is the name you wish to give the tip hook set BHE is the name of the element connecting the boom point to the hook and EL i are the names of the elements connecting the hook to a body All of these elements must have been previously defined with CONNECTOR commands must have a class category of SLING and must have a single node Additionally all of the node
58. RAMETER command e For intermediate fatigue points between tubular and conical sections an SCF will be computed as specified in API RP2A or DNV they are the same MOSES will also check for two tubes that have no braces and will compute an inline SCF as if the change in section was internal to the beam itself For other cases the SCF specified on the element command is used If no SCF is specified on the element command then that specified on the class definition is used If no SCF is specified on the class definition then that defined on the amp DEFAULT is used e In the case where one of the ends of a tubular element is part of a tubular joint then a part of the joint SCF will be used for the SCF of the element at that end To define the inline SCF between two tubular sections then the IN SCF TYPE option of KPARAMETER is used There type must be either DNV or a number The number is the exponent e used in computing the SCF according to SCF 1 A B A 3 T2 T1 T1 B T1 e T1 e T2 e Where T1 and T2 are the tubular thickness If DNV is specified a value of 2 5 will be used for e Here T2 is greater than T1 For the amp DEFAULT command the default SN curves at various points on and Rev Page 180 MOSES REFERENCE MANUAL element are defined with the option SCF TYPE 1 SCF 1 The SCF option defines default stress concentration factors for different types of section Here TYPE i defines a
59. REFERENCE MANUAL CLASS_NAME to the values specified To add a segment specify a value of zero for SEGNO The ED_CLASS command works in the input channel through INMODEL or under the MEDIT menu A string function is available that provides information regarding classes and has the following form amp CLASS INFO CLS_NAM SEGNO where INFO must be either ELEMENTS N_SEGMENT TYPE DIMEN SION FRICTION DENSITY EMODULUS SPGRAVI ALPHA FYIELD POI RATIO TENSTRENGTH B TENSION WTPLEN DISPLEN BUOY DIAMETER DRAGDIAMETER WINDDIAMETER AMASDIAMETER SECTION PERLENG LENGTH REFINE RDES POINTS REFER ENCE T_STIFF L_STIFF CFB F_TYPE R_SPACE P_FY M P ETA P_N SCF SN PLATE_DI NAME_DIM NAME_SEG CLUMP SOIL PYMULT TZMULT QWMULT SEND SLOPE DEPANC IG STIF PRM THRUST PR EFFICIENCY PR T ALIMITS PR R ALIMITS RR ALPAH PR GAMMA or PR_R_DIST Here CLS_NAM is the name of the class used to return informa tion and SEGNO is the segment number of the class Most of these return values of that one sets with options of the same name on a class command Some however require more information When INFO is TYPE the string function returns the type of class such as H CAT B CAT ROD SL_ELEM GSPR for flexible classes or any of the various structural section types such as PLATE or TUBE A value of N_SEGMENT returns the number of segments in a class while a value of ELE MENTS provides the element names using the specifi
60. SCF for each force response operator Rev Page 469 MOSES REFERENCE MANUAL Index 37 166 LO 214 224 220 230 3I amp CUTYPE B7 236 233 239 amp DATA A_TABLE 272 137 203 205 amp DATA CONVOLUTION 153 74 amp DATA CURVES ae amp DATA DURATION 169 EQ amp DATA ENVIRONMENT 166 GE amp DATA SHAPES GT 76 amp DATA SOIL LE amp DEFAULT LT amp DEFINE NE amp DESCRIBE ACTIVITY NOT 76 amp DESCRIBE BODY 191 OR amp DESCRIBE COMPARTMENT 276 0 amp DESCRIBE HOLE 4 L87 185 251 268 amp DESCRIBE INTEREST AMASS 268 amp DESCRIBE LOAD GROUP AREA 270 amp DESCRIBE NODE_NAS BUOY amp DESCRIBE PART DRAG amp DESCRIBE PIECE ELAT amp DESCRIBE PROCESS PLATE amp DESCRIBE SENSOR TABLE amp DESCRIBE SYSTEM TANAKA amp DEVICE TANKER amp DIMEN TUBE amp D_GENERATE WEIGHT amp ELEMENT Ba amp APPLY amp ELSE amp BODY amp ELSEIF amp BUILDG amp EMIT amp CHANNEL amp ENDIF amp CLASS amp ENDLOOP amp CMP_BAL amp ENDMACRO amp COLOR amp END_ amp D_GENERATE amp COMPARTMENT 298 amp ENV amp COMPARTMENT 296 amp ENV amp CONNECTOR amp EOFILE amp CONNECTOR amp EQUI amp CONVERT amp ERROR amp CTYPE amp EVENT STORE Rev Page 470 MOSES REFERENCE MANUAL amp EXIT amp EXPORT MESH amp EXPORT POINTS amp E_STRING amp FILE amp FINISH amp FORMAT amp
61. WAY The details of how the information is requested depend on the current user interface For a terminal interface it is all done with text and typing With a window interface different dialog boxes appear The first three types of WAY request for a file name a general string input and a YES or NO response respectively Here DATA is simply a description of the data requested For example amp INSERT amp GET FILE Select your MOSES custom file and amp INSERT amp GET RESPONSE Input your MOSES custom file name will both return a string but the first will pop up a file selection box and allow the user to browse and click on the desired file The second will pop up an input box and the string returned may or may not be a valid file name YES NO places DATA in a box with YES and NO buttons and returns either YES or NO depending on which button is pushed The last four types of WAY pop up a list and the user is allowed to pick from the list For PICK the form of DATA is MAX_PICK TITLE ITEM 1 ITEM 2 Here MAX PICK is the maximum number of items which can be chosen TITLE is the title of the dialog box and ITEM i are the items which can be chosen If more Rev Page 86 MOSES REFERENCE MANUAL than one item is chosen the string will be composed of the name of each item chosen The type of WAY of N_PICK stands for name pick and here the form of DATA is MAX_TO_PICK TYPE_OF_NAME TITLE Here TYPE_OF_NAME is a valid
62. WTPLEN DISPLEN and BUOYDIA For example WTPLEN 10 BUOYDIA 0 will set the submerged weight per length to 10 and WTPLEN 15 DISPLEN 5 BUOYDIA 0 will accomplish the same purpose The CLUMP options adds a clump weight of weight CW bforce at the end of the current segment If CW is less than zero then it is the negative of the maximum buoy displacement and CLEN is the length of the pendent A spring buoy cannot be part of the last segment where the segment attaches to ground Thus the connection will be constrained to lie on CLEN feet or meters below the water surface until the load that the lines exert on the buoy is equal to the maximum displacement The buoy will then sink so that the connection is in equilibrium The solution for the catenary is exact except that the water depth is ignored for the first segment i e MOSES does not consider the possibility of grounding between the spring buoy and the fairlead MOSES will assume that there is no friction between the seafloor and an BL CAT and that the sea bottom is flat unless altered by one of the options FRICTION or SLOPE Here BOTMU is the coefficient of friction between the line and the bottom and SLOP is the slope of the bottom from the vessel toward the anchor positive if the depth increases from vessel to anchor vertical distance horizontal distance Consider the following example for the description of a typical mooring line WIRE B_CAT 4 625
63. XY YZ and XZ planes respectively while the ISO view is an isometric of the se lected portion The three angles VA i are angles deg which move the structure from its initial position to the one for viewing The view produced is a projection of the rotated structure onto the plane specified by VIEW and if no VA i are specified then the bodies will not be rotated prior to projection For some types of data an alternative method of defining the view is provided with the option PLANE POI 1 POI 2 POI 3 TOL Here POI i are names of three points which will define a plane to be plotted Here the X axis is defined by a line connecting the first two points and the Z axis is perpendicular to the X axis in the direction of the third point When the plane is projected the X axis will point toward the left and the Z axis will point up Finally TOL is a tolerance feet or meters for members in the plane If it is omitted a default will be used To simplify viewing there is an option to incrementally change the view INC_VIEW WHAT AMOUNT Here WHAT describes the action one wishes to perform and optionally AMOUNT specifies an amount which depends on WHAT If WHAT is ROTATE then AMOUNT specifies the rotation increment in degrees If WHAT is TRANSLATE then AMOUNT specifies the translation increment as a fraction of scene size Two values of WHAT control the action of the mouse for GL pictures A value of SELECT
64. Y_DIM At the conclusion the current location will remain unchanged To draw a circular arc one issues ARC RADIUS ANG 1 ANG 2 The center of the arc is at the current location and the arc will have a radius of RADIUS The arc will be drawn from the angles ANG 1 to the angle ANG 2 These angles are measured from the x axis positive toward y If the two angles are omitted a circle will be drawn The current location is not changed by this command The final line primitive draws a line with an arrow at the end of it and is defined by DLINE X2 Y2 The line is drawn from the current location to the point X2 Y2 and the arrow is placed at the second end At the conclusion the current location is at X2 Y2 Four commands are available to annotate the picture The command CSYMBOL CSYM_NUM will produce a centered symbol of a type defined by CSYM_NUM at the current Rev Page 45 MOSES REFERENCE MANUAL location CSYM_NUM is an integer from 1 to 9 where each number produces a different type of symbol To write text one has three commands available none of which moves the current location The command TEXT ANGLE TXTSTR will write the string of text defined by TXTSTR beginning at the current location The text will be at an angle ANGLE from the x axis If ANGLE is omitted zero will be used The current location is not effected by this command Another way of drawing text is with the command CTEXT X2 Y2 TXTSTR
65. additional springs defined with SEND CONVOLUTION or X_PY which have nonlinear force deflection or viscoelastic behavior Here in contrast to the above GSPR connectors damping and py curves can only be defined in the element X direction A ROD cannot have a convolution An B_CAT can only be used to connect a body to ground while Rev Page 232 MOSES REFERENCE MANUAL the other types of connectors can connect a body to ground or to another body The PISTON option is used to define a hydraulic piston that is used to control the tension Here TYPE must be either MAX or MINMAX Lt and Ld inches or mm are the total stroke and the nominal position of the piston VLONG and VSHORT feet or meters sec are the lengthening and shortening velocities of the piston and TMAX and TMIN bforce are the minimum and maximum tensions desired The details of the behavior depend on TYPE If type is MINMAX then the piston starts at Ld and stays there until the tension exceeds TMAX or is less than TMIN If the max is exceeded the piston moves to increase the length with a velocity of VLONG and the tension is kept at TMAX If the position wants to exceed LT motion stops and the tension can exceed TMAX If the tension is less than the minimum then the piston moves to make the the decrease the length with a velocity of VSHORT and the tension is kept at TMIN If the position wants to be less than zero the motion stops and the tension constraint is
66. amp EXIT amp VARIABLE WHILE lt MACDBF gt COWS A COW amp TYPE The A_COW cow isa amp FVGET lt MACDBF gt COW DATA A_COW amp ENDLOOP Will type a line defining the class for each type of cow Functions are similar to files You open and close files but you amp READY and amp SUS Rev Page 99 MOSES REFERENCE MANUAL PEND functions The internal command amp READY FUNNAM makes the function FUNNAM available for extracting values When you are through with a function you can use the internal command amp SUSPEND FUNNAM OPTIONS The options must be either DISCARD SAVE or CLOSE If the function is discarded when it is suspended all data for the function is deleted from memory If the SAVE option is used all data for the function will be written to the data base file if it has changed and the function will remain active If the CLOSE option is used then the function will first be saved and then discarded In both the subroutine call and the internal command FUNNAM can include wild characters Thus one can suspend more than one function with one command One thing to know is that at the end of an INMODEL MOSES closes all function yours included Thus you may need to amp READY you functions Actually MOSES function are more general that what we have discussed but this is all that is available from the command interface Rev Page 100 MOSES REFERENCE MANUAL X THE DISPOSITION MENU At the conclusion
67. an INMODEL and in the MEDIT Menu Figures 15 through 18 show a square generalized plate with none one two and four edges refined Rev Page 257 MOSES REFERENCE MANUAL Original Mesh FIGURE 15 One Edge Refined FIGURE 16 Rev Page 258 MOSES REFERENCE MANUAL Two Edges Refined RNOO33 f RNOO15 f RNOO14 f RNOO32 f RNOO13 RN0031 FIGURE 17 QP1 All Edges Refined RNOO33 f RNOO32 RNOO31 FIGURE 18 QP1 RNOO38 RN0039 RN0040 QP2 Rev Page 259 MOSES REFERENCE MANUAL XII N 5 Connecting Parts Connecting parts is a rather delicate proposition Normally the only elements which do not belong to a part are connectors Connectors however are not designed to carry moments and are not as general as beams If however beams are allowed to span parts their element system is not properly defined Two alternatives are provided to circumvent these difficulties The first is that nodes can have an alias In other words a node which has an alias will have the same deflection as the alternative name of the node Defining a node alias is accomplished via ALIAS SLAVE 1 MASTER 1 SLAVE n MASTER n When this command is issued an element will be generated between SLAVE i and MASTER i No checking will be done as to the congruence of the locations of the two nodes
68. angle or the second intercept RARM 30 R 30 Page 362 MOSES REFERENCE MANUAL WHEELING ARM Max RA MARM Tl DWT a Ossi 4 ANGGMARM THELTMATTON AROUT AYTS RIGHTING ARM DANG ONWT T2 RANGE Page 363 Rev MOSES REFERENCE MANUAL ARMAR RA THETA2 ARE DFLD min RA DANG RA THETA2 ARE MARM RA M where M is the angle where R is a maximum ARE 30 RA T where T is minimum of 30 degrees DANG or THETA2 ARE 40 RA 40d where 40d is the minimum of 40 degrees DANG or THETA2 degrees e AREBTW RA 40d RA 30 where 40d is the minimum of 40 degrees DANG or THETA2 e ARM_RATIO R M H M where M is the minimum of DANG THETA2 or the angle of maximum righting arm e AR_WRATIO RA TW RA MANG AD Here the heeling arm is assumed to be a constant HAW 1 5 HA 0 Now TW is the second intercept of the constant wind arm and the righting arm AD HAW TW TT and TT MANG T1 Here we use the RA at a positive MANG even though the angle is drawn as negative on the figure This is equivalent to assuming that RAA is skew symmetric about the origin For checking intact stability the two commands discussed below will accept the following options I GM IGM I _AR_ RATIO IARATIO I RARM M30 IRARM M30 I_AR_WRATIO IAWRATIO MANG I ARM RATIO IARMRAT I DOWN H I DOWNH I ARE MARM IAREQMARM _I_ARE DFLD IAREGDFLD I_ ARE 30 IARE 30 I ARE 40
69. are normally the top and bottom nodes of each corner leg For deep water fixed leg structures the inside diameter of leg compartments can vary substantially For these situations there is a useful command for defining very accurate tank definitions which has the following syntax I_TANK TANK_NAM BOT_NOD TOP_NOD E_BOT E_TOP OPTIONS And the available options are F_VALVE VF_DIA VF_DIST V_VALVE VV_DIA VV_DIST ELEVATION PERMEABILITY PERM B_NODES BN 1 BN 2 Here TANK_NAM is the name given to the tank and BOT_NOD and TOP_NOD are the names of the bottom and top nodes on the jacket leg where the tank resides The variables E BOT and E_TOP provide the locations of the bottom and top of the tank respectively These are the bulkhead locations inside the leg If this information is not supplied the bulkhead locations will be assumed to be at the bottom and top nodes If the ELEVATION option is used these bulkhead locations will be Rev Page 333 MOSES REFERENCE MANUAL assumed to be jacket elevations where the jacket origin is at the inplace waterline and Z is vertical up Without this option the bulkhead locations are assumed to be the length along the leg from the bottom node Bulkhead locations are specified in feet or meters depending on the current units The diameter and location of the flood and vent valves are specified with the F_VALVE and V_VALVE options For this information valve diameter is
70. are three actions of the amp INFO string function that can be used to obtain information about categories amp INFO ACTION SELCAT Here ACTION must be either WT_CATEGORY BU_CATEGORY or MU_CATEGORY which will return the weights buoyancies or multipliers for the categories selected by SELCAT For the first two five tokens will be returned for each selected cate gory the name of the category either its weight or buoyancy and either its CG or CB These are for either the current part or the last part selected with the PART Rev Page 189 MOSES REFERENCE MANUAL option of a amp REL_SEL command The CG or CB will be in the part system The MU_CATEGORY action returns the name of the category and the category multiplier for each selected category Rev Page 190 MOSES REFERENCE MANUAL XII K Bodies and Parts The basic ingredients for performing a simulation are bodies For simulation purposes bodies are considered rigid and composed of parts A part is the smallest entity upon which a structural analysis can be performed Bodies are connected by parts which contain special elements called connectors In essence a part is simply a named portion of the model All properties of the system are described by the attributes of the parts In other words every attribute of the system must be an attribute of some part of the system Thus everything except bodies belong to some part In MOSES each body and each part will have a s
71. as the XP curve The F_STRESS option is a simple way of overcoming a deficiency in most of the published SN curves they are only defined over a limited range of cycles Most of the time this does not matter but the algorithm MOSES uses strictly considers only damage which occurs in the specified range Without any further action a beam with high stress might actually accumulate less damage if the stress were increased This occurs because increasing the stress moves more of the harmful cycles outside the range of the SN curve The value S_MULT is a multiplier which MOSES multiplies by the RMS of the stress spectrum to check for this bad behavior If the product S_MULT RHS is greater than the stress at the first point of the SN curve then the stochastic integration is not performed but damage is accumulated based on the first point in the SN curve This is simply an estimate to keep one out of trouble By default S MULT is 3 72 but you can set it to 0 to strictly obey the standard Rev Page 174 MOSES REFERENCE MANUAL algorithm Rev Page 175 MOSES REFERENCE MANUAL XILH 2 Associating SN Curves with Points An SN curve must be associated with each fatigue point The details differ based on the type of fatigue being computed but in all cases it is accomplished with an SN option For mooring line and tubular joint fatigue the current SN name will be used i e the last name specified on either a amp REP_SELECT command or
72. be used on an exterior compartment to define down flooding into non modeled volumes The string function amp COMPARTMENT CMP _SELE OPTION is useful when writing macros It returns a string containing the information defined by OPTION for each compartment selected by CMP_SELE For all values of OPTION there are more than one token returned for each compartment and the first token is the compartment name The available options are PART PIECES HOLES F TYPE MIN WT DOWN MIN NWT DOWN PERCENT MAX PERCENT AMOUNT MAX AMOUNT SOUNDING ULLAGE CG FULL _CG CG DERIVATIVE FS_MOMENT MAX DHEAD PRESSURE FLOW RATE PIECES returns the name of the compartment and the name of each piece used to define the compartment In a similar fashion PART provides the name of the compartment and the part name to which the compartment belongs F TYPE returns the flooding type and HOLES returns the names of the holes piercing the compartment The next two options return a single token in addition to the com partment name with MIN WT DOWN it is the minimum height of all weather tight down flooding points and with MIN_NWT_DOWN the minimum height of all non weather tight down flooding points For the next six options two tokens are returned in addition to the compartment name a measure of the amount of bal Rev Page 296 MOSES REFERENCE MANUAL last in the compartment and the specific gravity of the
73. by TDEP minus the draft times TLEN plus AEY Likewise the frontal wind area is Rev Page 274 MOSES REFERENCE MANUAL TDEP DRAFT TBEAM AEX In some cases using TANKER may cause forces in a direction opposite from one expects This is a function of the OCIMF data and not a problem with the software There are lift forces involved with the ship shaped hull forms this data represents sometimes causing this behavior The OCIMF results are based on extensive wind tunnel and tank tests on typical tankers We have incorporated digitized versions of these curves into MOSES therefore what is derived is essentially what was measured The question now becomes why are these forces in a direction opposite to what one may expect the answer is probably lift but this depends on your expectations and is what permits us to sail and fly The hull will behave like an aerofoil where the flow does not separate immediately at the bow and particularly if it is cylindrical as far as wind loads are concerned As a consequence the longitudinal force components may be negative i e up current or upwind for some directions Rest assured however the resultant force is always downweather so we can t sail or fly for nothing there is a net drag Rev Page 275 MOSES REFERENCE MANUAL XII P Compartments Compartments are entities used for three purposes e To define hydrostatic wind and current forces on complicated shapes e T
74. by far the most com plicated In fact we will distinguish six different types of structure sea loads buoy ancy added mass radiation damping viscous drag linear wave excitation and wave drift force To allow flexibility MOSES employs three hydrodynamic theories Strip Theory Three Dimensional Diffraction Theory and Morison s Equation When Mori son s Equation is used viscous drag is computed but no radiation damping The other hydrodynamic theories however consider no viscous damping but only radi ation damping Thus if one wishes to add some viscous drag to a system using a diffraction hydrodynamic theory he needs to define some Morison s Equation load attributes The primary objective of the MOSES modeling language is to minimize the number of additional load attributes which need to be defined To ease the definition process MOSES employs two additional concepts the load group and the compartment Compartments are used to define the loads associated with vessel like attributes and load groups are used to define loads associated with structural like attributes Compartments serve to define the loads which arise due to the interaction of the bodies with the water for things which cannot be adequately modeled with Mori son s Equation There are two classes of compartments interior and exterior The exterior compartments define the exterior of a body and the interior ones define sub divisions which may or ma
75. classes are used to define all elements of the model and as a result there are many ways to define them Basically a class definition consists of at least CLASS SEC_TYPE A B OPTION Here SEC_TYPE is a name which defines the types of elements which can use this class A B are dimensions inches or mm and there are many options In general certain options are only applicable to certain types of classes but two groups are available to all material options and load attribute options The material options are _SPGRAVITY SPGR DENSITY RHO EMODULUS EMOD POL RAT POIRAT ALPHA ALPHA FYIELD FYIELD TENSTR TENSTR SN CURVE TYPE 1 N 1 S N n All but TENSTR can be defaulted via the amp DEFAULT command The TENSTR option defines the tensile strength of the segment TENSTR ksi or mpa Rev Page 211 MOSES REFERENCE MANUAL The default value of TENSTR is 1 66 times the yield stress MOSES uses the class properties to compute various loads which will act on the body The options WTPLEN WTPFT DISPLEN DPFT BUOYDIAMETER B_DIAMETER DRAGDIAMETER D_DIAMETER WINDDIAMETER WOD AMASDIAMETER AMOD can be used to alter the properties which will be used to compute the loads Nor mally the weight per length is computed from the true cross sectional area and the density If however the W TPLEN option is specified the weight per unit length
76. command for beam attributes defines an applied load which belongs to user defined load set LSET OBJECT VALA 1 VALA 6 OPTIONS and the available options are VB VALB 1 VALB 6 LOCAL TOTAL A XA B XB LENGTH LEN Here VALA i shown as FA are the values of the attribute XA feet or meters from the A end of the beam and VALB i shown as FB are the values at XB feet or meters from the B end If VB is not specified then the values at XB will be taken to be the same as those at XA The units for VAL i are in bforce and bforce blength To define an attribute in beam coordinates one simply adds the LOCAL option To input a concentrated attribute one should specify LEN to be zero Figure 9 illustrates how the options are used The TOTAL command denotes the fact that the values input for VALA i and VALB i are total quantities and should be divided by the length to obtain the distributed properties The options A B and LENGTH operate in the same manner as the corresponding option for ELAT and were discussed above Rev Page 251 MOSES REFERENCE MANUAL FA FB k xa a Len _ x8_ 4 USER DEFINED LOAD SET FIGURE 9 Rev Page 252 MOSES REFERENCE MANUAL XII N 4 Generalized Plates A generalized plate is a structural element defined with a set of nodes along the exterior and perhaps a set of points defining a free edge of the general
77. contents The measure re turned the second token is defined by the option selected with PERCENT it is the percentage full with MAX PERCENT it is the maximum percentage full with AMOUNT it is the amount in the compartment in bforce units with MAX_AMOUNT it is the maximum amount in the compartment in bforce units with SOUNDING it is the sounding in feet or meters and with ULLAGEH it is the ullage in feet or meters With the next five options one token is returned in addi tion to the compartment name CG and FULL_CG return four tokens the name of the compartment and the X Y and Z part coordinates of the current location and full location of the center of gravity The option CG_DERIVATIVE also returns three tokens the name of the compartment and the longitudinal and transverse derivatives of the CG with respect to angle changes feet or meters deg The option FS MOMENT returns three tokens the name of the compartment and the lon gitudinal and transverse free surface moments in bforce blength the compartment The last three options return a single token in addition to the compartment name e the maximum differential head with MAX_DHEAD e the internal pressure ksi or mpa for PRESSURE e the flow rate FLOW RATE Rev Page 297 MOSES REFERENCE MANUAL XII P 4 Filling Interior Compartments Interior compartments can get contents in several ways An accident can occur which breaks a hole in the compartment
78. database itself has been saved Con trol over how often the database is saved is provided by the SAVE option If this option is omitted the database will be saved fifteen times during the time domain simulation If the option is used the database will be saved at SAVE_INCREMENT increments during the time domain In other words if SAVE 30 is used the database will be saved once every 30 computed time steps Historically launch has used a predictor corrector integration scheme With Rev 7 07 this scheme is used until separation and then the integration is changed to a Newmark method To keep the old method one can use the OLD YES option Rev Page 409 MOSES REFERENCE MANUAL XXIV CREATING A STATIC PROCESS The Static Process Menu of MOSES is used to simulate the process of altering the position of a body by either lifting or ballasting It is particularly useful for simulating the process of moving a jacket from the floating position achieved after launch to an upright position or lifting a body from a barge and lowering it into the water Since the results of most of these processes are sensitive to the order in which the operation is performed MOSES s interactive structure is ideally suited to such a situation To enter this menu one should issue the command STATIC_PROCESS BODY_NAME where BODY_NAME is the name of the body which will be considered The method of analysis here consists of issuing a sequence of commands to MO
79. database via commands The same device is used if one has computed hydrodynamic pressures and wished to save them for use later This capability can be quite useful when analyzing a large diffraction model For instance one could alter the mooring lines of system and use the importation feature to save time in the reanalysis Caution should be used here so that only changes to the model that do not effect hydrodynamic properties are performed To emit a hydrodynamic database one issues E_PRESSURE BODY_NAME OPTION where BODY NAME is the name of the body for which hydrodynamic databases will be emitted This command will export a pressure database for the packets currently associated with the body BODY_NAME Here the only option is NOTE which is just like the same option on model definition commands In particular you need to specify all five characters of the option and the note that you attach will be included as a comment in the emitted file Also the title and subtitle will be included if they are not blank No drift or total data will be emitted since it is recomputed when the pressure data is imported It is possible to export and subsequently import a total hydrodynamic database This is accomplished with E_TOTAL BODY_NAME OPTION The resulting output is substantially smaller than the pressure database Here the options and titles are the same as for the pressure database This file however consists data for both Total
80. days variable can be used to scale the damage from the time accumulated to TIME In other words if the sum of the durations was T1 and TIME was specified to be T2 then the damage will be multiplied by T2 T1 before reporting A command closely associated with fatigue is COUNT_CF OPTIONS where the available options are F_BINS T 1 T 2 T n ACCUMULATE CONN_SEL REPORT TIME Instead of accumulating fatigue however this command accumulates cycles of ten sion in specified ranges The ranges are specified with the F_BINS option where T i is in bforce and the other options function exactly as for the FAT CFORCE command If some of the connectors are rods then one has two additional commands available These commands compute statistics of the internal forces and the stresses in the rod To obtain the statistics of the internal forces one should issue ST_RFORCE ROD_NAME ENV_NAME OPTIONS where the available options are SEA SEA NAME THET HS PERIOD GAMMA SP_TYPE TYPE SPREAD EXP USE_MEAN YES NO Here ROD_NAME is the name of the rod one wishes to investigate If one is in Rev Page 398 MOSES REFERENCE MANUAL terested in a pipe assembly then he should use amp PIPE for ROD_NAME When issued the statistics for the rod internal forces will be computed One can use the USE_MEAN option to instruct MOSES to add the mean value of the force to the computed deviation with the sign of t
81. elements carry compression they are eliminated and a new hook attachment point is computed This process is continued until the sling elements all carry tension or zero load The CLOSURE and DISPLAY options were discussed above With the second command MOSES will alter the ballast in selected compartments until a termination criteria is satisfied Its form is FLOOD TNK 1 PERC 1 TRP 1 TNK 2 PERC 2 TRP 2 OPTIONS and the available options are CHEIGHT NDRAIN CLOSURE TOL 1 TOL 2 DISPLAY OLD 1 NEW 1 OLD 6 NEW 6 In general all compartments which match the tank selector TNK i will have their ballast altered by a percentage PERC i at each step The process terminates when all selected compartments have reached their termination percentage TPR i During this process the water added to a tank is free to move around in the tank as the body changes orientation In view of this problems sometime arise if long compartments which are almost horizontal are flooded Here the sloshing of water from one end to the other may inhibit closure of equilibrium residuals The flood increments PERC i may be either positive or negative If one is positive then TPR i is a maximum amount of ballast which will be placed in the compartments selected by TNK i If PERC i is negative then TPR i is a minimum amount which will be in each Rev Page 414 MOSES REFERENCE MANUAL selected tank The CHEIGHT
82. es eee eee eee eS ree 356 DAON 357 XVULD Longitudinal Strength aaa 482 358 eons 359 eee eee 362 XIX THE HYDRODYNAMIC MENU 370 ee Se ee ee ee ee ee 373 eeleseeteee bt eeuaree gt 379 Page iii XX THE FREQUENCY RESPONSE MENU 381 XX A Equation Post Processing 387 XX B Motion Post Processing 389 XX C sargo Force Post Processing 393 AAD Connector Force Post Processing 396 XX E Pressure Post Processing o e aaa 400 XXI FINDING EQUILIBRIUM ooohh ahaaa 402 XXII TIME DOMAIN SIMULATION ooa ahaaa 405 XXIII LAUNCH SIMULATION 2 4 eee de eee dw Re Ew 408 XXIV CREATING A STATIC PROCESS 410 XXV POST PROCESSING OF A PROCESS 417 DENTE 418 420 XXV C Post Processing Compartment Ballast 423 ey teagan 424 Serer cer 426 Dut dpa he eed 429 a 431 XXVI STRUCTURAL ANALYSIS amp APPLIED LOADS 432 eae Sot od 434 were 435 Eee oe sore 436 CETE EON 441 XXVII STRUCTURAL A NALYSIS amp amp APPLIED LOADS 444 a ee ae 449 aren eer eoere 452 E oes oe 454 oe 455 1 re 457 Sooo ubabe aan 459 Pere eee 460 fe Fatah tan 464 ee a ee ee ee 466 Page iv MOSES REFERENCE MANUAL I INTRODUCTION Our primary objective with MOSES is to provide engineers with the tools necessary to realistically design and analyze marine structures and operations The increasing sophist
83. file FILE NAME until either an end of file is encountered MOSES finishes or another COMIN command is specified The AUXIN option functions as the COMIN option except that it redirects the flow of information on the INPUT channel With both of these options if FILE NAME is amp E then MOSES returns to the default channel With these two options a fatal error occurs if the file specified does not exist If one does not desire an error if the file does not exist then he can use either ICOMIN or IAUXIN With these two options the command is simply ignored if the files fail to exist In some cases one does not know whether he wishes to redirect the input or the command channels but instead he wishes to redirect the current channel This can be accomplished by using the command amp INSERT FILE_NAME Here the current information channel will obtain its data from the file FILE NAME as discussed above Rev Page 36 MOSES REFERENCE MANUAL VI E Message Commands MOSES allows the user to issue messages to both the output and command channels via internal commands For the output channel the messages are limited to two title lines of data which are printed at the top of each page of output These can be defined via amp TITLE MAIN_TITLE amp SUBTITLE SUBTITLE Here MAIN_TITLE is used for the first title line and SUBTITLE is used for the second title line To issue messages to the command channel one uses
84. file currently connected to the GRA_DEV channel Then the command amp CHANNEL GRA DEV will result in GRA00001 eps being closed and the next graphics will be written to GRA00002 eps If GRAO0001 eps is empty then nothing will happen It may seem odd that the available channels and logical devices are the same but it offers quite a bit of flexibility For example if one has a postscript printer then he only needs one of the channels OUTPUT DOCUMENT or GRA_DEV and he can connect all three of these logical devices to it This makes the results of all three logical devices appear in order when printed A drawback of this approach however is that once the OUTPUT logical device is formatted for a particular device it may Rev Page 32 MOSES REFERENCE MANUAL become unreadable The TEX device is actually a file written in a format that can be processes by the popular text formatting program LaTeX When this device is connected to the DOC UMENT channel it generates a stand alone file for input into LaTeX Included in this file is a set of macros which make it work When connected to the OUTPUT channel the file is not complete in that it is missing the macros the prologue the begin document and the end document statements This occurs since one nor mally wants to input the output file into the document file to produce a complete document The DXF and UGX physical devices are for saving graphical results The DXF de
85. for the current process will be used to compute theses contributions The diffraction incident and the radiation mean forces are also used to apply a slowly varying force in the time domain as described earlier The coriolis acceleration contribution to the mean is not used in the time domain Instead it is computed exactly One can examine the drift data with the command V_MDRIFT BODY_NAME which will place one in the Disposition Menu to do whatever one wishes Simple estimates of the mean drift force can be created with the command G_MDRIFT BODY_NAME PKT_NAME OPTIONS and the available options are MD_TYPE DTYPE DIMENSIONS LENGTH BEAM DRAFT HEADING H 1 H 2 H n PERIOD T 1 T 2 T n Here DTYPE must be either FORMULAE or SEMI The DIMENSIONS option defines the size feet or meters of the body used in estimating the drift If it is omitted the actual body dimensions will be used The wave drift data computed here is not sophisticated and only mean drift is considered One can save a set of drift data for later use by issuing the command E_MDRIFT BODY_NAME which writes the drift data currently associated with body BODY_NAME to a file for later use The user can input his own drift database To define mean wave drift response operators one first enters a submenu with the command Rev Page 379 MOSES REFERENCE MANUAL I MDRIFT BODY NAME PKT NAME OPTIONS and the available options are
86. force and drift force For simulation purposes this is all Rev Page 374 MOSES REFERENCE MANUAL that is necessary but it cannot be used for computing structural loads When such a database is input a single warning to this effect will be given The format of an exported pressure database is the same as the one used to define the data directly to MOSES It begins with the command I_ PRESSURE BODY_NAME PKT_NAME DISPL OPTIONS which places the user in a submenu Here BODY_NAME is the name of the body for which the database is being generated PKT_NAME is a desired packet name DISPL is the displacement at the condition being defined and the options are PERIOD T 1 T 2 HEADING H 1 H 2 CONDITION DRAFT ROLL PITCH Even though these items are called options the first three of them are necessary to properly define the database The PERIOD option defines the periods sec for which the database will be defined and HEADING defines the headings deg for which the exciting forces will be defined The CONDITION option defines the vessel condition for which the database is defined and DRAFT ROLL and PITCH are the draft feet or meters roll deg and pitch deg defining the condition The remaining options were described previously Once the menu has been entered several commands are available First the com mand FP_MAP PANEL NAME PNT_SEL 1 PNT_SEL 2 defines a how the structu
87. foundation element for checking one uses the option SET STATE TYPE MULT of the amp CONNECTOR command Here TYPE must be either PRELOAD or NOMINAL and if TYPE is NOMINAL then MULT is a multiplier which will be use in computing the unity ratios otherwise it should be omitted See the discussion in the section on Process Post Processing of Connectors for details on the unity ratio computation A launchway assembly can be activated or deactivated by using the name amp LWAY for CONN_SEL i j Also one can alter some of the settings for the assembly of launchways with the options LWA _FRICT DYNFRC Rev Page 323 MOSES REFERENCE MANUAL LWA ANGLE MAX ANGLE Here one selects the launchways which will have their properties altered with CONN_SEL The LWA_FRICT option sets the dynamic coefficient of friction of the selected runners to DYNFRC and the LWA_ANGLE option sets the maximum angle for the first tiltbeam on the selected launchways to MAX ANGLE degrees The names of the launchways are amp LLEGi where i is a number assigned as the launchways were defined Some things with pipe assemblies can also be changed with the CONNECTOR command The options are _PIPE_TENSION TLOWER TUPPER DAV LENGTH NEWLEN MOVE ROLLER DX DY DZ LOC_ROLLER X Y Z A _ STIFF STADGX STADGY STADGZ TOP MOMENT YES NO ST ADDITION INONUM STADGX STADGY STADGZ Unless otherwise specified CONN_SEL shoul
88. from periods between 0 and 30 will be discarded to form the new function The SMOOTH option creates a new column by smoothing an old one but here a Savitzky Golay filter accomplishes the smoothing CS defines the column to be smoothed and NL NR and M define the smoother NL is the number of points to the left NR is the number of points to the right and ORDER is the order of polynomial used in constructing the filter The defaults are 8 for NL and NR and 4 for ORDER Since this algorithm does not use Fourier analysis it can be used to Rev Page 106 MOSES REFERENCE MANUAL smooth spectral or FFT data Rev Page 107 MOSES REFERENCE MANUAL X C Recasting Data There are three special commands in this menu SPECTRUM FFT and CULL All of these commands take a subset of the original data and transform it into a new set of data to be disposed This has the interesting effect of one being in the Dis position Menu from the Disposition Menu The first time and END is encountered one leaves the latest Disposition Menu but is still in the Disposition Menu Now however the original data is again available There are several options which can be used on more than one command RECORD BEG_RNUM END_RNUM VALUES CV VAL_MIN VAL_MAX The RECORD and VALUES options defines the records which will be con sidered Here a RECORD is simply a row of the matrix of data With the RECORD option the beginning and end record nu
89. have no title Rev Page 50 MOSES REFERENCE MANUAL VII D The amp BUILDG Menu A menu is provided so that the user can simply input data and use it in the Disposition Menu To exercise this capability one should enter the command amp BUILDG OPTION Here the data which must be entered can be thought of as a matrix The rows of the matrix correspond to the variables and each row of the matrix contains the values of the variables at a common event The details depend on what OPTION is selected If one does not specify an option MOSES will ask for the values of the legends The legends correspond to labels of the columns of the matrix Next the data is input One simply inputs the matrix a row at a time A null line terminates the input and puts the user into the Disposition Menu If one specifies the option BRIEF then MOSES will neither prompt for data nor query for correctness This enables one to read a file automatically which has been generated via a STORE command in the disposition menu or any file written with the same structure An example of this command is amp BUILDG BRIEF DATA_1 DATA_2 DATA 3 DATA 1 DATA 2 DATA 3 1 2 3 4 5 6 T 8 9 Here DATA 1 DATA 2 and DATA 3 are the labels that will be used in the graph The blank line between DATA 3 and the comment line is required The remainder defines the data points Each line defines potential points on a graph The Disposition Menu is entered when a blank line
90. horizontal deformation will produce a vertical deformation Delta_v Delta_h T Finally if D_v is greater than LEN the two deformations are Deltav Dv LEN Dh T Rev Page 227 MOSES REFERENCE MANUAL Delta_h D_h Now the force in the connector is computed from the two deformations and the two spring constants CONE with PIN on Z za OD2 CONE DIMENSIONS LMU CONNECTOR FIGURE 7 The IG_STIFF option is applicable for flexible connector classes as well as restraint classes With this option the stiffness of connectors attached to other bodies will not influence the structural results of the desired body Additional springs can be combined in series with the basic springs by including either or both of the options Rev Page 228 MOSES REFERENCE MANUAL SEND or X_PY The first of these defines a nonlinear spring where the stretch in the spring DEL resulting from a force F is given by DEL KE 1 F KE 2 F The units for KE 1 are ft kips ft l tons ft s tons m mt or m kn and for KE 2 ft kips 2 ft l tons 2 ft s tons 2 m mt 2 or m kn 2 The CONVOLUTION option allows one to add an additional spring but the behavior here is defined by a convolution CVL_NAME This allows one to define springs that are viscoelastic as well as elastic The X PY Y PY and Z PY options define nonlinear springs in series with the basic x y or z stiff
91. in the center of the logical beam and have a stiffener spacing of half the minimum buckling length Each element would have the same stiffener spacing but a stiffer weight of the weight of the ring times the element length divided by the buckling length As another example consider a beam for which we need a joint ring at one end The class LBEAM TUBE OD T TN_STIFF 1 JR EXTERNAL LEN 2 5 LBEAM TUBE OD T TN_STIFF 1 HR EXTERNAL We must use a segment to define the joint ring hence the first segment The hydro static ring defined for the second segment will be the middle of the second segment and the stiffener spacing here is half the length of the second segment Rev Page 221 MOSES REFERENCE MANUAL XII M 2 Class Shapes MOSES maintains a table of standard shapes Here a shape is nothing more than a partial class definition If one has an element made of one of these shapes he can simply specify it by SHAPE_NAME In other words one can specify CLASS W14X140 and nothing else is required Alternatively one can now add any valid class option to this definition to tailor it for his purposes One can obtain a list of the currently available shapes by issuing amp NAMES SHAPES The basic table supplied with the program contains AISC British and French shapes One can add to the default shape table by entering a new menu with the command amp DATA SHAPES This command should be followed by records of the form NAME TYPE
92. information about the surface current the ones beginning with T_ and RAMP return information about the time the ones beginning with W_ return information about the wind and the ones beginning with S_ return information about the sea WAT DEPT returns the water depth and WATER returns the specific gravity of water Rev Page 167 MOSES REFERENCE MANUAL WAVE GRID DEFINITION FIGURE 3 Rev Page 168 MOSES REFERENCE MANUAL XII G 1 Durations The purpose of a DURATION is to associate a time of exposure to an environment With mooring line fatigue this is done directly on the amp ENV command itself For all other cases it is done in the amp DATA DURATION Menu This is done in one of two ways depending on the type of analysis performed For either type of analysis the following command is used STRPOST amp DATA DURATION DURATION_NAME PRC_NAME OPTION where the only available option is TDOM DUR TIME Here DURATION NAME is the duration name When asking for fatigue results one selects the durations to be applied and PRC_NAME is the process name for which the duration will be applied The TDOM option signifies that one wishes to perform time domain fatigue on the process PRC NAME and that the total duration of this process is DUR TIME in days This is all that is required for a time domain process When DURATION is used without the TDOM option a sub menu is entered where frequency domain fatigue data will be
93. is called the range of the function and the elements in B are called the values of the function What we are going to discuss here are functions who s domain is either the set of positive integers or a variable and the range of these functions is a set of strings In this sense a variable is not a simple global or local variable It is in fact a set of names and a name is a string of up to eight characters The variable itself has a name which is a string of up to twenty four characters The name must be of the form lt DBFILE gt VAR_NAME Here DBFILE is the name of the database file where the variable will be stored Now we could spend a good bit of time talking about this but lets just say that there are two that are always available MACDBF and SYSDBF so you should use one of these preferably MACDBF VAR_NAME is simply the name of the variable To create a variable one uses the internal command amp VARIABLE VAR_NAME ADD NAME Which adds the name NAME to the variable VAR_NAME Now once a variable has names you can find out what they are with the string function amp VARIABLE WHILE VAR_NAME SEL WHAT extracts all the names in VAR_NAME that match SEL and sets the normal global or local variable WHAT to the value of the name It also returns a string FALSE if there are more names to be output or TRUE if it is finished Let s look at an example amp VARIABLE lt MACDBF gt COWS ADD JE
94. is replaced with SP_PLATE i e SP_BEAM ELE_NAME 1 CLASS 1 OPT 1 NODE 1 NODE m ELE_NAME 2 CLASS 2 OPT 2 NODE n SP_PLATE ELE NAME CLASS OPTIONS NODE 1 NODE m and there is an additional option which must be used ELEMENTS ELSEL 1 ELSEL n These commands create a pseudo elements which have all of the properties defined with their class and their geometry but gets their load information from the ele ments specified via the ELEMENTS option Here ELSEL i are selectors for the elements which will be considered to be a part of the SP_BEAM or SP PLATE As mentioned above these pseudo elements add nothing to the model no stiffness no weight nothing They are simply a useful way to look at parts of the model in the large for structural post processing In particular suppose that one had a plate model of a semi submersible After a structural analysis he has stresses in the plates but that is it Now to really analyze this situation one needs to check global buckling of the columns etc By creating SP_LBEAMS of the various pieces this can be easily accomplished For purposes of structural post processing pseudo elements are treated the same as structural elements Thus one can also find bending moments and shears in them stresses in them etc Rev Page 264 MOSES REFERENCE MANUAL XILO Load Groups The load group is a generalization of a nodal load Here a c
95. is the distance measured from the node to the body attachment point in the second part system feet or meters A special method for connecting two parts for the transportation of a structure on a vessel is provided by MOSES To utilize this method one must have a model which Rev Page 260 MOSES REFERENCE MANUAL consists of a single body with a body type of VESSEL and there must be a part named JACKET with a part type of JACKET This allows the part system of the jacket to be different from the vessel and MOSES will automatically rotate the jacket so that the part systems are the same Here one must also establish connections between the parts so that an analysis can be carried out The connections are of two basic types launchways which are continuous beams fastened to the vessel and upon which the jacket rests and tiedowns which fix the jacket to the vessel To use this feature one should issue the command TRANS_CON LOCJ XO YO ZO JLLEGS JS 1 JS n JLLEGP JP 1 JP n LWAYP X1 ZNA L CLASS BPSEL LWAYS X1 ZNA L CLASS BSSEL The launchways are generated by the program as two continuous beams Nodes on these beams are automatically generated by MOSES to match up with the nodes on the jacket launch legs and with suitable nodes on the vessel The jacket launch leg nodes are defined with the JLLEGS and JLLEGP options where JP i are nodes on the port launch leg and JS i are no
96. is used with a YES NO of YES then the top connection will apply a moment otherwise it will apply only forces The ZERO_BSTIF option changes the connection behavior at the bottom If it is used with a YES NO of YES then the stiffness at the bottom Rev Page 322 MOSES REFERENCE MANUAL will be applied otherwise the bottom will be free to move The option ST_ADDITION allows one to add a diagonal stiffness matrix at inter mediate points along the rod Here INONUM is the intermediate node number where the stiffness will be added These nodes are numbered with the bottom being 1 so that to add a stiffness one node above the bottom it should be added with INONUM equal 2 STADGX STADGY and STADGZ are the same as for A_STIFF One may alter the settings of a propulsion connector with with the option SET PROPULSION T_MULT T_ ANGLE R ANGLE of the CONNECTOR command Here T MULT is the fraction of the maximum thrust 1 lt T MULT lt 1 which will be applied TANGLE is the angle that the thrust will be applied and R ANGLE is the angle of the rudder Both of these angles should be 90 lt ANGLE lt 90 One may alter a tug connector with with the options T_FORCE FORCE T LOCATION ANG DIST T DYNAMIC PERCENT_FORCE PHASE of the amp CONNECTOR command The values for FORCE ANG DIST PER CENT_FORCE and PHASE have the same meaning as on the commands defining the connector To define the special states of a
97. it does not With amp FILE the DATA and OPTIONS depend on the value of ACTION and the valid values of ACTION are MKDIR RM MV CP USE ANS DIRECTORY OPEN CLOSE and WRITE The first four ACTIONS do not have any options amp FILE MKDIR A amp FILE RM A amp FILE MV A B amp FILE CP A B where the MKDIR ACTION creates the directory A the RM ACTION deletes the file A the MV ACTION renames file A to B and the CP ACTION copies file A to B The USE action is used to alter the default association of files and file TYPES The syntax here is amp FILE USE TYPE FILE_NAME and TYPE is the type of file which will be altered It is a either a user defined file Rev Page 94 MOSES REFERENCE MANUAL type or type PREFIX of a channel Also FILE_ NAME is the new file name which will be associated with the file type When this option is exercised the old file will be closed and the new one used until further notice The ANS_DIRECTORY action is used to alter the default association of files and file TYPES The syntax here is amp FILE ANS_DIRECTORY DIR where DIR is a directory in which the answers will be stored Before one can write to a file it must be opened with the command amp FILE OPEN TYPE TYPE NAME FILE NAME Here TYPE is a handle you can associate with the file and FILE NAME is the name of the file The handle can be any name of up to eight characters and is used to read write and clos
98. its equivalent For elements other than mooring lines there are three ways to define them on a amp DEFAULT command on the CLASS command or on the element definition command In any case failure to include a definition results in the last definition being used i e e The SN specified on the element command is used e If no SN is specified on the element command than specified on the class definition is used e If no SN is specified on the class definition then that defined on the amp DE FAULT is used For the amp DEFAULT command the default SN curves at various points on an element are defined with the option SN TYPE 1 SN1_A SN1_B SN1_R TYPE 2 SN2_A SN2_B SN2_R Here TYPE i defines a section type and must be either TUBE CONE BOX WBOX PRI IBEAM G_IBEAM TEE CHANNEL ANGLE D_ANGLE LLEG or PLATE SN1_A is the SN curve name for the A end of the element SN1_B is for the B end and SN1_R is for all remaining segments This sequence can be repeated for as many section types as desired Also if only one SN curve name is provided the same SN name is used for all locations along the element If two SN names are specified the first name applies to the A end of the element and the second SN names applies to the B end and all segments in between Of course the SN curve specified here must be defined to MOSES using the appropriate commands such as KREP SELECT For the element and c
99. joint deflection load t end amp picture iso events 0 1000 deflect 200 only movie Of course once the deflections are associated with the events the making of the picture is the same as with any animation Now suppose you have a combination case suppose you are doing an LRFD code check etc Then amp loop t 1 1000 amp set num amp string o_number 0000 cases combine c num t 1 some 1 amp endloop will have a time association while amp loop t 1 1000 amp set num amp string o number 0000 cases combine c num some 1 t 1 amp endloop will not Rev Page 453 MOSES REFERENCE MANUAL XXVIII C Post Processing Modes Structural Post Processing results for modes are obtained with the command MODES POST TYPE 1 TYPE i OPTIONS where TYPE i must be chosen from VALUES or VECTOR and the available options are LOAD LSEL NODE NODE_SEL With modes the load cases are the names M00000001 M00000002 etc where 1 designates the first mode 2 the second mode etc The LOAD option can be used to select modes based on this nomenclature If TYPE is VALUES then the eigenvalues natural frequencies for the selected modes will be reported If TYPE is VECTOR then the eigenvectors normal modes for each node selected by NODE NODE_SEL will be reported With a TYPE of VECTOR the command works the same way the joint deflections do In particular one can issue amp PICTURE TYP
100. mean value of the force to the computed deviation with the sign of the mean so that the reported force will be a measure of the total force and the remainder of the options are discussed above When dealing with irregular seas it is often of interest to know the variation of the sea and frequency response of the constraint forces connector with frequency and period To obtain results of this nature one should issue SP_CFORCE CONN_SEL OPTIONS where the available options are SEA SEA NAME THET HS PERIOD GAMMA SP_TYPE TYPE SPREAD EXP E PERIOD EP 1 EP 2 and they are discussed above Fatigue can be computed on the connectors if one has computed frequency response with an SRESPONSE command This is accomplished with the command FAT_CFORCE OPTIONS where the available options are INITIAL Rev Page 397 MOSES REFERENCE MANUAL ACCUMULATE CONN SEL REPORT TIME This command was designed to accumulate fatigue for several different environments SRESPONSEs When the command is issued with the INITIAL option all fatigue accumulators are zeroed When it is used with the ACCUMULATE op tion cumulative damage is computed for all connectors which match CONN_SEL and this damage is added to that which exists The duration used for the damage is that specified on the amp ENV command Finally when the command is used with the REPORT command a report of the cumulative damage is written The TIME
101. obtained As mentioned previously the data for these commands depends on the manner in which the original frequency response data was computed If it was computed with an RAO command then all options and data discussed here are available If it was computed with an SRESPONSE command then only geometrical data can be input In other words no environmental data can be specified Many of the commands here compute statistics of quantities and as a result have many common options In particular SEA SEA_NAME THET HS PERIOD GAMMA SPREAD EXP SP_TYPE TYPE E_PERIOD EP 1 EP 2 CSTEEP YES NO The statistical result is the statistic specified with the last PROBABILITY option on a amp DEFAULT command and If the original response data was produced with the SRESPONSE command then no additional sea data can be specified The remainder of the commands available for motions have a similar syntax in that the final portion of the command is identical to that of the amp ENV command In fact these commands not only initiate the computation of quantities in an irregular sea but are also amp ENV commands Thus when one issues one of these commands with a non blank ENV_NAME he is altering the definition of this environment within the database If ENV_NAME is omitted then the environment used will be totally de fined by the options specified The options SEA SPREAD and SP_TYPE are used to define the sea state to
102. of ACTION MOSES finds the point closest to a specified location but they differ in detail For an ACTION of OFFSET the specified point is the location of POINT plus the X Y and Z specified and any point which matches SEL in a part different than that of POINT is a candidate The string returned is GO1 the x y and z values of the offset from specified point to the close point and the string POINT itself For CLOSE the specified point is simply the location in the part PART_NAME defined by X Y and Z and all points which match SEL are considered for being close In either case the vector returned is represented in the part system of the close point As an example consider CONNECTOR CC amp POINT OFFSET 1 0 0 10 This will define a connector of class CC End 1 of the connector is at a physical location of 1 plus 0 0 10 in the part system of 1 and end two is at 1 This connection is actually defined via the closest point and an offset and the command set to MOSES will look like CONNECTOR CC GO1 XX YY ZZ B22 1 where XX YY ZZ and B22 will be values computed so that the end of the connector is at the correct location The ACTION of NEAREST takes a point name and a selector and returns the point which matches the selector closest to the given point In particular amp POINT NEAREST R R will return the name of the point which begins with R and which is not R itself that is closest the
103. of data is encountered Finally if one specifies the option CSV then MOSES will read the following as a csv file structure An example of this command is amp BUILDG CSV DATA_1 DATA 2 DATA 3 DATA 1 DATA_2 DATA 3 1 2 3 4 5 6 Rev Page 51 MOSES REFERENCE MANUAL END Rev Page 52 MOSES REFERENCE MANUAL VILE The amp TABLE Menu A menu is provided so that the user can simply input data and have it written as either a CSV comma separated value or a HTML file To exercise this capability one should enter the command amp TABLE OPTION followed by as many records as necessary to define the rows of the table You should have the same number of tokens in each row input record and if you want to have spaces in a token you should delimit the token with either a or a To have a cell blank you can use either or NA or NOT_USED The following options control the appearance of the table HEADING HEAD TITLE NCOL 1 CT 1 NCOL n CT n BOLD YES_NO H_ SKIP YES_NO ROW SHADE YES_NO FIGURES COL SEL RIGHT EXTR SHADE COL_SEL 1 COL_SEL 2 V LINES COL SEL 1 COL_SEL 2 After defining the rows you should end the table with END_ amp TABLE The HEADING and TITLE options define the text at the top of the table and you probably want more than one of each The headings and titles are emitted in the order the options are specified and the headings are emitted before the
104. of the plate Rev Page 186 MOSES REFERENCE MANUAL XII J Categories and Load Types As mentioned above the basic idea behind MOSES is that one defines attributes which the program then uses to compute loads Now an attribute may create load from different sources To distinguish these classes of loads MOSES employs the concept of the load type which is simply a name given to each of the sources of loads and is either 4 DEAD WIND BUOY AMASS or DRAG for the intrinsic loads or a user supplied name which begins with a for the applied loads These names are used to control which type of load is applied to each load attractor Here DEAD is the load due to weight WIND to wind BUOY is hydrostatic pressure AMASS is hydrodynamic pressure and DRAG is viscous water force For structural elements one can select which of these forces will be applied This is accomplished with two options on either amp DEFAULT BEAM or PLATE com mands USE USE 1 USE 2 USE i NUSE NOT_USE 1 NOT_USE 2 NOT_USE i Here the values of USE i and NOT_USE i are the selectors for the names of the load types defined above For example USE NUSE WIND Instructs MOSES to consider all of the load types except wind when computing the force on an element When a structural element is defined MOSES first sets the load type flags to those defined with amp DEFAULT Then either of these options encountered on
105. on beams are similar to longitudinal stiffeners on plates and are defined with the L_STIFF option discussed above and LN STIFF NUMBER STIF_CLASS WHERE Also here WHERE can also have the additional values of INTERNAL of EX TERNAL which make sense for closed sections In reality Z and EXTERNAL are the same as are Z and INTERNAL The difference between L_STIFF and LN_STIFF is that the first defines the location of the stiffener by a spacing here SPACE is in inches or mm and the second by the number of stiffeners Obviously SPACE DISTANCE NUMBER 1 Where DISTANCE is the distance over which the stiffeners are applied For tubes the distance is the circumference inner or outer depending on WHERE All other shapes are composed of rectangles Here DISTANCE and NUMBER are used for each rectangle of the section and DISTANCE is the longer dimension Thus for a PRI section the DISTANCE is the greater of A and B Fractional stiffeners are used and they are smeared over the full width Thus adding stiffeners increases both of the inertias of the section Transverse stiffeners on beams are the most complicated and are defined with either of the two options T STIFF SPACE STIF_CLASS WHERE LENGTH TN STIFF NUMBER STIF_CLASS WHERE LENGTH Here the values have the same meaning as those for longitudinal stiffeners on beams The new value LENGTH will be discussed in a minute One of the problems with
106. one to omit offsets which lie on a line from the model This is often desirable since MOSES gives the correct answers for planes of any size Here TOL is the cosine in the angles minus 1 which will be considered to be colinear The LOCATION option allows one to place and orient the generated piece with respect to the part system The position of the piece is defined by X Y and Z feet or meters These are the part coordinates of the origin of the local coordinates of the piece The orientation of the piece is defined by the three angles ROLL PITCH and YAW These are defined as follows Suppose that the piece is given successive rotations about the local Z axis then about the new local Y axis and finally about the new local X axis so that the piece after the three rotations is in its proper orientation in space These three angles can be thought of as a yaw followed by a pitch followed by a roll to move the piece from when it is aligned with the global system to its required position in space In this menu the actual definition of the surface is accomplished by a set of com mands PLANE X 1 X 2 X n OPTIONS and the available options are RECTANGULAR ZBOT ZTOP BEAM NB NS NT CARTESIAN Y 1 Z 1 Y 2 Z 2 Y n Z n CIRCULAR Y Z R THETA DTH NP E_CIRCULAR Y Z R THETA DTH NP where X i is a local X coordinate of the plane feet or meters and the offsets of the section are defin
107. only to distinguish be tween curves on the plot Normally the legend box is drawn in the domain of the plot and it is possible that some of the curves will be drawn in the legend box The CROP_FOR_LEGEND option tells MOSES to change the behavior so that a curve will never enter into the legend box The behavior of MOSES after the PLOT command is issued depends on the op tions NO_EDIT T MAIN T SUB T X T LEFT T RIGHT and LEGEND If none of these options were specified MOSES will go into edit mode and will ask the user which legend or title he wishes changed An empty line a simple carriage return will take MOSES out of edit mode Note that each legend is limited to twenty characters while each title may be up to seventy two charac ters in length With these options TITLE is a string probably delimited by to include blanks and the option keyword defines where the title will be placed For LEGEND NUMBER is the legend number where title will be placed After a graph has been made the user may elect to make another graph with the same variables but change some of the options The AGAIN command is provided for this purpose AGAIN OPTIONS Here any of the options valid for the PLOT command may be specified After a graph has been made a copy may be written to a file for later processing by using the SAVE_GRAPH command Rev Page 116 MOSES REFERENCE MANUAL SAVE GRAPH The file used by this command is
108. option alters the action which will be taken with the hook during the flooding Without the option compartments are ballasted holding the hook load constant Alternately if CHEIGHT is specified the compartments will be ballasted holding the height constant unless negative hookload is required If this occurs the height is allowed to change with zero load Without the NDRAIN option MOSES attempts to simulate a tank with an open valve In this case at each iteration a check of where the waterplane intersects the tank is made If the volume of the tank below the waterplane is less than the current percentage full then the flooded volume is taken to be the submerged volume instead of the current percentage full Thus compartments which are filled without the NDRAIN option can later lose ballast if they come out of the water Use of NDRAIN simulates pumping water into compartments Here no check on the submerged volume is made and the amount of water in a tank remains fixed during subsequent calculations As with all static process commands the conditions used at the beginning of a step are those which existed at the end of the last step The CLOSURE and DISPLAY options were discussed above At the conclusion of a command the user will be prompted for the next command To see data which was not displayed during the execution of a command the user can input the command REVIEW RTYPE E1 E2 where RTYPE is the type of data revi
109. options are EVENTS E_BEG EEND EINC MAG_DEFINE A 1 A n BODY B_ SEL FORCE FORCE NAME 1 FORCE_NAME n The first three options are discussed above and the FORCE option defines the types of forces which will be reported Here FORCE NAME i is a selector which selects forces from the list WEIGHT CONTENTS BUOYANCY WIND V_ DRAG R DRAG WAVE SLAM W_DRIFT CORIOLIS DEFORMA TION EXTRA APPLIED INERTIA A INERTIA C_INERTIA FLEX _CONNECTOI RIGID_CONNECTORS and TOTAL If this option is omitted only the total force will be computed The meaning of these forces can be found in the section of FORCES Rev Page 419 MOSES REFERENCE MANUAL XXV B Post Processing Drafts Points and Sensor Readings One class of command is always available within the Process Post Processing Menu the ones which deal with Interest points Draft Marks and Sensors There are four commands available SENSOR DRAFT POINTS REL_MOTION and P_MIN_DISTANCE The options common to most commands here are EVENTS EVE_BEGIN EVE_END EVE_INC MAG_DEFINE A 1 A n The EVENTS option selects the events which will be considered Here EVE_BEGIN and EVE_END are the beginning and ending event numbers for which the results will be computed and EVE_INC is the increment for computing results After the results have been computed MOSES places the user in the Disposition Menu so that he can dispose of the data The correspondi
110. or meters about the point PT The LDIST option defines the longitudinal distance over which the weight will be applied when computing traditional longitudinal strength Here X1 and X2 are the beginning and ending longitudinal coordinates feet or meters of the interval over which the weight will be applied To define an applied force within a load group one uses the command tLSET PT FX FY FZ MX MY MZ This command defines an applied generalized force with the magnitude of the com ponents given by FX FY etc bforce and bforce blength The force is applied at the point defined by PT and is a member of the load set LSET As with all user defined load sets one must activate the load set with an amp APPLY command before it will actually be applied To instruct MOSES to build an added mass matrix for the load group one should issue Rev Page 268 MOSES REFERENCE MANUAL AMASS PT DISP CX CY CZ RX RY RZ OPTIONS and the available options are CATEGORY CAT_NAME Here the added mass will be DISP G where G is the gravitational constant CX CY and CZ are the added mass coefficients and RX RY and RZ are added radii of gyration taken about the point specified by PT Similarly one can define a constant linear drag matrix with the command DRAG PT DISP D X D Y D Z R X R Y R Z OPTIONS and the available options are CATEGORY CAT_NAME Here the force that will be produced is
111. place the user in the Hydrostatics Menu where he can compute hydrostatic results for a single body The body which will be considered will be either the current body or the one specified on the HSTATICS command In this menu MOSES can perform four classes of hydrostatic analysis Curves of Form Righting Arm Curves Damage Stability Longitudinal Strength and Tank Capacities Unless specified the results obtained will be computed assuming that the water surface is flat To consider the effect of a wave one can use the option WAVE WLENGTH STEEP CREST on any of the commands in this menu Here WLENGTH is the length of the static wave feet or meters STEEP is the reciprocal of the wave steepness and CREST is the distance of the crest from the vessel origin feet or meters Notice that the wave height here is obtained by MOSES as the quotient WLENGTH STEEP Once specified the wave will remain in effect until it is nullified by specifying a WAVE option with zero height As far as MOSES is concerned there is no difference between hydrostatic proper ties for an intact vessel and a damaged one There are simply a different set of active compartments for one analysis than for another As an example suppose that one had just performed a set of righting arm computations for an intact ves sel To perform a similar analysis for a damaged condition he would simply issue a amp COMPARTMENT FLOOD TNK command to tell MOSES which ta
112. point R Another useful ACTION is REL_MOTION Here data is two point names P1 P2 and six numbers X X Y Y Z and Z What the function returns is the minimum and maxima of the relative location between the two points and the values input i e the output is part of the input which has been modified This is best seen by example Suppose that one issues amp SET ENVEL Rev Page 209 MOSES REFERENCE MANUAL amp SET ENVEL amp POINT REL_MOT 1 2 ENVEL You will find that at this point X X Y Y and Z Z and X Y Z is the vector from 1 to 2 in the 1 body system If you issue the second of these commands several times the result will be that ENVEL will contain the extremes of the relative position between the two points From the above example if this ACTION is used with null data the accumulation is initialized Also the values returned are in feet or meters Often one wants to transform vectors from body to global coordinates and conversely This is easily accomplished with the string function amp V_TRANSF ACTION BODY NAME DATA Here ACTION must be either V_B2G V_G2B V_P2B V_B2P L_B2G L_G2B L_P2B L_B2P F_B2G F_G2B F_P2B or F_B2P and DATA is either three or six coordinates feet or meters or six force components bforce bforce feet or me ters The function takes the input and transforms it returning the same number of components as DATA input If ACTION begins with
113. printed Summaries of the properties of compartments are obtained with the command COMPART_SUM TYPE 1 TYPE 2 OPTIONS Here TYPE must be chosen from PROPERTIES PIECES E_PIECES TUB TANK PANELS MESH STRIP or LONG_STRENGTH and the available options are those of the amp REP_SELECT command A TYPE of PROPERTIES produces a report for each compartment giving the name description specific grav ity volume weight full CG and the maximum derivative of the CG A TYPE of PIECES produces a report for each piece giving the compartment the piece the permeability the diffraction type the projected area and the integral of the normal over the area this should be zero Similarly a TYPE of E_PIECES gives a report of each piece which forms the exterior of the vessel The report gives the diffrac tion type the permeability the wind and drag coefficients and the water depth draft current force multipliers A TYPE of TUBTANK produces a report on the tubtanks defined for each compartment A TYPE of PANELS produces a list of the panels defining each piece of each selected compartment for the selected bodies and parts With this type the PANEL option of KREP SELECT is honored and if it is used only the panels selected will be reported A TYPE of MESH will produce a report of the diffraction mesh for all bodies which match the body selec tor A TYPE of STRIP will yield a report of the planes to be used for strip theory computation
114. provided with the SPEED TYPE_SPECT and STEEP options Here SPEED is the forward speed of the vessel in knots and the default is 0 forward speed SPECT_TYPE can be either ISSC JONSWAP or a previously defined user spectrum where ISSC is the default The STEEP option specifies the reciprocal of wave steepness and uses a value of 20 as the default A value of SPECTRAL can also be used in which case the first environment specified on S_ COND will be used to linearize the equations of motion The default for producing structural load cases for transportation is to create fre quency domain spectral load cases and no particular option is required to make this happen However one can also prepare time domain load cases by using the DO_TIME option Here TOB is the total time of observation in seconds while TINC is the time step increment What happens next is quite involved for such a deceptively simply option A time domain synthesis will be performed for the mo tions of the center of gravity for each piece of cargo for each environment specified Rev Page 339 MOSES REFERENCE MANUAL on S_COND Then for each of these environments the time for the extreme force or moment for each of the six degrees of freedom will be determined By extreme here we mean a maximum or minimum such as positive and negative roll These times are then used in the creation of deterministic structural load cases Regardless of the time of observation
115. removed For values of tension between there is no piston motion With a TYPE of MAX the piston behaves as above when the tension exceeds Tmax When the tension becomes smaller than Tmax then the piston moves to shorten the device with a velocity Vshort until the position is at Ld For both values of TYPE there is no stiffness in the connector when the tension is being set at one its limits The B_TENSION option is used to define a breaking tension BTEN bforce for each segment of the connector If this option is not specified then one will be computed based on the area of the element and the ultimate tensile stress This value is used to normalize the tension to report a unity check and in some cases to compute fatigue The option C_SN defines the curve used to compute fatigue for an element Here CSN can be the name of any defined SN curve The definition of SN curves is addressed with the amp REP_SELECT command Most of the time CSN will be either CHAIN or WIRE If this is true then the API curves will be used for computing the fatigue These curves are not really SN curves but curves of tension ratios to cycles For a multi segment connector of different materials it is not obvious which segment will have the most fatigue What is done is that the segment with the largest t tb ratio is used when this segment has a tension type SN curve and the segment with the largest stress is used when the critical t tb segment has a norm
116. rod elements the same task as F_CD_TUBE does for tubes The drag coefficient for generalized plates is defined with the DRGPLA option The added mass for generalized plates and panels is computed as described in the section on Forces and for tubes it is defined with the AMCTUB option The options WCSTUBE CSHAPE Rev Page 149 MOSES REFERENCE MANUAL REL_WIND YES NO control computation for wind forces The wind shape coefficient for tubular members is defined by the option WCSTUBE and here CSHAPE is the new value for the coefficient The REL WIND option defined whether or not the wind force will be computed based on the relative wind velocity or the wind velocity itself Normally MOSES computes slam loads on plates and tubes by computing the deriva tive of the added mass This can be a numerically sensitive computation and the two options SL_TUBE SCT SL PLATE SCP can be used to define a slamming coefficient that is independent of time A slam force will only be computed when the element has a waterplane intersection To return to the normal way one should specify AUTOMATIC for SCT or SCP Theoretically there should be slamming for both the element entering the water and when it is exiting The option SLAM BOTH YES NO controls this If YES NO is YES then slams occur for both cases If it is NO then slams only occur when the element is entering the water The option T_AVERAGE TYPE defines the way
117. root ppo The user may override this name by using the proper options of the amp DEVICE command There are three basic components to this file the load case name nodal loads if present and element loads A sample of this file is amp DIMEN DIMEN Feet Kips APLOAD LOAD CASE TWO 7 6 4185E 16 6 4185E 16 1 0000E 01 0 0000E 00 0 0000E 00 6 4185E 14 ae 6 4185E 16 6 4185E 16 1 0000E 01 0 0000E 00 0 0000E 00 6 4185E 14 ELMAPL T T 1 12 00 10 00 0 0000E 00 0 0000E 00 3 8378E 02 0 0000E 00 0 0000E 00 0 0000E 00 0 0000E 00 0 0000E 00 3 8378E 02 0 0000E 00 0 0000E 00 0 0000E 00 ELMAPL T T sal a 10 00 131 42 0 0000E 00 0 0000E 00 4 2654E 02 0 0000E 00 0 0000E 00 0 0000E 00 0 0000E 00 0 0000E 00 4 2654E 02 0 0000E 00 0 0000E 00 Rev Page 441 MOSES REFERENCE MANUAL 0 0000E 00 ELMAPL T T 1 2 131 42 141 42 0 0000E 00 0 0000E 00 3 8378E 02 0 0000E 00 0 0000E 00 0 0000E 00 0 0000E 00 0 0000E 00 3 8378E 02 0 0000E 00 0 0000E 00 0 0000E 00 The first line in the file indicates the units used and the second line is a comment line indicating the file content The next line indicates the load case name for the applied loads that follow All loads are reported in the part coordinate system If there are nodal loads in the structure they are next The format of the nodal loads starts with the node name followed by the forces and moments ac
118. save the current dimensions so that when REMEMBER is used the ones previously saved will be recalled In documenting the use of units confusion can arise due to the user s choice of force units To ameliorate this difficulty when a force which can be either kips long tons short tons metric tons or kilo newtons can be used we denote the force unit as BFORCE and the length unit as either BLENGTH or llength depending on the type of length unit required Here when blength is meters llength will be mm and when blength is feet length will be inches This notation of blength llength and bforce will be used throughout the remainder of the manual In most places the Rev Page 22 MOSES REFERENCE MANUAL units required for a given quantity are specified If they are omitted they are Rev Quantity time angles temperature length area volume velocity acceleration stress or pressure force moment weight per unit length weight per unit area Units seconds degrees degrees F or degrees C feet or meters ft 2 or m 2 ft 3 or m 3 ft sec or m sec ft sec 2 or m sec 2 ksi or mpa bforce bforce blength bforce blength bforce blength 2 Page 23 MOSES REFERENCE MANUAL VI DEVICES AND PROGRAM BEHAVIOR Perhaps one of the most confusing things which MOSES does is dealing with devices By device we mean either a physical piece of hardware such as a printer pen plotter terminal screen or logical de
119. section type and must be either BOX PRI BU W M S HP WT MT ST L C MC WBOX DL LLEG or PLATE The values SCF i are the stress concentration factor for the corresponding type Please notice that one cannot define a default SCF for a tube This would defeat the normal computation of SCF s for joint fatigue If you have a tube want to do beam fatigue and want an SCF other than 1 you need to manually do it on the command which defines the beam For class definition commands we have the option SCF SCF_BEG SCF_END Here SCF_BEG is the SCF which will be used at the beginning of the segment and SCF_END is the curve used at the end of the segment If one uses two SCFs for each segment the one in the middle will be defined twice If this is done the second definition will actually be used i e the first SCF specified will in fact be used for the beginning of the segment Also SCF_END needs to be specified only on the last segment The SCF definition for elements is accomplished with the SCF option which is followed by from one to eight numbers If there is no SCF option then the default SCF defined for this class will be used Here SCFA will change the values at the first end of the beam SCFB will change them at the other end and SCF1 will change them at the intersection between the first segment and the second etc If SCF is used then the stress concentration factor will be the same at all fatigue points For the en
120. selected classes that have soils defined Information about points selected by the node selector is generated with the com mand POINT_SUM TYPE 1 TYPE 2 OPTIONS where TYPE i must be chosen from NOSES POINTS N COINCIDENT SCF or PROPERTIES and the available options are those of the amp REP_SELECT command A TYPE of NODES will produce information about POINTS which are have structural elements connected to them i e NODES which are selected by the node selector This TYPE reports the node name the node type the X Y Z coordinates in the part system the X Y Z coordinates in the global system and the degrees of freedom of the node which are fixed Here the type is either TUBE JOINT TUBE TUBE TUBE CONE JOINT NODE or EXTREMITY The sec ond two types are used for nodes that have only two beams in a line connected JOINT is used for nodes that have more than one element connected but are not TUBE JOINTS A TYPE of NODE is used for two connected elements that are not TUBE TUBE or TUBE CONE types and EXTREMITY is used for a node with only one element connected A TYPE of POINTS will list all points which are not nodes their coordinates and the node associated with the point A type N_COINCIDENT will produce a report of the nodes in each part which are co incident Information about tubular joints are obtained with the last two TYPEs A TYPE of SCF will produce a report on the stress concentration factors and the Rev Page
121. single barge In anticipation of such an operation MOSES can simulate a launch from several barges which may be con nected By combining a nonlinear rod element with other connectors one can simulate the laying of pipe either from a stinger or from davits With MOSES all aspects of the problem can be modeled The lay vessel and the stinger can be modeled as separate bodies connected via the pipe hinges tensioners and rollers Once the system is assembled one can perform static time or frequency domain simulations of the laying process MOSES can perform a detailed stress analysis for events during a time domain simu lation a static process or a frequency domain process There are no essential limits on either the model size the number of bodies which can be analyzed or the num ber of load cases The solution algorithms are state of the art and the structural post processing is superior MOSES can consider not only linear but also spectral combinations of the basic load cases Thus if one performs a stress analysis in the frequency domain he can then consider member and joint checks spectrally In ad Rev Page 3 MOSES REFERENCE MANUAL dition spectral fatigue can be considered in beams generalized plates and tubular joints Rev Page 4 MOSES REFERENCE MANUAL II ANALYSIS OVERVIEW MOSES is a simulation language Thus the commands which are available are all designed to either describe a system or to perform a simula
122. single body can be composed of any combination of hydrodynamic elements The structure of a body can be de fined by any combination of beam and generalized plate elements and the user has control over whether or not a given structural element will attract load from either wind water or inertia A second primitive element of the MOSES system is the connector These elements in general attract no loads from the environment and serve to constrain the motion of the bodies There are five types of connectors flexible connectors rigid constraints launchways pipes and slings Here flexible connectors can be used to model mooring lines hawsers etc while rigid constraints are used for pins The user is free to define any combination of connections Connections are defined separately from the definition of the bodies and thus can be altered interactively to simulate different aspects of a particular situation Once a system bodies and connections has been defined the user is free to perform static frequency domain or time domain simulations There are also specialized sets of commands which provide information on the hydrostatics of one of the bodies the behavior of the mooring system or the upending of a body The results of each Rev Page 5 MOSES REFERENCE MANUAL simulation are stored in a database so that they can be recalled for post processing restarting or for use in a stress analysis After a simulation has been perform
123. specified in inches or millimeters and the valve location is specified in feet or meters The valve locations here are according to the use of ELEVATION If no valve information is provided a 4 inch flood valve will be located at the bottom node while a 4 inch vent valve will be placed at the top node The PERMEABILITY option allows one to specify the permeability for the tank Normally legs which contain tanks are straight The B_NODES option allows one to specify joints at which the leg has a break in slope The I TANK command will use the jacket model to prepare the proper TUBTANK definitions capturing all the changes to inside diameter along the elements defining a jacket leg including changes to segments in the elements Connector Data There are three different categories of connectors that can be defined for use in a simulation SLINGS TIEDOWN CONNECTORS and VERTICAL SUPPORTS Each of these categories uses the ICONNECTOR command followed by a type description and then the required data To define an upending sling assembly for use in a jacket upending analysis a type of UP_SLING is used and has the following syntax I_CONNECTOR UP SLING U1 L1 U2 L2 The data that follows the connector type is a set of node names and harness lengths in feet or meters The number of pairs defined gives the number of sling elements which will be attached For a body name of JACKET the order of the nodes is used to define the local body syst
124. specified on similar options of the amp DEFAULT command The applicable options are CO SCF SCF TYPE LEN FACTOR FRACHOL MAX_CHD_LEN MAXCHOL CHD _FIXITY CHD FIX _SCF_BOUNDS MIN SCF MAX_SF This computation is controlled by the CO_SCF option The valid values for SCF_TYPE are K amp S API MARSHALL and EFTHYMIOU With the au tomatic computation of SCFs two values are computed one for the root of the weld on the brace side and one for the root of the weld on the chord side The LEN FACTOR MAX_CHD_LEN and CHD _FIXITY options define pa rameters which are used by some of the methods in computing the SCFs For some methods the SCFs depend upon the length of the chord FRACHOL is a fraction of the actual chord length which will be used The default value of FRACHOL is one MAXCHOL is the maximum length which will be used and its default value is infinite Suppose that the chord length was 200 If FRACHOL is set to 5 and MAXCHOL is 50 the program will first set the length to be used to 5 200 It will then take the maximum of 100 and 50 and use this value in the computation The CHD_FIXITY option defines the chord flexibility CHD_FIX This is a measure of the bending support at the ends of the chord It should be a number between 5 and 1 The first of these corresponds to the chord ends being pinned and the later fixed The SCF BOUNDS option defines minimum and maximum values for SCFs Any computed SCF small
125. specified on the SECONDARY option of the amp DEVICE command MOSES will in general compute a scale for each axis of a graph so that the func tions will fill up the page In some circumstances one may wish to establish the same scale for several different plots This can be accomplished via the RANGE command the form of which is RANGE OPTIONS and the available options are X MIN_VALUE MAX_VALUE LEFT MIN_VALUE MAX VALUE RIGHT MIN_VALUE MAX VALUE If one of the options is issued and no data follows then the axis specified by the keyword will be automatically scaled To control the scaling of an axis one should follow the axis keyword with two numbers the minimum value for the axis and the maximum number for the axis These extremes will then be used to establish the scale Notice that when the automatic scaling is not in operation it is possible that some portion of the curves may be off of the page Rev Page 117 MOSES REFERENCE MANUAL X F Getting Data The final command in this menu is used to extract information from the database and place it in a variable where it is available to the advanced user Its form is SET_VARIABLE VAR_NAME OPTIONS and the available options are RECORD BEG_RNUM END_RNUM VALUES CV VAL_MIN VAL MAX NUM_COLUMNS NUM ROWS NAMES CS 1 CS 2 COLUMN CS 1 CS 2 STATISTICS CS 1 CS 2 MINIMUM CS_PUT CS_GET MAXIMUM CS_PU
126. that name is retrieved MOSES then proceeds to process the options which are used to alter the existing values Notice that if this is a new name you are altering the defaults and if it is an existing name you are altering the existing values When the options have been processed the new data is stored in the database for further use and modification With the use of names a user can save a considerable amount of input in certain situations In fact during Frequency Domain Post Processing several of the com mands also act as amp ENV commands For this reason there is some environmental data which may not appear to be environmental unless one views environmental in a rather general sense For the options requiring an environment direction SEA DIRECTION WIND_DIRECTION or CURRENT_DIRECTION the direction is positive from global X towards global Y as shown in Figure 2 The DURATION option is used for computing fatigue and simply defines the length of time in days that the environment will act Either of the two options WATER or SPGWATER serve to define the mass properties of water Here RHOWAT is the specific weight of water pounds ft 3 or newtons m 3 and SP GRWAT is the specific gravity of water density of water divided by density of stan dard water The PROBABILITY option is used to control the statistics which will be defined when computing statistics of quantities in an irregular sea STAT must be either
127. that no side of a panel is greater than the distances given by these two options This allows one to build a quite crude mesh and yet obtain solutions as accurate as desired by simply changing one of the two parameters The same caveat about struc tural loads also applies here The basic panels should have corners in a reasonable relationship to the structural nodes where one will ultimately apply the loads To examine how a mesh is refined by the two mesh refinement options the user can use amp PICTURE TYPEL MESH DETAIL This will produce the mesh refined according to the amp PARAMETER settings in effect when the command was issued As mentioned above the accuracy depends on the panel size particularly at higher frequencies The execution time however increases as the square of the number of panels for small meshes and as the cube for large ones Thus one should strive to have the minimum number of panels which are still small enough to produce an accurate solution Even though the same set of panels are used for both hydrostatics and hydrodynamics the computations are quite different For hydrostatics the computation is a simple integration over each panel Here it does not matter if two different pieces have common boundaries For Three Dimensional Diffraction however it is essential that the panels represent the true surface and that no part of space belongs to two different panels This makes the generation methods of the am
128. that the average period is computed when doing fatigue or cycle counting in the frequency domain If TYPE is DNV then the average period is the associated with the average zero up crossing frequency defined in DNV RP C206 Section 6 9 4 Otherwise it will be computed with the traditional formulae Tav 2 pi sqrt M2 MO 1 eps eps sqrt MO M4 M2 2 MO M4 The options API TDRAG YES NO AF _ ENVIRONMENT YES NO are used in computing velocity square forces The first one controls the relative Rev Page 150 MOSES REFERENCE MANUAL velocity for tubes If YES NO is YES then the relative velocity is the component normal to the tube as in API RP2A If YES NO is NO then it is the true relative velocity The second one controls the way wind and drag are computed on areas If YES NO is YES then the drag force is in the direction of the environment If YES NO is NO then it is perpendicular to the area One should use YES to have the force depend on the projected area In many cases MOSES will perform a numerical integration over either an area or a length The precision of this integration can be controlled via the options MAXLEN LENGTH MAXAREA AREA MAXREFINE REFINE NUMBER Here MOSES will divide an element into pieces such that each length or area of each piece will be less than LENGTH feet or meters or AREA ft 2 or m 2 The max imum number of pieces any one element will be broken
129. the first point specified via DATA and the second one These points will be in order with the first point specified being the first point returned and the second one specified as the last one returned The remaining values ACTION are different than those above in that the DATA are not strictly point names The ACTION N_BOX lt is different from the others in that the data here is a set of global coordinates X1 X2 Y1 Y2 Z1 and Z2 The function will return all points which are in the box defined by the six planes defined by these coordinates The ACTION RATIO will return the last value of joint unity ratio computed for the specified point and an ACTION of DEFLECTION will return the three components of the last computed deflection of the point The ACTION HOOK_LOC has a form for DATA of NN1 LEN1 NN2 LEN2 ame NN4 LEN4 and is used to find the global position of a hook which is connected to points NN1 NN2 etc It assumes that the harness lengths are LEN1 LEN2 respectively This function is useful primarily in setting up a lifting problem when Rev Page 208 MOSES REFERENCE MANUAL one models the sling as a collection of flexible connectors The values of ACTION OFFSET and CLOSE are used to find offsets Normally they are used in the definition of connectors The form of DATA for OFFSET is POINT SEL X Y Z and for CLOSE PART NAME SEL X Y Z Here X Y and Z are locations feet or meters For both values
130. the REPORT command If no data is specified on the FR FCARGO command then the data will be generated so that one get the G forces on the cargo and the angular accelerations in the same output report table Many of the commands here compute statistics of quantities and as a result have many common options In particular SEA SEA_NAME THET HS PERIOD GAMMA SPREAD EXP SP TYPE TYPE E_PERIOD EP 1 EP 2 Rev Page 393 MOSES REFERENCE MANUAL CSTEEP YES NO The statistical result is the statistic specified with the last PROBABILITY option on a amp DEFAULT command and If the original response data was produced with the SRESPONSE command then no additional sea data can be specified The remainder of the commands available for cargo forces have a similar syntax in that the final portion of the command is identical to that of the amp ENV command In fact these commands not only initiate the computation of quantities in an ir regular sea but are also amp ENV commands Thus when one issues one of these commands with a non blank ENV_NAME he is altering the definition of this envi ronment within the database If ENV_NAME is omitted then the environment used will be totally defined by the options specified The options SEA SPREAD and SP_TYPE are used to define the sea state to which the vessel will be subjected The E_PERIOD option can be used to generate results for seas of several different peri
131. the body After everything has been defined one deletes the temporary blocks renames those he wishes to keep and emits the model Any time during the process one can make pictures of the blocks with PICTURE BLOCK_NAME 1 BLOCK_NAME n One renames blocks with the command RENAME BLOCK BLOCK SEL OPTIONS where the options are POINT PNAM PANEL PNL SORT ORDER JUMP_NUM JUMP_TOL EQUIVALENT DIST The RENAME BLOCK command removes all blocks except those selected with BLOCK_SEL and renames the point and panel names according to the options used The POINT option specifies a point name prefix and should begin with an The PANEL option describes a panel name prefix while the SORT option defines a criteria for sorting the resulting point and panel names Here ORDER can be any combination of the letters XYZ Using this option points output to the file will be sorted according to their coordinates in the order specified JUPNAM is the integer amount added to a point name when there is a jump in the coordinates of a point of JUMP_TOL The EQUIVALENT option defines a distance DIST feet or meters which is used for point equivalence Two points within this distance are declared to be the same and references to the deleted point are removed from all panels This option is quite useful in removing small pieces of trash which results from combining blocks Renaming is not necessary but it provides a set of results
132. the data as given Consider the following example PILE TUBE 1066 80 25 4 DENSITY 77008 5 SOIL DIRT REFINE 20 FYIELD 360 PYMULT 0 001 CONNECTOR PILE1 PILE J6110 P110 Here a tubular class is defined the density is modified the soil name is specified and the pile is divided into 20 segments for a structural solution The yield strength and PY multiplier is also modified This class definition is then used to describe a connector where J6110 belongs to the part jacket and P110 belongs to the part ground Rev Page 225 MOSES REFERENCE MANUAL XII M 4 Flexible Connector Classes MOSES provides for several ways to flexibly connect bodies to one another or to ground These range from simple springs to assemblies of elements such as lifting slings and pipe assemblies MOSES bases the definition of a connection on the type of class defined for it To define an element with properties which vary along the length one should define multiple class commands with the same name In contrast to beam and pile classes every segment s length must be defined for flexible classes Also the order of the segments can be thought of as starting at the fairlead moving toward the anchor There are three classes which define connectors with zero length FOUNDATIONS LMUs and GSPRs The class definition of these is CLASS FOUNDATION SENSE DF 1 SPV 1 AF 1 DF n SPV n AF n OPTIONS CLASS GSPR SENSE DF 1 SPV 1
133. the default stack Now one can alter the defaults at will and upon issuing amp DEFAULT REMEMBER the initial set will again become active Most of the options here are again used on some command As a result the doc umentation here may be brief so that a more detailed discussion may follow If an option is used when one of these commands is issued then values specified by the option will be used Otherwise the default the values specified via amp DEFAULT will be used Defaults are also used to define the current coordinate system and frame of reference for defining nodes interest points and diffraction vertices The options defining these defaults are RECT CYLINDER SPHERICAL LOCATION XO YO ZO RX RY RZ LOCATION XO YO ZO PT 1 PT 2 PT 3 PT 4 The first three options define the meaning of the three numbers which define the local coordinates If RECT is the last of these specified then the numbers are rectangular coordinates in the current frame Likewise they can be either cylindrical if one specifies CYLINDER or spherical coordinates when SPHERICAL is used Cylindrical coordinates require a radius angle and Z coordinate while spherical coordinates require a radius angle in the XY plane and an azimuth angle The LOCATION option defines a new frame of reference Here XO YO and ZO Rev Page 144 MOSES REFERENCE MANUAL are the coordinates of the new frame of reference in the part
134. the mark On should use a DMARK option for each draft mark defined When deleting marks DM_NAME i are selectors which select the marks to delete The next two options PR NAME and MD NAME allow one to change the pressure packet name and the drift packet name associated with the body Here PR_NAME and MD_NAME are the new pressure or mean drift names In most cases the mean drift database is created as a consequence of creating the pressure database and a discussion of the mean forces can be found in the section of the HYDRODYNAMICS MENU and in the subsection on mean drift The next three options allow one to change the multipliers used with the mean drift force The MD FORCE option defines three scale factors MD FORCE MD_RADIATION and MD_CORIOLIS which are used in computing the total mean drift force The last two of these are multipliers of the radiation and Coriolis con tributions to the mean force as they are added to the diffraction contribution The MD_FORCE factor multiplies the total mean force before it is accumulated The current response operators for the current process are used when computing the ra diation and Coriolis contributions Finally the MD_PHASE defines a phase angle deg of the wave drift force in the frequency domain Here each drift force compo nent will have a phase PHASE relative to the wave crest being at the origin The default for these options is set with amp DEFAULT The next two options of
135. the second one and for a plate the local Z axis will be normal to the surface One of the other two directions can be chosen arbitrarily and the third will be defined by a cross product of the two vectors By default MOSES has two additional vectors which will be used to complete the local system definition a primary direction and a secondary one Normally the primary direction defines the direction that an axis points For beams this is the Z axis and for generalized plates it is the X The secondary direction is used if the special direction and the primary direction are parallel The primary and secondary vectors SAV1 and SAV2 are defined with the DIR PLATE or DIR_BEAM options of a amp DEFAULT command The SAV1 and SAV2 vectors are part system vectors This makes the business of connecting parts special since here one is dealing with two parts The local system of a part connector will be discussed below For a beam the local system is constructed as follows e If the beam X axis is not parallel to the SAV1 vector then the beam Y axis will be defined by the cross product of the SAV1 vector and the beam X axis e If the beam X axis is parallel to the SAV1 vector then the beam Y axis is determined by the cross product of the SAV2 vector with the local X axis and for a generalized plate e If the generalized plate Z axis is not parallel to the SAV1 vector then the generalized plate Y axis will be defined by the cros
136. the specified nodes to the nodes on the boundary Subelements will be generated so that the maximum distance of a side is less than or equal to the maximum distance between any two specified nodes The internal nodes will have names which begin with IN Figure 10 shows four typical generalized plates and Figure 11 shows the corresponding subelements The FSOPT options can be used to define concave generalized plates Here FP i are points which define a free edge The points define the geometry of the edge The nodes on the other edges will determine where the nodes which will define the subelements will be placed If FSOPT is HOLE then the free edge defines a hole contained within the gen eralized plate and FP i are points defining the geometry of the hole Here FP 1 Rev Page 253 MOSES REFERENCE MANUAL Plate Exterior Nodes FIGURE 10 Plate Subelements DX LZS W f y NN N i N TZ N FIGURE 11 Page 254 Rev MOSES REFERENCE MANUAL should be closest to NODE 1 and the order of the FP i should be the same order as NODE i The actual nodes on the free edge are at the intersection of the ray from the center of the generalized plate with the free edge Each of these defining rays passing through an exterior node Thus the more nodes on the exterior the better representation one gets of the hole The nodes created
137. this body or part until another amp DESCRIBE command is encountered This command also allows the user to alter the attributes of the body as the analysis proceeds The format of this command is Rev Page 191 MOSES REFERENCE MANUAL Zg Zv j jacket body system v vessel body system p part system for jacket g global system z 0 at MWL m J RELATIONSHIP OF GLOBAL BODY AND PART COORDINATE SYSTEMS ALL Y AXES OUT OF PLANE FIGURE 4 amp DESCRIBE BODY BODY NAME OPTIONS where the available options are IGNORE DOF 1 DOF 2 GEN DOF MODE SEL 1 MODE SEL 2 S_DAMPING CFRACTION SECTION EI X 1 SM 1 X n SM n LOCATION X 1 X 2 DMARK DM_NAME DPT 1 DPT 2 D_DMARK DM_NAME 1 DM NAME Q PR_NAME PR_NAME MD_NAME MD_NAME MD FORCE MD_FORCE MD RADIATION MD_CORIOLIS MD PHASE MD_PHASE FM_MORISON FM FACTOR SPE MULTIPLIER SPEMUL SP_ORIENT VX VY VZ HX HY HZ SP_HEIGHT X Y Z DT_CONVOLUTION DT_CONV FACT_CONVOLUTION CONV FACTOR PERI_USE PER WAVE _RUNUP YES NO To ease the difficulty of defining a model whenever a body is defined a part with the same name is automatically defined Any attribute defined before a part is specifically Rev Page 192 MOSES REFERENCE MANUAL defined becomes the property of the body part NOTICE that since everything must belong to some part of some body a amp DESCRI
138. this model may be converted into a useful one by a special purpose menu This menu may be entered via the command amp CONVERT MODEL_TYPE OPTIONS Here MODEL_TYPE defines the type of model to be converted and must be either SACS STRUCAD DAMS STRUDL HULL OSCAR or PLY The available options are _JPREFIX JP CPREFIX CP JRIGHT XXXXXXXX CRIGHT XXXXXXXX LOADS FLAG CNS DIA FLAG IG_DOFS FLAG When the amp CONVERT command is issued MOSES will read data from the current channel and write a MOSES model to the file MOD00001 TXT file in the answers ans directory This process will continue until the command END is encountered The conversion for SACS and STRUCAD models are relatively complete but only a subset of all of the dialects of STRUDL are honored A MODEL_TYPE of HULL will convert a hull description using the outdated STAT and OSET commands to the current description using the PLANE command One can also convert OSCAR miscellaneous additions such as LJNT LMEMT LMEMD LMEMS and JPLATE commands into the proper format by using the type OSCAR When an input is found which MOSES does not convert it is emitted as a comment Thus the file resulting from a conversion may contain quite a few comments before the converted data A MODEL_TYPE of PLY will convert a PLY polygon file into a MOSES mesh The name of the piece generated will be the value of the variable PIECE if it exists If this variable h
139. title If the BOLD option is specified with YES_NO if YES then the titles and headings will be set in bold type and if the H_SKIP option is specified with YES_NO of YES then a line will be skipped between each heading In actuality headings are simply a title which spans all of the columns of the table Titles however can span NCOL i columns The ROW_SHADE option instructs MOSES to shade the rows two at a time If this option is selected with YES_NO of YES you will get two white rows followed by two rows shaded in light green The FIGURES option offers a way to change the display of the numbers It says to change the number of figures after the deci mal point for columns selected by COL_SEL to be RIGHT figures You can specify more that one FIGURES option The EXTR_SHADE option is used to define the columns for which the maximum and minimum values will be shaded in a dif Rev Page 53 MOSES REFERENCE MANUAL ferent color Here COL_SEL i are selectors for the columns which will be shaded COL_SEL i can be a single number which selects that mode number or a pair of numbers A B which selects all modes from A to B The V_LINES option defines the columns where vertical lines will be drawn at the right Vertical lines are always drawn at the left of column 1 and to the right of the last column If you have a column selector of 1 then a vertical line will be drawn between columns 1 and 2 For CSV tables the H_SKIP BOLD ROW
140. to be fixed in space and the loads which yield some maximum will be generated as the load case The CHECK value defines what maximum will be checked If it is OVERTURN the maximum overturning moment about the mudline will be used as a criteria if it is SHEAR it will be maximum shear The actual operation of the program depends upon the type of wave specified If a periodic wave was specified then a search algorithm will be used which is substantially more efficient than simply passing the wave through the structure If one wants to override this algorithm for some reason he should set PERIODIC to PERIODIC If PERIODIC is specified as NO MOSES will then act as if a non periodic wave had been specified For non periodic waves the program will simply compute the forces on the structure for the times defined with the TIME option of the amp ENV command and pick the time which creates the maximum Two options of LCASE are available for use with frequency domain situations RAO TIME ENV NAME CASE 1 T 1 CASE i T i The RAO form is used to perform an analysis in the frequency domain It will generate a load case corresponding to the mean position of the structure and two RAO load cases for each heading and each period at which response operators were computed The names of these generated cases depend upon how many LCASE Rev Page 436 MOSES REFERENCE MANUAL commands have been issued Basically the names are FR
141. to echo commands which are being executed as part of a macro to be echoed to either the terminal and therefore the log file or to the output file Macros being used in the input data will be echoed in the output file if the OECHO YES NO is YES The options IDISPLAY and SILENT control the default displays The option IDISPLAY controls whether or not the valid internal commands will be displayed whenever valid commands are listed The SILENT option suppresses most of the terminal output and is useful in macros For all of these options the action will be taken if YES NO is YES and not if YES NO is NO The FN_LOWER option controls the way MOSES looks at the directory structure If YES NO is NO then the directory structure is viewed as case sensitive In some operating systems it really does not matter even if then results appear in upper and lower case In other words a file COW TXT is a different file from cow txt One may not want this behavior transferring files from a WINDOWS machine to a UNIX one for example In this case one can use the option with a YES NO of YES Now the complete path of the file will be treated as being lower case The final class of options controls where the program obtains its information In general commands enter through the command channel TERM and data en Rev Page 35 MOSES REFERENCE MANUAL ters through the input channel INPUT With the COMIN option MOSES gets command data from the
142. transverse stiffeners is that they are used for two purposes stiffeners against hydro static collapse and to stiffen joints Since transverse stiffeners on beams are normally used on tubes we will call them rings here To avoid confusion rings will be used Rev Page 220 MOSES REFERENCE MANUAL to stiffen joints only if the class has more than one segment and the stiffeners are in the segment closest to the joint Transverse stiffeners suffer from the same problems as does buckling lengths If an element is not fully supported on both ends then the longitudinal stiffener spacing may be longer than the element length This is where the value LENGTH comes in It provides a DISTANCE to be used in the conversion from spacing to number of stiffeners You can specify three things for LENGTH a length in feet or meters the token LENGTH or the token BLENGTH If LENGTH is specified the length of the element is used if BLENGTH is specified the minimum of the two buckling lengths is used a number input will be used directly and if this parameter is omitted the segment length will be used Let us consider two examples First suppose that we have an element which is actually part of a logical beam and suppose the logical beam has a single hydrostatic ring If all elements of the logical beam had the same properties they could be defined with the class LBEAM TUBE OD T TN_STIFF 1 SC EXTERNAL BLENGTH This class will place one ring
143. value of the amp NAMES command issue the com mand amp NAME NAMES to see what is available or see the documentation for amp NAMES TITLE is again the title of the pick box and MAX_TO_PICK is the maximum num ber of items which may be chosen With this type the list depends on the current state of MOSES in that the list is obtained from the current database This removes the macro writer from having to know the state As an example consider amp REP SELECT BODY amp GET N_PICK 1 BODIES Select A Body which will present the user with a list of the bodies defined and ask him to select one The last two types of WAY GET _LIST and GET_NAME have a form of DATA exactly the same as PICK and N_PICK respectively The difference is that with these types a combination EDIT PICK box is popped up Here one can type data into the edit box or select from the available list or do both Rev Page 87 MOSES REFERENCE MANUAL IX E Getting User Input On can use the amp GET string function to simply get a response from the user but for many situations this leads to a boring modal dialogs A more flexible method is using amp STRING macros and WIZARDS A wizard is a set of commands which are defined inside a amp STRING macro and A amp STRING macro is the same as an ordinary macro except that it can contain only internal commands and it can be executed only with an amp E_STRING command Let us look at an example suppose that one wanted to
144. which the vessel will be subjected The E_ PERIOD option can be used to generate results for seas of several different periods If this option is omitted then a single period of PERIOD will be considered With the option periods of PERIOD EP 1 EP 2 will be produced If CSTEEP is specified with a YES NO of YES then the height of the wave will be altered so that all seastates have the same steepness as the initial one Otherwise the wave height will remain constant To obtain the frequency response at a point one issues the command Rev Page 389 MOSES REFERENCE MANUAL FR_POINT WHERE OPTIONS Here WHERE can be either the body coordinates feet or meters of the point in question the name of a point or the names of two points If a single point is specified then the results are the motion of the point If two points are spec ified then the results are the relative motion of the two points The options are VELOCITY and ACCELERATION If no option is specified then the mo tion response is produced with WELOCITY velocity response is produced and with ACCELERATION acceleration response results If one specifies coordi nates MOSES assumes them to be coordinates of the current body To remove confusion in multi body situations it may be a good idea to issue an amp DESCRIBE BODY command to establish the current body before using coordinates When this command is issued the program will compute the response at t
145. which will be applied at the point of application With the MULT_WEIGHT option WMULT is a weight area bforce blength 2 which is multiplied by the area defined by either a 4PLATE or a AREA command to yield a weight applied at the centroid Both options can be used on the same command For any of the load attributes that follow the options TEXTURE NAME TEX X SCALE Y SCALE Rev Page 267 MOSES REFERENCE MANUAL COLOR COLOR 1 FRAC 1 COLOR n FRAC n can be used to define the color and texture of the attribute These will be used when one asks for a picture with COLOR MODELED Here NAME_COL is any color which has been previously defined See the section on Colors for a discussion on defining colors The NAME TEX value for TEXTURE is the name of a file in either X data textures or X data local textures here MOSES is store in X The X_SCALE and Y_SCALE are scale factors which will be applied to the texture The NAME_TEX of NONE will yield a null default texture Perhaps the most popular of the load group class commands is the one which asso ciates a weight with the group The form of this command is WEIGHT PT WT RX RY RZ OPTIONS and the available options are LDIST X1 X2 NUM_APPLIED NUMBER CATEGORY CAT_NAME This command instructs MOSES that a weight of WT bforce is attached to the part at the location specified by the point PT This weight has radii of gyration RX RY and RZ feet
146. 1 Deg F or 1 deg C and FYIELD is the yield stress ksi or mpa For a discussion on the SN option see the section on associating SN curves Three options define the default resize properties for classes These are RDE SELE TYPE 1 RD 1 TYPE 2 RD 2 KL R_LIMIT KLR D T_LIMIT DOT Here TYPE i defines a section type and must be either TUBE BOX PRI BU W M S HP WT MT ST L C MC WBOX DL LLEG CONE or PLATE The values RD i are a selector which defines the default redesign selector for the section type TYPE i KLR and DOT are the default KL R and D T limits on shape selection for tubes Several options are available define element defaults USE USE 1 USE 2 USE i NUSE NOT_USE 1 NOT_USE 2 NOT_USE i Rev Page 146 MOSES REFERENCE MANUAL FLOOD YES NO STW_USE YES NO KFAC KY KZ CMFAC CMY CMZ DIR BEAM SAV1 1 SAV1 2 SAV1 3 SAV2 1 SAV2 2 SAV2 3 DIR PLATE SAV1 1 SAV1 2 SAV1 3 SAV2 1 SAV2 2 SAV2 3 SCF TYPE 1 SCF 1 All but the last of these will be discussed in detail along with the discussion of modeling elements The last two define true default behavior For a discussion of the SCF option look in the section on associating SCFs with fatigue points The options MD FORCE MD_FORCE MD_RADIATION MD_CORIOLIS MD PHASE MD PHASE SPE MULTIPLIER SPEMUL FM_MORISON FM FACTOR SP_ORIENT VX VY VZ HX HY HZ
147. 133 MOSES REFERENCE MANUAL API strength unity ratio A type of PROPERTIES will produce a report of the diameter thickness yield stress and angles for each brace for the selected joints and the API strength unity ratio A final command is used to produce a summary of the wave elevation wave velocity and wave acceleration for all grids selected and its form is GRID_SUM OPTIONS Here the available options are those of the amp REP_SELECT command The selec tion criteria here is the one defined via DATA Rev Page 134 MOSES REFERENCE MANUAL XII THE MOSES MODEL MOSES operates using a database philosophy In other words the commands to the program are instructions to perform some operation upon the information which currently resides within the database Before one can obtain meaningful results he must have a database upon which to operate i e a model of the basic system must be defined for the program This model is defined via commands in a modeling language described below Although the distinction is somewhat arbitrary it helps to think of the model as being composed of two different types of data some which remain constant and some which change as the analysis proceeds The constant part is the basic model and the remainder are settings which normally evolve For example the physical description of a barge will normally remain constant throughout an analysis but the ballast configuration the draft trim and
148. 4 Bentley Sustaining nfrastructure REFERENCE MANUAL FOR MOSES Phone 713 975 8146 Fax 713 975 8179 Copyright Ultramarine Inc June 1989 and October 7 2013 Contents i the th ei ye te BS ae Be 9S BG BH ee wD 1 II ANALYSIS OVERVIEW aoaaa aaae 5 III OVERVIEW OF MOSES oaaae 8 IV MOSES BASICS 2 4 6 a we see pe one hee ew eee wd 10 IV A The MOSES Interface 2 2 22 2 0 11 IV B Commands Menus and Numbers 15 IV C Files and the ROOT Concept 18 IV D Customizing Your Environment 20 22 24 25 28 30 34 37 39 oe ai 40 ereen eaea Oe e a 43 VILC The amp D_GENERATE Menu Document Formatting 47 She hehe g hae om oe 51 a ee ee eee 53 VILI PICTURED sp whew od eea inaia gii a a ORS KS 55 Ae aaa ee eee ee ee e 57 VII B Picture Views oaaae 59 EOE a ape ee ee ee ere 62 2 te Ai oh Gv Bo A eS A Se 64 Grn ee E he een hte wee 66 VIILE Picture Ray Tracing ooo a aaa a 67 IX ADVANCED LANGUAGE FEATURES 68 IX A Variables oaa ke oe ewe BER ee eo 69 et Gro eats eee Saas 71 IX C Macross roe e te gusas wie nee a g a 73 IX D String Functions ooa 422462 eae a eee es 76 IX D 1 The amp INFO String Function 78 IX D 2 The amp NUMBER String Function 80 IX D 3 The amp STRING String Function 2 83 IX D 4 The amp TOKEN String Function 85 IX D 5 The amp GET String Function
149. 8 MOSES REFERENCE MANUAL VII GENERAL PURPOSE INTERNAL MENUS MOSES has several features of a general nature which are quite useful These will be discussed in this section before the more specific abilities are considered Rev Page 39 MOSES REFERENCE MANUAL VILA The amp SELECT Menu The Selection Process When communicating with MOSES one must often select data from a set For ex ample when one issues a command he is really selecting one command for processing from a set of valid commands In contrast there are cases where one may select more than one item from the set In either case data must be given to MOSES so that a selection can be made In most cases the data will consist of the names of the items to be selected Since simply issuing the names can become cumbersome MOSES uses a more general method the Selector A Selector can be a name a name containing either s or s or a Selection Criteria Here a is a wild character which stands for any character and an stands for an arbitrary number of characters In many cases the word MATCH will be used By a match we mean that two names are equivalent to within the wild characters As an example each of the following strings match the other ABCDEFGH A CDEFGH A H A Selection Criteria is a more general method of selecting data In essence it is a name SEL_NAME which must begin with a with which two sets of selectors are associated The first se
150. 8 CLASS NOD2 CNOD BUCKLING LENGTH RELATIONSHIP FOR X BRACES FIGURE 22 Rev Page 307 MOSES REFERENCE MANUAL XIII CONNECTIONS AND RESTRAINTS In MOSES bodies are connected together or to ground with special elements called connectors or restraints A restraint is an element which acts like a connector during a stress analysis but does not act during a simulation Basically restraints are of limited use Connectors however are quite important In general there are three categories of connector flexible rigid and connector assemblies Flexible and rigid connectors connect a body to either another body or to ground Connector assemblies are sets of simple connectors which act in unison and may connect more than two bodies Rigid and flexible connectors actually serve the same purpose they create a force between two points The real difference is how the force is computed With flexible connectors the force is computed based on a force deflection rule and the geometry of the system Rigid connectors yield constraints on the motion of the bodies Excepting numerics a very stiff flexible connection and a rigid connection should yield the same result In reality when the stiffness gets substantial numerical precision is lost and the solutions are either difficult or impossible to obtain In these cases rigid connections can ameliorate the difficulties Here we will call connectors simple if they are not assemblies All sim
151. A B H OPTIONS where the available options are the section options discussed above SECTION AREA IY IZ J ALPHAY ALPHAZ POINTS Y 1 Z 1 AX 1 AY 1 Y n Z n AX n AY n P_FY FY 1 FY 2 FY n M_P Zy Zz P_N Pn ETA ETA F_TYPE TYPE T_STIFF SPACE STIF_CLASS WHERE L_STIFF SPACE STIF_CLASS WHERE TN STIFF NUMBER STIF_CLASS WHERE LN STIFF NUMBER STIF_CLASS WHERE Here NAME is the name which one wishes to give the shape and TYPE is a valid class section type TUBE CONE BOX PRI WBOX IBEAM G_IBEAM TEE CHANNEL ANGLE D_ANGLE PLATE or LLEG and A B etc are dimensions inches or mm which are appropriate to define the shape When the shapes have been completely defined one should issue END_ amp DATA to exit Normally shapes defined via this menu are added to the basic shape table provided with the program and remain defined only for the duration of a given Rev Page 222 MOSES REFERENCE MANUAL database One can permanently add shapes to the basic table To find out how to accomplish this look in the section on Customizing Your Environment For the AISC shapes the standard names are used for most of the shapes The exceptions occur when the standard name exceeds eight characters Jumbo W shapes are denoted by a J suffix Angles are named Lddwwtt where dd is the depth in 1 10s of an inch ww is the width in 1 10s of an inch and tt is the thick
152. A AK check one damaged stab_ok 5 2 5 10 wind 100 yaw 0 damage 5p These two checks are identical except that the first one checks intact stability for a Rev Page 365 MOSES REFERENCE MANUAL draft of 5 feet while the second one checks stability with compartment 5p damaged When using STAB_OK or KG_ALLOW discussed below the NWT_DOWN points are used to check intact stability and both the NWT_DOWN and WT_DOWN points are used to check damaged stability The general form of the command is STAB_OK DRAFT RANG_INC NR_ANGLES OPTIONS where the options are R TOLERANCE HE RO PI YAW Y_ANGLE DAMAGE DAM CMP WIND WIND THWAV ANGLE_WAVE CEN_LATERAL XC YC ZC U_CURRENT COEF WIND W COEF COEF_RARM R_COEF WIND MAC RARM MAC any of the options discussed above The variable DRAFT sets the draft for which stability will be checked When the command is invoked it will rotate the vessel NR ANGLES times adding RANG_INC to the roll angle For each increment the program will iterate an equilibrium position for the other degrees of freedom and then compute the righting and wind heeling arms The R TOLERANCE option is the same as the one on the RARM command The values specified here will be passed to RARM whenever it is called Likewise the YAW is analogous to the same option on the RARM command and is used to compute righting arms about a skewed axis The DAMAGE option is used to select tanks that will be
153. ACE I CONNECTOR PCONNECT I CONNECTOR UP SLING L CONNECTOR V_BRACE I CONNECTOR V_CAN I CONNECTOR V_LWAY I CONNECTOR V_REST I CONNECTOR XY_DELTA LMDRIFT B79 I PRESSURE B75 LSET BSN ILSET C_CODE LSET CODE_LIM LSET DO_MOVIE SET FAT LIM I SET MARGIN SET N_CODE ISET NFAT LSET PER APPLY SET RENDER B29 LSET SCF LSET SN B30 LSET T_CODE I SET WDEPTH 329 Page 473 MOSES REFERENCE MANUAL L_TANK I TOTAL B76 INFO_SEL INMODEL INST_LAUNCH INST_LIFT OPTIONS INST LOADOUT INST_SPOST INST_TRANSP INST_UP B43 INTERSECT JOINT POST KG_ALLOW LAUNCH LAUP STD LCASE LDGFORCE LG_DELETE B04 LIFT LINE LIST BLOCK LIST_SEL LOADG_SUM LWFORCE M_DRIFT 380 M PAN FIX MAP MATRICES MD_MOTION MEDIT MESH MODEL IN MODES MODES POST MOMENT MOVE MOVE BLOCK MOVETO MPY MQW Rev MTZ 224 NAME P MIN DISTANCE P TANAKA PANEL PCONNECT PGEN PICTURE 290 PILE DESIGN PIPE B17 PLANE PLATE PLATE POST 404 PLATE SUM 13 PLOT PMOTION POINT SUM 13 POINTS 421 POSITION M31 PRCPOST PROPULSION PY Da QW Ea R_DETAIL R_ENVELOPE R_TANAKA R_VIEW 430 RANGE RAO RARM RARM STATIC REFINE 256 REFLECT BLOCK REL_MOTION RENAME_BLOCK REPO REPORT REST RESTRAINT_POST RESTRAINT SUM i an m ies Page 474 MOSES REFERENCE MANU
154. AL REVERSE REVIEW I5 S BODY S GRID S_PART SAVE_GRAPH SELECT SELECT_CONN SENSOR SET_VARIABLE SHOW_SYS SLING_DESIGN SP_BEAM SP_CFORCE SP FCARGO SP_PLATE SP_POINT SPECTRUM SRESPONSE ST_CFORCE ST_CLEARANCE ST_EXFORCE ST_FCARGO ST PANPRESS ST POINT ST_RFORCE ST_RSTRESS STAB_OK STABILITY STATIC PROCESS STATISTIC STORE STP_STD STRPOST STRUCTURAL 33 STYLE T_PRESSURE 166 TAB_ADD TABLE 346 TANK_BAL TANK_CAPACITY Rev TANK_FLD 423 TDOM TDOWN TEXT TEXT_ADD TIP HOOK TOWSOLVE TRAJECTORY TRANS _CON TRANSFORM TUBTANK TUG _DCHANGE TYPE TZ 224 UNION USE_MAC USE_VES V_EXFORCES V_MATRICES 374 V_MDRIFT 79 VERTICAL VIEW VLIST WEIGHT CONN WIDGET_ADD WIND_ARE WIZARD XBRACE Page 475
155. AVE DIMEN METERS K NTS defines the units which will be used in the analysis Two definitions are available to control the pictures ISET DO_MOVIE TRUE and ISET RENDER RENDER GL If the first of these is set TRUE then movies of a launch and or upending will be created provided you are rendering the pictures with GL The second one defines the rendering mode of the pictures If RENDER GL is set then pictures will be rendered with GL To save time you could use RENDER WEF Finally if you are using a TERMINAL interface all pictures will be rendered as WF pictures and no movies will be produced The following I SET WDEPTH 390 defines the water depth The margins or weight contingencies are defined by the two lines ISET MARGIN 5 I SET PER_APPLY 105 The first of these is for the basic steel in the model and the next is for any joint loads The line ISET T_CODE API WS defines the type of code checks which will be computed Here one can specify any code that is accepted by the BEAM_POST or JOINT POST commands For transporta tion the macros will automatically build the proper load cases but more information is required Rev Page 329 MOSES REFERENCE MANUAL I SET T_CODE API LRFD SO_FACTOR SM_FACTOR DM FACTOR Here the static internal forces and restraints are multiplied by SM_ FACTOR and combined with DM_FACTOR time the dynamic component before reporting or check ing a co
156. BE BODY should be at the beginning of each set of data Normally all bodies have six degrees of freedom Sometimes one wants to ignore some of these degrees of freedom This is accomplished with the IGNORE option Here DOF i is the name of the degree of freedom to be ignored and must be chosen from the list X Y Z RX RY and RZ When a degree of freedom is ignored the force in this degree of freedom is set to zero and the inertia is set to a very large number Normally bodies have six degrees of freedom The option GEN_DOF however allows one to use previously computed vibration modes as generalized degrees of free dom for a body For a discussion on computing modes for a body see the section on Extracting Modes Here MODE_SEL i are selectors for the mode numbers one wishes to use MODE_SEL i can be a single number which selects that mode num ber or a pair of numbers A B which selects all modes from A to B Once a body has more that 6 degrees of freedom some measure of its deformation and the deforma tion inertia is accounted for in any equilibrium time domain or frequency domain analysis Thus this is an excellent way to study the effect of flexibility on the results To the user however the number of degrees of freedom make no difference in how to accomplish various tasks The only effect is the computer resources required The S_DAMPING option defines the modal damping which will be used for the gen eralized de
157. CLASS MEMLOD DEFL The RESIZE option instructs MOSES to automatically resize any over stressed members in the model If the UP_CLASS option is used these changes are saved to the database The MEMLOD and DEFL options will provide detailed member loads and joint deflections respectively Rev Page 344 MOSES REFERENCE MANUAL XVI THE CONNECTOR DESIGN MENU There are two distinct reasons to analyze a system containing connectors one needs to assess their effect on the behavior of the system and one needs to design a con nector system to perform a given task The first is the result of simulating a process To aid in accomplishing the second MOSES has several commands which may be invoked from the Connector Design Menu This menu is entered by issuing the com mand CONN_DESIGN from the Main Menu When one has completed investigating his design he can return to the main menu by issuing END_CONN Most of the commands in this menu will place the user in the Disposition Menu at the conclusion of each command Here he can dispose of the results as he sees fit After leaving the Disposition Menu he is again in Connector Design Menu Rev Page 345 MOSES REFERENCE MANUAL XVI A Obtaining Connector Tables The TABLE command is used to obtain a list of the force distance properties of a connector The form of this command is TABLE LNAME Here LNAME is the name of the connector for which force distance proper
158. D RNUM VALUES CV VAL_MIN VAL MAX MAG USE This command offers the user the opportunity to view the selected data at the termi nal or if the HARD option is specified the results will be written to the output file The data viewed is defined by the column selectors CS 1 CS 2 If no column selectors are specified MOSES will prompt the user for all required data The STORE command is used to store the selected data in a table The result here is much the same as what you get in the amp TABLE menu i e either a CSV or HTML table The format of the command is STORE CS 1 CS 2 OPTIONS and the available options are HEADING HEAD RECORD BEG_RNUM END_RNUM VALUES CV VAL_MIN VAL_MAX MAG_USE TITLE NCOL 1 CT 1 NCOL n CT n Rev Page 103 MOSES REFERENCE MANUAL H_ SKIP YES_NO BOLD YES_NO ROW SHADE YES_NO EXTR SHADE COL SEL 1 COL SEL 2 V LINES COL SEL 1 COL_SEL 2 with the exception of RECORD and MAG _USE these option work exactly as documented with amp TABLE Rev Page 104 MOSES REFERENCE MANUAL X B Adding Columns Occasionally it is desirable to create a new column of data based on the existing columns or create a completely new column of data This can be performed with the command ADD_COLUMN NAME OPTIONS where the available options are COLUMN C 1 C 2 C n INPUT CS X 1 Y 1 X 2 COMBINE CS 1 F 1
159. D T_RESIZE CL_DELETE 04 CLASS_SUM Rev COLOR COMPART SUM CONFORCE CONN_DESIGN CONNECTOR COUNT CF COUNT_FM POST CSYMBOL CTEXT CTYPE CURR_ARE CUTYPE DELETE_BLOCK DEPTH 224 DESIRE_VALUE 352 DIFFERENCE DIMENSION DLINE DO REPO DRAFT E_MDRIFT B79 E_PRESSURE B74 E_TOTAL ED_CLASS ED_ELEMENT ED_POINT 178 EL_ACTIVE B04 EL DELETE 04 ELA DELETE B04 ELMFORCE EMIT 290 END END DATA 00 222 P24 P7 END_ amp SEL END_ amp SUMMARY END_ amp SURFACE END_ amp TABLE END_ amp UGX END_BLOCK END_DURATION END_FREQ_RESPONSE Page 472 MOSES REFERENCE MANUAL END_HYDRODYNAMICS END I PRESSURE B76 ENDI_TOTAL END_INPG END_M_DRIFT END MEDIT 136 END MESH END_PGEN END_PRCPOST END_REPO END REPORT END STRPOST END_STRUCT ENVIRONMENT 166 EQU_SUM EQUL H B57 EXCEPT EXFORCE EXP_ALOAD EXTREME 110 F_RAO _POST FAT_CFORCE FDELP B76 FFT FIG_NUM FILL FLOOD FOUNDATION FP_MAP 375 FP_STD FPANEL B75 FPPHI FR_2TIME B85 FR_CFORCE FR FCARGO FR_PANPRESS FR_POINT FREQ_RESPONSE G_MDRIFT B79 G_PRESSURE B73 GEN_OFFS Rev GEOMETRY GOTO GRID SUM H_AMASS H_DAMP 377 H_EULERA H_FORCE B77 H_ORIGIN H PERIOD B77 HOLE_FLOODING HORIZONTAL HSTATICS HYDRODYNAMICS LBEGIN LCONNECTOR 4_TIE B35 IL CONNECTOR PCONNECT I CONNECTOR H BRACE I CONNECTOR P_BR
160. DURATION_SEL defined via the DURATION option will be considered If no values are given for TYPE i then results for all TYPEs will be produced Here a TYPE of e DISPLACEMENT will produce the deflections of the selected joints e CODE_CHECK will produce a report of the joint checked against API RP2A Rev Page 466 MOSES REFERENCE MANUAL S_FATIGUE will produce a report of the API RP2A simplified fatigue check e CRUSH will produce a report of the crush unities based on effective closed ring analysis COUNT will produce the number of cycles of the stresses in bins and finally FATIGUE will produce CDRs computed using a stochastic fatigue approach The extent of the reports except for DISPLACEMENT and COUNT is controlled by which of the three report types were selected and the report limits With a STANDARD or SUMMARY report L i and T i are used to specify a range of code unity values for which a given report will be printed For a TYPE of FATIGUE the value is the CDR and for all others it is the code unity value One can specify as many ranges as he desires or he can omit all data following the option If no ranges are specified one report for all ranges of value will be printed An option of STANDARD will result in a report of the results for the maximum unity ratio over all selected load cases for each member selected If one specifies an option of SUMMARY this report will be reduced to the results for only the
161. E STRUCT immediately after the command to plot the mode shape Rev Page 454 MOSES REFERENCE MANUAL XXVIII D Post Processing Connectors amp Restraints To obtain post processing results for restraints and connectors one should issue the command RESTRAINT_POST TYPE 1 TYPE i OPTIONS where TYPE i must be chosen from ENVELOPE LOADS FOUNDATION or PILE_CHECK and the available options are CLASS CLS_SEL NODE NODE SEL 1 NODE_SEL 2 NODE_SEL 3 NODE_SEL 4 ELEMENT ELE SEL LOAD LSEL DETAIL STANDARD L 1 T SUMMARY L 1 T Here one will only receive results for elements which match the selectors defined with the CLASS NODE and ELEMENT options as described previously and for cases which match LSEL which is defined with the LOAD option If no values are given for TYPE i then results for all TYPEs will be produced With a TYPE of ENVELOPE the maximum and minimum restraint loads are summarized for all selected load cases and the DETAIL STANDARD and SUMMARY options are ignored A TYPE of LOADS will yield a report of the loads acting in the elements which restrain and connect the system A TYPE of PILE CHECK will yield an API code check of any piles used in the solution and a TYPE of FOUNDATION will produce a foundation check This check is the same as the FOUNDATION check in the Process Post Processing menu The only difference is that here the Nominal and Pre load cases
162. ECHO YES NO MECHO YES NO IDISPLAY YES NO SILENT YES NO FN LOWER YES NO COMIN FILENAME ICOMIN FILE_NAME AUXIN FILENAME IAUXIN FILE_NAME These options can be roughly divided into several classes The BATCH option defines when the program will terminate abnormally Here YES NO should be YES if one wishes to set the mode to batch and NO if one wishes the execution mode to be interactive The LIMERROR option defines the error limit If the program is in the interactive mode it will terminate when the error limit ERLIM is reached This limit is defined by the LIMERROR option In the batch mode MOSES will terminate when any error is encountered The next set of options define the way dates and figures are printed The US_DATE controls the style of the date which will be printed on the output reports If YES NO is YES the date will be the month followed by the day followed by the year If YES NO is NO then the day will be printed first followed by the month followed by the year The SET DATE options allows one to actually set the date string to the string which follows The CONT_ENTRY option allows one to define the next entry which will be added to the table of contents If the string follow Rev Page 34 MOSES REFERENCE MANUAL ing the option key word is blank then MOSES will revert to the default behavior The NAME_FIGURE option allows one to define the string which will be put
163. ED INERTIA A INERTIA C_INERTIA FLEX CONNECTORS RIGID CONNECTORS and TOTAL The meaning of these forces can be found in the section on FORCES The reports one receives with this command are usually written to the terminal If however one specifies the HARD option they will be written to the output file and no information will be received at the terminal The BRIEF option limits the scope of areport The precise effect of BRIEF depends upon the report being gener ated The PLOT option can only be used for the D _CONNECTOR S_ROD F_ROD SEA SEA SPECTRUM SEA_TSERIES or WIND_TSERIES re ports When this option is used the user will be placed in the Disposition Menu so that he can plot the results The General Information reports are given via a REP_TYPE of NAMES NOTE CURVES T CONVOLUTION F_ CONVOLUTION PARAMETER SIZE PROCESS or SN The first of these will produce a list of things names which can be used with amp NAMES and a description of them The second of these produces a list of database names and the notes one has associated with them For this type one can use the option NAMES NODE SEL to select only names in selected categories For example amp STATUS NOTE NAMES COMPARTMENT will produce only a list of compartments and their notes CURVES T CONVOLUTION and F CCONVOLUTION produce information about curves or convolutions All three of these types honor the SELE variable which defines the names for which a st
164. EFERENCE MANUAL IX D 4 The amp TOKEN String Function One useful string function is amp TOKEN ACTION STRING2 which returns a substring of STRING2 based upon ACTION If ACTION equals L then the last token of STRING2 is returned and if ACTION equals N the number of tokens in STRING2 will be returned In other cases ACTION will be a number a number followed by a or a pair of numbers separated by a Here the number N will return the Nth token of STRING2 N M will return Nth through Mth tokens and N will return the Nth through the last token If N is greater than the number of tokens in the string a null token is returned For example amp SET STRING ABCDEFGHIJK amp TYPE amp TOKEN L STRING amp TYPE amp TOKEN N STRING amp TYPE amp TOKEN 3 STRING amp TYPE amp TOKEN 3 5 STRING amp TYPE amp TOKEN 8 STRING will result in the following being written to the terminal K 11 C C D E and H I JK Rev Page 85 MOSES REFERENCE MANUAL IX D 5 The amp GET String Function When writing macros for MOSES it is often desirable to prompt the user for infor mation This can be accomplished by using the string function amp GET WAY DATA This string function returns a string and here WAY is the manner in which the response is obtained and DATA is the other information necessary to make the re quest WAY must be either FILE RESPONSE YES NO PICK N_PICK GET_LIST or GET_NAME and DATA depends upon
165. ELETE ELE SEL 1 ELE_SEL 2 These commands edit elements and classed and delete classes element load attributes load groups and elements respectively and the selectors are selectors defining the quantities to be deleted In using the commands which delete quantities care must be taken since if a class is deleted then all elements which use that class will also be deleted Also when using the ELA DELETE command notice that the selectors operate only on the element name In other words while one can define element load attributes by either class nodes defining the element or name one can only delete them by element name A word of caution is in order here Once something has been deleted from the database all data associated with this quantity is lost Thus if one has already performed a structural analysis and he deletes an element or class then the structural results for the elements deleted will be lost It is better to deactivate elements as described later than delete them Notice that there is no command for deleting a node Since nodes are simply points that are connected with structural elements there is no need for such a command In order to relocate a node simply redefine its associated point This will move the end of a beam or the corner of a plate that references the relocated node Often elements exist for some stages of an analysis and are absent for other stages This notion can be modeled by deac
166. ENCE MANUAL FA FB No o B xa se TRAPEZOIDAL ELEMENT LOADS FIGURE 30 Rev Page 443 MOSES REFERENCE MANUAL XXVII STRUCTURAL ANALYSIS amp APPLIED LOADS To perform a structural analysis or emit a set of applied structural loads one must enter the Structural Menu This is accomplished by issuing the command STRUCTURAL OPTIONS where the available option is INITIALIZE This command places the user in a sub menu where he can define a situation and perform an analysis If the option is selected then this will delete all previous struc tural results otherwise the results will be added to previous results so that all of them are available later for Structural Post Processing In general there are three types of commands available in this menu commands which define the load cases to be used commands which define the portion of the system which will be used and commands which produce the results When the solution has been completed one should issue END STRUCT to return to the main menu There are no re ports produced directly in this menu The results that are produced are the system deflections and element loads but to obtain a report of them one must enter the Structural Post Processing Menu Three general types of results can be obtained in this menu structural analysis results system deflections and element internal loads loads applied to the structure or vibration modes In the fi
167. ES thinks that the hole is entirely inside the box so nothing is subtracted To make things work properly one should define the hole as BLOCK HOLE PLANE 10 10 RECT 1 11 20 END_BLOCK Now there is no confusion as to whether or not the box intersects the hole The same rule applies to the other two operations Always make sure that the two blocks penetrate one another and two lines do not intersect Continuing with this example we can now create tanks in the box BLOCK AT PLANE 40 51 RECT 1 11 120 END_BLOCK BLOCK PTW LOC 0 40 port PLANE 60 60 RECT 1 11 11 END_BLOCK INTERSECTION BOX AT ATT INTERSECTION ATT PTW PAW The blocks AT and PTW are temporary blocks the first being a slice across the stern and the latter a slice along the port side Notice that in both cases care was taken so that these slices extended beyond the basic box The first intersection uses the temporary block to clip a true slice from the stern Here due to the simplicity this is not necessary but this produces a true piece of the ship from 40 feet aft The last intersection produces a tank at the port aft of the box If one defines more Rev Page 292 MOSES REFERENCE MANUAL longitudinal and transverse blocks all of the tanks can be easily created To complete this example we would emit the exterior of the box and the tank with RENAME BLOCK BOX PAW EQUIV 1 POINT P EMIT PART BOX EMIT BOX PIECE DIFTYPE 3DDIF PERM 1 00
168. ES to make a plot of the deflected shape of the strings Here DFLMAG is the magnification which will be applied to the deflection when making the plot To return to normal plots one should use the DEFLECT option with a magnitude of zero or less The ANOTATE option defines whether or not the strings will be annotated with text when they are plotted If WWHAT is NO no annotation will be made If WWHAT is NAMES the names of the strings will be plotted If WWHAT is POINTS only the names of the points strings with one vertex will be plotted Conversely if WWHAT is STRINGS only the names of strings with more than one vertex will be plotted To plot only class names of strings one should use PARENT If WWHAT is RATIO or STRESS then ratio or stress associated with the string will be used for annotation To plot only the ratio or stress of points one should use P_RATIO or P_STRESS To plot only the ratio or stress of strings with more than one vertex one should use S RATIO or S_STRESS The next set of options control the meaning of the color used for the plot By default different strings are assigned different colors based on familial relationships This mapping of color to string can be altered with the COLOR option Here CRI TERIA must be either MODELED BODY PART RATIO CDR STRESS FLOODED or SELECTED With a value of MODELED the color of a string Rev Page 64 MOSES REFERENCE MANUAL is determined by the color defined by either
169. G and TABS are used to define the text size and spacing Here CPI is the number of characters per inch which will be printed CHAR HEIGHT defines the height of the characters being printed and LED defines the amount of space between lines of type as a fraction of the type size Standard type has a ledding of 1 2 so that for a default device if one wants to double space text he should specify LED to be 2 2 The TABS option is used to define a tab character TBCHAR and a set of tab stops in characters The next three options define any indentation from the margins for this style Here RI is the indentation from the right margin LI is the indentation from the left margin and FI is the indentation for the first line of a paragraph Both RI and LI must be positive but FI may be a negative number of a value up to the value of RI Again Rev Page 28 MOSES REFERENCE MANUAL RI LI and FI are measured in points The BEFORE and AFTER options define the number of points of blank space which will be set before or after a paragraph while the JUSTIFY option is used to define whether or not the right margin of the text will be justified If YES NO is NO the margin will not be justified The FONT option is used to define the type style which will be used and the value for FONT_NAME must be either LGOTHIC or COURIER The FACE option defines the character of the type and FACE_NAME must be either NOR MAL UNDERLINE BOLD ITALICS or
170. GAPDIS LENSKD and FXLOC options define the geometry of the loadout Here GAPDIS is the distance between the land skidway and the beginning of the barge skidway and LENSKD is the length of skidway on the barge that actually provides support FXLOC is the final location of the jacket on the barge This is a distance from the end of the barge skidway nominally the bow to the trailing edge of the jacket It is positive if the trailing edge of the jacket is aft from the bow negative otherwise The trailing edge is defined as the end of the jacket that would come off last if the jacket were being launched from the barge It is assumed that the jacket is loaded out with the base of the jacket moving onto the barge first unless the option TOPLOAD is exercised It is further assumed that the stern of the barge is towards the fabrication bulkhead An over the bow loadout can be analyzed by specifying the proper values for GAPDIS and FXLOC The options PSUPNOD and SSUPNOD can be used to specify support nodes if the supports are different from PORT_NODES and STBD_NODES The variables PORT_NODES and STBD_NODES are defined in install dat This macro is designed to perform a simulation and a corresponding structural anal Rev Page 337 MOSES REFERENCE MANUAL ysis by default Next we will discuss the transportation analysis which has the following syntax INST TRANSP OPTIONS And the available options are NO SEAKEEPING NO_ VORTEX
171. INDEX is greater than ENDVAL The second form of amp LOOP is a while on the values in parenthesis In other words with this form the variable VAR will be set to the value LIST 1 for the first trip through the loop LIST 2 for the second trip etc The loop will terminate after LIST n has been used Alternately a loop will terminate whenever an amp EXIT command is encountered with a logical phrase of TRUE The commands between the amp LOOP and the amp ENDLOOFP are executed in order A jump to the bottom Rev Page 71 MOSES REFERENCE MANUAL of a loop occurs whenever an amp NEXT command is encountered with a logical phrase of TRUE An example of the first form of the loop command is shown below amp LOOP I 1 amp TOKEN N NODES 1 amp SET J AI amp NEXT amp LOGICAL J EQ 9 amp EXIT amp LOGICAL I GT 11 amp TYPE This is Loop Number 1 amp ENDLOOP Here I is the INDEX and the loop continues from 1 to the number of tokens in the variable NODES in increments of 1 The variable J is set to the value of I each pass through the loop and a message is typed to the screen If the J is equal to 9 the message is not printed If I is greater than 11 or if I is the number of tokens in the variable NODES the loop is terminated To terminate execution of either a macro or a command file one can use the com mand amp EOFILE LPHRASE When this command is encountered and LPHRASE is TRUE the com
172. L PAN SEL MAP MAP SEL DATA DATA SEL SELALL Here BODY_SEL PART_SEL LG_SEL CMP_SEL CLASS SEL NODE_SEL i ELE SEL MAP SEL PAN SEL DATA SEL and TAG_SEL define the manner in which quantities are selected They can be either selection criteria simple names or names containing wild characters If one of these options is not selected then the selector defined by the last use of the corresponding option will govern Node selection is more complicated than that of class or element Suppose that an element has two vertices Then for the element to be selected both nodes must match either NODE SEL 1 or NODE SEL 2 Thus to select all elements connected to a given node one should set NODE_SEL 1 to be the specified node and the remaining node selectors to be Alternately to select a single element one can set NODE_SEL 1 and NODE_SEL 2 to be the end nodes of the element In general the selectors define the things which will be reported However when one Rev Page 120 MOSES REFERENCE MANUAL asks for a report of elements the report will be restricted as follows e The class name of the element must match the class selector defined by the last CLASS option e The nodes which form the vertices of the element all must match a node selector defined by the last NODE option e The element tag must match the tag selector defined by the last TAG option and e The element name must match the element s
173. LIST LIST_TYPE OPTIONS Here LIST_TYPE is the type of list and must be chosen from ITEMIZE or USE_FIRST and if omitted ITEMIZE will be used A LIST_TYPE of ITEMIZE will put a bul let as the beginning of each list item while USE_FIRST will use the first non blank character in the list as the item delimiter Now the list is composed of items which are simply paragraphs To exit LIST mode one uses LIST There is one option SPACE SPACE which defines the vertical space in points at the beginning and end of the list The final formatting construct is TABLE mode which is entered with TABLE TABLE_TITLE OPTIONS and exited with TABLE A table consists of a centered title TABLE_TITLE and a matrix The matrix is defined as each paragraph being a row The general definition of a table row is column 1 column 2 where the beginning of the row is indented rows are viewed as paragraphs The delimit the definition of the elements within the row By default the element will be centered within the column width If one does not wish the elements to be centered he can use lt or gt as the first character of a part to either left or right justify the part within the column There is one option MARK SEP CHAR which is used to change the column separation character from to SEP CHAR A degenerate list of a single row can be simply defined with CENTER part 1 part 2 This table will
174. LTIPLIER can be either GAUSSIAN or WINTER STEIN GAUSSIAN is the default If WINTERSTEIN is used then FACTOR will be computed according to the paper Nonlinear Vibration Models for Extremes and Fatigue by S R Winterstein If one is using both PEAKS and GAUSSIAN then factor is different than that given above Here it is FACTOR sqrt 2 Log r Np sqrt 2 Log Np In other words here the given peak is scaled up based on the ratio of the predicted extreme in three hours to that predicted by the current sample In some cases however the independent variable is not time but frequency and the other columns are either Fourier Coefficients or spectral ordinates For frequency data different statistics are computed If the frequency data resulted from either a FFT or SPECTRUM command in the Disposition Menu then MOSES automatically knows how to treat the data If however the original data was frequency type then one must use the TYPE option to define how to treat it STYPE can be either Fourier or SPECTRUM With frequency data the report consists of Oth Moment lst Moment 2nd Moment 3rd Moment 4th Moment Root Mean Square Significant Ave of 1 10 Peaks Ave of 1 100 Peaks Ave of 1 1000 Peaks 3 Hour Max TP Peak Period TV Visual Period TZ Zero Up Crossing Rev Page 113 MOSES REFERENCE MANUAL TC Crest Period moments of the spectrum averages of the peaks and several periods of the data Here in c
175. MASS SCLEN SCLEN as defined with the SCFACT option It is the product of the input values times the scale factors which should have the di mensions defined above The scaling for the damping matrix is similar to that for the added mass except that SCDRAG is used instead of SCMASS The desired units for the product of the input values and the scale factors is damping coefficient divided by displaced mass The H_FORCE command defines the wave exciting force for the heading H which has been defined by the HEADING option on the ITOTAL command The first twelve values define the Froude Krylov force the next twelve define the diffraction force The first three values for each force will be scaled by SCFOR and the last three will be scaled by SCFOR SCLEN as defined on the SCFACT option The product of the input values times the scale factors should be either bforce and feet or meters depending upon the last amp DIMEN command Rev Page 378 MOSES REFERENCE MANUAL XIX B Mean Drift Data In most cases the mean drift database is created as a consequence of creating the pressure database This is simply the average of the nonlinear forces over time In general there are three contributions to this force diffraction incident potentials radiation potentials and the coriolis acceleration The mean force due to diffrac tion incident potentials is independent of the motion while the other two depend on the motion Here the last RAOs computed
176. MB 1 to the current number will be printed If NUMB 1 is an then the entire log will be printed and if both NUMB 1 and NUMB 2 are positive the commands between the two numbers will be printed For example P 10 20 lists all the commands between command number 10 and 20 P 10 20 N does the same thing except no command number will be printed P 10 will show the last 10 commands Another benefit of the command log is that previous commands can be re executed by either the command PHRASE or by the method discussed below Here PHRASE can be either nothing a number or a string If it is nothing the last command executed will be place in the command box so that it can be edited and executed This is equivalent to the cursor up key on a window interface Repeated use of the cursor up key will move up the command history If it is a number MOSES will simply execute the specified command If it is a string then MOSES will search up the command log until it finds a command containing STRING and will then execute that command Rev Page 14 MOSES REFERENCE MANUAL IV B Commands Menus and Numbers Each input record can contain three types of data The first word on the record is called the command or description name and it conveys to the program the type of data being communicated with this record The format of all records does not require that the data be in any particular column but instead the various data is separated
177. ME causes MOSES to load up the color scheme C_NAME and then what follows will only change what is in C_LNAME Thus if one uses this option he need only specify those things that he wishes to be different from C_NAME Likewise if one issues amp COLOR NAME and the color scheme NAME exists then he is actually editing NAME There are several color schemes predefined in MOSES DEFAULT BASIC_FRAME BASIC MENU WIDG_FRAME WIDGET and H_COPY The first of these is the basis for most things BASIC BASIC_FRAME and MENU are used for the components of the MOSES User Interface Window and WIDG_FRAME and WIDGET are used for things that pop up in this window H_COPY is used for things which are written to hardcopy devices In general the only difference between these is the color of the background All of these colors themselves are defined with the options N BACKGROUND C_NAME S BACKGROUND CNAME N_FORGROUND CNAME S_FORGROUND C_NAME N _BEDGE C_NAME 1 C_NAME 2 S_BEDGE C_NAME 1 C_NAME 2 N SELECT C_NAME 1 C_NAME 2 _SELECT C_NAME 1 C_NAME 2 N_LINES C_NAME 1 C_NAME 2 0 0 C_NAME 6 _LINES C_NAME 1 C_NAME 2 0 0 C_NAME 6 The options N_BACKGROUND and S_BACKGROUND define the back ground colors Here and what follows the prefix N_ defines normal colors and S_ defines special ones The options N_ FORGROUND and S_FORGROUND define the foreground
178. MIN NWT DOWN WT DOWN MIN WT DOWN E PIECES I PIECES MAX BUOYANCY MAX CB DISPLACE CB GM G ROLL I VECTOR F_WEIGHT F_CONTENTS F_BUOYANCY F_WIND F_V_DRAG F_WAVE F_SLAM F_R_DRAG F_CORIOLIS F_W_DRIFT F_DEFORMATION F EXTRA F_APPLIED F_INERTIA F_AINERTIA F_CINERTIA F_FLEX_CONNE F RIGID CONNECTORS F_TOTAL B_CG B_ WEIGHT B RADII B MATRIX A CG A WEIGHT A RADII A MATRIX D CG D WEIGHT D RADII or DMATRIX The action CURRENT is special in that it should have no other input i e no BODY_NAME and no OPTIONS It returns the name of current body All other action need a body name If this name is omitted the current body will be used Thus if your model contains only a single body the name may be safely omitted The action E NODES returns the names of the extreme nodes for the body and P_NAMES returns the names of the parts in the body The action EXTREMES returns the length width and height of a body where these quantities are mea sured along the body X Y and Z axes respectively The action DRAFT the reading of the draft marks will be reported while the actions LOCATION VE LOCITY MXSUBMERGENCE and BOTCLEAR return the requested data on the location of the body WT_DOWN and NWT_DOWN will return a list of the down flooding points of the specified type and MIN_WT_DOWN and MIN_NWT_DOWN return the minimum height of the points about the water The actions E PIECES and I PIECES return a list of the external or
179. MOSES The next three change to picture mode with the first using the type of picture last rendered as the type and the other two using the render mode specified G for a GL picture W for a wire frame See the section on Pictures for details These four shortcuts are always available The remainder of them discussed here work only when one is focused on the text display or the command line The next four commands simply move the user s reading position TOP put one a the beginning of the display and BOTTOM at the end P command moves up a page and P moves down one The last two commands move up and down one command in the command history In addition to storing the entire terminal input output history MOSES also saves a record of the commands which have been issued While there are numerous uses of this command log the primary one is to allow the user to see where he is This is Rev Page 13 MOSES REFERENCE MANUAL accomplished by the P command the form of which is P NUMB 1 NUMB 2 When this command is issued a portion of the command log will be printed to the terminal If no option is specified then the commands printed will be preceded by the command number and if N is specified as an option then the numbers will not be printed If neither NUMB 1 nor NUMB 2 is specified then the last command issued will be printed and if NUMB 1 is a negative number then the commands from the current number plus NU
180. MOSES REFERENCE MANUAL XVI C Finding the Restoring Force The MOVE command is used to obtain the restoring force on a body as a function of either excursion or angle The form of this command is MOVE BODY_NAME OPTIONS and the available options are LINE TH DIST NUMBER ROTATE EXCUR THINC NUMBER where BODY_NAME is the name of the body to be moved If this is omitted the current body will be used If no options are specified then the default is the same as LINE with no data The option LINE is used to move the body ina line Here TH is the direction deg in which the body will be moved measured from the global X axis positive toward global Y DIST is the total distance of the move and NUMBER is the number of positions calculated Notice that the position increment is the quotient of the distance and the number of positions If only the body name is specified then this command will move the body in thirty 30 equal increments in the direction TH from the initial configuration until a termination criteria is met This criteria is when the most heavily loaded line has a horizontal force equal to the maximum in the table The ROTATE option is used to move the body around in a circle Here EXCUR is the distance from the initial position feet or meters and this will be a constant TH_INC and NUMBER are the angle increments deg and the number of angles respectively If these are omitted 10 degrees and 36 will be u
181. NAME is the piece about which information is desired and ACTION must be either CURRENT PAN ELS DIFTYPE PERMEABILITY CS_WIND CS_CURR AMASS LO CATION or OBSTACLE and the type CURRENT returns the current piece name PANELS returns the names of the panels in the specified piece and all of the others return the data defined with the options of the same name After the piece has been defined its geometry is defined by a set of convex polygons called panels Each panel is defined by points at its corners with the command PANEL PAN_NAME PTNAM 1 PTNAM n Here PAN_NAME is the optional name assigned to the panel and PTNAM i are names of its vertices If PAN NAME is omitted a panel name will be assigned internally A panel can contain from three to fifty vertices The order of the definition of the vertices should be clockwise when the panel is viewed from outside of the body In other words the normal to the surface when defined by the right hand rule should point into the body One can alter this convention by using the command REVERSE OPTIONS and the available options are YES NO The counterclockwise order for the vertices should be used following a REVERSE YES command If one wishes to change back to the basic convention he should then issue REVERSE NO The string function amp PANEL ACTION NAME can be used to return information about a panel Here NAME is the panel about which information is desir
182. NG VSHORT TMAX TMIN B_TENSION BTEN C_SN CSN TAB LIM TABLE LIMIT DEPANCHOR DEPTH CLUMP CW CLEN BUOYDIAMETER BOD DRAGDIAMETER D_DIAMETER WINDDIAMETER WOD AMASDIAMETER AMOD FRICTION BOTMU SLOPE SLOP A ROD is the only connector which can have forces other than buoyancy and weight which act along its length It is also the only connector which is assumed to respond dynamically MOSES treats rods as an assembly of large deflection tubular beam elements with inertia The option LEN is used to define the length of each segment of the rod with L being the length feet or meters The option REFINE is important for ROD elements This option instructs MOSES to subdivide the segment into N elements and thus create N 1 nodes If this option is omitted a single element will be used for the entire segment The maximum number of elements for all segments of a rod is 100 Since a rod is nonlinear the number of elements influences the accuracy of the solution Any of the material options can be used to define the properties of the rod and WTPLEN DISPLEN BUOYDIA WINDDIA DRAGDIA and AMASDIA can be used to change the force computations as for a beam The remainder of the flexible connectors are in essence a set of springs in series a dashpot and a hydraulic tension control device All of these elements have linear stress strain behavior but they all can be combined with three
183. NOTATE POINTS to show specific points in the model The RATIO CDR and STRESS options selects strings for plotting based on the value of their ratio cdr or stress Only strings with a ratio cdr or stress between BEG_RATIO and END_RATIO will be plotted With the NAMES Rev Page 62 MOSES REFERENCE MANUAL BODY PART PIECE PARENT CATEGORY or ENDS options the selectors NAME_SEL BODY_SEL PART_SEL PART_SEL PIECE_SEL CAT_SEL and END_SEL 1 END_SEL 4 will select strings based on the values of the appropriate quantities associated with the string To qualify for being in a picture a string must be selected by all five selection criteria Rev Page 63 MOSES REFERENCE MANUAL VIII D Picture Special Effects In addition to the other things the options WATER_ COLOR YES NO DEFLECT DFLMAG ANOTATE WWHAT COLOR CRITERIA BACK_ COLOR YES NO CULL BACK YES NO CROP_FOR_TITLE YES NO SHRINK AMOUNT T_SIZE TITLE_SIZE A_SIZE ANO_SIZE WG_MIN SIZE can be used for special effects The WATER COLOR option with a YES NO of YES will use a different color slightly darker for things under the water than the color for those above It will also result in the intersection of a panel with the waterplane being drawn A YES NO of NO will not produce the intersection and all lines of a panel will be drawn in the same color The DEFLECT option instructs MOS
184. NPUT is specified for GRID_TYPE then the user is placed into another sub menu where the grid can be defined This is accomplished via the commands HORIZONTAL X WELEV VERTICAL Z 1 VX 1 VZ 1 AX 1 AZ 1 END_INPG The HORIZONTAL command defines the locations along the wave where the grid is to be defined X is the distance from the wave crest feet or meters and WELEV is the elevation of the wave above mean water level feet or meters Once the horizontal location has been defined one should input as many VERT commands as necessary to define the wave velocity and acceleration Here Z i is the depth of the point below the mean water surface negative for points above the mean water surface VX i and VZ i are the horizontal and vertical wave velocities ft sec or m sec and AX i and AZ i are the horizontal and vertical wave accelerations ft sec 2 or m sec 2 When the grid has been completely defined one should issue END_INPG to return to the ENVIRONMENT sub menu There is a string function amp ENV INFO Which returns information about the current environment Here INFO must be S_HEIGHT S PERIOD S GAMMA S CREST S HEADING S_SP_TYPE S PERIOD W SPEED W_ DIRECTION W SPECTRUM W DESIGN W PROFILE W PERIOD or CSPEED C DIRECTION WAT DEPT TIDE WATER MD PERIOD T_ OBSERVE T INCREMENT RAMP T REINFORCE The values beginning with S_ return information about the sea the ones beginning with C_ return
185. NUAL columns to consider including the first one The command ADD_COLUMN NEW NORM 3 3 will find the norm of columns 3 4 and 5 The RMS option is similar to NORM except that here one specified the columns to be combined directly factor The POWER option is a generalization of the above Here P_C is the power each column is raised before summing and P_N is the power to which the sum will be raised e g ADD_COLUMN NEW POWER 52314151 Gives the same result as the NORM example and ADD COLUMN NEW POWER 1 133 Gives the same result as the COMBINE example The DERIVATIVE and INTEGRAL adds new columns which are the deriva tive or integral of column CS 2 with respect to column CS 1 and the LN and EXP options add columns which are the natural log and the exponential of the original column The FILTER option filters a column of temporal data using a Fourier Transform Here R_ TYPE defines the type of ranges to be input FREQUENCY for angular frequency or PERIOD for periods MOSES will then compute the Fourier Trans form of the function with domain in column CS 1 and range in column CS 2 After the transform all values within any of the ranges defined will be discarded and an inverse transform will be computed for the new column For example ADD_COLUMN NEW FILTER PERIOD 1 4 0 30 will produce a new column named NEW from the old curve defined by columns 1 and 4 Here column 1 is TIME or EVENT All of the contribution
186. OD B_ CAT H_CAT SL_ELEM and TUG_BOAT This report includes a basic summary for a mooring spread including connector forces and local and global headings of the connectors The LINES type produces a report about the BLCAT connectors which include the horizontal distance between the fairlead and anchor the length of the first segment the line on bottom the tension and ratio at the top and the horizontal and vertical pull on the anchor The DG_CONNECTOR type produces a detailed report of the geometry of the connectors selected by SELE A type of CL_FLEX produces a report of the data for the classes of the flexible connectors and a type of TIP HOOK produces a report detailing the geometry of the boom tip and hook during an upending simulation PIPE reports the active length tension in the tensioner and tensioner limits for a pipe assembly PILE produces a summary of the soil and the multipliers associated with each pile and finally the report obtained with ALIAS_NODE is a list of all pairs of nodes and their alias Compartment Information reports are obtained viaa REP_TYPE of PIECES COM PARTMENT CG_COMPARTMENT or S COMPARTMENT The first of these produces information about the pieces which comprise the compartment The remainder deal with exterior compartments The first of these produces the type of filling the specific gravity of the contents the maximum and current amounts of ballast and the minimum maximum current percentages fu
187. ORMAL NX NY NZ FRICTION F FACTOR Here AREA is the cross sectional area of the valve inches 2 or mm 2 POINT NAME is the named of a point defining the centroid of the hold NX NY and NZ are the components of the normal of the hole and FRICT is the friction coefficient for the hole and piping system The normal to the hole is actually the normal to the area of the hole and points out of the compartment If some of this data is omitted defaults will be used The flow rate is calculated by MOSES using the following equation Q U AREA SQRT 2GH SQRT F_FACTOR where Q is the flow rate in cubic feet per minute or cubic meters per minute G is the gravitational constant H is the differential head feet or meters and U is a constant which makes the units work out correctly The average flow rate between two subsequent events of a static process is used to calculate the time to flood a compartment For many cases one does not need all of this complexity In particular if one only wants to check the intact stability of a vessel all he needs is a list of down flooding points To save work in this case MOSES allows these to be defined directly on the amp DESCRIBE COMPARTMENT command with the options WT_DOWN WD 1 WD Q NWT_DOWN ND 1 ND 2 Here the WDs and NDs are the names of points Often one does not wish to build Rev Page 295 MOSES REFERENCE MANUAL a complete model so these options can
188. OSES responses to the commands Rev Page 19 MOSES REFERENCE MANUAL IV D Customizing Your Environment In the directory where the software is installed there is a subdirectory named data This subdirectory stores data required for the execution of the software and files that allow the user to customize an installation The data directory is further divided into subdirectories The ones of interest here are named local progm and site The files moses aux mMoses mac moses man and moses pgm are stored in the progm directory These files contain auxiliary shapes data program macros the on line reference manual and program parameters and default settings respectively Also at this directory level is the original moses cus file provided with the installation The files in the progm directory are read each time the program is executed as part of program initialization and should not be altered by the user The local directory is provided for user customization When the program is executed it checks for the existence of a local database If these do not exist then it builds them During the building of these databases the program will attempt to read files moses mac and moses aux from the local directory This allows one to add a set of site specific macros and structural shapes to those which are normally available You should simply create files with the above names and then delete the file moses sit on a UNIX machine or moses dsi on a PC Th
189. OTE Interior Beams CLASS This defines a beam associates it with a Category INSIDE and defines a description of the Category Interior Beams Load Groups have a multiplier for the total force of the group Initially this multiplier is set to one Control of all of these multipliers is available with the command amp APPLY OPTIONS where the available options are PERCENT FRACTION FORCE NAME 1 VAL 1 NAME n VAL n LOAD_GROUP NAME 1 VAL 1 NAME n VAL n TIME NAME CNAME CATEGORY CAT 1 NAME 1 VAL 1 NAME n VAL n MARGIN CAT 1 VALINC 1 CAT n VAL_INC n The first two options define the way the VAL i are interpreted If a VAL is preceded by a PERCENT option it is interpreted as a percent If it is preceded by a FRACTION it is a multiplier If neither of these options precedes a value it is interpreted as a percent In essence percents are divided by 100 to convert them into multipliers The FORCE option defines multipliers for user defined load sets Here NAME i Rev Page 188 MOSES REFERENCE MANUAL are selectors for these sets and VAL i are the multipliers one wishes to associate with the set By default all user defined load sets have a multiplier of zero Thus they will not be applied unless one uses this option The LOAD GROUP option defines multipliers for load groups By default these multipliers are one Thus one normally does not need
190. OW_DEFLECT When it is issued MOSES will include all applied loads the ballast in all tanks the defined weight and the buoyancy in the strength calculations The values used for the buoyancy are those of the current state i e the buoyancy is computed considering all parts which are active and the current draft roll and trim The current state can be set with either an amp INSTATE EQUI_H or amp EQUI command It is possible that the shear curve will not close particularly if the vessel is not in static equilibrium To close the shear curve one should either issue an EQUI_H amp EQUI amp WEIGHT COMPUTE or amp CMP BAL command to establish equilibrium before issuing the MOMENT command If one is interested in longitudinal strength in waves he should issue EQUI_H with the WAVE data before the MOMENT command If not the vessel will normally not be in equilibrium and the shear curve will not close In applying the loads the default procedure is to include a load even if all of its distribution is not applied within the geometric limits of the vessel When this occurs the overhanging part of the load is transferred as an applied load and moment at the vessel end If the end of the load is forward of the beginning the end is set to be very close to the beginning When a load is completely off of the vessel it is applied as a concentrated load and moment at the end and again the shear and moment curves will not close After the r
191. PE SELE OPTIONS Here REP_TYPE specifies the type of information one wishes to report and it must be either For General Information NOTE NAMES CURVES T CONVOLUTION F_CONVOLUTION PARAMETER SIZE PROCESS or SN For System Information BLW FORCE CONFIGURATION BODY DRAFT B_LMATRIX A MATRIX D_ MATRIX or MOTION For Environmental Information ENVIRONMENT SEA SEA SPECTRUM SEA_TSERIES or WIND_TSERIES For Connector Information F_LLWAY G_LWAY F_CONNECTOR G_CONNECTOR DG_CONNECTOR S_ROD F_ROD CL_FLEX SPREAD LINES PIPE PILE TIP HOOK or ALIAS_NO For Compartment Information PIECE COMPARTMENT CG_COMPARTMENT or S COMPARTMENT For Compartment Hole Information VLHOLE PLHOLE WT_DOWN or NWT_DOWN e For Load Group Information M_LOADG or F_LOADG e For Categories and Load Sets M_LSET CATEGORY M_CATEGORY or D CATEGORY e For Element Information ELEMENT or F ELEMENT e For Map Information MAP or N MAP e For Structural Solution Information S CASE R CASE or AMOD The amount of information obtained is controlled by the selection criteria SELE The available options in addition to those on the KREP SELECT command are HARD BRIEF PLOT Page 125 MOSES REFERENCE MANUAL FORCE FORCE_NAME 1 FORCE_NAME n Here FORCE_NAME i is a selector which selects forces from the list WEIGHT CONTENTS BUOYANCY WIND WIND V_DRAG WAVE R_DRAG SLAM CORIOLIS W_DRIFT DEFORMATION EXTRA APPLI
192. PERIOD The SPREAD option controls the spreading of the seas and EXP is the exponent which defines the wave spreading function F F THET COS H THET EXP for pi 2 lt THET lt pi 2 Rev Page 162 MOSES REFERENCE MANUAL F THET 0 Otherwise Here H is the mean wave heading If the SPREAD option is not used a value of 200 will be used for EXP The MD_PERIOD option defines the periods TD I at which wave drift forces will be generated when performing a time domain simulation If they are omitted the values specified via amp DEFAULT will be used Similarly the S_PERIOD option defines a set of periods which will be used to synthesize wave frequency excitation If they are omitted the values specified via amp DEFAULT PERIOD will be used In the case when a spectrum will be used to synthesize a time domain sample of a sea the RAMP TIME and T REINFORCE options are used to control the synthesis The variable RAMP TIME of the RAMP option defines the time interval over which the sea will be linearly ramped from zero to its full value If either option RAMP or T_REINFORCE are omitted the values defined via DEFAULT will be used The TIME option sets the observation time and time increment of the synthesis Here TOBSERV is the end time of the synthesis and DELTA TIME is the time increment TTRA SET can be used to set a time translation If TTRA SET is a number then this number translates time equal ze
193. PTIONS where the options are BEGIN BOX COMMENTS LINE COMMENTS END Perhaps the best way to illustrate this command is with the following example amp EMIT BEGIN amp DESCRIBE BODY TEST amp EMIT BOX This is the main hull model PGEN HULL CS_WIND 1 1 1 CS CURRENT 111 PLANE 0 50 100 150 200 250 300 RECT 0 20 90 END amp EMIT LINE Cargo Wind Area PGEN CARGO LOCATION 0 0 20 CS WIND 111 PLANE 100 150 200 RECT 0 40 100 END amp EMIT END The BEGIN option causes MOSES to declare the units being used The BOX and LINE options simply add comments to the resulting file which is useful for documentation of a model The BOX options places a box around the comments while the LINE option places the comments at the end of a line The END option stops the emit process and returns MOSES to parsing modeling commands as normal If the program finishes without using amp EMIT END MOSES will automatically include this command as part of closing all files The commands to be emitted must come through the input channel typically the root dat file None of the modeling commands following amp EMIT will be parsed as they normally would Instead the modeling commands complete with comments are placed in the post processing output file typically root ppo Rev Page 140 MOSES REFERENCE MANUAL XII A Converting Models Often one is given a model in a format which is not suitable for use in MOSES In certain cases
194. QMEAN i for the mean and RAO i NUMBxX for the ones corresponding to the response operators Here i is equal A for the first equal to B for the second set etc The values NUMB are numbers corresponding to the headings and frequencies Both the frequencies and headings are in sorted numerical order and the values for NUMB are 1 2 N for frequency 1 and headings 1 through N For frequency 2 they are N 1 N 2 etc The final part of the name X is used to denote the real and imaginary part Here I denotes the imaginary part and R denotes the real part The results from the structural solution for the RAO load cases are deflections and element loads resulting from a regular sea of given period and heading and a height of 1 database unit In MOSES the database unit is an inch regardless of the current values set with amp DIMEN Thus if one wishes to interpret the results directly he should use the CASES COMBINE command to scale them to more meaningful units The TIME option is used to perform a snap shot analysis of the frequency domain results Here ENV_NAME is the name of a seastate which was previously defined by a amp ENV command CASE i is the name which the user wishes to give to the case and T i is the time at which the loads will be combined to produce the snap shot The next option for LCASE is used to perform a solution for selected times during a process This is similar to the situation discussed above with t
195. ROP_FOR_TITLE option allows one to set the upper boundary for a picture to be below the title if YES NO is YES If YES NO is NO then the picture will be drawn over the title The SHRINK option will move the outline of a string inward toward its center an amount AMOUNT This is quite useful when using color to select things in a mesh model Without shrinking the color of a panel can be overwritten by the color of its neighbor Also this option is useful when looking for missing panels or in conjunction with BACK_COLOR when looking for incorrectly ordered panels The T_SIZE and A_SIZE options allow one to change the size of titles and annotation characters respectively The defaults are 10 pixels for both Finally the WG_MIN options defines the minimum wave grid size to be SIZE Rev Page 65 MOSES REFERENCE MANUAL VIILE Picture Animation Normally one receives a single picture in response to a amp PICTURE command If however this command is issued from either the Static Process Menu or the Process Post Processing Menu an animation of the process will be plotted For an animation the number of frames can be controlled with the option EVENTS EVE_BEGIN EVE_END EVE_INC Here EVE_BEGIN is the first event for which a picture will be drawn ESTOP is the last event for which a picture will be drawn and EVE_INC is the increment at which pictures will be drawn between EVE_BEGIN and ESTOP One can specify multip
196. RP2A 21st edition the e API WJ API WJG API _WJP API_WJ_WET APIWJG_WET API_WJP_WE API_CJ API_CJG and API_CJP from API RP2A 2nd supplement to the 21st edition the e API_CHAIN and API_WIRE curves from API RP2F e HSE_TP curve from HSE and the e DNV_B1 DNV_B2 DNV_C DNV_C1 DNV_C2 DNV D DNV E DNV F DNV F1 DNV F3 DNV_G DNV_W1 DNV_W2 DNV_W3 DNV T DNV B1 WET DNV B2 WET DNV C WET DNV C1 WET DNV_C2_WET DNV D WET DNV E WET DNV F WET DNV F1 WET DNV F3 WET DNV G WET DNV_W1_WET DNV_W2_WET DNV W3 WET and DNV_T_WET curves from DNV RP C203 2008 For the WJ and CJ curves the ones with _G include weld improvement due to grinding and the ones with _P include improvement due to hammer peening To define a curve one first specifies TYPE which defines the type of curve TYPE should be STRESS for a normal curve or TENSION for a curve like the WIRE and CHAIN curves The values S i and N i define the stress or tension break tension and the corresponding number of cycles After the curve is defined one uses the THICK_SN option to define a correction which depends on thickness Most documents say that this is a reduction of the SN curve but in MOSES it is viewed Rev Page 173 MOSES REFERENCE MANUAL as an increase in SCF Thus our factor is greater than one and is the inverse of what would be a reduction of SN The only real difference is that POWER here is positive where with a reduction it is ne
197. RSEY amp VARIABLE lt MACDBF gt COWS ADD HOLSTEIN amp VARIABLE lt MACDBF gt COWS ADD ANGUS Will build a variable lt MACDBF gt COWS which has three names in it JERSEY Rev Page 97 MOSES REFERENCE MANUAL HOLSTEIN and ANGUS Here we will be using the command amp LOOP without any entries This advanced method of using amp LOOP creates an infinite loop Now amp LOCAL LIST amp LOOP amp EXIT amp VARIABLE WHILE lt MACDBF gt COWS A_COW amp SET LIST LIST A_COW amp ENDLOOP will produce the local variable LIST which contains the three names of cows Fi nally there is the string function amp NUMVAR VAR_NAME that returns the number of names in the variable VAR_NAME e g amp NUMVAR lt MACDBF gt COWS will return 3 Often one wishes to while items which are in the database This can be accom plished with amp LOOP N amp NAMES NODES amp ENDLOOP Unfortunately for large models this will produce a buffer overflow When this happens you need to change the above to amp SET NOD_VAR amp NAMES NODES V amp LOOP amp EXIT amp VARIABLE WHILE NODE_VAR A COW amp ENDLOOP The first line above uses the amp NAMES string function and the option V to get the names that MOSES uses to store the data which allows you to use the MOSES data directly As mentioned above functions are build on top of variables Before one can add values to a function
198. RY DRZ CONDITION NAME DRAFT ROLL TRIM Rev Page 198 MOSES REFERENCE MANUAL POINT PNT 1 H 1 PNT 2 H 2 PNT n H n DRAFT DMARK 1 D 1 DMARK 2 D 2 DMARK n D n GUESS NODE 1 NODE 2 NODE 3 VELOCITY NAME VX VY VZ VRX VRY VRZ SL_SET LINES ACTIVE LSEL 1 TEN 1 LSEL 2 TEN 2 EVENT EVE_NUM PREVIOUS C FORCE FLAG The uses of the option keywords are LOCATE positions a body in space abso lutely X Y and Z are the global coordinates of a point on the body and RX RY and RZ are the new Euler angles The MOVE option moves a body relative to its last known position in this case the parameters are changes in position and orien tation CONDITION is the same as LOCATE except that only 3 degrees of freedom are necessary Here NAME is the name of either a body or a report point If a point name is specified then the position specified will be for that point If a body is specified then the location will be the location of the origin of the body All of the units for these options are feet or meters and degrees The three options POINT DRAFT and GUESS all set the body according to the positions of a set of points With the GUESS option MOSES will change the orientation of the body so that the three nodes NODE 1 NODE 2 and NODE 3 will lie in the waterplane Here the three nodes cannot be colinear and one cannot rotate a body ninety de
199. SES which are in the same order in which the corresponding operation would be performed in the field Collectively the set of commands which one issues is called a static pro cess Two main commands are available LIFT and FLOOD defined later in this section When one of these commands is issued MOSES will then use the equilib rium position at the last event change the situation as designated by the command and iterate a new equilibrium position In this menu three degrees of freedom are considered the movement of the body vertically and two angular motions Before entering the Static Process Menu one normally defines a lifting sling This is accomplished by first entering the MEDIT Menu and issuing the proper sling assembly commands In most cases these commands will take care of all of the preliminaries so that one can perform a static process If one does not have a sling assembly or the situation is unusual he may need to alter the orientation of the body via a amp DESCRIBE PART MOVE command before entering the menu In general it is advisable that the orientation of the body be such that the body X and Y axes will be close to parallel the waterplane when the process begins During a static process MOSES iterates equilibrium positions and as a result there are certain instances in which a position satisfying the tolerance within the specified number of iterations is not found MOSES employs two closure tolerances It will first
200. SET SCF Efthymiou I SET SN XP ISET B_SN AWSE The first of these defines the limits for which the fatigue reports will be broken down If this is not changed one will receive 3 reports for joint and beam fatigue The first Rev Page 330 MOSES REFERENCE MANUAL will have CDRs above 1 the second will have CDRs between 25 and 1 and the last will have CDRs between 0 and 25 The next two lines deal with tubular joint fatigue Here SCF defines the type of SCFs which will be computed during fatigue The SN variable defines the SN curve for Joint Fatigue In either of the variables multiple curves can be used For example I SET SN XP X will produce fatigue results for both the XP and the X curves The B_SN variable defines the SN curve which will be used for Beam Fatigue and the amp REP_SELECT command defines a new type of SN curve AWSE Here the default SCFs for beam which are not tubes are set to 1 and the AWSE curve is used for beam fatigue Report Data The following command defines the cover page for the report Be sure to enclose the variables in single quotes if they are more than one word I BEGIN OPTIONS And the available options are TLINE1 XYZ EXPLORATION and PRODUCTION TLINE 2 8 Pile Jacket for the COWABUNGA Field TLINE3 Installed Offshore Timbuktu CLIENT QRS Engineering Inc FOOTER 8 Leg Jacket Barge Data This data is necessary only for a launch or tr
201. SHADE EXTR SHADE and V_LINES options have no effect Rev Page 54 MOSES REFERENCE MANUAL VIII PICTURES As mentioned above one can obtain a picture of the current situation by issuing the command the amp PICTURE command This command is used to get pictures of everything and as a result it has options to control The type of data used in the picture The title of the picture The portion of global space to paint The annotation of the picture The production of a deflected shape picture The use of color in the picture and The names of things included in the picture Once something is specified on a amp PICTURE command it is remembered through out a MOSES session unless however it is changed There are Tool Bar controls for all of the things on the picture command as well as a set of keyboard shortcuts to make life easier There is quite a bit of data which can be defined to create a picture which is precisely what one wants To make it easier to reproduce these pictures MOSES employs the concept of a user defined view One defines a view with the command amp PI_VIEW OPTION V_NAME Here V_NAME is the name which will be given to the view and the data which follows is any data which can be placed on the amp PICTURE command The OPTION may be either ADD or DELETE For DELETE only VNAME is required Now once a view has been defined a picture can be produced with amp PICTURE
202. T CS_GET SELECT CS_PUT CS_GET VAL 1 VAL 2 The results of this command are stored as a string in the variable VAR_NAME The first of theses options is different from the others in that it simply changes the records that will be searched by any following option All of these others actually produce results The simplest of the remainder of the options are NUM COLUMNS and NUM ROWS which simply writes a string defining the number of columns or rows of data which exist The NAMES option will write the variable names for the columns CS 1 CS 2 etc into the variable The COLUMN option simply copies the values of the columns CS i into the string Here the values of each column are copies for each record The STATISTICS option operates in the same manner as the STATISTICS command Here CS 1 is the column number of the independent variable and CS 2 is the column number of the data for which statistics will be returned This will result is numerous tokens being defined in VAR _NAME one for each row obtained when the STATISTICS command is issued Also the order of the tokens is the same as the order of the row The remainder of the options deal with two columns of data and write numbers into the global variable based on the values of the two columns The first column specified is called the put column and the second the get column The MINIMUM and MAXIMUM options will write the values of the put column into t
203. TA CURVE W HISTORY The W PERIOD option defines the periods TW T at which wind forces will be generated when performing a time domain simulation If they are omitted the val ues specified via amp DEFAULT will be used Finally W_MD_CORRELATION defines the relative phase of the wind velocity components with the wave drift com ponents If FACTOR is 0 then the two have phases 90 degrees apart if FACTOR is one then the two phases are the same Intermediate values of FACTOR produce relative phases between these two extremes The current is defined via the CURRENT option There are two styles for this option With the first one simply specifies a current speed VC ft sec or m sec constant with depth and the direction from which it comes CURRENT_DIRECTION deg The second method is used to define more complicated currents Here PRO_NAME i is the name of a current profile defined in the amp DATA CURVE C_PROFILE and CURRENT_DIRECTION is again the direction from which the current comes Notice that one can define several different profiles from different directions MOSES will combine each of the profiles to yield the true current velocity at any depth The tide is defined by the TIDE option where CHANGE is the change in feet or meters of the water level The water depth is set with the DEPTH option using units of feet or meters The marine growth on the structure is specified by the M GROWTH option where MG_NAME is a name
204. TBD_NODES Rev Page 332 MOSES REFERENCE MANUAL are on the starboard side When specified these nodes define the orientation of the structure on the barge They are also used to define barge structure connections if a V_LWAY connection is specified or if one performs a loadout analysis For a structure which is not symmetrical about the barge centerline the orientation scheme is different Here the ORIENT option is used This option defines three nodes The first node is where distances for positioning will be measured and is normally at the bottom of the leg that is parallel with the deck edge assuming the top of jacket faces aft The second node is along the leg from the first node and the third node is on the other side of the barge usually along the horizontal level in line with the first node Y is the distance from the centerline of the barge to the first node positive towards starboard Note that if one specifies starboard nodes and a negative Y then the jacket will be placed under the barge TOP_NODE option is used for an initial guess during upending and stability springs for other types of analysis This node should be on the face of the structure which is the highest above the water in the initial floating position and should not be attached to any slings Points used for reporting purposes can be specified with the EXTREMES option Here a point name and node name is required for each point of interest For a jacket these
205. THRUST is the max imum thrust of the unit in bforce units The thrust applied is the efficiency at the relative water particle velocity times the maximum thrust times the fraction of thrust applied The last factor and the thrust and rudder angles are defined with an option on a amp CONNECTOR command The next three values define the optional rudder R_DIST is the distance feet or meters of the rudder shaft aft of the connector point R_ALPHA ft 3 or m 3 and R GAMMA ft 2 or m 2 define the force that is exerted normal to the rudder as Fn p R GAMMA p 5 rho s vn Here Fn is the force normal to the rudder rho is the density of water p is the pressure s is speed the relative water velocity and vn is the component of the relative velocity normal to the rudder The relative water particle velocity v is given by v vr vt vt abs thrust 5 rho R ALPHA Here vr is the relative water particle velocity in the absence of the thrust and vt is the water particle velocity induced by the thrust The options R ANGLE LIMITS and T_ANGLE LIMITS are used to define limits on the angles of the rudder and the thruster and they should be between 90 and 90 If no limits are given then 90 and 90 will be used The thrust fraction can be between 1 and 1 so that by default the thruster can act in any direction For a thruster which can act in a fixed direction only one simply limits the angles with T ANGLE
206. TORS CONE_SEL POINTS PNT SEL D MIN D MAX ONE_VERTEX 1V_SEL RATIO BEG_RATIO END_RATIO STRESS BEG_RATIO END_RATIO CDR BEG_RATIO END_RATIO NAMES NAME SEL BODY BODY SEL PART PART SEL PIECE PIECE_SEL PARENT PART_SEL CATEGORY CAT_SEL ENDS END SEL 1 END_SEL 4 The three options XG_WIND YG_WIND and ZG_WIND provide the abil ity to select portions of the model for viewing MOSES checks the coordinates of each element of the picture against a window in space and scales the plot so that only those strings which are within the window will be plotted Here X_MIN and X MAX define the limits of the window in the global X direction Likewise Y_MIN and Y_MAX define the window in the global Y direction and Z_MIN and Z_MAX do so in the global Z direction One may select only a portion of the strings for viewing by using some of the remaining options listed above The CONNECTORS POINTS and ONE_VERTEX options define a selector defining the connectors points or one vertex elements strings with a single vertex which will be plotted If the selector is then all all will be shown if it is blank then none will be plotted etc The values D MIN and D MAX define the minimum and maximum diameter inches or mm of the shape used to represent the points The diameter used will be based on the diameter of the elements in the model The POINTS option can be used in conjunction with AN
207. V1 vector should be the vector defining vertical in the part system In other words if Z is the part vertical then SAV1 would be 0 0 1 Alternately if Y is the part vertical then SAV1 would be 0 1 0 In either case SAV2 simply handles the special case and can be chosen to either suit one s fancy or to conform to some existing practice The relationship of the local coordinate system is shown in the following figure Rev Page 244 MOSES REFERENCE MANUAL XII N 2 Element Options In general the available options are DIR LOC SAV1 1 SAV1 2 SAV1 3 SAV2 1 SAV2 2 SAV2 3 CA CHANG REFN REFNOD SCFi VALUES 1 VALUES n SNi CURVE COLOR NAME_COL TEXTURE NAME_TEX X_SCALE Y_SCALE GOi X Y Z LOi X Y Z RELi REL 1 REL 2 REL 5 CATEGORY CAT_NAME USE USE 1 USE 2 USE i NUSE NOT_USE 1 NOT_USE 2 NOT_USE i FLOOD YES NO STW_USE YES NO NUM_APPLIED NUMBER The options DIR LOC CA and REFN where discussed above and for a discus sion of the SCF and SN options see the sections on associating SCFs Associating SCFs with Tubular Joints and SN curves with fatigue points The options COLOR and TEXTURE define the color and texture of an element These will be used when one asks for a picture with COLOR MODELED Here NAME_COL is any color which has been previously defined See the section on Colors for a discussion on d
208. VNAME Here VNAME is the name of a view defined via amp PI_VIEW and what follows can be nothing or any valid amp PICTURE data If additional data is specified it modifies the picture defined in V NAME To make it easy to plot all of your views you can use the string function amp NAMES PIVIEW which returns all of the user defined views The form of the command is Rev Page 55 MOSES REFERENCE MANUAL amp PICTURE VIEW_DATA OPTIONS With so much going on here it is easy to get a picture which is worthless The option RESET will reset the defaults so that something appears By default the current title and subtitle are placed at the top of the picture The options TITLE and SUBTITLE can be used to alter these values TITLE M TITLE SUBTITLE S TITLE The RENDER R TYPE option defines the manner in which the picture will be rendered If you are in the GUI user interface you can specify a R TYPE of SOLID to have the picture rendered as a picture of solid objects Alternative a R TYPE of WF will render the pictures as a wire frame WF rendering is the only thing available with a WIN interface When rendering a solid picture connectors are rendered as lines so that they will appear regardless of their diameter and or distance If however you exercise the option CON_SOLID YES NO with a value of YES then they will be rendered as round elements with the proper diameter Finally a pictur
209. WEIGHT BUOYANCY DCOSINES BLENGTH LENGTH SEG LENG RATIO STRESS CDR NODES RELEASES E COORDINATES OFFSETS CFB CM KFACT LAMBDA HAS_P D and FLOODED WIDTH AREA CENTROID THICKNESS SUBELEMENT and DATA is normally an element name The first one however is different Here DATA is a set of node names and the data returned will be a list of element names all ends of which are in the set of node names If one specifies only one node then it returns all elements connected to the specified node The remainder of ACTIONs take an element name Rev Page 240 MOSES REFERENCE MANUAL and return element information based on action Most of these are obvious for ex ample the next four types of ACTION take an element name and the last computed unit check value the last computed axial load and the last computed cumulative damage ratio The next set of options are applicable to all types of elements The first of these returns the class name the next the category name and the next the element type BEAM is returned for beams PLATE for plates and OTHER for anything else STRW_USE returns YES if the stiffener weight is included NO otherwise WEIGHT and BUOYANCY returns respectively the weight and maximum buoy ancy of the element SN and SCF returns the SN curves used and the SCFs Here the order is from the first vertex to the interface between segments and finally the sec ond vertex for a beam For a generalized pla
210. XT_ADD TEXT will simply add the text TEXT to the current tab and the current location Rev Page 89 MOSES REFERENCE MANUAL WIDGET ADD WIDGET TYPE W PREFIX W_DESC W_LIST OPTIONS and the available options are INITIALIZE W_INITIAL_VALUE SUFFIX W SUFFIX L DESCRIPTION L_DESCRIPTION ACTIVATE KEY TO Here WIDGET TYPE defines the type of widget which will be created and it must be chosen from either YES NO BOX RADIO SEL ONE or SEL MULTIPLE The YES NO widget has a check box If it is checked then the prefix will be emitted if it is not checked then the prefix will not be emitted The BOX widget has an input box in which the user can put input If he enters data then it and the prefix will be omitted The RADIO widget has a list with a circle If one clicks on the circle the the text shown will be emitted with the prefix Only a single value can be selected The SEL_ONE and SEL_MULTIPLE widgets are drop down selection boxed Only a single item can be selected with a SEL_ONE widget but multiple ones can be selected with SEL_MULTIPLE W_PREFIX defines the prefix which will be emitted when the user selects the widget It can be blank W_DESC is the brief text which will be placed to the left of the selection part of the widget and W_LIST is a list of things which can be selected The text defined here is what will be emitted after the prefix The order in which widget results are emitted is the order in which they were inpu
211. Y MQW MULQ MULW MTZ MULT MULZ The basic rule here is that one first defines a depth All of the properties then defined until a new depth is encountered apply to the specified depth Here ZDIS is the positive distance from the mudline to point of interest feet or meters For points between two depths a linear interpolation is performed and for points outside the table the last closest point is used The PY QW and TZ commands define the force deformation behavior of the soil Here e PY defines the lateral behavior P is the lateral force per unit length of pile bforce llength which is required to produce a lateral deflection of Y inches or mm Rev Page 224 MOSES REFERENCE MANUAL e TZ defines the skin friction T is the skin friction per unit length of pile bforce llength which is required to produce a deflection on the pile surface of Z inches or mm e QW defines the end bearing Q is the force bforce at the end of the pile resulting from a vertical deflection of W inches or mm The commands MPY MQW and MTZ can be used to establish multipliers for the curves This is particularly important since all of the basic curves depend on pile size With these commands the ith set of values will be multiplied by MULi before the data is stored in the database As an example if your PY data is given in tonnes and meters and your current units are kilo newtons and meters you could issue MPY 1 1000 1000 and input
212. Y and KZ with respect to the point of application Here the location of the cg and the magnitude of the radii of gyration are to be interpreted in the Body System If bending moments are computed the load will be represented as a trapezoidal load acting over the entire body length By default the loads resulting from the defined weight will be distributed to all nodes in the body part of BODY_NAME or the part PART_NAME As was implied above while bodies are the basic ingredients of simulations they have virtually no properties other than the parts which belong to them and all of the physical properties of the bodies are inherited from their parts This is quite important since one can move parts between bodies create new bodies etc While it may seem to be of limited use this is not really the case Suppose that one wishes to investigate the behavior of a jacket throughout its installation First one may wish to examine the loadout where the only thing of interest is the jacket itself Here a single body of jacket is needed Next however one wants to consider the transportation Here a new body composed of the two parts jacket and the barge would be of interest Finally during launch two bodies the jacket and barge would be used The activity of bodies and parts is controlled with the command amp DESCRIBE ACTIVITY OPTION1 OPTION2 SEL 1 SEL 2 and the available options are BODY PART ACTIVE and INACTIVE H
213. Z and Z inches or mm define gaps for the roller Here a roller is assumed to consist of four physical rollers A pair of these restrain motion in each of the pipe system Y and Z directions The Y and Y values are the dimension from the end of the connector to the physical roller The same can be said for the Z dimensions To get a one sided constraint use Z equal 0 and Z equal 10000 This says that the bottom roller is at the connector node and the top roller is 10000 above the node Since the pipe is unlikely to move this much the top roller will never be active All of these elements must have a single node and the second end will be taken care of in the assembly itself There are four classes which can be used to define a connector with finite length CLASS ROD OD T LEN L Rev Page 230 MOSES REFERENCE MANUAL REFINE N OPTIONS CLASS B CAT OD FLAG LEN L DEPANCHOR DEPTH OPTIONS CLASS H CAT OD FLAG LEN L OPTIONS CLASS SL ELEM OD FLAG LEN L OPTIONS Here OD and T are the outside diameter and thickness inches or mm In reality a ROD is the accurate solution to the problem including local dynamics and the others are different levels of approximation Also a ROD can have temperature pressure and contents as specified with T PRESSURE option on the amp ENV command and an T_ PRESSURE command A SL_ELEM is an element whose force depends only upon the distance be
214. _DAY TITLE SUBTITLE ROOT or CWD The first of these returns the current menu while Rev Page 78 MOSES REFERENCE MANUAL the second returns the date and the third the twenty four hour time when the function was called TITLE and SUBTITLE return the title and subtitle respectively ROOT returns the root file being executed as a file alone and CWD returns the current working directory of the program Thus to have a fully qualified path name of a file with the same path and primary name as the root but with an extension of NEW one would use amp INFO CWD amp INFO ROOT NEW Unit information is obtained with either BFORCE LFORCE BLENGTH or llength If BFORCE is used then a string describing the unit used for big force kips l tons s tons kn or tonnes is returned The other admissible values return the names for little force pounds or newtons big length feet or meters and little length inches or mm File information is obtained with either C_FILE C_PATH C_IFILE C_IPATH C_CFILE C_CPATH FILE_ EXISTS or CHA_FILE Here C_FILE and C_PATH return the names of the last file and path used by MOSES C_IFILE and C IPATH return the last used input file meaning names ending in dat and input file path Types of C_CFILE and C_CPATH return the last used command file meaning names ending cif and the command file path FILE_EXISTS returns TRUE or FALSE based on where DATA is a file which exists CHA
215. _TYPE EXP W_DESIGN DTYPE DURATION W_SPECTRUM STYPE W_HISTORY HISTORY_NAME W_PERIOD TW 1 TW 2 TW n W_MD_CORRELATION FACTOR CURRENT VC CURRENT_DIRECTION CURRENT PRO_NAME 1 CURRENT_DIRECTION 1 PRO_LNAME 2 CURRENT_DIRECTION 2 TIDE CHANGE DEPTH WATDEP M GROWTH MG NAME T_PRESSURE TMP_NAME USE_MEAN YES NO Here ENV_NAME is the name of the environment If it is omitted then one is Rev Page 158 MOSES REFERENCE MANUAL working with the default environment and the precise action that MOSES takes will be different than if a name is specified In either case the system will be subjected to the environment specified by this command until another amp ENV command is issued If no ENV_NAME is specified all of the environmental data is set to its default value In essence the default environment is a null environment with the density of water the water depth the ramp time and the wind profile taken from those defined by an amp DEFAULT command The options are then processed which are used to alter these defaults If an ENV_NAME is specified the action is a bit more complicated In this case MOSES will check the database to see if an entry corresponding to this name exists If it does not exist then a new entry is created which corresponds to the name and the environmental data is set to the defaults If an entry does exist then the environmental data corresponding to
216. a process already exists a launch time domain upend etc then it will corrupt the existing data The string function which returns data for processes is amp PROCESS ACTION and ACTION must be either PROCESS C EVENT MAX EVENT or MIN EVENT Which return the process name the current event the maximum event and the min imum event for the current process Rev Page 327 MOSES REFERENCE MANUAL XV AUTOMATIC OFFSHORE INSTALLATION Both the strength and weakness of MOSES is its flexibility there is virtually nothing that one cannot accomplish provided they are willing to spend the time While the flexibility allows one to analyze everything the price one pays is the cost of learning If however one is willing to establish some rules and to decide on a fixed objective for a given analysis then that analysis becomes routine A system of macros has been developed for the analyses of the installation of a jacket deck or other structure In general they can be used for loadout transportation lift upend and launch Considerable flexibility has been incorporated into this system so that most cases can be easily considered This system has been designed so that several simulations that represent different phases of a structure can be performed load cases generated and one code check over all load cases can be produced With this system one defines all of the data necessary for a transportation launch upend lift or loadout ana
217. ad the string 2 3 8 2 and convert it to a number and then convert this number back into a string with eight significant figures It is this final string which will be passed to the command interpreter The function with a type of INTEGER operates in a similar manner except that here the result will be an integer The idea behind these two is that in some cases a string representing a number may become too long to convert therefore strings can be compressed with this function The first several TYPEs take a single number as input and return a single number The particular conversion which occurs with most values of TYPE is rather obvious from the name In particular SIN COS TAN produce strings with the value of the trigonometric functions of the same name and with the argument in radians The trigonometric functions which end in D assume that the argument will be in degrees The functions ATAN ATAN2 ACOS and ASIN are inverse trigonometric func tions and ATAN2 returns the angle who s tan is X Y The angles returned here are in radians The types of LN EXP SQRT and ABS produce the natural logarithm the exponential the square root and the absolute value respectively The remainder of TYPEs take more than a single number as arguments The MAX and MIN return the extremes of the arguments A type of MEAN returns the mean of a set of numbers while a a type of SORT sorts a set of numbers in ascending order INTERPOLATE take
218. afts to be considered KG_MIN and KG_MAX The last two of these are used in setting the limits which will be searched and normally should not be needed KG_MIN has a default of 0 and thus it is assumed the vessel has been coded up according to the documen tation or that if the KG is at the keel the vessel will pass the stability requirements If you get a message that LOWER BOUND FAILS then you need to use this op tion with some negative KG so that the message goes away The KG_MAX value defaults a value which yields zero GM If you have a partial run which establishes an upper bound on the allowable KG you can use it here to minimize the computational effort For each draft specified the command will find an allowable KG for the set of damages and yaw angles specified By allowable we mean that any KG greater than to within KG_TOL that found will fail one of the stability requirements for some damage and yaw angle Basically this command simply incorporates an iterative algorithm and repeatedly calls STAB_OK to find the allowable The command uses the following search technique e It first sets a lower bound KL to MIN_KG and checks to make sure that this Rev Page 368 MOSES REFERENCE MANUAL passes all cases intact and all damages for all yaws It then sets the upper bound KU to about where the GM is MIN_GM or that specified with MAX_KG An estimate of the KG KC is obtained as a KL b KU and each cases is
219. ail later Rev Page 148 MOSES REFERENCE MANUAL XII C Parameters The amp PARAMETER command is used to define parameters used in various compu tations One of these commands is included in the file moses cus so that one can alter these settings to suit their particular purposes This file should be consulted to ascertain what settings are being used This command functions in a manner similar to the amp DEFAULT command in that any option specified on some other command with the same name as that here will override the default The form of this command is amp PARAMETER OPTIONS Again as with amp DEFAULT there are two basic options SAVE REMEMBER which allow for temporarily altering the parameters and returning to the previous ones In particular the SAVE option instructs the program to save the current dimensions so that when REMEMBER is used the ones previously saved will then be used The options DRGTUB RE 1 DC 1 RE 2 DC 2 _F_CD_TUBE CDTFREQ _FM_ROD ROD_FACTOR DRGPLA DCP AMCTUB AMT define the hydrodynamic properties of generalized plates and tubular members The added mass coefficients of tubular members and generalized plates are taken to be constant The drag coefficient for tubular members is a function of the Reynold s Number in the time domain and constant in the frequency domain and are defined with the options DRGTUB and F_CD_TUBE The FM_ROD option per forms for
220. ain the appropriate commands to adequately describe the cargo such as PGEN and WEIGHT The variable NAME defines the type of structure Any name up to eight characters may be used but the names JACKET and TRIPOD are special Also for multiple structures on one barge the first three characters of the name must be unique This definition controls the type of connections which are established for transportation and the initial setup for upending For upending with a type of TRIPOD the axes system will not be moved when slings are added The variables X Y and Z define the location of the origin of the structure on the barge Here X is the location aft of the bow Y the distance off of the centerline and Z is the height above the barge deck The meaning of origin changes with how the structure is oriented Normally the two options PORT_NODES and STBD_NODES define the orientation If they orient the body the origin is the midpoint of the trailing port and starboard nodes If the ORIENT option is used the origin is the first node specified The two options PORT_NODES and STBD NODES are used to define the names of the nodes on the launch legs The first node for each variable is the node at the leading edge of the jacket and the last is the node at the trailing edge of the jacket The leading edge is defined as the end of the jacket that enters the water first The PORT_NODES are on the port side of the barge while the S
221. al SN curve Nothing prohibits one from using a normal SN curve such as X for the fatigue If one has not used an EXACT FLAG for a B CAT MOSES will tabulate the force distance properties of each line The values required during execution are then in terpolated from this table This table will consist of thirty points for each line and will start at zero horizontal force and increase up to some maximum value This Rev Page 233 MOSES REFERENCE MANUAL maximum is set to the maximum breaking tension over all segments or it can be set by the user with the inclusion of TAB_LIM where TABLE_LIMIT bforce will be the maximum tension in the table For values which exceed the range of the table extrapolation will be used An B_CAT class describes a catenary line with possibly more than one segment The depth at the anchor is defined with the DEPANCHOR option where DEPTH feet or meters is the vertical distance feet or meters from the waterplane to the anchor The length of the segment L feet or meters is defined with the LEN option The area of the cross section is computed from the OD inches or mm assuming that the section is circular The stretch in the line is computed based on the sectional area and Young s Modulus defined with the EMODULUS option The submerged weight per unit length of the catenary is computed from the area and the density and the density of water The weight per length can be changed with any combination of
222. al approach When however one looks at the forcing from a Morison s equation element it does not appear as attractive Here one is saying that the linearized coefficient depends only on the velocity for a single Fourier coefficient The alternative is a spectral linearization Here it is assumed that the seas are unidirectional so that the RAOs for a set of periods and given direction are linearized at one time The spectrum is used to compute the RMS of the relative velocity at a point and this is used to compute the drag coefficient The two approaches yield somewhat different results depending on the difference in the peaks of the response and the spectrum For SRESPONSE the spectral method is always used However the linearization here is not only over periods but also over headings In this light it can be seen that frequency domain forces are no longer for zero speed and the interpretation of wave heading is different than before That is the frequency domain forces are those used to compute the response Sometimes these are force wave amplitude results RAOs and sometimes these are Fourier coefficients depending on the use of SRESPONSE Response operators are computed by simply issuing the command RAO OPTIONS where the available options are HEADING H 1 H 2 H N PERIOD T 1 T 2 T N SPEED VR ITER MAXIT SPECTRUM ENV_NAME STEEP ST PBCHEI CHEI ROD_STEEP ST PBCHEI CHEI
223. al pressure and the density of the contents of a beam The first of the command provided is ELAT OBJECT WTPFT DPFT BOD DOD AMOD WINOD OPTIONS and the available options are TOTAL CATEGORY CAT NAME A XA B XB LENGTH LEN This command is used to define additional intrinsic load attributes for a logical beam and OBJECT is the name of the object to which they apply If OBJECT is two node names they may include wild characters but must begin with an the attributes will apply to all beams between those two nodes Remember there may be more than one beam defined between the same two nodes Also these two selectors can be used to define load attributes on a logical beam For example suppose that there is a beam between 1 and 2 and a beam between 2 and 3 If these two beams are colinear then ELAT 1 3 will apply the load to both beams If OBJECT is an attribute class name begins with a then the attributes will apply to all elements which belong to classes which match OBJECT If OBJECT begins with neither an nor a then the attribute will be applied to all members whose names match OBJECT The data defines the attributes which will be added to the element Here WTPFT is a weight per foot bforce blength DPFT is a buoyancy per foot bforce blength BOD is the diameter inches or mm which will be used for buoyancy DOD is the diameter inches or mm which will be used for viscous drag AMOD is th
224. ame specified MOSES will then set the current process to be the one specified Here by simulation results we mean the initial and current configurations the events for the process the activity status of the connections the lengths of each mooring line the load group multipliers and the load set multipliers In other words all events of a simulation the initial conditions and any of the data defined by amp COM PARTMENT amp CMP BAL amp APPLY and amp CONNECTOR commands is stored by process name By altering the process name one can actually consider sev eral different connection situations using the same model This is important since one can also perform a structural analysis for several processes with the same factored stiffness matrix Two types of data are stored by process name constants and data which depends upon event Most of the data mentioned above are constants and only one value will be associated with a process The data which is stored by event is the configura tion the forces acting on the bodies and any results of the COMPARTMENT amp CMP_BAL amp APPLY and amp CONNECTOR commands The constants are the results of the amp ENV command Thus a given process can have only a single environment When the process name is altered the new process will have all of the same settings and initial condition as the situation immediately before the name was changed but the results of the previous simulatio
225. amp DESCRIBE BODY deal with viscous damping and both of them override defaults set with amp DEFAULT The FM_MORISON option defines a factor which will be multiplied by the computed viscous force to yield an applied viscous force in the frequency domain The option SPE MULTIPLIER defines the spectral linearization multiplier When nonlinear quantities are linearized with a spectral linearization in the frequency domain the RMS of the velocity is multiplied by the factor SPEMUL and used in computing a constant drag coefficient When performing a simulation in the Static Process Menu one needs to define two vectors which are used to measure the roll and pitch angles and a point which is used to measure height This is accomplished with the two options SP ORIENT and SP_HEIGHT All of these quantities used with these options are defined in the part system of the body The height used to terminate a lift is defined by X Y and Z The pitch angle is defined as angle formed by the vector VX VY and VZ with the waterplane and the roll angle is the angle formed by the vector HX HY and HZ with the waterplane Here VX VY and VZ are the components of a vector in the part system which will be vertical when the jacket is in the installed condition If these options are omitted the values defined with the same name on an Rev Page 194 MOSES REFERENCE MANUAL amp DEFAULT command will be used The last four options provide the user ways in wh
226. amp DEFAULT or the string attribute itself With values of BODY or PART the color of a string will be determined by its body or part Each string has as attributes a ratio a cdr and stress and each point has a deflection By specifying RATIO orCDR a color will be asso ciated with each string based on the value of its ratio or cdr Likewise STRESS associates a color based on the ratio of the string s stress to its yield stress For a CRITERIA of FLOODED or SELECTED the entire picture will be plotted in a weak color while also honoring any window options For FLOODED the flooded beams will be plotted in a bright color Likewise for SELECTED strings selected by the RATIO CDR NAMES BODY PART PARENT or ENDS options are then plotted in a bright color This is an excellent way to identify where these selected strings are located in an overall view of a model Notice that using SELECTED with an ANOTATE option and any selection option will yield a picture that only annotates the selected portion yet allows you to see the complete picture The option CULL_BACK with a YES NO of YES will omit the plotting of any polygon which faces toward the back of the view Use of this option with a YES NO of NO will revert to plotting all polygons The BACK_COLOR option with a YES NO of YES will use a different color for back facing polygons Of course a YES NO of NO will paint all polygons of the same class in the same color The C
227. an specify the ones displayed by the option DISPLAY OLD 1 NEW 1 OLD 6 NEW 6 n either a BEGIN FLOOD or LIFT command where OLD defines the original type of data for a column and NEW defines the type of data which one wants to have in that column The values for OLD must be either PITCH ROLL HOOKH HOOKL TBALLAST or CBALLAST while the values of NEW must be either one of the valid values for OLD or MTENSION WPA GMT or GML The default values displayed are PITCH ROLL HOOKH HOOKL MTENSION and TBALLAST A DISPLAY option with no parameters will reset the display to the default values Most of the commands here have two common options When the user is placed in the Static Process Menu his task is to construct a static process which satisfies the installation criteria The idea behind MOSES is that the user will alter an existing process until he achieves one he likes Before this can be accomplished however he must have something to modify The definition of an initial process to MOSES is accomplished by issuing Rev Page 411 MOSES REFERENCE MANUAL BEGIN OPTIONS and the available options are PERFUL TANK_NAME 1 PER 1 TANK_NAME 2 PER 2 CHEIGHT CLOSURE TOL 1 TOL 2 DISPLAY OLD 1 NEW 1 OLD 6 NEW 6 which instructs MOSES to find an initial equilibrium position If however one has generated a static process previously the results are stored in the database so that whe
228. an the norm From a stress analysis point of view a MOSES model consists of a set of beams generalized plates and connectors Here however these structural elements can also model load generating attributes To allow for other types of loads one can define areas and masses along with con structs called hulls This gives MOSES the ability to compute hydrodynamic forces on a system via three hydrodynamic theories Morison s Equation Two Dimensional Diffraction theory or Three Dimensional Diffraction theory With MOSES connectors are not simply restraints but the way one connects different bodies One can select from catenary mooring lines tension only and compression only nonlinear springs rigid connectors such as pins and launchways and even true nonlinear rod elements These connectors are automatically applied during a stress analysis so that one can correctly perform a stress analysis of several connected bodies The MOSES modeling language is rich enough so that models suitable for other programs can be converted to MOSES models with minimal effort In fact interfaces are available for several programs and others can be quickly developed Not being content with simply analyzing a given situation MOSES provides a menu which aids in the design of mooring lines and lifting slings Commands are also available which will automatically alter connectors so that different scenarios can be assessed with minimal effort W
229. and the results of any previous simulation for this process name will be lost unless one wishes to restart the simulation This is ac complished by adding either the RESTART or RESET option to the TDOM command In either case RESTART_TIME is the time at which the previous sim ulation will be restarted When one restarts a process the events up to the restart event of the previous process will be saved and a new process will be computed for events afterwards Normally one restarts a time domain so that a different time step can be used or to extend the observation time In some cases however one wished to change the model at some time Here one uses RESET Suppose for example that at time 100 one wishes to activate a set of connectors This can be accomplished with amp INSTATE EVENT 100 amp CONNECTOR C1000 ACTIVE TDOM RESET 100 This first sets the initial state to that at event 100 activates the connectors and then resets the time domain at 100 With RESET the connector and compartment settings at the initial state will be used at the reset time During the computation of a time domain the data is stored in the database The user has some control over this data storage with the option STORE The state of Rev Page 406 MOSES REFERENCE MANUAL a configuration will be written to the database at STORE_INCREMENT increments of computed steps If the option STORE is omitted the data will be written every
230. and an assumed point of application There are three alternatives here e By default MOSES assumes that the force is equilibrated by a pressure dis tribution which has a center of pressure at the vessel center of buoyancy For certain types of vessels this assumption may not be applicable e This center can be specified using the CEN_LATERAL option Here X Y and Z are the coordinates of the center of lateral resistance in the local body system e Finally the Current Model can be used to compute the assumed application point To utilize this method one simply specifies the option U_CURRENT MOSES will then compute a current force on the vessel which equilibrates the wind force and use this to compute the application point If FLAG is INITIAL then the application point will be computed at the first condition and the same point used for all other conditions If FLAG is any other value MOSES will compute the application point for each heel angle This probably should be the default but it requires a proper drag model The W_COEFF and R_COEFF options allows one to define a heeling restoring moment which will be added to that computed from the load attributes Here WCO WC1 WC2 and WC3 or RCO RC1 RC2 and RC3 define that additional moments as MW WCO WC1 H WC2 H H WC3 H H H WIND_SPEED KD MR RCO RC1 H RC2 H H RC3 H H H where H is the roll angle in degrees and MW is in bforce blengt
231. ansportation USE_VES BARGE The data for the barge being used is more restrictive than that for the structure Again guidance on how to make your own barge model can be found here The reason for this is that the barge tilt beam data and many other things are necessary Thus the barge used must be one of the barges supplied or a new barge defined in the same format Here BARGE should be the name of the barge one wishes to use Structure Data This section of data needs to be completed for any analysis Here one is calling a Rev Page 331 MOSES REFERENCE MANUAL macro which sets up the data required for each structure to be analyzed The syntax of the macro is MODELIN NAME FILE X Y Z OPTIONS And the available options are PORT_NODES P1 P2 P3 STBD_NODES S1 S2 S3 ORIENT 01 02 03 TOP_NODE TOP_NODE EXTREMES P_NAM 1 P_NODE 1 P_NAM 2 P_NODE 2 The variable FILE defines the file which contains the model for the structure Even thou the PORT_NODES and STBD_NODES are listed as options they are necessary If you have a transportation analysis with multiple structures you should have a MODELIN for each structure Sometimes you may have a jacket and deck on the same barge or two deck sections on the same barge The MODEL_IN command can also be used to input files that describe miscellaneous cargo such as piles or boat landings In this case FILE for each cargo would cont
232. are reported while if the option DETAIL is selected one will receive results for all 36 angles around the joint The stresses are computed by superimposing stresses due to each brace load and using the formulae for circular rings in Roark s Formulas for Stress and Strain Sixth Edition Here the length of the ring is taken to be the effective length of the joint according to API RP2A For each brace two cases are added first a uniform load distributed over a segment of the chord equal the brace diameter and second a shear around the circumference of the chord The SN F_STRESS and THICK_SN options are used to define the SN curve which will be used in computing the cumulative damage ratios and are discussed in detail in the section on Defining and Associating SN curves The two options LIFE and WL_RANGE are applicable only to a TYPE of S FATIGUE Here DLIFE is the design life which must be either 20 or 40 The two parameters ELEV and ELEV define the distances below and above the water surface between which members will be considered to be waterline members ELEV should be a negative number and ELEV should be a positive one The DURATION option is applicable only to types of FATIGUE and COUNT and tells MOSES to use only the sets of duration data which match DURATION_SEL The S_BINS option is applicable only to a type of COUNT It is used to define a set of bins by stress range to accumulate the cycle data
233. are set to 1 To alter these multipliers one should Rev Page 449 MOSES REFERENCE MANUAL use the AMOD option Here MULT is the new allowable stress modifier for cases which match any of the names NAME i and it can contain wild characters The allowable stress modifiers operate on cases either load cases or combine cases They do not operate on the constituents of a combine Thus suppose one issues the following CASES AMOD 1 3 CASES COMBINE DOG CAT 5 BIRD 5 Since the combine case DOG was defined after the definition of the allowable stress modifiers a default modifier will be assigned If one wishes DOG to have a different modifier he must either issue another CASES AMOD command or define DOG before the AMOD The NOMINAL and PRELOAD options define load cases and multiplier to be considered as the nominal and pre load cases during a foundation code check They play the same role here as the SET STATE option on amp CONNECTOR play for a Process Post Processing FOUNDATION check If either of these are not defined the values defined via amp CONNECTOR will be used The TIME option is used to produce a time domain snap shot from results obtained via a frequency domain structural solution Here ENV_NAME is a seastate name which has been previously defined on an amp ENV command and NEWNAME i is the name given to the snapshot of the system at time T i All of the other options deal with converting re
234. are somewhat different from the other commands in the Structural Post Processing Menu in that one is placed in the Disposition Menu so that the results can be graphed viewed or saved To obtain these results one should issue the command BMOM_SHR SELE_DATA OPTIONS here SELE_DATA is the data that selects the beams to be processed and is either BMOM_SHR ELE 1 ELE 2 ELE n 1 OPTIONS or BMOM_SHR NODE 1 NODE 2 NODE n OPTIONS where the only option is LOAD LSEL With the first form of this command one defines a string of beams which lie in a line by specifying their names ELE i With the second the elements are defined by the elements connecting a string of nodes With this form of the command the string function amp NODE N_2NODES NODE 1 NODE n can be used here to find the intermediate nodes i e an alternative to the above is BMOM_SHR amp NODE N_2NODES NODE 1 NODE n OPTIONS Please notice that SP_BEAMS are not real elements so that for this type of element the first form of the command must be used When either of these commands is issued MOSES will find the beams connecting the nodes and store the element forces for each stress point of each beam according to the distance of the stress point from the first node of ELE 1 or NODE 1 depending upon how the command was issued The loads for up to 10 loads cases selected by LSEL will be considered After the data has been obtaine
235. are those defined with the NOMINAL and PRELOAD options of the CASES command If these are not defined then the values defined with the amp CONNECTOR command will be used The extent of the reports which will be produced is controlled by which of the report types were DETAIL STANDARD or SUMMARY was selected and the report limits With a STANDARD or SUMMARY report L i and T i are used to specify a range of unity ratios for which a given report will be printed One can specify as many ranges as he desires or he can omit all data following the option If no ranges are specified one report for all ranges of unity ratio will be printed An option of STANDARD will result in a report of the results for the maximum unity Rev Page 455 MOSES REFERENCE MANUAL ratio over all selected load cases for each member selected If one specifies an option of SUMMARY this report will be reduced to the results for only the selected element in each class which has the greatest unity ratio Finally if one specifies DETAIL as an option the original report will be expanded to include checks of all members for all selected load cases at all load points Notice that DETAIL STANDARD and SUMMARY may all be used on the same command to produce reports of all three types Also if no options are specified then a default of STANDARD is assumed Rev Page 456 MOSES REFERENCE MANUAL XXVIII E Bending Moments and Shears Bending moments and shears
236. argin The CG and radii of gyration are returned in the part system One can define mass added mass viscous damping linear damping wind and buoy ancy attributes for a load group Here the linear damping is not strictly associated with wave radiation since it is a constant Both the added mass and viscous drag are computed according to Morison s Equation Most of the load attributes defined are applied at a point previously defined by the user If the point reference is omitted then the loads will be applied at the part origin Many option apply to all load attributes described In particular all load group Rev Page 266 MOSES REFERENCE MANUAL attributes are assigned a Category of the default extra category by default If one wishes to alter this he may use the CATEGORY option where indicated Thus one can have load attributes associated with different categories within the same load group Also MOSES associates a multiplier with the load group as a whole This multiplier may be changed as can the multipliers for categories with the amp APPLY command This allows one to be able to turn off an entire load group as well as alter the force computations for some of the attributes Each of the attributes allows one to define a NUMBER defined by an option NUM APPLIED which multiplies the results of an attribute before it is applied In other words the force mass drag and added mass are first computed based on th
237. around the free edge will be named beginning with CN A word of caution here The weight and centroid of this generalized plate are computed properly but any other load is computed ignoring the hole If FSOPT is FREE_EDGE then the free edge defines a concave portion of the exterior of the element exterior Here the points FP 2 and FP 2 are actually NODES defining a face opposite the free surface i e here we actually have a shape which can be mapped into a lattice with the face between the nodes FP 1 and FP 2 opposite the free edge Also the NODES i and FP 3 FP n should be in order around the element Another word of caution since the generalized plate may not be convex it also may not be star shaped with respect to its centroid If it is not any load other than weight will be in error Figure 12 shows a generalized plate with a free edge defined with 17 points beginning with the characters CP Plate with a Free Edge Geometry Model sop gdCP 85 EP7 7g 0P 80 FIGURE 12 EP3 EP2 EPA and Figure 13 shows the corresponding nodes and subelements Finally and Figure 14 shows what happens if the number of nodes opposite the free Rev Page 255 MOSES REFERENCE MANUAL Plate with a Free Edge Basic Structural Model CN0026 FIGURE 13 EP3 EP2 EP1 edge is increased The only non intrinsic load attribute one can specify for a generalized plate is a temperature speci
238. ary shortcomings are that for stiff systems very short time steps must be used and for larger time steps considerable numerical damping is induced The New Rev Page 405 MOSES REFERENCE MANUAL mark method ameliorate these difficulties The two parameters BETA and ALPHA are the two Newmark parameters If they are omitted the defaults of BETA 25 and ALPHA 5 will be used The CONVERGE option defines the convergence parameters when a Newmark method is used Here convergence is defined as the change in location between two iterations at the same time step MOSES will take at most NUMB iterations until the norm of the change in location is less than TOL The default for NUMB is 5 and TOL is 5e 2 The Predictor Corrector method does not iterate In general a time domain simulation will begin at time equal zero with current loca tions and velocities The environment to which the system will be subjected is that specified on the last amp ENV command Events will be computed every DELTA_TIME seconds until time TOBSERV is reached where DELTA_TIME and TOBSERV are also specified on the amp ENV command At the conclusion of the time domain simulation no results are automatically re ported Instead they are stored in the database for further use To obtain reports graphs or other types of information about the simulation one should issue the PRCPOST command to enter the Process Post Processing Menu When one issues a TDOM comm
239. as not been defined then the name will be PLY During the conversion process MOSES adds something to each node and class name It will always add a to a node name and a to the class name but if instructed it will add more What is added is controlled by the options The JPREFIX option defines a set of characters JP which will be added to the beginning of each node name and the CPREFIX options defines characters which will be added to the beginning of each class name The default for JP is J and the default Rev Page 141 MOSES REFERENCE MANUAL for CP is to add nothing If one wants to add only a he should use for JP Normally the beginning character either a or the prefix and the original name are simply concatenated without blanks to form the new name If one wishes he can overlay the new name on a template This is accomplished by the CRIGHT and JRIGHT options As an example suppose that one issued the command SACS JPREFIX J JRIGHT 0000 and that one has a joint name 1 Then MOSES will first construct the template J0000 and the right justified name 1 The right justified name will then be overlaid on the template to produce the new name J0001 Care should be used with the name altering options since it is possible for two original names to be mapped into the same new name This can occur when the original names have more characters than 7 minus the number of c
240. ass definition command for each segment of the element When more than one segment is defined the first set of properties are associated with the beginning or A end of the element and the last set of properties associated with the B end of the element The lengths of the segments are defined by the LEN option with L feet or meters being the length For BEAM classes the length of every segment but one should be defined MOSES will then compute the length of this segment so that the total length of the element is correct Also one can define the segment lengths with the PERL option Here PERL is the percentage of the total length of the element which will be attributed to a given segment When one uses a shape type of CONE MOSES will automatically divide the beam into a number of prismatic segments based on the number specified with the Rev Page 218 MOSES REFERENCE MANUAL REFINE option Thus if REFINE is not specified then the beam will consist of a single tube with a diameter which gives the correct volume The thickness of the approximate cylinder is T Ti R1 R2 2 Ra where Ti is the thickness input R1 and R2 are the radii at the ends and Ra is the diameter of the approximate cylinder This is an approximation of the correct thick ness for small values of R1 R2 L Here the first dimension given is the outside diameter inches or mm at the beginning node of the element the second dimen sion is th
241. attempt to get the norm of the residual less than TOL 1 If this cannot be achieved within twenty iterations it checks a second tolerance TOL 2 If the residual is less than this value MOSES will terminate iteration If not the above step will be repeated three times The user can alter the default values of these tolerances with Rev Page 410 MOSES REFERENCE MANUAL the option CLOSURE TOL 1 TOL 2 on either a FLOOD LIFT or BEGIN command The default values for these two tolerances are 1E 5 and 1E 4 and they are compared to the sum of the squares of the normalized residuals In other words the tolerance is compared against RES RV WTJ 2 RR WTJ JL 2 RP WTJ JL 2 where RV is the residual vertical force RR is the residual roll moment RP is the residual pitch moment WTJ is the body weight and JL is the body length Notice that with the default tolerances the maximum error in the vertical force is 32 or 1 of the body weight depending upon which tolerance is used These will also result in a maximum difference in location between the centers of buoyancy and gravity of 32 or 1 of the body length Once the closure values have been set they remain in effect until they are reset by using the option on another command As each event is computed the results at that event are written to the screen Since however the screen is only eighty characters wide only six numbers will be displayed The user c
242. atus will be produced All three honor the PLOT option so that the data results can be plotted T CONVOLUTION will give the status of the time convolution for selected names and F CONVOLUTION will produce information about the Fourier Transform of the time convolution If SELE is a body name the results are for the convolution associated with that body PARAMETER simply reports some of the values set with the amp PARAMETER command SIZE produces a report of the number of various things in the model PROCESS produces the name of the current process and a list of all process names A REP_TYPE of SN provides a Rev Page 126 MOSES REFERENCE MANUAL report of the defined SN curves System Information status is obtained via a REP_TYPE of BLW FORCE CON FIGURATION BODY DRAFT B_ MATRIX A MATRIX D MATRIX or MOTION The first of these B_W contains the weights acting on each body the buoyancy the radii of gyration and perhaps the metacentric heights The last of these are reported only if they are meaningful i e the weight is within one percent of the buoyancy Detailed information about the forces on bodies can be obtained with FORCE which reports a breakdown of the forces acting on the body due to each class of environment and constraint CONFIGURATION contains the location of each body in the system and the total force acting on each body BODY will produce a report of the body properties set with the options D_DMARK FM_MORISON
243. available to create pictures The origin of the coordinate system is in the upper left hand corner of the page the x axis is parallel to the top of the page and the y axis is parallel to the left hand side of the page All dimensions given here are in points To allow for a UGX picture to be correctly mapped onto any device the command BBOX X MAX Y MAX will automatically establish a non distorting scale so that the picture will fit on the Rev Page 43 MOSES REFERENCE MANUAL current physical page Here X MAX and Y_MAX are the maximum X and Y values which are used in the picture Notice that by the choice of origin there are no negative X or Y coordinates in this system To allow one flexibility in defining a picture one can change the frame of reference at will by issuing the command TRANSFORM XO YO OPTIONS and the available options are SCALE X_SCALE Y_SCALE ANGLE ANGLE MATRIX Q11 Q21 Q12 Q22 After this command is issued a transformation from the input coordinates to the frame described above is established which works as follows o t Q S i Where the two components of t are defined by XO and YO the Q matrix is defined by either ANGLE or the components of Q and the S matrix is a diagonal matrix with components given by X SCALE and Y SCALE Normally one does not need the MATRIX option and instead defines the transformation via the ANGLE option Here ANGLE is the angle in degrees through which
244. beams will be checked using EUROCODE 3 No National Annex changes are considered and class 4 sections are treated as failures None of the codes are clear in how to treat non prismatic members with respect to buckling If one uses the EQUIVALENT option with NO then each section is checked using a slenderness based on the geometrical properties of that section the k factor and the length If however this option is used with YES then the slenderness of each section will be based on an estimate of the true buckling load of the element i e a Raleigh Quotient will be used to compute the Euler critical load in the element and then a slenderness and hence a radius of gyration will be computed for each section which when combined with the standard formulae yield the estimated Euler buckling load The RESIZE option directs MOSES to resize the selected classes so that each member will have a unity ratio less than one for the load cases considered If CONT is UP and a class has a unity ratio less than one no change in the class will be made If either the unity ratio is greater than one or CONT is UPDOWN the class will be resized The manner in which MOSES picks a new member depends upon the table selector specified on the RDES option for the class definition command The shapes selected by the selector are assigned a cost based on the two unit costs defined via the COSTS option Here STCOST is the cost of steel in monetary units per bfor
245. bined in a variety of ways using the commands UNION BLOCK _NAME 1 BLOCK_NAME 2 ANSNAM INTERSECT BLOCK _NAME 1 BLOCK NAME 2 ANSNAM DIFFERENCE BLOCK_NAME 1 BLOCK_NAME 2 ANSNAM Here BLOCK_NAME 1 and BLOCK_NAME 2 are names of blocks to be com bined and ANSNAM is the name of the resulting combination The command names describe what happens when two blocks are joined in the specified manner For in stance a UNION simply joins two blocks together Since however we want a closed surface as a result the volume inside will be removed Both the INTERSECTION and DIFFERENCE commands can be thought of a throwing away part of a block A DIFFERENCE of two blocks subtracts the part of BLOCK_NAME 2 inside BLOCK_NAME 1 from the resulting block An INTERSECTION keeps only the part of BLOCK NAME 1 inside BLOCK_NAME 2 In either case the result is a closed surface With either of these commands strange things may hap pen if BLOCK_NAME 2 does not contain any of BLOCK_NAME 1 As a general rule UNION is used to combine two blocks for creating the exterior of a body DIFFERENCE is used to make holes in a body and INTERSECTION is used Rev Page 289 MOSES REFERENCE MANUAL for making compartments from the exterior The basic design here is that one defines a set of simple blocks and combines them to create the exterior Now one uses the exterior more special blocks and DIFFER ENCES to define all of the compartments for
246. ble USE COMMENTS which is set to TRUE by default If you want to ignore the comments change the setting to FALSE Also the load macros allow for a factor to be used and the factor is set to a variable with the load case name In this way one can reproduce the weight of a structure with several load cases combined with different factors The values of the factors are defined before Rev Page 142 MOSES REFERENCE MANUAL the load data itself The option CNS_DIA instructs MOSES to include the redesign option based on a constant diameter in the class definition The final option IG_DOFS allows one to pass the information on deleted degrees freedom to the MOSES model Normally this information is not transmitted since it almost certainly will be incorrect If you use this option you must be quite careful that the model is properly restrained In general the conversion process works quite well With a STRUDL model however one must be careful STRUDL is not only a modeling language but also a command language The action commands are ignored when a model is converted and hence the conversion may not be what occurs in the original file In particular if the file ignores members then generates dead loads the MOSES model will have loads on the ignored members Another difficulty occurs with units Some versions of STRUDL will actually allow the abbreviation of T for TONNES The MOSES converter requires at least TONN
247. buoyancy of a portion of the system WIND The wind force acting on a portion of the system V_DRAG The viscous drag acting on a portion of the system This is the velocity squared term in Morison s equation the viscous roll damping or the viscous drag on a piece with the CS_CURRENT option This can be either an excitation due to wave or current or a damping in still water e WAVE This is the linear exciting force on a portion of the system e R_DRAG The radiation damping due to hydrodynamics or that due to a DRAG load attribute e SLAM This is the force due to mass transfer into the system i e it is the velocity time the mass flow rate term in the equations of motion e CORIOLIS This is the force due to Coriolis acceleration It also produces a slowly varying force e W_DRIFT This is the nonlinear part of the wave force or the slowly varying wave drift force In MOSES it does not contain an approximation of the Coriolis force This is different than most other programs e DEFORMATION This is the force on a body due to deformation of the body This only occurs when a body has generalized degrees of freedom e EXTRA This is a extra force that can be added to produce equilibrium in a given configuration This is useful to cover up modeling errors or errors in the environment APPLIED This is a true force applied to a portion of the body INERTIA This is the mass of the body times the acceleration
248. but also for making movies While commands discussed later give the user complete control over the results he obtains a single command has been provided to produce a set of standard results which suffice in many circumstances The form of this command is FP_STD X Y Z OPTIONS where the options are WEIGHT WEI RX RY RZ Rev Page 385 MOSES REFERENCE MANUAL HEIGHT WAVE_HEIGHT This command is not applicable to nonlinear spectral results If it is issued with no options then the response operators will be computed at the point X Y and Z feet or meters and these results will be reported and graphed If the HEIGHT option is used then statistics of the motions will be computed in an ISSC sea of height WAVE_HEIGHT feet or meters for periods from 4 to 18 seconds Again these results will be reported and plotted Finally if the WEIGHT option is used the response operators of the forces acting on a body of weight WEI bforce with radii of gyration RX RY and RZ feet or meters located at this point will be computed The response operators will be reported and graphed If both the WEIGHT and HEIGHT options are used then the statistics of the forces will be computed reported and graphed for the same set of conditions as the motions Rev Page 386 MOSES REFERENCE MANUAL XX A Equation Post Processing The commands discussed in this section allow one to post process the data used to compute the response
249. by a comma or by as many blanks as desired The remainder of the information on the record is of two types DATA or OPTIONS DATA must be in the order specified while OPTIONS may be in any order So that the program can distinguish between data and options all options begin with a If the last word of a record image is a then the following record is a continuation of the current record Also the option lists consist of data which may or may not be needed As many pieces of this data as required can be specified in any order and usually consist of an alphanumeric option keyword followed by the corresponding alphanumeric or numeric data Alphanumeric names may consist of up to eight characters and numeric values may contain up to twenty characters The general form of a command line is COMMAND DAT1 DAT2 OPTION1 OD11 OD12 OPTIONn ODn1 ODn2 While the options can be input in any order sometimes different results may be obtained with a different order of the options This will occur when the data used by one option is altered by another one MOSES parses options from left to right so options which change data that another option will use should be placed first When it comes to the actual task of defining a number to MOSES one can accomplish the task in many ways The flexibility is due to the fact that the command inter preter will perform a conversion of numerical data in accordance with FORTRAN co
250. cargo normally will not Another way of viewing this difference is that the constant model normally consists of a relatively large amount of data while the variable part is much smaller MOSES has two different menus for defining the constant part of the model the INMODEL menu and the MEDIT menu It was originally intended for the user to read in a model and then edit to add some additional features or fix some mistakes The situation has evolved so that now it is not necessary to first read in the model One can define it in its entirety from the MEDIT menu A small price must be paid however In the INMODEL menu it is assumed that one starts with nothing and ends with a complete model This allows MOSES to defer some associations until it completes reading the model In the MEDIT menu the assumption is that a model already exists and thus it must be kept up to date The difference in philosophy requires that in MEDIT a piece of data must have been previously defined before it can be referenced Also defining a model with INMODEL is computationally more efficient Data defined via the INMODEL menu is input from the INPUT channel a file root dat and the process is initiated with the command INMODEL OPTIONS There are two options available here OFFSET PROCESS PRC NAME Here OFFSET will cause local axial offsets to be computed at the ends of any tubular member connected to a tubular joint and PROCESS a
251. ce and RCOST is the corresponding cost of adding a single hydrostatic Rev Page 462 MOSES REFERENCE MANUAL ring The selected shapes are then tried in order of increasing cost until a workable shape is found If UP_CLASS is specified with YES NO equal YES then the new sizes will be stored in the database Otherwise the original sizes will remain If B_LOAD is specified with YES NO equal to YES a third line will be added to the code check output This line contains the loads which produced the reported stresses For a TYPE of ENVELOPE the maximum and minimum internal element loads are summarized for all selected load cases This is quite useful in understanding the nature of loadings in the beam elements of a structure If DETAIL is specified as an option the envelope of loads is reported at all load points With an option of STANDARD the maximum and minimum values are reported once for any location on the beam The S_BINS option is applicable only to a type of COUNT It is used to define a set of bins by stress range to accumulate the cycle data Here S 1 ksi or mpa marks the top of the first bin S 2 the top of the second bin etc The stresses which are accumulated include the stress concentration factor The options SLA COEFFICIENT SLA DAF SLA _CDAMP SLA_FIXITY or SLA MULTIPLIER are applicable only to a TYPE of FATIGUE They de fine the parameters used in frequency domain slamming fatigue are are
252. cified configuration This will probably not be an equilibrium configuration but it will be a good starting place for one The LINES option instructs MOSES to alter the lengths of the flexible connectors which match ACTIVE so the system will be as close to equilibrium as possible The additional data controls the operation of the algorithm so that the connectors which match LSEL i are altered to make the resulting tension compression in the connector as close as possible to that specified by TENS i For connectors which are not selected by any of the selectors the algorithm will attempt to make the tension as close as possible to the current tension As mentioned above the objective is an equilibrium configuration but this cannot always be achieved In particular anchor lines cannot be used to alter the vertical force on a body so that if one has only anchor lines then there is no guarantee that the vertical forces will balance at the conclusion of the command Likewise if one has only vertical connectors the horizontal forces may be out of balance The EVENT option sets the initial configuration to be the one at event EVE_NUM of the current process and PREVIOUS is used to replace the initial state with the previous one Here previous is the state existing before the last command which changed the state before EVENT was issued Finally the C_FORCE option computes an extra force on each body
253. colors The options N_BEDGE and S_BEDGE each define two colors The first color is for a sunken box and the last for a raised box The op tions N_SELECT and S_SELECT also define two colors the first for quantities selected and the second for those not selected Finally the options N LINES and Rev Page 26 MOSES REFERENCE MANUAL S_LINES define six colors for logical lines 1 6 These are used in both graphs and pictures For example when drawing a graph the foreground color is used for the border and the axes and line color 1 is used for the first curve line color 2 for the second curve etc Rev Page 27 MOSES REFERENCE MANUAL VI B Defining Styles Whenever MOSES writes a report or draws a picture it is done using a set of at tributes which are called a style Precisely which style is used when will be discussed later but styles are defined to MOSES by a command amp STYLE ST_NAME OPTIONS where ST_NAME is the style name and the available options are COLOR_SCHEME CS_NAME PITCH CPI POINTS CHAR HEIGHT LEDDING LED TABS TBCHAR 1 2 R_INDENT RI L INDENT LI F INDENT FI BEFORE BEF POINTS AFTER AFT POINTS JUSTIFY YES NO FONT FONT NAME FACE FACE NAME USE OLD NAME CSYM HEIGHT CSY_HEIGHT LINE WIDTH LIN WIDTH The COLOR SCHEME option here defines the color scheme which will be used when displaying this style The options PITCH POINTS LEDDIN
254. computed time step In other words a default of STORE_INCREMENT equal 1 will be used The string function amp SLAM PAR_SELE E 1 E 2 DE is useful for determining slam events This function looks at event between E 1 and E 2 in increments of DE in the current process and finds the events where any part of the parts selected by the part selector PAR_SELE are submerged If E 1 E 2 and DE are omitted then all the events in the database will be used The result returned is a set of pairs el e2 where some of the selected parts is submerged between el and e2 Rev Page 407 MOSES REFERENCE MANUAL XXII LAUNCH SIMULATION To initiate a launch analysis the following command must be issued LAUNCH OPTIONS where the available options are RESTART RESTART_TIME MAXTIME MAX TIME MAXOSCILLATIONS NUM _OSCILLATIONS TSTEP DT0 DT1 DT2 WINCH V0 QTIP QSEP NOYAW NO CAPSIZE YES NO SAVE SAVE INCREMENT STORE STOREINCREMENT OLD YES NO If RESTART is specified then this is a continuation of a previous launch analy sis and integration will be restarted at RESTART_TIME Four of the options con trol the termination of launch simulation For the options MAXTIME and MAXOSCILLATIONS MAX_TIME is the final simulation time and NUM_OSCILLATIONS is the number of oscillations allowed after separation The time step increment during the simulation is controlled with the TSTEP option where DT0 DT1 and DT2
255. con sidered i e for each intact and damaged condition each yaw angle is considered until one fails or all pass Here a and b are chosen based on the number of cases to be considered number of damage compartments 1 times the number of yaw angles The reason for doing this is that it costs much more to check a condition that passes than it does to check one that fails Thus the coefficients are chosen to minimize the total cost of the search e If all pass the KL is replaced by KC and the above process is repeated e If one fails KU is replaced by KC and the process is repeated e This continues until KU KL is less than TOL and the allowable is taken to be KL All of the above was done with no reporting After an allowable KG has been found all of the cases are again considered and a report of the stability are printed If more than one draft was specified a plot of the allowable KG vs draft will be made Since the algorithm favors failure it is much more efficient if you order the data properly In particular you should input the damage cases in order of most likely failure The same can be said of the yaw angles Rev Page 369 MOSES REFERENCE MANUAL XIX THE HYDRODYNAMIC MENU The Hydrodynamics Menu contains commands which allow the user to build alter and maintain databases of hydrodynamic properties which act on body panels The Hydrodynamic Database provides MOSES with the ingredients used in almost all ty
256. d Here you will find a shortcut to msys You can drag this to your desktop double click on it and a window will open Be warned that this window is a UNIX shell and here you will need to use instead of for path separators GUI Interface This is the standard interface for interactive MOSES sessions The interface consists of six parts The Menu should be familiar to users of the previous versions of MOSES New to this version is the Help menu which takes you to the new hyperlinked help system available in this release The Top Button Bar is where you ll find features that are used often or are only found in this interface not in the text or win interfaces e Save lets you save wire frame or GL images as you see them The current picture is added to your graphics device file e Copy will copy either text or graphics to the clipboard for use in other programs Rev Page 11 MOSES REFERENCE MANUAL e Paste will paste text from the clipboard to the current cursor position e Help brings up the new hyperlinked indexed help system The Left Button Bar These controls are specifically for the graphics windows and are documented in the Controls section The Right Side Bar The right SideBar is currently used to display information about the model in 3D graphics mode The user can use the select tool to get information about any part of the model This SideBar is customizable and scriptable from MOSES macros
257. d the user is placed in the Disposition Menu to dispose of it as he sees fit Another command which deals with moments and shears is Rev Page 457 MOSES REFERENCE MANUAL COUNT_FM_POST ELE 1 ELE 2 ELE n 1 OPTIONS or COUNT_FM_POST NODE 1 NODE 2 NODE n OPTIONS where the options are FM _BINS F 1 M 1 F n M n DURATION DURATION SEL which allows one to have the number of cycles of the bending moments and shears bro ken down into bins The beams are selected for processing as with the BMOM_SHR command The FM_BINS option defines the values for force F i bforce and mo ment M i bforce blength which are used to delimit the bins and the DURATION option selects the durations which will be used to count the cycles Rev Page 458 MOSES REFERENCE MANUAL XXVIII F Force Response Operators Response operators of the forces in beams and connectors are obtained with the command F_RAO_POST OPTIONS and the available options are CLASS CLS_SEL NODE NODE SEL 1 NODE_SEL 2 NODE_SEL 3 NODE_SEL 4 ELEMENT ELE_SEL DETAIL STANDARD L 1 T SUMMARY L 1 T 1 REPORT YES NO FILE YES NO Here one will only receive RAOs for elements which match the selectors defined with the CLASS NODE and ELEMENT options as described previously The extent of the reports which will be produced is controlled by which of the three report types DETAIL
258. d be amp PIPE The PIPE TENSION option sets the lower and upper bounds for the tensioner tension TLOWER and TUPPER bforce The DAV_LENGTH option changes the length of the davit elements selected by CONN_SEL to be NEWLEN feet or meters If DELEM se lects the first davit element then the entire assembly will be re initialized and all of the lengths will be changed as when the assembly was defined If the first ele ment is not altered then the selected lengths will be changed and a new equilibrium configuration of the pipe will be computed The two options MOVE_ROLLER and LOC_ROLLER both result in the assembly being completely re initialized The first of these options moves rollers which match CONN_SEL from their cur rent location by an amount DX DY and DZ feet or meters The second simply defines the new location of the roller to be X Y and Z feet or meters in the stinger body system The last three options A_STIFF ST_ADDITION and TOP_MOMENT operate on the pipe exactly as they do for a simple rod con nector and were discussed above Winch assembly properties can also be altered with the CONNECTOR command by using the option L_DYNAMIC ACTION MULT BOUND where CONN_SEL selects the winches to be altered Here ACTION must be either MOTOR BRAKE or the name of a CT_LENGTH curve that defines the Rev Page 324 MOSES REFERENCE MANUAL rate of change of length feet or meters sec of the line
259. d here is not effective To avoid a possible singularity in the stiffness we augment the stiffness with a fraction of the inertia i e in place of the stiffness we use Kb K FRACT 2 I where FRACT is a small parameter which we can specify This should fix the sin gularity problems because for degrees of freedom where K is not singular the inertia term will be negligible and for singular degrees of freedom of K it adds a term on the diagonal The OMEGA option is used to set FRACT and the default values of it are 2236 if there are no flexible connectors and 02236 if there are flexible connectors When using this modified Newton method there are two reasons that one may not find a configuration with tolerance the step size MOSES takes may be too small or it may be too large When one is far from equilibrium large steps are needed if one is to get close within the maximum number of iterations Here limits on step size may need to be increased so that larger steps can be taken This may not help if FRACT is what is limiting the step size You see the term we added to minimize the chance of a singular stiffness also reduces the step size For systems with large inertia and small stiffness the small extra can actually dwarf the stiffness The fix here is to decrease FRACT Caution is however in order The defaults are set for reliability Following the above advice can create the other problem too large a step For very stiff
260. d remains at the same height as the referenced node on the structure DELTA_X and DELTA_Y refer to the distance from the referenced node to the barge end of the tiedown Vertical supports that take gravity load can be defined with these I CONNECTOR types ICONNECTOR V_LWAY I CONNECTOR V_CAN CAN CLASS C1 C2 OPTION I CONNECTOR V_REST REST_CLASS R1 R2 The V_LWAY type will create a vertical connector using the node names provided on the PORT_NODES and STBD_NODES options of MODELIN This will actually create a structural element that simulates the launchway on a barge using the launchway information provided in the barge model If this launchway informa tion is not available a WBOX beam is generated that is 48 inches deep 48 inches wide with 1 inch plates for the flanges and sides and 2 inch plate for the center plate The connections created here are gap elements For spectral load cases only a linear structural solution can be performed so the gap elements have no effect on these cases For time domain load cases a nonlinear structural solution is performed which involves iteration over the support nodes to release those supports that show tension The connector type V_CAN provides a vertical support can with the properties pro vided by the can class CAN_CLASS A beam element is created from the referenced node to the barge deck with moments about the local Y and Z axes released at barge end If one specifies the option
261. d spectral value of the sea spectrum The value reported here is the sum of the values over all headings The value of SEA_TSERIES reports information about the Fourier Coefficients that will be used to generate the sea in the time domain and WIND_TSERIES reports similar information for the wind Connector Information reports are obtained via a REP_TYPE of F CONNECTOR G CONNECTOR DG CONNECTOR S ROD F ROD CL FLEX F LWAY G_LWAY SPREAD LINES PIPE TIP HOOK or ALIAS NO The scheme here is that things which begin with a F_ produce reports of forces those with a G produce geometry those with a S_ produce stresses and those with a DG produce Rev Page 127 MOSES REFERENCE MANUAL detailed geometry What follows the _ defines the type of connector for which results will be reported CONNECTOR normal connectors ROD rod connectors LWAY launch way connectors Thus F_LLWAY and F CONNECTOR produce reports of the forces which currently act in the launchways and connectors respectively while G_LWAY and G_CONNECTOR produce reports on the geometries of the same quantities The commands DG_CONNECTOR S_ROD and F_ROD for de tailed geometry honor the value SELE and the PLOT option Here SELE should select only a single connector If more are selected an error will be reported and only the first will be used The last of these reports do not follow the convention A type of SPREAD provides a report of the flexible connector types R
262. damaged for damaged stability If one does not wish to check damaged stability then this option should not be used The next set of options control the computation of wind heeling The WIND option is used to define the wind which will be considered The CEN_LATERAL U_CURRENT COEF_WIND and COEF_RARM options simply pass their data directly to the RARM command so that their data is the same as that for the option to the RARM command of the same name To include the roll owing to wave action a wave angle can be included with Rev Page 366 MOSES REFERENCE MANUAL THWAV The righting and wind arm calculations will begin at the angle AN GLE_WAVE to windward Alternatively the WIND MAC option will call the macro COEF_SET yaw draft and the RARM_MAC option will call the macro COEF_RSET yaw draft immediately before each invocation of RARM If you use this option then you must write the macro COEF_SET or COEF_RSET It takes the two arguments and set a variable An example is amp MACRO COEF SET YAW DRAFT amp SET COE_WIN W_COEF ABCD amp ENDMACRO amp M_ACT COEF SET RARM amp MACRO COEF_RSET YAW DRAFT amp SET COE_WIN R_COEF ABCD amp ENDMACRO amp M_ACT COEF_RSET RARM One can add any logical he wishes here to change the coefficients based on draft and yaw The values A B and C are numbers depending upon the situation By default righting arms are computed about the equilibrium position which is compu
263. dding are reported Conceptually no vortex shedding occurs within Region II Finally a comment is added to check beams which may be subjected to vortex shedding This comment occurs whenever the smallest critical speed is below the be ginning of Region IT and whenever a critical speed is greater than the end of Region II and less than the specified velocity The velocities which are used in the check ing criteria are WIND_VELOCITY knots and CURRENT_VELOCITY ft sec or m sec specified with the two options W_VELOCITY and C_VELOCITY In computing natural frequencies several assumptions have been made which may prove to be inapplicable to the situation In particular it is assumed that the mode of vibration is given by mode sin n pi x k L where x is measured from the left end of the beam The diameter used in computing both the Reynolds number and the critical wind speed is a length average of the wind diameter for all element attributes To obtain a summary for generalized plates one should issue PLATE SUM TYPE 1 TYPE 2 OPTIONS where TYPE i must be chosen from PROPERTIES FACE SUBELEMENT or VERTEX and the available options are those of the amp REP_SELECT command The first of these produces a report similar to PROPERTIES for beams The second one reports the faces for the generalized plate the third on reports the subelement names area and centroids for each generalized plate and the last one repor
264. de Also the static case times SO_ FACTOR is also checked One should not use an LRFD code for any other type of analysis The line ISET CODE LIM 1 33 1e6 1 1 33 0 9 1 0 0 0 9 defines the limits for the code check and joint check reports If you do not change this line then the checks will be broken down ratios between 1 and 1 33 the next for ratios between 9 and 1 and the last for ratios between 0 and 9 The elements for which code checks and or fatigue will be performed are defined by the following ISET C_CODE SELECT EXCEPT dum I SET N_CODE SELECT EXCEPT ISET N_FAT SELECT EXCEPT Here CLASS defines a variable that is used to determine the classes which will be considered for all three categories If a class is not defined here no element in this class will be considered for Beam Check Joint Check or Joint Fatigue N CODE is a variable which defines the joints which will be considered If a joint is not selected no results for Joint Check or Joint Crushing will be produced for this joint Finally N_FAT defines the joint to be considered for Joint fatigue Fatigue Data If one wants to consider fatigue then he must define several things One thing which is essential is that the duration data which will be used must be specified This is with an option of the transportation macro and is discussed below Also one may wish to alter one or more of the following ISET FAT_LIM 1 1 c6 0 25 1 0 0 25 I
265. defined In other words for frequency domain the DURATION command is followed by a series of records of the form WTIME i OPTIONS Where the available options are SEA SEA NAME THET HS PERIOD GAMMA A SEA SEA NAME THET HS PERIOD GAMMA Here WTIME i is the time days which the system will be exposed to the seastate defined by the remainder of the record Here the parameters SEA_NAME THET HS PERIOD and GAMMA are the same as those used to define a sea with the amp ENV command If a duration environment is defined with more than one spectrum then MOSES provides two ways to compute the average period The choice is governed with the T_AVERAGE option of the PARAMETER command When all of the duration has been defined one exits the sub menu with an Rev Page 169 MOSES REFERENCE MANUAL END_DURATION command Notice that one can perform both time domain fatigue and frequency domain fatigue in the same run and both types of fatigue can be computed for the same process Rev Page 170 MOSES REFERENCE MANUAL XIILH Fatigue and Cycle Counting Fatigue is a particularly complex topic as there are several components to consider e The SN curve which defines the number of cycles of a given maximum hot spot stress the material can withstand without breaking e The Stress Concentration Factors SCF which define maximum stresses in terms of the nominal ones and e The duration which defines lifetime history o
266. defined for the selec tion criteria The two commands SELECT and EXCEPT are used to define the names for selection and exception respectively The LIST_SEL command gives a list of selection criteria which have been defined and the INFO_SEL command gives the specific S NAMEs and E_NAMEs for the selection criteria SEL_NAME Both LIST_SEL and INFO_SEL accept the option HARD If this option is omitted the reports will be written to the terminal if it is included they will be written to the output file If no S NAMEs are defined for a given SEL_NAME then all of the available list will be selected in the first step and if no ENAMEs are defined then all values selected by the S NAMEs will be selected Thus a SEL_NAME which has not been defined will select everything As an example of how to assemble these commands consider amp SELECT NAME COW SELECT 1 2 3 4 M EXCEPT M1 M2 M3 NAME DOG SELECT D END_ amp SEL Here two selection criteria are defined COW and DOG The first one selects 1 2 3 4 and everything beginning with M except M1 M2 and M3 DOG simply selects everything beginning with a D In many cases one can define a selection criteria quickly by using the abbreviated command Rev Page 41 MOSES REFERENCE MANUAL amp SELECT SEL_NAME OPTIONS where the options are SELECT S_NAME 1 S NAME n EXCEPT E_NAME I ENAME n With the abbreviated form of the command the selectors de
267. des on the starboard launch leg In both cases the nodes must be ordered so that a given node is further aft than all of the nodes which precede it The jacket location on the vessel is given on the LOCJ option where XO YO ZO are distances feet or meters in the body system from the vessel origin to the point midway between JP 1 and JS 1 With the jacket located on the vessel the two launchways are defined using the LWAYP and LWAYS options Here X1 is the vessel coordinate of the beginning of the launchway feet or meters ZNA is the vessel coordinate of the launchway neutral axis feet or meters L is the length of the launchway feet or meters CLASS is the name of the class property defining the section properties of the launchway BPSEL is a selector for the nodes to be rigidly connected to the port side LWAYP launchway and BSSEL is a selector for the nodes to be rigidly connected to the starboard side LWAYS launchway Figure 19 shows the effect of the above command To connect parts elastically one employs tiedowns in one of two formats TDOWN CLASS JN SEL 2 TDOWN DX DY DZ CLASS SEL 1 SEL 2 The first format generates tiedowns at a single jacket node which are connected using beams of section CLASS to several vessel nodes Thus CLASS is the name of the Rev Page 261 MOSES REFERENCE MANUAL ZV Nodes created for gap element by program Gap Rigid Elements Links N
268. ding INT_PRE CMP SEL 1 CMP_SEL n INTPRE EMP_FRACT COMPRESSOR HOL_NAME 1 HOL_NAME n PCOMP FLCOMP PUMP HOL_NAME 1 HOL_NAME n PCOMP FLCOMP The INT_PRE option is used to define the initial internal gage pressure air pres sure in the compartment minus atmospheric pressure in the compartment ksi or mpa If INTPRE is zero then all vents in the compartment are open if INTPRE is greater than zero then all vent valves on the compartment will be closed If there are holes with a type of VENT then there will be no internal pressure otherwise the internal pressure will limit the capability of the compartment to flood EMP_FRACT specifies the percentage full of air in the compartment at the stated internal pressure If this value is left blank MOSES assumes INTPRE is the pressure acting when the compartment is 100 percent full of air The COMPRESSOR and PUMP com pressor or a pump attached to a compartment which will act during a time domain simulation Here PCOMP is the rated gage pressure ksi or mpa while FLCOMP is the rated flow rate of the pump or compressor in cubic feet per minute or cubic me ters per minute The pump or compressor are connected to holes in the compartment and here HOL NAME i are selectors for the holes which will receive the pump of compressor Now to pump contents into a compartment one has the flags CORRECT CMP_SEL 1 CMP_SEL 2 APPROXIMATE CMP SEL
269. discussed in the section on Beam Fatigue Due to Slamming If you do not want to consider slamming you should use SLA COEFFICIENT 0 Also with FATIGUE the meaning of DETAIL STANDARD and SUMMARY is a bit different DETAIL is ignored For STANDARD one receives the total CDRs for all computed points where the maximum of the CDRs lie between L i and T i Finally for SUMMARY one only receives a report of the maximum CDR for all of the computed points which lie in the specified range Rev Page 463 MOSES REFERENCE MANUAL XXVIII H Post Processing Generalized Plates Structural Post Processing results for generalized plates are obtained with the com mand PLATE_POST TYPE 1 TYPE i OPTIONS where TYPE i must be chosen from STRESS LOADS FATIGUE or COUNT and the available options are CLASS CLS_SEL NODE NODE SEL 1 NODE_SEL 2 NODE_SEL 3 NODE_SEL 4 ELEMENT ELE_SEL LOAD LSEL DURATION DURATION SEL DETAIL STANDARD L 1 T 1 L n T n SUMMARY L 1 T 1 L n T n REPORT YES NO FILE YES NO S_BINS S 1 S 2 S n CDR_VONMISES FLAG Here one will only receive results for elements which match the selectors defined with the CLASS NODE and ELEMENT options as described previously and for cases which match LSEL which is defined with the LOAD option For FATIGUE all durations which match DURATION_SEL defined via the DURATION optio
270. discussed above one must issue G_PRESSURE BODY_NAME PKT_NAME OPTIONS and the available options are HEADING H 1 H 2 H n PERIOD T 1 T 2 T n MAX DIST DIST When this command is issued MOSES will take the system in its current configu ration and compute frequency domain pressures and a total hydrodynamic database for the body BODY NAME This data will be stored by the name PKT_NAME in the database The HEADING option is used to change the default values of vessel heading for which results will be computed H i is the ith value of heading deg to be considered Here heading is measured as an angle from the X axis positive toward Y Hence for a vessel described with the origin at the bow head seas are 180 degrees The PERIOD option is used to alter the default values of encounter period and T i is the ith value of encounter period in seconds As many of these options as needed can be input so long as the number of periods does not exceed 200 The defaults for heading and period are set with options on amp DEFAULT When the G_ PRESSURE command is issued MOSES takes the vessel description and the condition defined and converts the vessel description into one describing the vessel below the waterplane The program will then compute the added inertia and damping matrices and the applied forces on the vessel These computations will be performed for the periods and headings defined by the command In conv
271. dition Rev Page 430 MOSES REFERENCE MANUAL XXV G Post Processing Static Processes When one is post processing a static process two commands are available Both of these commands have a single option EVENTS E_BEG E_END E_INC Here E BEG and E_END are the beginning and ending event numbers for which the results will be computed and E_INC is an event increment The corresponding form of the REPORT command is REPORT OPTIONS The only option available for reporting is EVENTS The first considers the event number the pitch angle the roll angle the hook height i e the elevation of the hook above the waterplane feet or meters the hookload bforce the total ballast bforce the ballast in flooding compartments bforce the bottom clearance feet or meters and the maximum tension in one element of the harness bforce The form of this command is POSITION OPTIONS and the only available option is EVENTS EVE_BEGIN EVE_END EVE_INC Alternately the results available with the STABILITY command are the event number the waterplane area ft 2 or m 2 the transverse GM feet or meters the longitudinal GM feet or meters the error in the vertical force on the jacket bforce the displacement bforce the virtual CG of the jacket i e the location of the center of the jacket weight and hookload and the jacket center of buoyancy which should have the same X and Y coordinates as the virtual CG T
272. ds of the beam the form of this option is SCFi VALUES 1 VALUES n One can input 0 1 3 4 8 or 24 values Zero values sets the SCFs to the default values If 1 values is input then it will be used as the SCF for axial and for strong and weak axis bending If three values are input then they are the axial strong axis and weak axis binding SCFs The remaining numbers 4 8 or 24 are used to override the computed SCFs when the beam is part of a tubular joint The first four values here define the SCFs at the brace at the saddle crown in plane bending and out of plane bending If only four values are given then these will be repeated for all three load classifications and for Rev Page 181 MOSES REFERENCE MANUAL the chord With eight values the second four values define the SCFs for the chord and the brace chord values will be used for all joint classifications If twenty four values are specified the first twelve are for the chord in K joints T amp Y joints and X joints and the last twelve are the corresponding values for the chord K T amp Y and X See section on Associating SCFs with Tubular Joints for more information Also the joint SCFs are used when computing beam fatigue Here the maximum of the crown and saddle SCFs and the maximum inplane and out of plane SCFs for all classifications will be used at the end when computing beam fatigue This will result in beam fatigue which will be a bit less that tha
273. ds on type and will be described later With a report option of SUMMARY only the result with the greatest value for a class is a candidate for reporting One can specify as many ranges as he desires or he can omit all data following the option If no ranges are specified one report for all ranges of value will be printed An option of STANDARD will result in a report of the results for the maximum value over all selected load cases for each member selected If one specifies an option of SUMMARY this report will be reduced to the results for only the selected element in each class which has the greatest value Notice that DETAIL STANDARD and SUMMARY may all be used on the same command to produce reports of all three types Also if no options are specified then a default of STANDARD is assumed For a type of STRESS the reporting criteria is the Von Mises stress divided by the yield stress for a type of FATIGUE the value is the CDR and for all others except LOADS it is the code unity value For a TYPE of LOADS the value used for determining the range is the absolute value of DOF in bforce or bforce blength units For this type The DOF_SEL option is used to specify the degree of freedom to be used as the reporting criteria With this option DOF is selected from the list FX FY FZ MX MY MZ SHEAR or MOMENT Only one value may be selected and the default value is Rev Page 461 MOSES REFERENCE MANUAL FX
274. duced here are based on the results of the last FR FCARGO com mand and the options are defined above Rev Page 395 MOSES REFERENCE MANUAL XX D Connector Force Post Processing If connectors were attached to the system when the frequency response was computed the frequency response of the constraint forces was also computed To obtain the frequency response of the forces which the connectors exert on the first body to which they are connected one can issue FR_CFORCE CONN_NAME Here the user is placed in the Disposition Menu with the frequency response of the connector which matches the selector CONN_NAME He can then proceed to dispose of these results To obtain statistics of the forces which the connectors Many of the commands here compute statistics of quantities and as a result have many common options In particular SEA SEA_NAME THET HS PERIOD GAMMA SPREAD EXP SP_TYPE TYPE E_PERIOD EP 1 EP 2 CSTEEP YES NO The statistical result is the statistic specified with the last PROBABILITY option on a amp DEFAULT command and If the original response data was produced with the SRESPONSE command then no additional sea data can be specified The remainder of the commands available for connector forces have a similar syntax in that the final portion of the command is identical to that of the amp ENV com mand In fact these commands not only initiate the computation of quantities in an irregular s
275. due to eddy making In MOSES we refer to this as Tanaka damping after the person who first formulated the results for eddy making damping In MOSES we use the formulation outlined in a paper by Schmidke in The Transactions of the Society of Navel Architects and Marine Engineers 1978 The default value here is defined by an option of the same name for the DEFAULT command The option ROLL_DAMPING defines a quadratic damping factor ROLL_DAMP_FACTOR in sec 2 feet or meters bforce rad 2 When defined it applies a roll moment given by roll moment ROLL_DAMP_FACTOR omega 2 and omega is the roll angular velocity CAUTION if either of these option are used in conjunction with CS_CURRENT then roll will be over damped The COLOR and TEXTURE options can be used to define the color and tex ture of the piece These will be used when one asks for a picture with COLOR MODELED Here NAME_COL is any color which has been previously defined See the section on Colors for a discussion on defining colors The NAME_TEX value for TEXTURE is the name of a file in either X data textures or X data local textures here MOSES is store in X The XSCALE and Y_SCALE are scale factors which will be applied to the texture The NAME_TEX of NONE will yield a null default texture The string function Rev Page 280 MOSES REFERENCE MANUAL amp PIECE ACTION NAME can be used to return information about a piece Here
276. dy of knowledge for automatically computing the SCFs and the associated hot spot stresses For non tubular joints the information is much less extensive Thus for tubular members one can do joint fatigue to capture the damage at the ends but one must do element beam or generalized plate fatigue to get CDRs at intermediate locations Also element fatigue must be used to get the CDRs at the ends elements which are not part of tubular joints As with stress concentration factors an SN curve must be associated with each fatigue point Again tubular joints are special in that one normally has only two choices for SN for a tubular joint and the association of SN is different for doing JOINT fatigue Rev Page 171 MOSES REFERENCE MANUAL than it is for doing BEAM fatigue The definition of the environmental history depends on whether a time domain or a frequency domain simulation is being used For frequency domain a set of RAOs are computed and they are used along with a scatter diagram of environments which act for a specified time In the time domain one time domain simulation is performed per process Load cases are defined at a reasonable number of times during this simulation and the system solved for the time traces of the stresses A Rainflow Counting technique as outlined in ASTM E 1049 Standard Practices for Cycle Counting in Fatigue Analysis is then used to compute the stress cycles and perhaps the cumulative damage These re
277. e The length here defines an element X offset from the nominal beginning of the element to the spring In reality a FOUNDATION is simply a GSPR generalized spring which has zero length and will be checked in a FOUNDATION check The SYMMETRIC option can be used with connectors which are symmetric about the element X axis If this option is used then one should only define the Y properties and MOSES will automatically take care of the rest By default YES NO is NO for GSPR and FOUNDATION connectors and YES for LMU connectors A LMU has geometry a length and two diameters and is intended to model a pin in a cone The cone and pin geometry are illustrated in Figure 7 Here all three numbers are in inches or mm It too is a GSPR with a SENSE of COMPRESSION but the deformation is not measured from the two points It is best to think of the two point for the connector as the tip bottom of the pin and the top of the cone Let us define T OD 2 OD 1 2 LEN Which is the tangent of the cone angle Now if the pin tip is above the cone top then there will be no force Now let D_v be the distance the pin tip is below the cone top and D_h be the horizontal distance that the pin tip is away from the cone center If D_v is less than LEN then we will have a horizontal deformation given by Deltah Dh T LEN Dv If we assume that the force between the sides of the cone and the pin is perpendicular to the surface then
278. e at which an extreme occurred This report will contain the values of all of the variables and a remark as to which variables have suffered an extreme The report will be written to the terminal unless the HARD option was used in which case it will be written to the output file The STATISTIC command generates a report on the statistics of the data It produces statistics for the results from BEG RNUM to END RNUM for each type of data selected The specific form of this command is STATISTIC CS 1 CS 2 OPTIONS and the available options are HARD BOTH RECORD BEG_RNUM END_RNUM VALUES CV VAL_MIN VAL_MAX MAG USE HEADING HEAD 1 HEAD 2 TYPE STYPE EXTREMES TIME DEVIATION MULTIPLIER Where the report is written depends on the use of the HARD and BOTH options Here CS 1 is the independent variable against which the statistics will be computed Normally it is event so that the remaining columns of data can be considered to Rev Page 111 MOSES REFERENCE MANUAL be time samples If this is the case MOSES will compute the following quantities Mean Variance RMS Std Deviation Skewness Kurtosis Av of 1 3 Highest Av of 1 3 Lowest Av of 1 100 Highest Av of 1 100 Lowest Av of 1 1000 Highest Av of 1 1000 Lowest Maximum Minimum Pred Max Pred Min Av of 1 3 Highest Mean Av of 1 3 Lowest Mean Av of 1 100 Highest Mean Av of 1 100 Lowest Mean Av of 1 1000 Highes
279. e blength The last three values are the total length of wire on the drum the radius of gyration of the drum plus wire when full and the radius of gyration of the drum plus the wire when the winch is full in feet or meters Rev Page 320 MOSES REFERENCE MANUAL XII G Altering Connectors So that many different situations can be analyzed MOSES provides the ability to partially alter the definition of the connector system This is performed with one command amp CONNECTOR which has several options most being applicable to a particular class of connector The form of this command is amp CONNECTOR CONN_SEL 1 1 CONN SEL n 1 OPTION 1 CONN SEL 1 2 CONN SEL n 2 OPTION 2 CONN SEL 1 m CONN_SEL n m OPTION m where the options applicable to all connectors are INACTIVE ACTIVE which makes a set of connectors inactive or active Each option operates on the list of connectors immediately preceding it The first option defines the connectors whose names are selected by the selectors CONN_SEL i to be inactive Inactive connectors can be reactivated by simply issuing the second option For connectors with types of ROD SLLELEM B_CAT and H_CAT more things can be accomplished with CONNECTOR To alter the length of the first segment of a line use the options LENGTH LEN L DELTA DLEN L_ HORIZONTAL FORCE L TENSION FORCE Here CONN_SEL i j are the selectors for lines whose leng
280. e diameter inches or mm which will be used for added mass and WINOD is the diameter inches or mm which will be used for wind With this command one defines a line buoyancy with DPFT as well as a diameter which will be used for computing buoyancy Both can be used at the same time The added mass and viscous drag computed will be based on Morison s Equation The TOTAL option denotes the fact that the values input for WT PFT and DPFT are total quantities and should be Rev Page 250 MOSES REFERENCE MANUAL divided by the length to obtain the distributed properties By default loads produced from the properties specified with ELAT are assigned to the default Extra Category This can be changed with the CATEGORY option Also the load attribute defined here will by default act over the entire length of the elements selected If one wishes he may alter this distribution with the options A B and LENGTH Here the attributes are defined over a segment of the original beam beginning XA feet or meters from the A end of the beam and extending to XB feet or meters from the B end and the length over which it is applied is LEN The defaults are that both XA and XB are zero and LEN is the length of the beam Thus for a load over the entire beam none of the option list is needed Notice that the B end of an attribute can be defined by either XB or LENGTH Both should not be used on the same command The second
281. e first two cases both the load cases and the portion of the system to be considered must be defined before the commands to compute the results are issued With vibration modes a single command suffices The remainder of this discussion is applicable only to structural analysis and applied loads Before proceeding however it is best to make a distinction between load cases and load sets A load set is either one of the intrinsic load sets that the program generates or a user defined load set Load sets are combined to form load cases It is these cases that are used to obtain the results When emitting applied loads or when performing a structural analysis it is the load cases which will be used It is beneficial to think of the solution as being performed in one of four types Frequency Domain Time snap shots of a frequency domain Events during a MOSES generated process or At events in a user defined process Rev Page 432 MOSES REFERENCE MANUAL Here the types refer to the type of loadings which will be applied to the structure MOSES is different from most programs in that the structural dynamics is included directly in the analysis via generalized degrees of freedom Thus if generalized degrees of freedom are included during an analysis the deformation inertia is automatically included when the load case is generated The result is a true load case which accurately describes the static as well as the dynamic behavior The type
282. e next time the program is executed the databases will be recreated with your data included Most customization that one needs is available with the moses cus file This process is even easier than that described above There can be many different copies of moses cus and they are read in order First the copy in the data progm directory is read next the one in data local These are basically used to set variables for the entire network After these two MOSES looks for two more first in location defined with the environment variable HOME HOME in WINDOWS and then in the current working directory The last two of these allow for customization at the user and job level If you are homeless do not know your home you can find it by typing in a command prompt echo home on WINDOWS or echo home on anything else The cus file contains MOSES commands that localize MOSES for your situation In addition there is another set of files which contain user preferences MOSES looks for moses ini or moses ini in each of the location it looks for moses cus When looking in the MOSES install directories the name without the is used and in the home and local directories the name with the is used The ini files are again simple text files that you can edit with a text editor but you can also maintain the moses ini file in your home directory directly in MOSES Simply use the Customize Rev Page 20 MOSES REFERENCE MANUAL me
283. e properties defined Then each of these quantities are multiplied by the number specified before they are applied to the body The forces which will be applied are determined by a set of multipliers defined by the WIND DRAG and AMASS options These multipliers are similar to shape coefficients in that a force is computed and then the multiplier is applied If any of these options are omitted the corresponding multiplier is set to one The forces which result from these commands are computed according to Morison s Equation Wind only acts on the area defined by AREA if its center is above the water surface Similarly water loads are only attracted when the center of area is below the water surface WAVE_PM is used to define WAVMUL which is a multiplier for wave particle velocity and acceleration If WAVMUL is greater than zero it is used to factor the wave particle velocity and acceleration before it is added to the other velocities and accelerations to compute a force The default value of WAVMUL is zero in which case wave velocity and acceleration will not be considered for the load attribute The buoyancy due to these commands is defined by the BUOY_THICK option Here BTHICK is a thickness inches or mm which when multiplied by the sub merged area will yield the buoyancy force Weight can also be defined with the other commands by using one or both of the options TOT WEIGHT or MULT WEIGHT Here WT is a weight in bforce
284. e results are expressed in the body system of the first point The form of this command is Rev Page 421 MOSES REFERENCE MANUAL REL_MOTION PNT_NAME 1 1 PNT_NAME 2 1 OPTIONS The additional option here is MAG DEFINE A 1 A n and it has the same meaning as it they did for the POINTS command There is no DATA for the report command The final command here P_MIN DISTANCE PIECE PNT_SELE OPTIONS reports the minimum distance of from the points selected by PNT_SELE to the piece PIECE Here the minimum distance is the smallest of the distance from the vertices of the piece to the points or the distance from the points to the panels perpendicular to the normal of the panel Normally one interested in finding whether of not a body hits something The reason for using a piece here instead of a body is that this computation can be quite lengthy goes like the square of the number of panels in the piece By using an arbitrary piece you can define a piece that does nothing zero permeability and bounds the body for a quick check Rev Page 422 MOSES REFERENCE MANUAL XXV C Post Processing Compartment Ballast MOSES provides three commands for the post processing of the ballast in compart ments For all of these CMP_SEL defines the compartments or holes for which results will be reported and the only option is EVENTS EVE_BEGIN EVE_END EVE_INC Here EVE_BEGIN and EVE_END are the beginning and ending ev
285. e that has been created may be written to a file for later processing by using the option SAVE_PIC The file used by this command is specified on the SECONDARY option of the amp DEVICE command Rev Page 56 MOSES REFERENCE MANUAL VIII A Types of Pictures The type of data used to construct a picture is specified with the option TYPE TYPE Here TYPE must be selected from DEFAULT STRUCTURE MESH or COM PARTMENT When this option is used the selected data appropriate to the TYPE specified will be extracted from the database converted into strings which can be plotted and stored in a different portion of the database If an amp PICTURE com mand is issued within the SURFACE MENU then blocks will be used instead of the current TYPE The TYPE DEFAULT will show all exterior compartments and any beams which have load attributes There are two levels of control over the data to be plotted First one can select parts of the model by using the options for a amp REP_SEL command issued prior to selecting a TYPE Only data selected will then be passed to the picture painter Ad ditional control is available in the picture painter itself Each string is assigned names for NAME BODY PART ENDS PARENT and PIECE The NAME of a string is the element names if it is a structural element or connector the panel name if it is a panel or the load group name if it is a load group attribute The BODY and PART are
286. e the file Once a file has been opened you can write to it with the command amp FILE WRITE TYPE STRING which writes the line STRING to the file with type of TYPE After writing a file you should close it with amp FILE CLOSE TYPE OPTIONS If you specify DELETE then the file will be deleted You cannot read and write to a file at the same time Instead it must be written closed reopened and then read As an example consider amp FILE OPEN TYPE COW NAME MILK COWS amp FILE WRITE COW Brown amp FILE WRITE COW Black and White amp FILE WRITE COW Holstein amp FILE CLOSE COW amp FILE OPEN TYPE COW NAME MILK_COWS amp LOOP amp EXIT amp F_READ COW VAR amp TYPE VAR amp ENDLOOP Rev Page 95 MOSES REFERENCE MANUAL amp FILE CLOSE COW which writes three lines to a file named MILK_COWS and then reads them Rev Page 96 MOSES REFERENCE MANUAL IX H Functions While one can accomplish almost anything with the tools that have been discussed previously one finds that if this is all he has then things get convoluted quickly MOSES has a concept called functions which can be used to organize data more effectively This concept is based on the true mathematical definition of a function Suppose that A and B are two sets and for each element of A there is associated an element of B This association of elements is called a function from A to B The set A is called the domain of the function the set B
287. e thickness inches or mm and the third dimension is the outside diameter inches or mm at the end node of the element The options which alter the load attributes are not honored for cones and one cannot use a cone section as the one with zero specified length if when defining beams composed of different shape types if the section is refined MOSES has an ability to automatically redesign a class of members so that all mem bers within that class have favorable code checks All resizing is performed on a subset of the shape table more will be said about this in the next section The subset considered during resizing is defined by a single selector and two limits define with the RDES option The program will consider only those shapes which match the selector For tubes only sections which satisfy the d t and kl r limits specified will be considered MOSES will consider all shapes selected to produce a shape which will yield a minimum cost and which satisfies the code check criteria MOSES allows one to define stiffeners for structural elements Both longitudinal and transverse stiffeners can be defined and they add both stiffness and weight to a model In addition to adding weight and stiffness stiffeners are used in checking some codes In general stiffeners are associated with a previously defined class The weight added to elements by stiffeners can be eliminated with the use of the ST_USEW option of either amp DEFAULT or
288. e used to change the first component of the CS_CURRENT values Here CS_VELOCITY_NAME is the name of a curv what has been defined with the command CS_VELOCITY with the command amp DATA Rev Page 279 MOSES REFERENCE MANUAL CURVE CS_VELOCITY If this option is used then the relative speed at each panel will be used to interpolate a drag coefficient The AMASS option defines a multiplier for an estimate of the added mass of a piece If the name AM CURVE is omitted then MOSES will estimate the added mass in these three directions as a function of submergence These estimate are based on the projection of the box containing the submerged piece onto the body coordinates for surge and sway and on the waterplane for heave Here you will get three polygons one for each coordinate direction The added mass in each direction is obtained as if this polygon is an isolated plate If AMA MULT is zero no added mass will be accumulated for this piece The slopes of the heave curve are also used to compute slam loads in heave If you wish you can define a curve with a type of AM PRESSURE with the command amp DATA CURVE AM_PRESSURE Notice that this is an excellent way to estimate added massed for isolated plates and for things which will change their submerged shape considerably but it should be turned off for pieces which are used for diffraction or strip theory hydrodynamics The option TANAKA defines a multiplier for the damping
289. ea but are also amp ENV commands Thus when one issues one of these commands with a non blank ENV_NAME he is altering the definition of this envi ronment within the database If ENV_NAME is omitted then the environment used will be totally defined by the options specified The options SEA SPREAD and SP_TYPE are used to define the sea state to which the vessel will be subjected The E_PERIOD option can be used to generate results for seas of several different periods If this option is omitted then a single period of PERIOD will be consid ered With the option periods of PERIOD EP 1 EP 2 will be produced If CSTEEP is specified with a YES NO of YES then the height of the wave will be altered so that all seastates have the same steepness as the initial one Otherwise the wave height will remain constant exert on the first body to which they are Rev Page 396 MOSES REFERENCE MANUAL connected one can issue ST_CFORCE CONN_SEL ENV_NAME OPTIONS where the available options are SEA SEA_NAME THET HS PERIOD GAMMA SP_TYPE TYPE SPREAD EXP E_PERIOD EP 1 EP 2 USE MEAN YES NO The command produces irregular sea results for the first connectors which are se lected by the selector CONN SEL This command works exactly as the ST_POINT command except here the results are for constraint forces instead of motions Addi tionally one can use the USE MEAN option to instruct MOSES to add the
290. ead if one is interested in the forces which a set of launchways exert on the jacket then he should issue the command LWFORCE OPTIONS Here the only option is EVENTS E_BEG E_END E_INC The command TIP HOOK OPTIONS provides the length of the boom line and the forces in the boom and sling elements as a function of time Again the only option is EVENTS E_BEG E_END E_INC Rev Page 428 MOSES REFERENCE MANUAL XXV F Post Processing Rods and Pipes When a system contains either rod elements or a pipe assembly commands are avail able to obtain additional information about the behavior of the rod elements in volved Here one can look at the configuration of the rod the forces in the rod and the stresses and utilization in the rod If one is interested in a pipe the value of ROD_NAME discussed below should be amp PIPE otherwise it should be the name of the rod for which information is desired At the conclusion of the command the user will be placed in the Disposition Menu to dispose of the data as he wishes All of these commands have a common option EVENTS E_BEG E_END E_INC Here E BEG and E_END are the beginning and ending event numbers for which the results will be computed and E_INC is an event increment The corresponding form of the REPORT command is REPORT REP_NAMES 1 REP_NAME 2 OPTIONS Here REP_NAMES i is a set of report names which may be selected and will depend on the command is
291. eces as required There are two basic ways to define a piece by defining each panel or using a more powerful language to generate the panels In the next section an even more powerful method of generating panels by Boolean operations on existing pieces will be discussed In addition to geometry pieces have several additional attributes all of which are defined as options on the command which defines the piece Here we will first discuss defining pieces via panels and then turn to the easy way A panel description of a piece begins with the command amp DESCRIBE PIECE PIECE_NAME OPTIONS and the available options are PERMEABILITY PERM OBSTACLE DIFTYPE TYPE CS_WIND CSW_X CSW_Y CSW_Z CS_CURRENT CSC_X CSC_Y CSC_Z CS_VELOCITY CS_VELOCITY_NAME DD_MULT DDR 1 MULT 1 DDR n MULT n AMASS AMA_MULT AM_CURVE TANAKA TANAKA FACTOR ROLL DAMPING ROLL_DAMP_FACTOR COLOR COLOR 1 FRAC 1 COLOR n FRAC n TEXTURE NAME_TEX X SCALE Y SCALE Here PIECE_NAME is the name of the piece If this is omitted a name will be automatically generated by MOSES The PERMEABILITY option can be used to alter the buoyancy of a piece Here PERM is the permeability of the piece and it should be positive for a buoyant piece and negative for a hole or a flooded compartment A value of one corresponds to 100 percent of the piece s volume The default value for permeability is 1 for an exterior piece
292. ecisely the number or type of the arguments which will be specified In this case only the macro name should be specified when defining the macro In all cases the arguments actually supplied to the macro by the user will be available in the local variable ARGV Thus one can parse the values himself using amp TOKEN and ARGV The arguments are local variables to the macro When the macro is invoked or executed the user defines the values of the variables on the command In other words to execute the above macro one would issue the command NAME ARG1 ARG2 ARGn Now suppose that for some command in the macro the user had used the value for Rev Page 73 MOSES REFERENCE MANUAL ARGI1 which was accomplished by including the line COMMAND ARG1 When the macro is executed the string ARG1 will be replaced by the string which is passed to the macro The options in macro arguments allow one to construct macros which have optional arguments Any string on the macro definition line which begins with a is considered to be a macro option The string following the option name OPTVAR i is the name of the option variable which is set to FALSE if the option is not exercised when the macro is executed and to TRUE if the option was exercised The other strings following an option ARG i are optional data The values of the optional data are all blank if they were not specified when the macro was executed Additional
293. ected are called nodes All other points are associated with some node Both points and nodes are defined in a coordinate system which belongs to the part The structural attributes of the model are defined by a set of beam and generalized plate elements which connect the nodes Since there are many elements in a structure which have common properties MOSES allows one to associate a name with a set of properties This set of properties is then associated with the applicable elements by specifying the name on the element definition command The name associated with Rev Page 137 MOSES REFERENCE MANUAL a set of properties is called the class name of the properties and it must begin with the character The concept of class is important in MOSES since it is used not only for defining properties but as a way of associating elements for post processing and redesign The remainder of the attributes of a part are used to compute the loads which act upon it In general there are four sources of loads which MOSES can consider applied inertia wind and water Notice that there is a conceptual difference between the applied loads and the others in that the other loads arise due to the interaction of the system with its environment Thus for applied loads one models the loads themselves while for the other classes he must model the physical attributes which give rise to the loads Of these sources of loads the system sea interaction loads are
294. ectors is computed with the aid of a lookup table The force properties of the line are computed as a function of distance from the anchor and stored in a table when the connector is defined or its properties changed Now this table produced quite accurate results for changes in horizontal directions but the changes due to vertical motion are approximated If one is interested in moving a body vertically he may need to recompute the table as the body moves The The option G_TABLE will force MOSES to recompute the table at the current position For ROD connectors three additional things can be altered with the amp amp CON NECTOR command with the options A_STIFF STADGX STADGY STADGZ TOP_MOMENT YES NO ST ADDITION INONUM STADGX STADGY STADGZ ZERO_BSTIF YES NO Normally the top of the rod is pin connected to the body and a default stiffness is assigned for the connection at the first node the anchor The default depends on the type of rod if it is a straight rod a large stiffness is used while for a mooring line type of rod a much smaller stiffness is defined The option A_STIFF allows one to redefine the anchor stiffness Here STADGX STADGY and STADGZ are the global X Y and Z values of the stiffness in bforce blength If one uses A STIFF 0 0 0 then the rod will have no restraint at the anchor Similarly the TOP MOMENT option changes the connection behavior at the top If it
295. ed The SAVE option instructs MOSES to save the current settings for page numbers etc and the NO_CONT option says not to write a table of contents To exit this menu one issues a command CMD_FILL_CHAREND Here CMD_FILL_CHAR is the same character specified with the CMD option i e if no CMD option were issued the menu would be exited with amp END_ amp D GENERATE The basic job of the document formatter is to take a paragraph of text and rearrange it according to a user defined style which was discussed earlier and a set of formatting commands Formatting commands are enclosed within a pair of and To associate a given style with a paragraph one should use the formatting command STYLE ST NAME The style ST NAME will be used for all paragraphs until another style name is selected Notice that if one uses a style before it is defined an error will result Notice that this is the general form of a formatting command a immediately followed by a command name followed by a token delimiter followed by data for the command and finished with a Until now paragraphs have been discussed but not defined MOSES uses a method of implicit paragraph generation In other words a paragraph is a collection of lines Rev Page 47 MOSES REFERENCE MANUAL delimited by either a line beginning with a blank or certain formatting commands This scheme works well for most text but on occasion one wishes to format the text
296. ed the user can perform a stress analysis for selected parts of the system at selected events during the simulation Here MOSES will compute all of the loads on the selected part at the event in question and convert these into nodal and member loads for use by the structural solver If the body has more than six degrees of freedom then the loads applied include the deformation inertia The restraints which correspond to the connectors will be added to the structural model The resulting structural system will be solved for the deflections at the nodes and the deflections and corresponding element internal loads will be stored in the database The post processing of MOSES is one of its strongest points Virtually all of the results produced from either a simulation a mooring command or a hydrostatic command can be viewed at the terminal graphed or written to a hardcopy de vice In addition many results based on the simulations can be computed in the post processors In the structural analysis post processor code checks joint checks deflections elements loads and stochastic fatigue can be reported These reports can be restricted to a small subset at the request of the user A flow chart of the procedure just outlined is shown in Figure 1 With the generality provided within MOSES it is virtually impossible to delimit the tasks which can be accomplished There are certain things however which can be done simply Jacket launch from o
297. ed and ACTION must be AREA NORMAL E COORDINATES PERIMETER or G CENTROID These return the obvious things with E COORDINATES returning the part coordinates of the ends and G CENTROID returning the global centroid While the above method is certainly general in that all possible surfaces can be Rev Page 281 MOSES REFERENCE MANUAL defined as accurately as desired actually defining a mesh with panels can become quite tiresome As an alternative MOSES provides a menu for generating a piece This menu begins with the command PGEN PIECE NAME OPTIONS and the available options are PERMEABILITY PERM OBSTACLE DIFTYPE TYPE CS_WIND CSW_X CSW_Y CSW Z CS_CURRENT CSC_X CSC_Y CSC_Z CS_VELOCITY CS_VELOCITY_NAME DD_MULT DDR 1 MULT 1 DDR n MULT n AMASS AMA_MULT AM_CURVE TANAKA TANAKA FACTOR ROLL DAMPING ROLL DAMP FACTOR COLOR COLOR 1 FRAC 1 COLOR n FRAC n TEXTURE NAME_TEX X SCALE Y SCALE STBD PORT BOTH TOL OFF TOL LOCATION X Y Z ROLL PITCH YAW and ends with an END_PGEN command Here most of the options are exactly the same as those for the PIECE command and the last five define how to interpret the plane data which will follow In this menu the closed surface of the piece will be defined as a sequence of polygons called planes In contrast to panels these planes do not define the surface directly but define cuts through i
298. ed are defined with the values of a column of data Here CV is the column number for which the values will be obtained and VAL_MIN and VAL MAX are two numbers VAL_MIN is less than VAL MAX BEG_REC is then the largest record number which the values of column CV is less than or equal VAL_MIN and END_REC is the greatest record number where the value of this col umn is greater than VAL_MAX If neither VALUES nor RECORD are specified all records will be considered The MAG_USE option instructs MOSES to add a second heading line based on the definition of magnitude defined with the MAG_DEFINE option The FIGURES option offers a way to change the display of the numbers It says to change the number of figures after the decimal point for columns selected by COL_SEL to be Rev Page 102 MOSES REFERENCE MANUAL RIGHT figures You can specify more that one FIGURES option Perhaps the easiest command to explain is the REPORT command which produces a formatted output file report The format of this command is REPORT DATA OPTIONS The form of the REPORT command depends upon the original command that placed the user here Often only REPORT is necessary Some original commands allow for data and options to be specified on the REPORT command These details will be discussed with the original command The next of these is VIEW CS 1 CS 2 OPTIONS and the available options are HARD BOTH HEADING HEAD RECORD BEG RNUM EN
299. ed by the options The X values for a piece must be defined in non decreasing order i e one should not have PLANE 10 10 If the section is rectangular it can be completely defined by one RECTANGULAR option Here ZBOT is the local Z coordinate of the bottom of the section feet or Rev Page 283 MOSES REFERENCE MANUAL meters ZTOP is the local Z coordinate of the top of the section feet or meters and BEAM is the width of the section full width feet or meters Normally the section is defined with 4 points but this can be changed with the values NB NS NT NB defines the number of points along the bottom NS the side and NT the top For other types of sections the CARTESIAN CIRCULAR or E CIRCULAR options are used With the CARTESIAN option Y i Z i are local Y and Z co ordinates of the ith offset point feet or meters The CIRCULAR option allows one to input data in polar coordinates Here Y and Z are local coordinates of the center of the circle feet or meters R is the radius of the circle feet or meters THETA is the angle of the first point degrees measured from the negative local Z axis positive toward Y DTH is the increment in angle degrees and NP is the number of points to be generated It is important to notice that any number of CIRCULAR and CARTESIAN options can be used to define the section The E_CIRCULAR option is the same as the CIRCULAR option except that the radius which is specif
300. ed by two The assumption here is that tiedowns are arranged as inboard outboard pairs and the tension that would have otherwise developed on one side goes into compression on the opposite side If the tiedowns can really develop tension at the barge deck use the TIETEN option In this case the multiplier for the tiedown load cases will be one The DURATION option is used to define the duration data for fatigue dur ing this process DUR _FILE is a file containing the duration data for the tow Also DUR_TIME is the total time for which the data in DUR_FILE will act and DUR_VELOCITY is the average velocity of the tow One can issue several INST_TRANSP commands For each command issued a process will be created and the results will be post processed This is an automated way in which to consider situations with different drafts trims etc and still have a single fatigue results for all of them The automated lift analysis needs almost no user involvement and is invoked with Rev Page 340 MOSES REFERENCE MANUAL the following command INST_LIFT OPTIONS And the available option is NO_ STRUCT This command will use the information provided in install dat to setup the analysis and prepare lift load cases with appropriate load factors according to API RP2A If you only want to determine the equilibrium position using the specified sling lengths and not perform the structural analysis use the NO_STRUCT option The syntax fo
301. ed class name When INFO is DIMENSION the dimensions of the specified segment of the class are returned These dimensions could be diameter for class types such as H_CAT or cross section dimensions for structural classes The value of INFO of NAME_DIM returns to name of the dimensions returned with DIMENSION e g Diameter and Thickness Finally the value of INFO of NAME_SEG returns the name of the segment type e g Rod Rev Page 213 MOSES REFERENCE MANUAL XII M 1 Structural Classes There are quite a few different section types which one may use in defining a class for a structural beam or plate CLASS SHAPE _ NAME PT PW OPTIONS CLASS TUBE ABCD OPTIONS CLASS CONE ABC PT PW OPTIONS CLASS BOX ABCD PT PW OPTIONS CLASS WBOX ABCDE PT PW OPTIONS CLASS PRI AB PT PW OPTIONS CLASS IBEAM ABCD PT PW OPTIONS CLASS GIBEAMABCDEF GH PT PW OPTIONS CLASS TEE ABCD PT PW OPTIONS CLASS CHANNEL ABCD PT PW OPTIONS CLASS ANGLE ABCD PT PW OPTIONS CLASS D ANGLE A BCD PT PW OPTIONS CLASS LLEG ABCDEFGH PT PW OPTIONS CLASS PLATE ABCD OPTIONS Here the letters A through H which follow the section type are dimensions inches or mm which describe the size of the section and are defined in Figures 5 and 6 at the end of this section The remaining two pieces of data PT and PW define the thickness and width inches or mm of any attached plate one wishes to include in the section Any attached plate is always attached at the side of t
302. ed to be the identity Once a transformation has been defined it will be used until it is redefined by another similar command The H_ PERIOD command defines the period for all quantities which follow until a new H_PERIOD command is encountered Here T is the period sec and it must have been defined by the PERIOD option on the IL TOTAL command If the period defined by an H PERIOD command is the same as one previously used the data following will be added to the previous data for the same period Thus one can define the properties of a complicated body by inputting the properties for each piece of the body and letting MOSES combine them to form the properties of the body The remaining commands are used to actually define the hydrodynamic properties Rev Page 377 MOSES REFERENCE MANUAL for the current period and they can be repeated as many times as desired until an END is encountered This marks the end of the hydrodynamic database definition for a given body The H_ AMASS and H DAMP commands define the added mass and linear damp ing matrices respectively The data is input on the command by columns of the matrix The values which MOSES needs for the added mass matrix are added mass divided by displaced mass and the length units should be feet or meters When an H_ AMASS command is input the top 3x3 is multiplied by SCMASS the two coupling 3x3 matrices are multiplied by SCMASS SCMASS and the bottom 3x3 is multiplied by SC
303. ed to include checks of all members for all selected load cases at all load points Notice that DETAIL STANDARD and SUMMARY may all be used on the same command to produce reports of all three types If no options are specified then a default of STANDARD is assumed The options REPORT and FILE operate only with a TYPE of LOADS These options are used to control whether or not the results are written to a post processing file or the standard output file The default is to write them only to the output file If FILE YES is specified then the results will be written to both places If FILE YES REPORT NO is specified then the results will only be written to the post processing file The last options are applicable only to a TYPE of FATIGUE or COUNT The sets of duration data which will be used are those which match the selector DU RATION SEL defined with the DURATION option The S_BINS option is applicable only to a type of COUNT It is used to define a set of bins by stress range to accumulate the cycle data Here S 1 ksi or mpa marks the top of the first bin 5 2 the top of the second bin etc The stresses which are accumulated include the stress concentration factor If stress used in computing the CDR depends on the value of FLAG following the CDR_VONMISES option If it is YES the Von Mises stress will be used If it is NO then the principle stresses will be used Also with FATIGUE the meaning of DETAIL
304. efining colors The NAME_TEX value for TEXTURE is the name of a file in either X data textures or X data local textures here MOSES is store in X The XSCALE and Y_SCALE are scale factors which will be applied to the texture The NAME_TEX of NONE will yield a null default texture If one wishes to offset the vertices of an element from the nodes he can employ one of the options GO or LO The GO options are used to define offsets at the ith vertex of the element Here GO1 defines offsets at the first end etc The values X Y and Z define the coordinates of the offset inches or mm For the GOi options these coordinates are defined in the part system while for the LO options they are defined in the member system If only GO or LO are specified then all vertices will have the same offsets In all cases an offset is defined as the vector from the node to the vertex of the member Releases are governed by the options REL These options are used to define releases at the ith vertex of the element Here REL1 defines releases at the first end Rev Page 245 MOSES REFERENCE MANUAL etc The values REL i define the particular releases to be applied They must come from the list FX FY FZ MX MY MZ but only as many as 5 may be specified If REL is specified then all vertices of the element will have the same releases The loads due to the properties of the element are controlled with the options
305. egrees of freedom Here one is simply looking for a reasonable subspace of the N degrees of freedom which adequately describe the deflection of the system The correct connections and the correct mass will be added when any generalized degree of freedom analysis is performed As with the other commands in the STRUCTURAL menu MODES produces no reports directly One can look at the modes and the eigenvalues in the Structural Post Processing Menu Rev Page 434 MOSES REFERENCE MANUAL XXVI B Frequency Domain Transportation Solution If one wishes to investigate the frequency domain behavior of a structure being towed on a vessel MOSES provides an easy method to obtain the solution To fully utilize this command however one should have created a model consisting of a single body with a part named jacket and connected this part to the vessel with transportation connectors In this case one does not need to worry about defining load cases selecting parts etc but he simply issues a single command TOWSOLVE OPTIONS and the options will define the type of solution desired The available options are RIGID GAP TIME SEANAME CASE 1 T 1 CASE 2 T 2 CASE i T i The RIGID option is used to select only the jacket for structural analysis and to support it on a rigid vessel If omitted all of the structural model will be used The GAP option is used to select a nonlinear structural connection between the ve
306. elector defined by the last ELEMENT option The TAG option restricts only on the class of item being reported e g if one is reporting properties of elements then only elements whose tag matches TAG_SEL will be reported or if one is reporting classes then only those tag matches TAG_SEL will be reported Occasionally one does not want the last selection criteria to remain active This is achieved with the SELALL option which resets all previous selection criteria and selects everything in the database Rev Page 121 MOSES REFERENCE MANUAL XI A Obtaining the Names of Quantities Often it is useful to be able to obtain a list of names which are available in the database In MOSES one can obtain such a list by issuing the command amp NAMES NAME OPTIONS where the available options are the options of the KREP SELECT command and HARD or using the string function amp NAMES NAME SELECTOR The value of NAME defines the category for which names will be listed and it must Rev Page 122 MOSES REFERENCE MANUAL be one of BODIES CATEGORIES CLASSES COMPARTMENTS CONNECTORS DMARKS DURATIONS ELEMENTS ENVIRONMENTS GRIDS HOLES INTEREST IN_BODIES IN_ELEMENTS IN_PARTS I SPECTRA LOADGROUPS LSETS MACROS MAPS M_GROWTH NAMES NODES PANELS PARTS PIECES PI_ VIEWS POINTS PROCESSES PROFILES SELECTORS SHAPES SN SOILS TVARS VARIABLES S_CASES R_CASES NG_S_CASES Rev Active
307. em The origin of this system is the midpoint of the vector connecting the first two sling nodes The local Y axis is in the direction of the first node toward the second the local Z axis is from the second node to the third and the local X axis is given by the right hand rule To perform a lift analysis you will need a connector type of LIFT_SLING I CONNECTOR LIFT_SLING L1 LEN1 L2 LEN2 L3 LEN3 L4 LEN4 A sling will be constructed from each of the nodes specified to the common hook Rev Page 334 MOSES REFERENCE MANUAL point Tiedown connectors for a transportation analysis can be defined using the following I_CONNECTOR types I_CONNECTOR 4_TIE TD_CLASS TIE1 TIE2 ICONNECTOR V_BRACE TD_CLASS TIE1 TIE2 I CONNECTOR P BRACE TD CLASS TIE1 TIE2 I CONNECTOR H BRACE TD CLASS TIE1 TIE2 I CONNECTOR PCONNECT TIEDOWN DATA I CONNECTOR XY DELTA TD_CLASS DELTA_X DELTA Y TIE1 TIEZ 33 When the 4_TIE connector type is specified 4 tiedowns with the properties of TD_CLASS will be generated at each node specified The TD CLASS must be defined before it is referenced on the ICONNECTOR 4_TIE command The tiedowns will be arranged in star pattern with each tiedown 45 degrees from a lon gitudinal axis that passes through the tiedown node and is parallel to the barge centerline The longitudinal and transverse distance from the referenced structure node to the deck end of the tiedown is the same as the vertical distance o
308. ent environment is defined with amp ENV WIND 100 90 CURRENT 3 0 45 SEA ISSC 135 10 7 The results of this comand will be a table with four columns labeled Heading Max Wind Max Current and Max Wave The column labeled Max Wind is the maximum wind speed at 90 degrees acting in concert with a current of 3 at 45 degrees and a sea of significant height of 10 at 135 These are reported as a function of vessel heading Rev Page 351 MOSES REFERENCE MANUAL XVII THE REPOSITION MENU To investigate different ways to reposition bodies using connectors MOSES provides the Reposition Menu This menu is entered using the command REPO and must be exited using an END REPO command At this menu level several commands are available to specify prefer ences for performing the repositioning display the selected values and perform the repositioning These commands are DO_REPO WEIGHT CONN WT SC 1 SC 2 SC n BOUNDS CONN UB LB 8C 1 8C 2 C n SELECT_CONN 8C 1 SC 2 C n DESIRE_VALUE DES SC 1 C 2 SC n TUG_DCHANGE WFMUL WDMUL TS 1 TS 2 TS n SHOW_SYS The DO_REPO command instructs MOSES to find new line lengths and tug forces so that the system will be in equilibrium at the current position subject to the controls specified with the other commands This problem will not always have a solution as specified and it is up to the user to check that he finds the results suitab
309. ent loads e CODE_CHECK will produce a report of the elements checked against the code specified by the CODE option e H_ COLLAPSE will produce an API hydrostatic collapse check e ENVELOPE will produce an envelope of beam stresses or loads e STRESS will produce the stresses at stress points for each longitudinal location on the beam e COUNT will produce the number of cycles of the stresses in bins and e NT FATIGUE or FATIGUE will produce fatigue results Here NT_ FATIGUE will consider only sections of beams which are not part of tubular joints and FATIGUE will consider all beams With the exception of a TYPE of COUNT the extent of the reports which will be produced is controlled by which of the three report types were selected and the report limits With a STANDARD or SUMMARY report L i and T i are used to specify a range of values for which a given report will be printed Remember the beams for which results are computed is already restricted by the CLASS NODE and ELEMENT selectors and the load cases by the LOAD selectors Thus here we are talking about restricting what is reported out of what is computed The easiest of these to describe is DETAIL Here all the results are printed With STANDARD only the result with the greatest value is a candidate for reporting and it will only be reported if the value is between the report limits specified for that report What is meant by value depen
310. ent numbers for which the results will be computed and EVE_INC is an event increment The corresponding form of the REPORT command is REPORT OPTIONS where the only option is EV ENTS The TANK_BAL command simply reports the percentage full sounding ullage amount of ballast pressure head maximum differential head across the compartment wall and flow rate in the selected compartments TANK BAL CMP_ SEL OPTIONS The HOLE_FLOODING reports the pressure external head internal head differ ential head and flow rate for each hole HOLE_FLOODING CMP_SEL OPTIONS The TANK_FLD command is something of a combination of TANK_FLD CMP_SEL OPTIONS the other two commands It reports both capacity information flow information and if there is only a single active hole head information It also estimates a time required to perform the flooding and thus is useful when one has a static process but wishes to estimate the time required Rev Page 423 MOSES REFERENCE MANUAL XXV D Post Processing Applied Forces There are two commands which allow one to examine the forces applied to the system These forces are computed in the post processor so the time step of the computation is that at which the forces are computed The options common to both commands are EVENTS EVE_BEGIN EVE_END EVE_INC MAG_DEFINE A 1 A n FORCE FORCE_NAME 1 FORCE_NAME n The EVENTS option selects the events which will be co
311. enter the Structural Post Processing Menu This is accomplished by issuing the command STRPOST At this point the commands discussed in this section become available When one is finished with Structural Post Processing he should issue END_STRPOST to return to the main menu For any of the commands in this menu which produce reports the selection criteria discussed for the KREP SELECT command is operative In fact each of these report commands has as a subset of options the options of the amp REP_SELECT command Thus it is a simple matter to obtain reports for a single element or for any subset of elements In particular for commands which deal with elements beams generalized plates connectors or restraints only the following will be selected e The class name of the element must match the class selector defined by the last CLASS option e The nodes which form the vertices of the element all must match a node selector defined by the last NODE option and e The element name must match the element selector defined by the last ELEMENT option A similar scheme is used for joints and will be discussed later In all cases only cases which match the last LOAD selector defined will be considered A common mistake is to define a selector to limit one report and forget that it will also limit all subsequent reports until the selector is redefined In most cases the answer to the question of why did I not get is answe
312. eparate coordinate system associ ated with it Since MOSES can consider bodies which move in space we also employ a global coordinate system The global system is fixed in time and is used to locate positions in space Its origin is arbitrarily located on the water surface and its Z axis points upward The part coordinate system is used to define the geometry of a part In other words e The location of the points e The load attributes applied to the part and e The resulting structural displacements of the elements Thus the part system is used in defining the model and in the definition of the structural deflections The body system is used for simulations In most cases the body system will be identical to the part system of the part which has the same name as the body The axes of the body system are parallel to the global system when roll yaw and pitch are zero The orientation of the body system defines the orientation of the body by three Euler angles yaw followed by a pitch followed by a roll An illustration of the global and part coordinate system along with a jacket and vessel body system during a launch is shown in Figure 4 To distinguish between different bodies and parts a block concept is used i e all of the data for a part and body is defined contiguously in the input One defines the different parts and bodies by amp DESCRIBE commands All of the data which follows one of these commands will be associated with
313. eports the user defined load sets applied to beams A type of SECTION is used for reporting beam section properties A type of CLEARANCE produces a report giving the distance from the extremities of a member to the extremities of all of the other members not connected to the given one A type of SCF gives the stress concentration factors for the selected beams along the beam In addition to the SCF the type of connection the thickness the SN curve also reported A type of TUBE produces a report of the diameter thickness yield stress and length of each segment of the selected tubular members A type of ENDS reports the part coordinates of the ends of the selected beams Finally a type of VORTEX is used to obtain information about vortex shedding on the selected beams It will produce two reports one for beams out of the water where wind provides the excitation and one for beams in the water where current provides the excitation Either of these reports can be limited to only those beams which should be checked by using the BRIEF option Here the first three natu Rev Page 131 MOSES REFERENCE MANUAL ral frequencies of vibration of the beam both inplane and out of plane are computed These frequencies are used to compute the critical velocities velocities at which vor tices will be shed at the same frequency as the natural frequency of the beam In addition the wind speeds that mark the beginning and end of Region II of vortex she
314. er is stated using SPGC The last option defines the holes which pierce the surface of the compartment HOLES HOLE 1 HOLE n Holes are defined with the command amp DESCRIBE HOLE HOL_NAME HOL_TYPE OPTIONS Here HOL_NAME is the name of the hole and HOL_TYPE is its type which must be either F VALVE WT_VENT M VENT VENT or V_VALVE The type is used to control when water may flow into the compartment so the distinction between vent and flood valves is strictly for operational purposes i e both allow water into the compartment the same way when open Of the vents the WT_VENT is peculiar Rev Page 294 MOSES REFERENCE MANUAL It never allows water to flow into the compartment and is used strictly for reporting A M_VENT is a magic vent in that it never goes under the water The difference between a VENT and a V VALVE is that a vent cannot be closed and hence a compartment with a vent can not have an internal pressure VENTs and WT_VENTs are used to define traditional down flooding points The difference between the two is that the non weather tight points can get water inside due to splash etc These points are used primarily when assessing stability but one can obtain amp STATUSes of them Down flooding points vents are ignored when a compartment is flooded Holes have a location an area a normal and a friction factor and these are defined with the options POINT POINT NAME AREA AREA N
315. er of flotation and the metacentric heights The second contains the condition the wetted surface the load to change draft and the moment to trim If no data is specified on the REPORT command in the Disposition Menu then both reports will be printed The form of the command for curves of form is CFORM DRAFT ROLL TRIM OPTIONS and the available options are DRAFT INC NUM ROLL INC NUM PITCH INC NUM WAVE WLENGTH STEEP CREST Here the initial draft roll and trim are specified by DRAFT ROLL and TRIM and the number of conditions and the increment are defined by one of the first three options If the DRAFT option was specified then draft will be incremented by INC feet or meters NUM times Similar results are obtained with either ROLL or PITCH except that here INC is in degrees and roll and or pitch will be incremented Finally the WAVE option controls the static wave li as discussed previously Rev Page 356 MOSES REFERENCE MANUAL XVIII C Finding Floating Equilibrium The method for finding an equilibrium position is fundamental to the manner in which MOSES considers hydrostatics Instead of using a specified draft and trim to determine the weight ballast and cargo for a vessel system MOSES allows the user to input these weights and ballasts directly via internal commands discussed earlier After the system has been defined the question remains as to where the vessel will float This que
316. er than MIN_SCF or greater than MAX_SCF will be replaced with the limit If stiffeners are associated with either of the two chord classes then they will be used in computing the crushing of the joint in computing the code check for the joint and in computing the stress concentration factor for the joint The number of stiffeners will be the sum of the number for both chord segments For situations where two classes define the chord with different stiffener attributes then the prop erties of the last one encountered will be used Here the stiffeners are smeared over the effective length or true brace footprint of the joint The SCFs computed by whichever method are reduced according to Lloyd s Register of Shipping Recom Rev Page 178 MOSES REFERENCE MANUAL mended Parametric Stress Concentration Factors for Ring_Stiffened Tubular Joints Rev Page 179 MOSES REFERENCE MANUAL XII H 4 Associating SCFs with Element Points In computing fatigue in elements the element SCFs are used For elements there are four ways to define them on a amp DEFAULT command on the class definition command on the element definition command or in some cases from the tubular joint SCFs In any case failure to include a definition results in the last definition being used i e e For intermediate fatigue points between tubular sections an SCF will be com puted based on the algorithm specified on the IN_SCF option on the amp PA
317. ere one first uses either BODY or PART to specify what type of entity will be changed Next he specifies either ACTIVE or INACTIVE to specify the activity status Any body or part selected after the second option will have its activity status set according to the option As many options as one wants can be used on a single command When a body is set inactive its parts are not set inactive There is no reason for this since only active bodies will be considered and this would make it more difficult to reactivate a body In addition to the above the entire system can be redefined with the command amp DESCRIBE SYSTEM BODY BODY _NAME 1 PART 1 PART i BODY BODY_NAME 2 PART 1 PART i When this command is issued all bodies and parts are set to inactive Then the bodies named BODY_NAME 1 are either activated or defined and the parts specified after the BODY NAME i and before the next BODY are activated and Rev Page 201 MOSES REFERENCE MANUAL associated with the body BODY_NAME i Rev Page 202 MOSES REFERENCE MANUAL XILL Geometry The geometry of the model is defined by a set of points in the part system The names of all points begin with a The location of the points can be specified with respect to either the part origin or another point At least one point in the model however must be specified with respect to the part system Every point belongs to a part and to allow for s
318. ered With the option periods of PERIOD EP 1 EP 2 will be produced If CSTEEP is specified with a YES NO of YES then the height of the wave will be altered so that all seastates have the same steepness as the initial one Otherwise the wave height will remain constant Rev Page 401 MOSES REFERENCE MANUAL XXI FINDING EQUILIBRIUM To find the equilibrium configuration of the system due to the current loading ballast damage and constraints etc one should issue amp EQUI OPTIONS and the available options are DEFAULTS ITER MAX MAX ITER TOLERANCE TOL IGNORE B_NAME DOF 1 DOF 2 OMEGA FRACT MOVE MAX MAX TRANSLATE MAX ANGLE When this command is issued the program will iterate to find an equilibrium position until either the residual is less than the default convergence tolerances or until the default maximum iterations are taken The options define parameters which are used to control the algorithm The parameters are remembered from one invocation of the command to the next To change a value use the option which alters it To get back to the default settings use the DEFAULTS option Upon completion of this command the initial condition is reset to be the new equilibrium condition If this is not desirable use the amp INSTATE PREVIOUS command to return to the initial condition To alter the default tolerances or the maximum number of iterations one should use the options ITER MAX a
319. ers can be used in the picture painter to alter the color mapping so that one can pictorially represent something other than the configuration Only joints beams and plates have a cdr or cumulative damage ratio Connectors have a ratio which corresponds to their current unity ratio Compartments have a ratio which is their current percent full The numbers associated with the structural elements are assigned in the Structural Post Processing Menu Until one enters this menu all numbers will be zero For nodes the ratio is the maximum punching shear unity ratio for all load cases the deflection is the last deflection reported with a JOINT DISPLACEMENT command and the stress is zero For beams the ratio is the maximum code check ratio for all load cases the stress is the largest Von Mises stress divided by is yield that is reported by a BEAM command and the deflection is zero These numbers are stored in the database so that at any time after the Structural Post Processing one can issue amp PICTURE and see the results Rev Page 58 MOSES REFERENCE MANUAL VIII B Picture Views As mentioned above the data for an amp PICTURE command is data describing the view This data is VIEW_DATA VIEW VAX VAY VAZ Here the values of VIEW and VA i define the projection which will be plotted There are seven valid values for VIEW TOP BOTTOM STARBOARD PORT BOW STERN and ISO The first six of these produce projections in the global
320. erting the model the two options M_DISTANCE and or M_WLFRACTION of the amp PARAMETER command are used to refine the computation Use of these op tions allows one to define a quite crude mesh and have MOSES automatically refine it to achieve any desired degree of precision Also the option MAX_DIST pro vides a way to get approximate solutions to large diffraction problems with reduced computational effort This option defines a maximum distance feet or meters for panel interaction Any two panels which have a distance between them greater than DIST will have a zero for their coupling terms in the diffraction matrix For very long slender bodies this option can be used quite effectively to save computer effort Rev Page 373 MOSES REFERENCE MANUAL For a body 4000 ft long with 6000 diffraction panels answers within 10 of the exact ones can be obtained in 66 of the time Once one has a pressure database it can be examined in the Disposition Menu In particular the command V_MATRICES BODY NAME will gather the added mass and damping matrices for the pressure packet currently associated with body BODY_NAME and place the user in the Disposition Menu Alternately the command V_EXFORCES BODY_NAME will do the same thing with the wave excitation forces For both of these commands the results are about the origin As mentioned earlier it is possible to define the hydrodynamic pressure distribution and or the total hydrodynamic
321. es the body part with respect to the body system To orient the part system suppose that the part and the reference systems are aligned and that the part system is rotated an amount NRZ about the reference Z axis Next rotate the part system about the current part Y axis and amount NRY and finally rotate an amount NRX about the new part X axis The string function amp PART ACTION PART_NAME OPTION returns the current data about a part Here PART_NAME is the name of the part for which data is desired and ACTION must be either CURRENT MAX CB MAX BUOYANCY CG WEIGHT RADII or E NODES The action CUR RENT returns the name of current part while the WEIGHT CG and RADII actions simply return the current weight CG and radii of gyration of the part These are the dry values of the part without any compartment contents The MAX BUOYANCY and MAX_CB return the non compartment buoyancy its center when the part is totally submerged If no option is specified then the results are in the part system Alternately one can specify BODY or GLOBAL to return the values in another system The action E NODES returns the names of the extreme nodes for the part After a set of bodies have been defined it is necessary to place them in space as the point of departure for a simulation This is accomplished via the command amp INSTATE OPTIONS where the options are LOCATE NAME X Y Z RX RY RZ MOVE NAME DX DY DZ DRX D
322. escriptions and questions One issues com mands to MOSES to accomplish tasks issues descriptions to define a system for analysis and asks questions to find out the results of the commands The database consists of the union of all descriptions issued and the results of all commands When one asks a question the answers are obtained by querying the database While MOSES can be utilized in both batch and interactive environments it is per haps best to view all commands as being issued from a terminal Since the results of all previous commands are available in the database it is no more difficult to produce a set of results by making several small runs as it is to make one big one The majority of the system which will be analyzed is defined to MOSES by a set of descriptions contained in the INPUT file These descriptions are commands in what is called MOSES Modeling Language and are processed by the program whenever instructed by the user When the Modeling Language is processed the description is converted into an internal model within the job database so that the model has to be processed only when it has been altered After a model database has been generated the user is free to perform simulations Before proceeding however one may wish to alter the definition of the system from that defined by the modeling language The type of things which can be altered are the weight of the bodies the connections among the bodies o
323. ese buttons represent either another drop down set of buttons or a command The entire system is user programmable with a command and STRING macros The basic command here is amp MENU ACTION NAME TITLE 1 RETURN 1 Here ACTION is the action which must be either CREATE DELETE or ADD NAME is the name of the menu RETURN is the return string Of course the last two items are required for each line in the menu The NAMEs associated with menus are up to the user except the one T BAR which is the name of the Tool Bar itself Normally the only action one needs is CREATE but with T BAR one can ADD a menu to it or DELETE one he has added The TITLE i are the strings which are printed on the buttons For the Tool Bar itself these are best left short as the real estate is limited Remember here if you have spaces in any thing you need to enclose them in either or pairs Now RETURN i can be either the name of another menu the name of a amp STRING macro or a true return string Let us look at an example Suppose that one wanted to add a button to the Tool Bar to set the dimensions to meters This can be accomplished with amp MENU ADD T BAR DIM2M amp DIMEN D METERS TONNES Now when you push this button the dimensions will be changed to meters and tonnes Suppose however that you sometimes wish to use kilo newtons To allow for this you must interact with the user and a amp STRING macro is re
324. ese types of elements cannot be mixed MOSES assumes that pipe is laid in the negative X global direction so that all of the connectors must lie along the global X axis when the assembly is defined The pipe itself is given a name amp PIPE and the assembly has a name of amp PIPE ASSEMBLY The use of the PIPE_TENSION option depends on the type of connection For an assembly of ROLLER elements TLOWER defines the smallest allowable tensioner value bforce and TUPPER the largest allowable tension bforce With a ROLLER assembly the last roller defined is the tensioner With a DAVIT assembly the value of TLOWER bforce is the nominal initial tension in the pipe where it connects to the first davit and TUPPER is not used A special situation occurs when one has only a single roller In this case MOSES will treat the pipe assembly as a vertical pipe with a tensioner so that one can simulate a riser Here the bottom of the rod is placed directly below the roller connection so that the pipe will have a tension of TUPPER When initializing a pipe assembly other than a vertical one it is assumed that the pipe behaves as a catenary Thus the use of the word nominal as regards the initial tension MOSES uses this assumption as initial estimates for the configuration of the assembly and then iterates a solution to the nonlinear problem A stinger is initially tensioned so that either the slope of the pipe matches the slope of the last two rollers
325. esults have been computed the user is placed in the Disposition Menu so that he can dispose of the results generated The ALLOW option is used to define the allowable deflection and stress in the vessel Here ALLOW_STRESS is the allowable stress ksi or mpa and ALLOW_DEFLECT is the allowable deflection inches or mm Rev Page 358 MOSES REFERENCE MANUAL XVIII E Righting and Heeling Arm Curves To compute righting and heeling arm results the user should issue a command of the form RARM INC NUM OPTIONS The options available are ECHO YES NO FIX NUMITER ITER MAX TOLERANCE HE RO PI WAVE WLENGTH STEEP CREST YAW YAW_ANGLE WIND WIND_SPEED CEN LATERAL X Y Z U CURRENT FLAG W_COEFF WC0 WC1 WC2 WC3 R_COEFF RCO RC1 RC2 RC3 STOP HOW WEIGHT SF WEIGHT The ECHO option controls the trace of iterations which is printed at the terminal If YES NO is YES then the trace will be printed otherwise it will not The option FIX fixes the trim of the vessel during the iterations The option NUMITER is used to override the default 20 number of iterations and TOLERANCE is used to override the default closure tolerances for heave roll and pitch respectively The values are a percentage of weight for heave and arms for the angular motions and the defaults are 0 0001 0 01 0 5 Finally the WAVE option controls the static wave as discussed earlier When the command is invoked it will r
326. et of specific commands he needs to perform repetitive tasks Rev Page 10 MOSES REFERENCE MANUAL IV A The MOSES Interface MOSES actually has four different user interfaces By default it starts in GUI mode The other three are a terminal a silent interface and the old GUI mode which we refer to as the window interface Silent Interface With the silent interface MOSES produces no terminal output except that directed by the internal command amp S_BACK This option is quite useful for running MOSES in a pipe While the details discussed here differ slightly between the graphical and terminal interfaces the operation is much the same MOSES is and at heart will remain a language where commands are input and results produced The graphical interfaces are simply more efficient at their job Terminal Interface With the terminal option MOSES simply runs in the existing terminal or console window It only has a display area and commands are input directly into it With a terminal interface the actual commands listed must be used and none of the keyboard shortcuts are operative Of course pictures or graphics can only be viewed in one of the graphic interfaces A WINDOWS command prompt will not properly display a MOSES terminal session To use this type of interface on WINDOWS machine you should start a MinGW sh and use it to run MOSES You should navigate to c ultra bin win32 msys or wherever MOSES is installe
327. ewed RT YPE must be either POSITION WATERP CBCG HEIGHT ACTION or PLOT The values El and E2 are the event numbers over which the data will be printed If omitted all events will be reviewed If all types of data are reviewed essentially all data in the output reports will be displayed If one specifies PLOT then an animation of the process will be plotted To check the current amount of water in any tank simply issue an amp STATUS COMPARTMENT During a static process the stability of the body can become a critical question While the metacentric heights provide some measure of the initial stability of the system at each event they do not address the question of the range of stability This question is properly addressed via a righting arm computation MOSES provides an easy method of computing the righting arms at any event during a process simulation by simply issuing the command Rev Page 415 MOSES REFERENCE MANUAL RARM_ STATIC EVE_NUMBER OPTIONS where the options are TRANS ANGLE_INC NUM_ANGLE LONG ANGLE_INC NUM_ANGLE Here EVE_NUMBER is the event number about which the righting arms are to be computed ANGLE_INC is the angle increment deg for the computation and NUM ANGLE is the number of angles for which the righting arms will be computed The option key words specify which angle is to be incremented After the righting arms are computed the user is placed in the Disposition Menu so that he can dispo
328. excluded in the new data For example consider CULL 1 0 50 200 300 The new data will contain all of the original except those rows where column 1 had values either between 0 and 50 or 200 and 300 One obvious use for this command is to extract starting transients from a time sample Another use is to partition frequency domain data to compute independent statistics on each part Rev Page 109 MOSES REFERENCE MANUAL X D Extremes and Statistics There are several options which can be used on more than one command HARD BOTH HEADING HEAD RECORD BEG RNUM END RNUM VALUES CV VAL_MIN VAL_MAX MAG_USE They will be defined here and then listed for the commands for which they are applicable By default the results for commands that produce reports except for the REPORT command discussed above is to write the results to the terminal The HARD option instructs MOSES to produce a report on the OUTPUT channel and the BOTH option writes the results to both the OUTPUT channel and the terminal When these reports are written they have a single line generic heading The HEADING allows one to replace the generic heading with one you specify You can specify as many of these options as you wish The will appear on the page in the order you specify them The RECORD and VALUES options defines the records which will be con sidered Here a RECORD is simply a row of the matrix of data With the RECORD optio
329. f contents while those beginning with a D deal with the define weight for the body What follows the _ define the type of data returned WEIGHT for the weight CG for the centroid of the weight radii of gyration for RADII and MATRIX for the 6X6 weight matrix mass matrix divided by g Parts are defined similarly to bodies In particular the command to describe a part is amp DESCRIBE PART PART_NAME PART_TYPE OPTIONS and the available options are MOVE NX NY NZ NRX NRY NRZ or MOVE NX NY NZ PT 1 PT 2 PT 3 PT 4 Here PART NAME is the name to be given to the part and PART_TYPE is the part type The values one can use for PART_TYPE are somewhat arbitrary but the two types of JACKET and PCONNECT have special significance The part type JACKET is used to denote the portion of the system which will be treated differently when the special transportation facilities of MOSES are employed To avoid confusion elements which connect parts elements which are connected to nodes in different parts must belong to a part with a type of PCONNECT Thus the only elements which can span parts are connectors or PCONNECTors A PCONNECT part should not have any nodes which belong to it There is a special part GROUND which does not belong to any body and it is in this part that elements which connect bodies reside These elements which are called connectors are quite important since they define both the boundary co
330. f the environment to which the structure has been exposed Normally the result of interest is a Cumulative Damage Ratio CDR This is simply a sum of ratio of the fraction of the life used for all stress ranges Sometimes however one wishes to view the loading history independently of the SN curve Thus MOSES has the capability for counting either load cycles or stress cycles sorted into bins One can compute fatigue or cycles for BEAMs PLATES tubular JOINTs and mooring lines and the details will vary with type In general one can compute fatigue in either the time or frequency domains One is really interested in fatigue at all points in an element but in reality we only consider it at a set of fatigue points the ends at points along a beam where the section changes or at welds Generalized plates are special in that fatigue is computed at the centroid of each subelement To really complicate these matters some fatigue points have automatic methods to compute stress concentration factor and others do not In particular MOSES has automated methods for computing stress concentration factors for tubular connections tube cone connections and tubular joints Stress concentration factors must be manually associated with all other fatigue points In MOSES there are two ways to compute fatigue damage on an element by element basis or on a tubular joint basis The reason for the two methods is that for tubular joints there is a bo
331. f the most useful and its form is amp POINT ACTION DATA OPTION Here ACTION must be either COORDINATES D NODE PART EULER ANGLES N_2NODES N_BOX RATIO DEFLECTION HOOK_LOC OFFSET CLOSE NEAREST or REL_MOTION The details of DATA vary with ACTION but nor mally DATA will be one or more point names If ACTION is COORDINATES this function returns the location of the point specified with DATA Here the lo cation returned will be in the part system unless one of the options BODY or GLOBAL has been specified If the point has not been defined a null string will be returned One can use this function during an INMODEL to define locations which may be required provided that the point referenced has been previously de fined If ACTION is DLNODE the function will return the distance between the two points specified via DATA If ACTION is PART the part name of the point specified with DATA is returned When changing frames of reference the ACTION EULER_ANGLES may be useful This action returns a set of Euler angles from three points specified via DATA These angles will establish the new x axis along the line from first point to second a new Z axis perpendicular to the plane formed by the three points and a new Y axis given by the right hand rule The Z axis is defined by the cross product of the X axis and the vector from the first to the third point The ACTION N_2NODES returns all points along the line segment between
332. f the refer enced node above the barge deck Connectors types of V_BRACE P_BRACE and H_BRACE are all very similar to one another The names here refer to Vertical Brace Pitch Brace and Horizontal Brace respectively The V BRACE takes only dynamic vertical load no grav ity load and creates an element from the referenced node to the barge deck The P_BRACE takes only longitudinal dynamic load and creates a horizontal element that is 5 feet or meters long The H BRACE takes only transverse dynamic load and creates a horizontal element from the referenced node to the side shell As with the 4_TIE type the referenced TD_CLASS must have been previously defined For all these tiedown types the connection at the barge end of the tiedown takes no moments meaning a pinned connection If none of the above tiedown connector types are suitable one can still define connec tors explicitly and place this definition in this file For tiedowns this is done with the ICONNECTOR PCONNECT command While this format allows for any valid PCONNECT data the following information is normally provided I CONNECTOR PCONNECT DX DY DZ TD CLASS NOD B For structure descriptions that include tiedowns the tiedowns should be removed from the structure file and placed in this file using the above ICONNECTOR Rev Page 335 MOSES REFERENCE MANUAL PCONNECT method The ICONNECTOR XY_DELTA command provides an easy way to define tiedowns where the barge en
333. fied with the T PRESSURE option on the amp ENV command and a T PRESSURE command One can refine the edges of generalized plate elements with the command REFINE MAX DIST WHAT SEL 1 SEL 2 This command causes the edges of all generalized plates selected by the selectors specified to be refined so that the maximum length of an edge is MAX_DIST feet or meters Here WHAT can be either EDGE ELEMENT or BOX If one specifies EDGE the following SEL i should be in pairs of selectors e g a pair Q R will select any edge that has two nodes which match the two selectors If one specified ELEMENT the following selectors select elements based on element name e g QP refines all edges of elements whose name matches QP Finally a WHAT of BOX refines edges which are totally with a box Here the values of SEL i should be X MIN X MAX Y MIN Y MAX Z_MIN and ZMAX These are distances feet or meters specified in the part system Notice all of these things can be used together For example one can have a BOX inside of a BOX with the interior one having a smaller MAX_DIST Then the interior one will have the interior MAX_DIST and the exterior one the larger distance The nodes added as a result of a refinement have Rev Page 256 MOSES REFERENCE MANUAL Plate with a Free Edge Refined Structural Model FIGURE 14 EP3 EP2 EPA names which begin with RN The REFINE command can be issued both when performing
334. fined in a fashion similar to bodies and parts In other words the data for a compartment follows an amp DESCRIBE command naming the com partment amp DESCRIBE COMPARTMENT CNAME OPTIONS Here CNAME is the name of the compartment and the options define additional attributes for interior compartments and will be discussed later Tube tanks are a computationally efficient way to define interior compartments The only restriction is that the physical shape defined by a tube tank must be a circular cylinder A given compartment can have as many tube tanks as desired and each Rev Page 276 MOSES REFERENCE MANUAL one is defined by TUBTANK DIA PNT 1 PNT 2 Here DIA is the diameter inches or mm of the tank and PNT 1 and PNT 2 are the names of two points defining the ends of the tank Alternately the coordinates of the ends feet or meters can be input instead of point names If one uses coordinates points will be defined with these coordinates These tanks can be mixed with other pieces for an internal compartment If one attempts to define a tube tank for an exterior compartment an error will result Rev Page 277 MOSES REFERENCE MANUAL XII P 1 Pieces For more complicated geometries compartments are defined with pieces In essence a piece is a closed surface in space Each piece is in turn defined by a set of connected areas called panels Both interior and exterior compartments can be composed of as many pi
335. fined in the example above can be quickly defined by amp SELECT COW SELE 1 2 3 4 M EXCEPT M1 M2 M3 amp SELECT DOG SELE D Rev Page 42 MOSES REFERENCE MANUAL VII B The amp UGX Menu As was mentioned previously MOSES has a language for describing a picture on a page There are two uses of this format A way to save graphics for later viewing and a way to define pictures The amp UGX Menu allows pictures to be converted from the UGX format into some other format Alternately one can use the commands in this menu to generate pictures of his own creation The UGX Menu is different from most menus in that it is accessible only though a macro Each trip into the amp UGX Menu is used to produce a single page of graphics To enter this menu one simply issues amp UGX WHAT WHERE where WHAT is the name of a previously defined macro and WHERE can be used to alter the definition of the logical device to which the picture will be written WHERE must be either SCREEN DEVICE or SAVE and if it is omitted then the picture will be written to the primary graphics device A valid UGX macro is like any other macro except that it contains the commands listed below and it has the command END_ amp UGX as its last command For example amp MACRO LINE MOVETO 0 0 LINE 20 20 END_ amp UGX amp ENDMACRO amp UGX LINE will cause a picture to appear on the screen consisting of a single line Several commands are
336. fines the name of the body for which the modes will be extracted and the option NUM EVAL defines the number of modes NEV which will be extracted If NUM_EVAL is omitted 20 modes will be computed The NO_FIX option controls the manner in which connectors and restraints are treated MOSES uses the subspace iteration method outlined by Bathe in the book Finite Element Procedures in Engineering Analysis The way in which MOSES can use the modes as generalized degrees of freedom make the extraction of the modes themselves an interesting question Normally one takes the body in the specified configuration with the defined connections and computes the modes For use as generalized degrees of freedom however we really want the unconstrained modes Also the body will move and as a result its mass matrix will also change What is the correct mass to use and what should be done about the connections These questions are left to the user The mass due to ballast weight and any Morison s Equation added mass will be used when the modes are extracted No added mass due to diffraction will be used since it is frequency dependent If the NO_FIX option is used then all active connectors and restraints will be used Without the option the last node in the stiffness matrix will be fixed and no restraints or connectors will be applied Neither the concern about mass nor about connectors is very important if you intend to use the modes as generalized d
337. fy the num ber of jacket oscillations allowed after separation before the simulation stops The initial winch speed of the jacket is specified with WINCH and the default is 1 foot second If one uses the option NO REPORT then detailed post processing will not be performed This macro is designed to perform a simulation and a corresponding structural analysis by default If the structural analysis is not required simply use the NO_STRUCT option The options FLEXIBLE NONLINEAR ALL_POINT FLX RIG and AMOD are used to control various aspects of the structural analysis of a jacket launch The AMOD option specifies the allowable stress modifier for the structural code check and has a default of 1 The other options control the way the solution is constructed e FLEXIBLE Flexibility of the barge is included pre tipping and post tipping load cases use gap elements e NONLINEAR Rigid barge assumption pre tipping and post tipping load cases use gap elements e ALL_POINT Provides gap elements for post tipping load cases Without this option post tipping cases use the rocker load as applied loads based on a trapezoidal load distribution e FLX_RIG Makes two passes through the structural solver Before tipping barge flexibility is included after tipping a rigid barge is assumed Of course with any option that provides gap elements a non linear structural solu tion is produced If none of the above options are
338. g lengths is provided with either of the two commands XBRACE ELE_NAME 1 ELE NAME 2 ELEINAME n XBRACE CEN_NODE NODE 1 NODE n With either of these commands one is defining the buckling length of an element to be based on the tension compression behavior of another element With the first form of this command the buckling length of ELE NAME 1 is based on ELE NAME 2 ELE_NAME 2 on ELE_NAME 3 and ELE_NAME n on ELE_NAME 1 The second form accomplishes the same thing but here CEN_NODE is the common node between a set of elements and NODE i are the other ends In other words the two forms are identical provided ELE NAME 1 is an element between NODE 1 and CEN_NODE ELE _NAME 2 is between NODE 2 and CEN_NODE etc An illustration of the use of the XBRACE command is shown in Figure 22 For a complete discussion on how the buckling length depends on the brace element see the section on defining elements Notice that with either of these forms one should Rev Page 305 MOSES REFERENCE MANUAL define either the nodes NODE i or the elements ELE_NAME i in order around the center node Rev Page 306 MOSES REFERENCE MANUAL NOD3 NOD4 XBRACE ELNAM1 ELNAM2 ELNAM3 ELNAM4 or XBRACE CNODE NOD1 NOD2 NOD3 NOD4 equivalent BEAM ELNAM1 BLENG ELNAM2 CLASS NOD1 CNOD BEAM ELNAM2 BLENG ELNAM1 CLASS NOD4 CNOD BEAM ELNAM3 BLENG ELNAM4 CLASS NOD3 CNOD BEAM ELNAM4 BLENG ELNAMS
339. gative Here TO is the nominal thickness inches or mm and POWER is the power of the correction i e the curve will be corrected by a factor FACT where FACT MIN THICK TO POWER MAXCOR and THICK is the thickness The details here are governed by FLAG If FLAG is USE_BRACE then FACT computed as above with THICK equal to the brace thickness is used for both the brace and the chord Otherwise FACT is computed for both the brace and the chord using their respective thicknesses Here MAXCOR can be omitted and it will be set to infinity The S_IMP_FACTOR option is used to define a stress improvement factor This factor simply reduces the SN curve by SFACTOR i e the stress in the SN curve is divided by SFACTOR Neither the API X nor XP curves built into MOSES have any thickness correction The reason is that there is quite a bit of ambiguity in API RP2A about how to treat this question In particular depending on the details no correction may be needed If you do need it however it can be included with amp REP_SELECT SN X THICK_SN 1 25 1 5 USE BRACE This tells MOSES to use a correction on any brace having a thickness greater than 1 inch with a power of 25 up to a maximum factor of 1 5 and to use the brace factor for the chord The 1 5 maximum comes from the fact that RP2A says that the X curve need not be reduced below the XP curve and the X curve reduced by a factor of 1 1 5 has the same endurance limit
340. ght feet or meters PERIOD is the period sec SEA DIRECTION is the mean heading deg and for a name of JONSWAP GAMMA is the peakedness factor The precise definition of PERIOD depends upon the value of TYPE specified with the SP_TYPE option or which was speci fied on a amp DEFAULT command If TYPE is PEAK then period is the period at which the spectrum has a maximum If it is MEAN then the period at which the spectrum peaks is given by Tp 1 2958 PERIOD Notice that for an ISSC spectrum GAMMA 1 PERIOD is the mean period For values of GAMMA other than one PERIOD has no meaning other than that given above If one is using a sea defined by a wave grid then the period and height are ignored and for anything other than JONSWAP GAMMA is ignored When an input spectra is used the input values are scaled so that the sea will have the specified significant height Also with an input spectrum one can omit the PERIOD and the spectrum will be as input If one does add a period the spectrum will be scaled so that the peak frequency will move according to an ISSC spectrum All of the ISSC JONSWAP and 2JONSWAP spectra can be represented by the Rev Page 161 MOSES REFERENCE MANUAL equation S f alpha 172 8 HS 2 z exp 1948 184 z p f where f is the frequency in rad sec RSE CLS ip A p GAMMA exp beta 1 2 2 sigma 2 beta Tp f 2 pi sigma is 07 for frequencies
341. grees With DRAFT one specifies a set of draft marks and the draft readings at the marks and with POINTS one specifies a set of points and the height of these points above the water MOSES then finds the draft trim and heel of the body that gives a best fit to the data specified The VELOCITY option defines the initial velocities of a body Here again the velocities specified are for a point a node or the origin of the body in ft sec or m sec and degrees second In general when rigid constraints have been defined between two bodies it is neces sary to locate only one of the bodies If one attempts to specify both he may have a difficult time in locating the various bodies without violating a constraint In other words if only one body is specified MOSES will locate this body and locate the other bodies in such a way as to satisfy the constraints Also one may not give a body a yaw RZ after you have connected launchways to it Positioning a system of bodies with connections is not a trivial task The next two options are designed to minimize this difficulty With these options not only is the configuration of the system altered but the lengths of some of the connectors are also changed The objective is to have the system be in equilibrium The SL_SET option simply computes the proper length for the tip hook element of each tip hook Rev Page 199 MOSES REFERENCE MANUAL set so that the lines have no slack in the spe
342. grees of freedom Here CFRACTION is the fraction of critical damping to be used If this option is omitted 01 will be used Two options of amp DESCRIBE BODY serve to override defaults when computing longitudinal strength The SECTION option is used to define the section prop erties Here EI is the stiffness of the body The X i s are the X locations along the body where one wishes to compute longitudinal strength results and SM i is the body section modulus at X i If only a single location is specified then MOSES will redefine this data so that results are computed at each station and the section mod ulus will be constant along the length of the body For SM the units will be either ft 3 or meters 3 and for EI force ft 2 or force meters 2 If one simply wants to define the locations at which the results are reported he can use the LOCATION command The option DMARK is used to define draft marks and D_DMARK is used to delete draft marks Draft marks are rays along which one measures draft Each mark is defined by two points The first point is the origin of the draft mark and the second is used to define the direction of the mark Draft is the distance along this ray from the first point to where the waterplane intersects the line Here DM_NAME is a name given to the draft mark DPT 1 a point defining the origin of Rev Page 193 MOSES REFERENCE MANUAL the mark and DPT 2 is a point defining the direction of
343. gs one can choose two check boxes and one pick from a set of radio buttons A WIDGET command defines a single widget which will be placed in the tab and the first token after WIDGET defines the type of widget The second token defines a prefix which will be added before the main data selected by the widget The fourth token is a title The YES NO widgets select whether of not the prefix is added to the command and the RADIO widget will add on of the prefix DIMEN and the text selected Now let s be more precise The command WIZARD Main Title OPTIONS instructs MOSES to enter the Wizard Menu and the options available here are COMMAND First Part of Command SIZE SHOR SVER NCOL BUTTON TEXT Text On Button Here the COMMAND option was discussed above and the SIZE allows the user to specify the horizontal and vertical size of the wizard window in pixels and the number of columns Every wizard has a button that the user must push to exit the wizard and execute the command The BUTTON_TEXT option defines the text on the button If this option is omitted OK will be used As mentioned above every wizard must have at least on tab and it can have many of them Each one is defined with the command TAB_ADD STRING where STRING defines the text which will be painted on the top of the tab Once a tab has been defined all text and widgets defined will be added to the tab until a new TAB_ADD command is issued The command TE
344. h and MR is in feet Rev Page 360 MOSES REFERENCE MANUAL or meters The STOP option is used to stop the computation after a specified event has occurred If HOW is RARM then it will stop when the righting arm crosses zero For a value of NET termination will occur at the second intercept point Finally DOWN will terminate when the minimum NWT down flooding height becomes negative One of the results computed during this process is the minimum height of all down flooding points on the vessel The user can define and alter this set of points with amp DESCRIBE COMPARTMENT commands If he has not defined a point then the height of the vessel origin will be reported The WEIGHT option is used to redefine the scale factor used to convert righting moments into righting arms By default the apparent weight of the vessel is used If the option is exercised SF_WEIGHT bforce will be used At the conclusion of the command the user is again placed in the Disposition Menu so that he can dispose of the results Rev Page 361 MOSES REFERENCE MANUAL XVII F Stability Check amp Allowable KG Stability is a simple concept but is extremely complicated in practice To simplify assessing stability MOSES has two commands STAB_OK and KG_ALLOW What they do is compute several things from the basic results reported by the RARM command and if you ask it to it will check to see if the value computed is greater than a specified value These check
345. haracter of a load attribute The first character of an element stiffness attribute name Page 17 MOSES REFERENCE MANUAL IV C Files and the ROOT Concept To perform an analysis the user must input a complete description of the state of the system plus commands defining the type of analysis to be performed The data communicated to the program will enter through one of two input channels 1 the INPUT channel or 2 the COMMAND channel Generally commands enter through the COMMAND channel while descriptions normally enter through the INPUT channel In other words the database is defined to the program via the INPUT channel while the COMMAND channel is used to tell the program what to do with the data in the database It helps to think of the database as being defined by an input file while the commands are issued interactively at a terminal Even though the program can be executed in a batch mode as well as interactively it is best to think of all execution as being interactive While the details may vary with the installation you have these two channels are files MOSES organizes files according to a root name concept In other words the files associated with a job have the same prefix or root and the suffix defines the type of file associated with the root When MOSES is executed one normally furnishes a root on the command line MOSES will then first look for commands to be executed in a file ROOT CIF It will exec
346. haracters in the prefix when appending or more than the number of characters in the template plus the number of characters in the prefix when overlaying Normally MOSES will convert all load data in the existing model into weights In the process the weight is assumed to be the weight of something in air The con verted load will use a macro that has an option SGRAV which specifies the specific gravity of the material used as steel If the loads were coded on a different basis the conversion can be changed via the LOADS option If FLAG is WATER then a variable will be set so that the weight input will be appropriate for air and again the specific gravity will be used to compute a buoyancy If FLAG is SIGN then it is assumed that the sign of the Z component of the load defines a weight if it is negative and a buoyancy if it is positive Here no specific gravity is used This option works only for a SACS or STRUCAD model If FLAG is LOAD then the loads are really converted as loads In general the load data is divided into load cases and often commented as to the origin of the load In MOSES one can use either of these two schemes to create Categories of load A amp DEFAULT command is inserted before each load case to set the default Category to be the load case name Also if the loads are commented the comment is available to further separate the loads The use of the comment is governed by the varia
347. have a command which prompts for the units to use This can be accomplished with amp STRING D2M amp DIMEN DIMEN amp GET PICK 1 PICK UNITS Feet Kips Feet S tons Feet L tons Meters Tonnes Meters KN END amp ENDSTRING amp E STRING D2M Notice that there is an END command at the bottom of the definition of the amp STRING macro D2M This command signals the end of the execution of the macro At first glance this looks like a concept which is of no value of all but this is not true First as we will see later amp STRING macros can be associated with buttons on the menu bar Also WIZARDS must be defined with a amp STRING macro For example the above could be accomplished with a WIZARD as amp STRING D2M WIZARD Dimensions COMMAND amp DIMENSION SIZE 450 410 TAB_ADD To Use WIDGET_ADD YES NO REMEMBER Remember Previous WIDGET_ADD YES NO SAVE _ Save Current WIDGET_ADD RADIO DIMEN _ Settings Feet Kips Feet L tons Feet S tons Meters Tonnes Meters KN END amp ENDSTRING Rev Page 88 MOSES REFERENCE MANUAL amp E_STRING D2M Basically what happens here is the the wizard will build a command from the user s actions The beginning of the command will be amp DIMENSION and this is defined with the COMMAND option This wizard has one tab labeled To Use all wizards must have a tab and three thin
348. he BEFORE option of the style defines how far down from the bottom margin or top of the page the header or Rev Page 48 MOSES REFERENCE MANUAL footer will be printed In many instances one is producing a document which requires a table of contents and which has sections This is facilitated by the commands SECTION TEXT PART TEXT SUBPART TEXT BPAGE TEXT CONTENTS TEXT INDEX TEXT For the first three of these commands a section label will be created the section heading will be printed using the style SECTION and a table of contents entry will be generated The next command will simply create a blank page with a single line of text in the center of it The next command will either place the table of contents at this position in the document or create a place for it The last command will place the index at this position in the document In addition to the general formatting via styles MOSES has the ability to temporarily override styles within a paragraph This is accomplished by enclosing parts of the text within a set of delimiters To set some text bold one should use b at the beginning of the bolding and de at the conclusion Likewise for underlining one uses U at the beginning and U at the end For italics one uses the pairs I and T Often on wishes to format a list of things This is accomplished by entering the LIST mode with Rev Page 49 MOSES REFERENCE MANUAL
349. he FM_MORISON option of amp DESCRIBE BODY is used to define the multiplier Spectral frequency response is computed by issuing the command Rev Page 383 MOSES REFERENCE MANUAL SRESPONSE ENV NAME OPTIONS where the available options are PERIOD T 1 T 2 T N HEADING H 1 H 2 H N FIX TEN YES NO ITER MAXIT Here ENV NAME is the name of the environment which will be used to compute the response and the options operate in the same manner as with the RAO command If ENV_NAME is omitted then the current environment will be used Here one will definitely want to specify the PERIOD option since the objective is to investigate the effect of non wave excitation frequencies When this command is issued MOSES will take the environment and expand the direct wave excitation the wave drift force and the wind force in a Fourier series of the periods specified with PERIOD The direct wave force and drift force series will also be expanded with headings specified with HEADING The wind series will be applied to the heading closest to the specified wind heading These series of forces will be used to obtain the Fourier coefficients of the response series This is precisely what is called spectral response The option FIX TEN can be used to fix the tensions Since the connector tensions are normally a nonlinear function of the motions the linearization necessary in the frequency domain will not be nearly as effec
350. he form of this command is STABILITY OPTIONS The only option is EVENTS EVE_BEGIN EVE_END EVE_INC Rev Page 431 MOSES REFERENCE MANUAL XXVI STRUCTURAL ANALYSIS amp APPLIED LOADS To perform a structural analysis or emit a set of applied structural loads one must enter the Structural Menu This is accomplished by issuing the command STRUCTURAL OPTIONS where the available option is INITIALIZE This command places the user in a sub menu where he can define a situation and perform an analysis If the option is selected then this will delete all previous struc tural results otherwise the results will be added to previous results so that all of them are available later for Structural Post Processing In general there are three types of commands available in this menu commands which define the load cases to be used commands which define the portion of the system which will be used and commands which produce the results When the solution has been completed one should issue END STRUCT to return to the main menu There are no re ports produced directly in this menu The results that are produced are the system deflections and element loads but to obtain a report of them one must enter the Structural Post Processing Menu Three general types of results can be obtained in this menu structural analysis results system deflections and element internal loads loads applied to the structure or vibration modes In th
351. he global Rev Page 118 MOSES REFERENCE MANUAL variable for the record at which the get column is either a minimum or maximum The SELECT option operates in a similar manner except that here the values written into the global variable will be the values of the put column which corre spond to specified values of the get column For example suppose that the get column had values of 1 2 3 4 5 and 6 and the put column had values of 10 11 12 13 14 15 and 16 If one now used the SELECT option with values of 1 5 and 5 5 then the strings stored in the global variable would be 10 5 and 15 5 Rev Page 119 MOSES REFERENCE MANUAL XI REPORT CONTROL amp INFORMATION When obtaining written information about the system the user has control over the extent of information provided This control is exercised by using a set of selectors which can be defined as options on the report generating command or on an in ternal command amp REP_SELECT Once one of these options has been specified it remains in effect until it is explicitly redefined on either an amp REP_SELECT command or on a reporting command The form of the command is amp REP SELECT OPTIONS and the available options are BODY BODY_SEL PART PART_SEL LGROUP LG_SEL COMPARTMENT CMP SEL CLASS CLS_SEL NODE NODE SEL 1 NODE_SEL 2 NODE _SEL 3 NODE_SEL 4 TAG TAG_SEL ELEMENT ELE_SEL PANE
352. he mean so that the reported force will be a measure of the total force The remainder of the options are discussed above Stresses in rods are computed via the command ST_RSTRESS ROD_NAME ENV_NAME OPTIONS where the available options are SEA SEA_NAME THET HS PERIOD GAMMA SP_TYPE TYPE SPREAD EXP USE_MEAN YES NO which operates exactly the same as the ST_RFORCE command Rev Page 399 MOSES REFERENCE MANUAL XX E Pressure Post Processing The commands discussed in this section deal with the frequency response of the pres sure on a panel As mentioned previously the data for these commands depends on the manner in which the original frequency response data was computed If it was computed with an RAO command then all options and data discussed here are avail able If it was computed with an SRESPONSE command then no environmental data can be specified To obtain the frequency response of the average pressure over a panel issue the command FR_PANPRESS PAN SEL OPTIONS Here PAN_SEL is a selector for the panels you want pressure on and the only available option is FILE If one uses this option the pressures on panels selected by PAN_SEL will be written to the ppo file and the Disposition Menu will not be entered Alternatively if the option is not used PAN_SEL should select only a single panel and the user is placed in the Disposition Menu to dispose of the results as desired To compute statis
353. he must first define it with the internal command Rev Page 98 MOSES REFERENCE MANUAL amp DEFINE FUNNAM OPTIONS Here FUNNAM is the name of the function and the available options are DOMAIN DOMNAM MEMORY Here FUNNAM is the name of the function and it follows the same rules as those for a variable name DOMNAM define the domain of the function If the option DOMAIN is omitted then the domain of the function will be the set of positive integers otherwise it is the variable DOMNAM The option MEMORY instructs MOSES that the primary residence for values of the function will be in memory rather than on a file If omitted the primary residence will be on the database file Normally memory resident functions are accessed more quickly but not always Once a function has been defined you should define its values This is accomplished with the internal command amp FVPUT FUNNAM VAR STRING Here FUNNAM is the name of the function VAR is the value name in the variable DOMAIN associated with STRING For example amp DEFINE lt MACDBF gt COW_DATA DOMAIN lt MACDBF gt COWS amp FVPUT lt MACDBF gt COW_DATA JERSEY Milk amp FVPUT lt MACDBF gt COW_DATA HOLSTEIN Milk amp FVPUT lt MACDBF gt COW_DATA ANGUS Beef defines the function lt MACDBF gt COW_DATA and associates data for three types of cows To get the values from a function one uses the string function amp FVGET FUNNAM VAR The following amp LOOP
354. he one specified by the preceding PROCESS option The SPECTRA option allows one to combine the frequency domain results to obtain spectral ones Here ENV_NAME i are the names of environments which have been previously defined via amp ENV commands or in the amp DATA Menu The cases defined by this option will have the same names as the environments These cases will be formed as follows First the RMS of each force or deflection will be computed based on the spectrum The statistic selected by the PROBABILITY option on the amp ENV command will then be computed Finally if the USE MEAN option was selected when the environment was defined the statistical result will be added to the mean using the sign of the mean In other words the mean and the deviation will be combined by adding the absolute value of the two quantities and using the sign of the mean Here the mean is either the appropriate FRQMEAN or MLCNAME Rev Page 451 MOSES REFERENCE MANUAL XXVIII B Post Processing amp Pictures Whenever one computes joint or element code checks or fatigue or beam loads the last values computed will be stored for use with pictures Storing only a single value is in keeping with the philosophy of checking all cases and using the maximum to size the structure With animations however we have a different problem Here we may want to look at the deflections of the structure or at code checks as a function of time Before you can do this
355. he only option available for reporting is EVENTS Many of these commands accept an addition option MAG DEFINE A 1 A n This option defines how the magnitude of the force is computed You can have one two or three A i and each on must be either X Y or Z If you specify all three the default then the magnitudes will be the length of the vectors Alternatively the magnitude will be the length of the vector projected on two either a line if one is specified or a plane For example MAG DEFINE X Y will give you the length of the vector projected onto the X Y plane Often the details of the forces are not required only their magnitude When this is the case a more concise report can be obtained via the second command The first of the connector commands is the CLLENGTH command C_LENGTH CONN_SEL OPTIONS This command reports the length of the connectors selected by CONN_SEL and the available option is EVENTS E_BEG EEND E_INC A the next three commands produce results on force in connectors selected by Rev Page 426 MOSES REFERENCE MANUAL CONN SEL The command CONFORCE CONN_SEL OPTIONS produces the force the magnitude of the force the magnitude of the force divided by the breaking strength the length of line on bottom the vertical pull on the anchor and the horizontal pull on the anchor for the selected connectors The available options are EVENTS E_BEG E_END E_INC MAG_DEFINE A 1 A n
356. he plane formed by the sling nodes makes with the waterplane roll is the rotation of the line defined by the first two sling nodes and height is measured to the midpoint of the line connecting the first two nodes Once the sling is defined the lengths of the tip hook elements can be changed with amp INSTATE SL_SET MOSES will place the system in the specified configuration and compute the lengths of each tip hook element so that there is no slack in the assembly Also the amp CONNECTOR command can be used to change the length of the boom element and deactivate the tip hook set The name to use here is the NAME the name given the set Rev Page 316 MOSES REFERENCE MANUAL XIII D Defining a Pipe or Riser Assembly A pipe assembly is a ROD element along with a set of elements which connect the ROD to a set of bodies The connecting elements can be either DAVIT or ROLLER elements Here DAVIT elements are lines which connect the pipe while ROLLERs are one sided constraints which keep the ROD on a pipe lay route Such an assembly is defined by the command PIPE PIPE_CLASS EL 1 EL i OPTIONS and the available options are PIPE_TENSION TLOWER TUPPER Here PIPE_CLASS is the name of a ROD class which will be used to define the properties of the pipe and EL i are the connector element names of elements which have been previously defined The connector elements must be either DAVIT or ROLLER elements and th
357. he section in the beam Z direction The area of the plate is not included in the axial area of the section but the inertia and resulting change in neutral axis is considered Notice that a PLATE can be corrugated if one inputs the three additional lengths which define the corrugation If only one number is input the plate is flat All of these sections except the LLEG are connected to the nodes at the neutral axis unless instructed otherwise with the option REFERENCE WHERE Here WHERE must be either TOP or BOTTOM When this option is used the node will be attached at the center of the top or bottom of the section With symmetric section this is quite clear but with non symmetric ones it is a bit harder to describe An angle for example will be connected at the center of the flange if BOTTOM is used but the bottom of the web when TOP is used A LLEG section is Rev Page 214 MOSES REFERENCE MANUAL special in that by default the node is connected to the center of the tubular portion The shapes are as show below The option REFLECT can be used on shapes which are not symmetric about the neutral axis to reflect the shape about it This has the same effect as specifying CA 180 as an option on all of the elements which use this class In addition to the standard options discussed above there are several ones specific to beam classes the first group of these are SCF SCF _BEG SCF_END SN CURVEA CURVEB
358. he specified location for every period and heading at which the original response was computed When placed in the Disposition Menu the results for all headings are available The names of the variables are prefixed by HEDXXX where XXX is the heading angle in degrees When using the REPORT command in the Disposition Menu one can selectively report the response If there is no data on the REPORT command all headings will be reported To report data for only some headings one should specify the angles of the heading to be reported on the REPORT command To compute statistics of responses in irregular seas one should issue ST_POINT ENV_NAME OPTIONS where the available options are SEA SEA NAME THET HS PERIOD GAMMA SPREAD EXP SP_TYPE TYPE E_PERIOD EP 1 EP 2 CSTEEP YES NO The options were discussed above When computing motions and using more than one period there are three reports available with the REPORT command in the Disposi tion Menu If the REPORT command is issued without data then all three reports will be written To select a subset of these three the REPORT command should be given followed by MOTION VELOCITY and or ACCELERATION in which case only the reports specified will be written When dealing with irregular seas it is often of interest to know the variation of the Rev Page 390 MOSES REFERENCE MANUAL sea and response spectra with frequency and period To obtain results of this natu
359. hes to input a he must use This is particularly important on a PC when this character is used in defining directory paths In addition to the special characters discussed above MOSES employs several others A full list of the special characters are Rev Page 16 Rev MOSES REFERENCE MANUAL used to remove the special meaning of the following character and to provide for command line continuation used to denote the end of record Any data which follows this character is ignored hence it is useful for adding comments used to denote the wild character One or more of these may be placed anywhere in an alphanumeric name used to denote some number of wild characters If this character is placed in a name it acts like some number of wild characters used to delimit a name which contains blanks and or commas The name must be enclosed by a pair of s used to repeat command names or for a second level of quoting If this is the first word of a record the first word of the previous record will be used If it is encountered in a position other than the command position it act the same as a Here it allows for a double level of including blanks The first character of an option name The option is usually followed by a list of parameters in order to specify some desired action The first character of an internal command The first character of a selection criteria The first character of a point name The first c
360. hese are the free surface moments divided by the current amount of ballast in the tank We are being a bit vague here for a reason Different stability rules require that certain values be used for Xo and A in certain conditions Thus the different filling types specified by the flags above a way to treat the problem approximately and satisfy the rules The filling FLAGS correspond to different choices of Xo and A as follows e CORRECT compute the CG and its derivative at each point in a simulation e APPROXIMATE use the correct CG and its derivative when the com partment is filled e APP_NONE use the correct CG when it is filled and use zero for the deriva tive no free surface correction e APP_WORST use the correct CG when it is filled and the derivative which yields the largest free surface moment Here maximum is the maximum over the depth of the tank Rev Page 300 MOSES REFERENCE MANUAL e FULL_CG use the CG of the tank when it is full for the reference CG and use the correct derivative when the tank was filled e FCG_NONE use the CG of the tank when it is full for the reference CG and zero for the derivative e FCG_WORST use the CG of the tank when it is full for the reference CG and use the derivative which produces the maximum free surface moment e INPUT use the input values for the CG and its derivative Here AL and AT are the longitudinal and transverse derivatives in feet or meters deg and Gx G
361. hich was most critical The number of things which failed The number of classes resized The load case which produced the worst value and The loads six numbers which produced the worst value The only ACTION which produces exactly what it says is E CHECK The others differ from the above as follows E_CHECK follows the above exactly E_FATIGUE has only the first three values E LOADS does not have number of classes resized E STRESS does not have number of classes resized J_CHECK has neither the number of classes resized nor the six loads J_FATIGUE has only the first three values C_CHECK does not have number of classes resized C_LOADS does not have number of classes resized Rev Page 447 MOSES REFERENCE MANUAL e C FOUNDATION has neither the number of classes resized nor the six loads Rev Page 448 MOSES REFERENCE MANUAL XXVIII A Post Processing Cases In all commands in the Structural Post Processing Menu one has the option to specify precisely which cases to consider One always has the basic cases obtained directly from the structural solution available but one of the more powerful capabil ities of MOSES is the ability to combine the results of the fundamental load cases to obtain new cases for post processing For most situations this capability is exercised via the CASES command As mentioned above most of the control of post processing cases is accomplished with the command
362. himself To allow for this MOSES can operate in the pre formatted mode where text is simply transmitted to the output device without rearranging it In the pre formatted mode each line is a paragraph To enter this mode one issues the formatting command PRE and to exit PRE In addition to the general commands described above there are several others avail able which may expedite special tasks In particular SKIP POIREL MOVE POLABS EJECT EODD allow for positioning text on a page Here POI_REL is a number of points relative to the current position at which the next text will be printed and POI_ABS is a absolute position on a page where the next text will be printed The EJECT and EODD commands cause next text to be printed on a new page The KODD command will create a blank page if the current page is an odd numbered one and the document is double sided To control the general appearance of the pages one can use RPAGNUM NUMB HEAD TEXT FOOT TEXT The first of these commands sets the current page number to be NUMB and HEAD and FOOT are used to define headers and footers The styles used for headers and footers are HEAD and FOOT respectively The TEXT on a header or footer can be any one line of text containing positioning instructions and it can contain the special symbol which will be replaced with the current page number when the text is written For both footers and headers t
363. his color Thus to define yellow one should use amp COLOR COLOR_ADD YELLOW 255 255 0 By default there are over 400 colors already defined more than the colors in the X11 file rgb txt To see what colors are predefined one can use the command amp COLOR NAMES The amp COLOR command is also used to define the color maps used for pictures i e the map which maps ratios and intensities to colors This is accomplished with the options S_MAP C_NAME 1 C_NAME 2 CNAME n and R_MAP C_NAME 1 C_NAME 2 C_INAME n Here S_MAP defines the color map used for stress coloring and R_MAP defines the map for ratio coloring C_ NAME i are the names of colors and there can be from two to 128 names If d 1 N 1 where N is the number of names specified then C_NAMEF1 is used for ratios between 0 and d C_ NAME 2 between d and 2d C_NAME n 1 between n 2 d and 1 and C_LNAME n for ratios greater than 1 The final thing accomplished with the amp COLOR command is the definition of color Rev Page 25 MOSES REFERENCE MANUAL schemes A color scheme is two sets of colors one normal the other special Each of these has a background color a foreground color box edge colors selected colors and line colors The normal colors are those used except when a special effect is desired Reverse video for something selected in a menu or a line that is below the water The option USE C_NA
364. i e C integral_Oinfinity K s X t s K is called the kernel and x is the motion velocity etc While the convolution is really the integral we will sometimes call the kernel the convolution Convolutions arise in MOSES in two ways e MOSES computes hydrodynamics and from the frequency domain results MOSES computes an inverse Fourier Transform to obtain a kernel or e the user defines a kernel The amp DATA command is used to define kernel which used are various computa tions Here one associates a name with a function set of data and then uses that name to refer to the function The form of this command is amp DATA CONVOLUTION TYPE NAME DATA OPTIONS Here TYPE is the type of data which is being defined either FREQUENCY or TIME NAME is the name you wish to give to the convolution and DATA is the numbers used to define the convolution DATA is a set of numbers T 1 K 1 1 K 2 1 T n K 1 n K m n Here T is either the time or frequency and K is the corresponding value of the kernel Normally you define a curve with an independent variable and a single dependent variable but if you specify the option NDOF M Then you can have M values of K for each value of T The behavior of any of these can be obtained with amp STATUS TYPE NAME PLOT Where NAME is the name of the curve about which you want information and TYPE is either T C ONVOLUTION or F CONVOLUTION depending on what type of data
365. ication of the offshore industry coupled with the rapid evolution of the com putational power available has made it obvious that to achieve this goal a major departure from the traditional approaches would be necessary In the past a problem was analyzed in several distinct parts each requiring a differ ent view of reality and subsequent model While this approach is suited to existing organizational structure it is highly inefficient and error prone Different models are ipso facto different A substantial quality assurance effort has been required to rec oncile these differences and more importantly one could not hope to obtain a proper analysis of the complete picture by simply viewing selected parts of it Obviously what was really necessary was something that integrated all aspects of the problem To bridge this gap we have created MOSES a new language for modeling simulating and analyzing the stresses which arise in marine situations This new language offers the necessary flexibility along with the rigor of a programming language Now one can easily create new models document them and assess their validity all with a single program In addition to specialized capabilities the MOSES language is rich in general utilities to make one s life easier Most results of a MOSES simulation are available for inter active reporting graphing viewing in three dimensions and statistical interpretation Instead of manually repea
366. ich to tweak the hydrodynamic data to suit his purposes All these options use as defaults values defined with an option of the same name on an amp DEFAULT command The first three options control the way the frequency dependent nature of the added mass and damping are considered in the time domain As described in the Hydrodynamics section mathe matically this results in a convolution This convolution is however often difficult to deal with numerically One of the leading causes of numerical instability is a badly behaved convolution In fact with a convolution it is possible to take too small a time step There is a limit to how much velocity history can be stored For ex tremely small time steps this history may not be long enough to adequately describe the damping The DT_CONVOLUTION option defines the time increment at which the convolution will be integrated This must be equal or greater than the time step at which the time domain is computed If you use TIME STEP for DT_CONV then the convolution will be computed at the time steps used to integrate the equa tions of motion otherwise it will be computed for times steps of DT_CONV This option allows one to use a reasonable time step around 1 4 second to compute the convolution and a smaller one to integrate the equations of motion which ameliorate the above problem An alternative way of dealing with this problem is by using the last two options The FACT CONVOLUTION option scale
367. ied is not the one which will be used Instead a new radius will be computed so that the area of the polygon defined by the new radius is the same as that of the circular sector The number and size of the panels determine the accuracy of the results Of course the computational effort required is quite sensitive to the number of panels and so one is constantly seeking a good compromise between fidelity and efficiency Complicating this however is the fact that there are several different things for which accuracy is important The algorithm which computes hydrostatic results from the mesh is exact in that the results obtained from a given mesh are the same as those obtained from a refined mesh for the same body Thus from a pure hydrostatic point of view the most desirable mesh is the coarsest one which properly defines the surface of the body In a structural analysis however a different problem arises By default the structural loads on a panel are mapped to the nodes closest to the vertices of the panel If you have a large number of nodes in comparison to the number of panels then the default will not yield a good load distribution If the default scheme is to work properly then there should be a reasonable relationship between structural nodes and corners of panels In other words if one has a single panel for the side shell of a barge he should at least have points on the panel at each longitudinal location where he has structu
368. ill change the type of filling for tanks ONE TWO and all tanks which match S Rev Page 301 MOSES REFERENCE MANUAL to CORRECT A tank half full can be specified as amp COMPARTMENT PERCENT ONE 50 or amp COMPARTMENT FRACTION ONE 5 A tank full of two different fluids can be defined by amp COMPARTMENT PERCENT ONE 50 1 025 amp COMPARTMENT ADDITIONAL ONE 50 800 Here the heavier fluid will be at the bottom of the tank and the ballast will correctly reflect the combination of the fluids The vertical CG however will be approximated by the center of volume of the two fluids For an example of moving water in a compartment statically consider amp COMPART OPEN_VALVE PERCENT ONE 50 INT_PRE ONE 3 100 In this case fluid will flow out of the compartment if the specified internal pressure is greater than the ambient pressure at the valve location To initially ballast a tank half full and have it flood dynamically one issues amp COMPARTMENT PERCENT ONE 50 DYNAMIC ONE and to turn off dynamic flooding amp COMPARTMENT PERCENT ONE 50 To simulate a compressor attached to a compartment consider the following amp COMPART DYNAMIC ONE PERC ONE 50 INT_PRE ONE 1E 5 5 COMPRE ONE 05 10000 Here the vent valve is closed by providing a non zero value for INTPRE To analyze what happens as the compartment empties one should issue a TDOM command To automatically ballast a body to achieve a desired condit
369. ined Notice that for a GAP connector to be properly defined the two nodes cannot be coincident The vector from the second node to the first is called the gap direction and the length of this vector when the gap was defined is called the gap distance The gap direction is considered to be a vector in the body to which the first node is attached During a simulation MOSES will compute the distance measured along the gap direction between the two nodes and not allow this distance to be less than the gap distance A gap cannot produce tension If a gap has a specified friction coefficient COEF then it will behave differently during a simulation than during a stress analysis For the stress analysis the treatment is according to Coloumb s Law For a simulation a rigid connection is created perpendicular to the gap direction Rev Page 236 MOSES REFERENCE MANUAL whenever the gap is active i e when the gap is active it prevents all relative motion between the two points Rev Page 237 MOSES REFERENCE MANUAL XII M 6 Propulsion Connector Classes In MOSES one can simulate the effect of a propulsion unit These units have a thruster and optionally a rudder A propulsion connector class is described using CLASS PROPULSION E NAME MAX THRUST R_ ALPHA R GAMMA R_DIST where the available options are R_ANGLE_LIMITS RAMIN RA MAX T_ANGLE_LIMITS TAMIN TA MAX Here E NAME is the name of an efficiency curve and MAX
370. ing this type of dependence is provided in the MEDIT Menu with the XBRACE command The CFB option defines compression flange brace spacing CFSPAC inches or mm If this option is omitted then the value will be taken to be the element length Again this is the length after accounting for any offset The HAS_ P DELTA option tells MOSES that this beam has nonlinear effects taken into account If YES NO is YES then no interaction effects will be taken into account when the codes are checked If YES NO is NO or no option is used then standard interaction formulae will be used in the code checking For a tube they are generally computed Rev Page 248 MOSES REFERENCE MANUAL based on the load path and the formulae specified For other type sections they are input As an example of defining beams consider STF TUBE 30 75 FY 42 LEN 3 STF TUBE 30 675 FY 42 LEN 0 STF TUBE 30 75 FY 42 LEN 3 BEAM STF RELA MY GO1 10 12 AAA1010 BBB1010 Here we have defined a single beam connecting the nodes AAA1010 and BBB1010 with properties defined by the class name STF The beam consists of 3 segments hence the three STF commands The first and third segments are tubular sections with 30 inch OD and 0 75 inch wall thickness while the middle section has the same OD but only a 0 675 inch thickness The first and third segments have a length of 3 ft and the length of the middle segment is to be computed by the program All seg
371. instructs MOSES to use the mouse for selection while a value of ROTATE says to use it for rotation The final two unusual values here are OBSERVER and MODEL which defines what move the observer or the model The remaining values of WHAT are of the form AB_DIR Where A can be either a Rev Page 59 MOSES REFERENCE MANUAL blank F or S B can be either R or T and DIR can be UP DOWN IN OUT LEFT RIGHT PORT or STARBOARD The A part of WHAT defines the change of the move A blank says to take the normal increment F says to take 4 times the normal and S to take 1 4 The B part of WHAT defines the what will change A R says the move will be a rotation and a T says it is a translation UP and DOWN define translations up and down vertically and roll rotations of the model or pitch rotations of the observer PORT and STARBOARD define yaw rotations of both the observer and the model There are keyboard shortcuts for all of these actions OBSERVER O MODEL M SELECT S ROTATE R TIN Up Arrow T_OUT Down Arrow T_LEFT Left Arrow T_RIGHT Right Arrow T_UP Page Up T_DOWN Page Down R_UP Home R DOWN End R PORT Insert R STARBOARD Delete Here the first column is the value of WHAT and the second is the key that maps to it In addition holding the CTL key down and then using a mapped key is the same as adding a F and holding the MOD key down is the same as adding a S The Left Button Bar duplicates some of the above functionality and adds t
372. internal pieces in the body The actions MAX BUOYANCY and MAX CB return the non compartment buoyancy and its center when the body is completely submerged while the actions actions DISPLACE CB and GM return the current value of these things For the actions CB MAX_CB LOCATION and VELOCITY the option GLOBAL can be used to change the returned data from being in the body system to being in the global system The G ROLL returns an angle which is the angle of inclination of the body from the vertical More precisely if v is a vertical vector represented in the body system then G_ROLL is the arc tangent of the sqrt v 1 v 1 v 2 v 2 v 3 The IWVECTOR returns a vector which if a moment is applied in this direction will cause the inclination to increase or I VECTOR v 1 v 2 0 sqrt v 1 v 1 v 2 v 2 The actions which begin with a F_ return forces acting on the body The data following the _ specifies the type of load which will be returned The meaning of these forces can be found in the section on FORCES If no option is specified then the results are in the body system Alternately one Rev Page 196 MOSES REFERENCE MANUAL can specify GLOBAL to return the values in the global system The remainder of the actions deal with the weight of the body Those beginning with a B are applicable to the basic weight of the body those beginning with an A to the apparent weight of the body basic weight plus weight o
373. intersection of the elements forming the joint Once a point has been defined its properties can be changed with the ED_POINT command which is available either during an INMODEL or in the MEDIT menu Its form is ED_POINT PSEL OPTIONS Here PSEL is a selector selection criteria or name which may contain wild charac ters of the points for which the options are applicable and the options can be any option valid for the point definition command Often it is desirable to obtain information about certain points on the bodies during Rev Page 203 MOSES REFERENCE MANUAL a simulation The points at which these reports will be issued are defined by the command amp DESCRIBE INTEREST OPTIONS and the available options are DELETE PNT_SEL 1 PNT_SEL i ASSOCIATE PNT_SEL 1 PNT_SEL i Here PNT_SEL k are selectors for points The option DELETE deletes the inter est points selected by all of the selectors and ASSOCIATE makes interest points of all points selected by the selectors Interest points have a bit more information associated with them than the other types of points In particular each time the amp DESCRIBE INTEREST is issued the global location of the interest point is saved These locations are used for a reference in measuring motion in several reports Once a set of points for a part have been defined they can be exported to a file for later use with the command amp EXPORT POINTS
374. into is REFINE_NUMBER The option M_DISTANCE DISTANCE is used to define the amount of refinement which will be performed on a diffraction mesh when hydrodynamic properties are computed Here DISTANCE feet or me ters defines a maximum distance which the side of a panel or the length of a strip can have Use of this option allows one to define a quite crude mesh and have MOSES automatically refine it to achieve any desired degree of precision The options STRETCH_SEA YES NO NONL_SEA YES NO control how the wave kinematics are computed If YES NO is YES for the first option then the sea will be stretched above the mean water level If not then the linear kinematics equation will be used directly above the mean water level If YES NO is YES for the second option then the wave profile will be computed using an estimate of the nonlinear pressure term This results in the wave crest being Rev Page 151 MOSES REFERENCE MANUAL higher than a trough is low If it is NO then a linear wave profile will be generated The option IN SCF TYPE is used to define the method used to compute the inline stress concentration factors between two tubular sections The section on SCF Binding discusses this in greater detail Rev Page 152 MOSES REFERENCE MANUAL XII D Convolutions Convolutions are powerful mathematical tools Simply a convolution is the integral from 0 to infinity of a function K times a history
375. ion In other words if EXP is equal 1 7 then the wind will vary with height according to a 1 7 power law To specify the type and duration of the design wind speed the W_DESIGN option is used Here DT YPE can be either API or NPD and DURATION is the design wind speed average in seconds To define the temporal or frequency behavior of the wind one uses either the W_SPECTRUM or W_HISTORY options The first of these defines the type of wind spectrum to be used For this option STYPE can be API NPD HARRIS DAVENPORT OCHI or the name of a spectrum previously defined with amp DATA CURVE with a TYPE of either FSPECTRUM or PSSPECTRUM Most of these standard spectra can be found in a paper Wind Turbulent Spectra for Design Consideration Of Offshore Structures OTC 5736 by Ochi and Shin The API spectrum is taken directly from the API RP2a 21st edition and the NPD spectrum is taken from NORSK STANDARD N 003 ACTIONS and ACTION EFFECTS Revl February 1999 It should be noted that there is a contradiction between the turbulence factor and the wind spectrum for the NPD spectrum For this case Rev Page 164 MOSES REFERENCE MANUAL MOSES uses the spectrum for the shape and the intensity for the variance Instead of using a spectrum the time variation of the wind can be defined with the W_HISTORY option This option instructs MOSES to use a previously defined wind history of HISTORY NAME This history is defined with amp DA
376. ion one should use the command amp CMP_BAL BODY_NAME CMP_SEL 1 OPTIONS CMP_SEL n Rev Page 302 MOSES REFERENCE MANUAL OPTIONS where the available options are LIMITS MIN MAX HARD Here BODY NAME specifies the name of the body to be ballasted and CMP_SEL i specifies the compartments in which ballast will be altered MOSES will then move water into and or out of specified tanks until the body is in equilibrium The mini mum and maximum amount compartments will be ballasted can be defined with the LIMITS option All compartments mentioned after this option will not be bal lasted below MIN percent full nor will they be ballasted greater than MAX percent full If a LIMITS was not used all active compartments will have a minimum of the minimum allowed in the tank and a maximum of 100 Rev Page 303 MOSES REFERENCE MANUAL XII Q Editing a Model In the MEDIT Menu one can define and delete elements nodes load groups and element load attributes in much the same way as when defining a model One can also redefine mapping of panel loads to nodes In fact all commands used during INMODEL can be used in MEDIT To delete objects already in the database the following commands are provided MEDIT ED ELEMENT OBJECT OPTIONS ED CLASS CLASS_NAME SEGNO CL DELETE CLS_SEL 1 CLS_SEL 2 ELA DELETE ELE_LOAD SEL 1 ELELLOAD_SEL 2 LG_DELETE LG SEL 1 LG SEL 2 EL D
377. is the increment during sliding tipping and after separation respectively defaults are 0 75 seconds for all 3 The WINCH option is used to specify VO the initial winch velocity in feet or meters second default 1 feet second QTIP causes the simulation to quit after the jacket begins to tip and QSEP causes the simulation to quit after the jacket separates from the barge s The simulation will terminate if any of the above conditions are met whichever one occurs first Using NOYAW provides an additional force applied at the trailing end of the jacket to eliminate any relative yaw between the barges and the jacket until the jacket tips Normally if a body has a roll or pitch angle greater than 90 degrees the program will stop the simulation anticipating that something occurred that was not intended If the NO_CAPSIZE YES option is used no checking for capsizing will be per formed During the computation of a time domain simulation the data is stored in the database The user has some control over this data storage with the options Rev Page 408 MOSES REFERENCE MANUAL SAVE and STORE The state of a configuration will be written to the database at STORE_INCREMENT increments of computed steps If the option STORE is omitted the data will be written every computed time step In other words a default of STORE_INCREMENT equal to 1 will be used Even though the data is stored in the database it will be inaccessible unless the
378. ith a rod connector the effect of the inertia and damping of the connections may be assessed As with connectors MOSES allows for the basic computations traditionally per formed by a naval architect One can compute the curves of form the intact or damaged stability and the longitudinal strength of a vessel MOSES however does not stop here One can specify interactively the ballast in any or all of the vessel s tanks and immediately find the resulting condition If one wishes he can ask MOSES to compute a ballast plan which will achieve a given condition and then alter it Fi nally if desired one can ask MOSES to perform a detailed stress analysis of the condition The program will take care of all of the details of computing the correct inertia loads and restraints Once a suitable condition has been found a traditional seakeeping study can be performed with MOSES by issuing a single command MOSES will then use the hydrodynamic theory selected from the three available to compute the response op erators of both the motions of each body and the connector forces An entire menu Rev Page 2 MOSES REFERENCE MANUAL of commands is available to post process these response operators One can easily find the statistical results for specified sea conditions and create time domain sam ples of the results to assess phasing All results can be graphed or reported Only four additional commands are necessary to produce a detailed stress a
379. ithin TOL_B of the boundary in the plane of the panel and within TOL_OP of the plane of the panel then it is on the boundary of the panel If a point is inside the panel a distance greater than TOL_B away from the boundary and inside the panel and within TOL_OP of the plane of the panel then it is inside the panel If the BOUNDARY option is used all points inside the panel and on the boundary of the panel will be used for the map Alternatively without the BOUNDARY option only points inside the panel will be used To fix a mesh that is being mapped to a generalized plate model this is normally all that is necessary The panels are available for selection are defined by selectors by matching the se lectors defined with the NODES COMPART PIECE PANEL and POINTS options In other words a panel is available for selection if its name matches PAN SEL and it is in a piece selected by PIECE_SEL which is in a compartment selected by CMP_SEL Finally for a panel to be selected it must be inside a box defined in the part system with the options X Y and Z If the average of the Rev Page 285 MOSES REFERENCE MANUAL vertices of the panel lie inside this box the panel will be remapped The default for each selector is and the default box is all of space Thus if none of these options is used all panels will be remapped Normally only nodes will be considered for the mapping If however one want
380. itional option here is MAG DEFINE A 1 A n This defines how the Magnitude is computed You can have one two or three A i and each on must be either X Y or Z If you specify all three the default then the magnitudes will be the length of the vectors Alternatively the magnitude will be the length of the vector projected on two either a line if one is specified or a plane For example MAG_DEFINE X Y will give you the length of the vector projected onto the X Y plane The avail able REP_NAMEs available here are LOCATION MOTION HEIGHT GS or REL VELOCITY The first of these reports the location velocity and acceler ation of the points The second reports the location of the points their motion the wave elevation at the points and the clearance between the point and the sea while the third reports only the height of the points above the waterplane With a report name of GS the dynamic G loads for the selected points are reported Finally the last report gives the wave elevation the wave clearance and the wave particle velocity minus the point velocity in global coordinates If no report name is specified all reports are produced For certain situations it is desirable to know the location velocity and acceleration of one point relative to another point The REL_MOTION command is provided for this and instructs MOSES to compute the relative location velocity and acceleration for a pair of points Th
381. ized plate An edge of the generalized plate is the line segment between two adajent nodes on the plate and a face is all edges which are on a line A generalized plate is defined with the command PLATE ELE_NAME CLASS OPTIONS NODE 1 NODE 2 NODE 3 NODE 4 NODE n FSOPT FP 1 This command defines a generalized plate element of class CLASS connected to nodes named NODE 1 through NODE n The nodes must be specified so as to go around the element in one direction Here ELE NAME is a name which can be assigned to the element omitted MOSES will assign a name The OPTIONS have been discussed above They may be omitted or valid options may be inserted directly at this location within the command The class name CLASS is used to specify the generalized plate s attributes in exactly the same manner as for the beam element A generalized plate is composed of subelements triangular plates contained within the defined perimeter and can be any convex shape and some special concave ones The number of subelements depends on the shape of the perimeter and the number of nodes on each face For three nodes you get no subelements and with four nodes you get four subelements If the generalized plate has four faces the subelements are generated as if it were composed of strips of quadrilateral elements If not the subelements are generated along rays line segments from the average of the coordinates of
382. l and a set of forces The total time domain force is obtained from the frequency domain force by using a Fourier series for each heading and by interpolating a total force from the heading ones and the current vessel heading If there is no pressure data available null data will be used for the conversion This will result in MOSES using the input added mass and damping matrices for the hydrodynamic interaction and there will be no wave exciting force due to the vessel The only wave excitation will be due to wave drift and any Morison s elements Normally if a body has a roll or pitch angle greater than 90 degrees the program will stop the simulation anticipating that something occurred that was not intended If the NO CAPSIZE YES option is used no checking for capsizing will be per formed The EQUI option is useful for finding equilibrium solutions for particularly difficult or complex situations With this option MOSES will enter the time domain with only the mean forces applied This is conceptually the same as using the amp EQUI command except that here the user can examine the results for each time step Two methods are available for integrating the equations of motions a Predictor Corrector method and a Newmark method The default is to use the Newmark Method If however NEWMARK NO is specified then the Predictor Corrector method will be used This method has been around for years and works well in many cases Its prim
383. l of the data is stored in the database in a neutral format When one inputs data the units are converted to the computational units of the program and when results are reported they are converted to an output set of units MOSES is informed of the units the user wishes to employ via the internal command amp DIMEN Since this is an internal command it takes effect immediately Thus one can input a model using different units for various portions He can also receive reports of results in a unit system different from that which defined the model The form of this command is amp DIMEN OPTIONS and the available options are DIMEN LEN FOR SAVE REMEMBER The DIMEN option controls the current program dimensions Here LEN is the length unit which must be either FEET or METERS and FOR is the force unit If LEN FEET then FOR must be either KIPS L TONS or S TONS and if LEN METERS then FOR must be either K NTS or M TONS When a amp DIMEN command with a DIMEN option has been issued MOSES will expect any subsequent input to be consistent with the units specified on the command and all output will also be consistent Notice that this scheme allows for the input of the data in a system of units different from the output with the insertion of a new amp DIMEN DIMEN command The last two options allow for temporarily altering the dimensions and returning to the previous ones In particular SAVE instructs the program to
384. lar the damp ing stiffness mass matrices and the force are multiplied This option works only with flexible connectors The final option is applicable only to TUG connectors Here ANGLE is the global direction of the tug positive when measured from the global X axis towards the global Y axis DIST is the distance feet or meters from the attachment point on a body PT to the tug The string function amp CONNECTOR CON_SELE OPTION returns the current data for each connector selected by the selector CON_SELE The first token is the name of the connector and the remainder depends upon the options Rev Page 309 MOSES REFERENCE MANUAL For a type of e TENSION the remainder is by the magnitude of the force in the connector e HORIZONTAL the remainder is the magnitude of the X and Y components of the force FORCE the remainder is the X Y and Z components of the force in the connector RATIO the remainder is the ratio of the acting force in the connector to the breaking strength E_NAMES the remainder is the names of the points at the ends of the connector E_COORDINATES the remainder is the coordinates of the ends of the connector in the body system of the body e ANCHOR the remainder is the three coordinates of the anchor e LENGTH the remainder is the current length of the first segment of the connector HEADING the remainder is the local body heading of the connector G HEADING the re
385. lass definition commands the situation is a bit different Here we know how many fatigue points we have so we can directly define an SN curve for each one of them Thus for classes we have the option for each segment of SN CURVEA CURVEB Here CURVEA is the SN curve which will be used at the beginning of the segment and CURVEB is the curve used at the end of the segment If one uses two names for Rev Page 176 MOSES REFERENCE MANUAL each segment the one in the middle will be defined twice If this is done the second definition will actually be used i e the first curve specified will in fact be used for the beginning of the segment Also CURVEB needs to be specified only on the last segment For elements we have SNi CURVE which defines the SN curve for the ith fatigue point of the element to be CURVE Here SNA defines curve at the A end SNB defines curve at the B end SN1 defines curve at the end of the first segment etc Rev Page 177 MOSES REFERENCE MANUAL XII H 3 Associating SCFs with Tubular Joints Like SN curves a set of stress concentration factors SCFs must be associated with each fatigue point The details differ based on the type of fatigue being computed For tubular joint fatigue the SCFs will normally be computed based on the joint geometry and the load path and is controlled by a set of options on the point definition or ED_POINT command and the default for all of these parameters is
386. le for his purpose This command changes only those connectors selected by the latest SELECT_CONN command and will keep the tensions tug forces between the upper and lower bounds as specified for each connector using BOUNDS_CONN Here UB is the upper bound while LB is the lower bound both in bforce units The equilibrium so lution keeps the force in each connector as close as possible to the desired value DES bforce defined with DESIRE VALUE The command WEIGHT CONN is used to specify the relative desirability of changing a given connector With this command WT is the relative weight factor to be used for the specified connectors For all these commands SC n and TS n refers to a selection criteria containing connector names or can refer to the connector name itself The SHOW_SYS com mand will produce a report showing the selection status current force desired force upper and lower bounds and the weight value for each connector Normally MOSES will change force in tugs instead of changing their direction The Rev Page 352 MOSES REFERENCE MANUAL command TUG_DCHANGE allows for a tug to change direction as well Here WFMUL and WDMUL are the relative desirability factors for changing force and direction respectively Rev Page 353 MOSES REFERENCE MANUAL XVIII THE HYDROSTATIC MENU To perform hydrostatic computation with MOSES one should issue the command HSTATICS BODY_NAME from the main menu This command will
387. le is defined using the amp DATA menu amp DATA A TABLE T NAME FLAG where T NAME is the name of the force table In this menu the commands available are ANGLE ANG1 WIND_ARE WAX WAY WAZ WAMX WAMY WAMZ CURR_ARE CAX CAY CAZ CAMX CAMY CAMZ The ANGLE WIND ARE and CURR_ARE commands are repeated for each angle for up to 36 angles If FLAG is specified as REFLECT the angles specified should range from 0 to 180 degrees If this is not specified the angles specified should be from 0 to 360 degrees These angles are either wind angles relative to the body system or relative body current velocity angles The body velocity used is that computed at PNT specified in body coordinates as X Y and Z The force acting at PNT is calculated by multiplying the specified coefficients by the square of the relative velocity These force coefficients also create damping in the frequency domain For the WIND_ARE and CURR_ARE commands X Y and Z are force coefficients while MX MY and MZ are moment coefficients The prefix WA is for wind area and CA is for current area Remember to exit this menu using END _ amp DATA If one wishes he can associate a Tanaka Damping load attribute with a load group This is accomplished with the command Rev Page 272 MOSES REFERENCE MANUAL TANAKA WETSUF OPTIONS and the available options are ROLL SECTION FRACTION BLOCK DEPKEEL KG BEAM BILRAD PITCH SECTION FRACTION BLOCK DEPKEEL
388. le sets of these three values and pictures will be drawn according to each set By default all events in the process will be plotted If this goes by too fast use this option with EVENTS 0 9000 1 which plots frames at 1 increments If this is still too fast change 1 to something smaller Of course increasing the increment will speed up the picture If one one has an animation the option MOVIE M_TYPE F_RATE P MULT will produce a movie When this option is used the movie will be written to the a file and then operation will return to normal Here M_TYPE is the format of the movie and it must be either AVI or MPG F RATE is the frame rate and P_MULT is the play multiple This will result in a movie with frames between EVE_BEGIN and ESTOP defined with the EVENTS option discussed below at P_MULT F_RATE second intervals Notice that if PLMULT is 5 then the movie will be played at one half of the default speed The defaults are to use a frame rate of 5 to play the entire process and to use a play multiple of 1 If this is not smooth enough you may want to increase the frame rate but this will increase the time required to generate the movie Finally if you use M_TYPE of AVI then Windows Media Player will not play it unless you have DviX codecs installed Rev Page 66 MOSES REFERENCE MANUAL VIII F Picture Ray Tracing For achieving an even higher image quality or generating high resolution images of
389. less than the peak and 09 for those greater than the peak and alpha is a parameter computed to make the total area under the spectrum equal to HS 2 16 With these spectra the significant height is twice the square root of the area For 2JONSWAP the value of GAMMA is not input instead it is obtained from the DNV guidelines Unfortunately their relationship between GAMMA and the slope is dimensional What we have is s Tp sqrt g 2 pi Hs GAMMA 5 for s lt 4 5 GAMMA 1 for s gt 6 2 GAMMA exp 5 86 94 s for 4 5 lt s lt 6 2 There is almost never a need to define a spectrum by its ordinates Many users think that because someone gives them a Bretschneider or a PM spectrum that they need to resort to such measures but this is not necessary The problem comes from the lack of consistency in the manner in which sea data is provided All of the sea spectra we know of have the same form as the one above The difference is in the manner in which the period variable is specified Sometimes a peak period is specified sometimes a significant sometimes a mean other times none at all The easiest case is when one is given a PM or Pierson Moskowitz spectrum and no period is specified Here one can use PERIOD sqrt 23 27 2 pi HS g which says that the ratio of mean wave length to height is 23 27 In other cases one should find where the specified spectrum has a peak and use the result above to obtain
390. ling MOSES has a special command SLING DESIGN NOD 1 NOD 4 BEGHEI MAXHEI NUM When this command is issued MOSES will take the body to which the nodes are connected in the initial configuration and compute the lengths of each element of the sling so that the hook point is above the center of gravity This computation is made for a hook height beginning at BEGHEI for NUM heights feet or meters measured from the highest sling attachment point until the height exceeds MA XHEI At each height step the tensions in each sling element are estimated so that the hook load equals the body weight The height step increment is calculated as BEGHEI MAXHEIT NUM 1 At the conclusion of the computation the user is placed in the Disposition Menu where he may dispose of the results as he sees fit Rev Page 350 MOSES REFERENCE MANUAL XVILF Obtaining Propulsion Weather Envelopes The PROPULSION command is used to obtain an envelope of the maximum wind current and wave which yields one propulsion unit having maximum thrust The form of this command is PROPULSION CNAME Here CNAME is the name of the control assembly which will be checked When issued this command will use the current environment and iterate a the maximum wind wave and current These will be done in order so that the results will be the maximum maximum environmental component which can act with the others at their nominal values For example suppose that the curr
391. ll and the sound ing The next produces the type of filling the current weight current percent full sounding the CG and the CG derivative with respect to angle change Finally S_COMPARTMENT produces a report of the location of the sounding tube Compartment Hole Information reports are obtained via a REP_TYPE of V HOLE P_HOLE WT_DOWN or NWT_DOWN The V_HOLE produces a report of the valve data for the compartment while PLHOLE produces differential head and pressure data The WT_DOWN and NWT_DOWN REP_TYPEs produce a re port of the current heights of the weather tight or non weather tight down flooding Rev Page 128 MOSES REFERENCE MANUAL points Load Group Information is obtained via a REP_TYPE of M LOADG or F_LOADG The reports obtained with M_LOADG give the values of the multipliers currently being used for each load group F LLOADG gives more localized information Here a breakdown of the force acting on the element or load groups selected by SELE is reported The option FORCE can be used to select the types of force reported If FORCE is not specified then only the total will be reported Category and Load Set Information is obtained via a REP_TYPE of M_CATEGORY M_LSET CATEGORY or D CATEGORY The reports obtained with the first two of these simply list the current value of multipliers for Categories and Load Sets respectively CATEGORY yields a report of the weight and buoyancy mul tipliers the weight center of gra
392. llows setting the current process to be PRC_NAME after the INMODEL is complete After an INMODEL command has been issued it should be re issued only if one wishes Rev Page 135 MOSES REFERENCE MANUAL to substantially alter the model Doing so will result in all previous results being deleted from the database If you want to have a second INMODEL a amp DEVICE AUXIN command must be re issued During the INMODEL process you can use two commands USE_VES VES_NAME or USE_MAC MAC_NAME to load a predefined vessel model or macro When one of these is issued MOSES will look in a set of predefined places to see if it can find the specified name By default the order will be the current directory the ultra data local directory and then the places where MOSES supplied vessel models and macros are located You can use the command amp PATH TYPE ADDITIONS to add places to be checked Here TYPE must be either VESSEL or MACRO and it defines which path is being altered ADDITIONS is simply a list of new places to check When this is done the search order will be the current directory the places specified by ADDITIONS and then the previous places Defining or altering a model with MEDIT is initiated with the command MEDIT and is exited via an END MEDIT command All of the valid INMODEL commands are valid during MEDIT as well as several additional ones In general the extra commands are those which delete things change thing
393. ls defined with the FPPHI com mand and thus there will be 3 times as many values as on the FPPHI command If these are viewed as complex numbers then the first three numbers are the derivatives with respect to X Y and Z of the first potential on FPPHI The first 36 values 18 complex numbers are gradients of the radiation potentials The gradients of the diffraction potentials follow for each heading After all of the panels have been defined the menu is exited with an END_ILPRESSURE command To define a total hydrodynamic database one first issues I_TOTAL BODY_NAME PKT_NAME DISPL OPTIONS One can then describe the hydrodynamic data and issue END_I_TOTAL to exit the menu Here BODY_NAME is the name of the body for which the database is being generated DISPL is the displacement at the condition being defined and the options are PERIOD T 1 T 2 HEADING H 1 H 2 CONDITION DRAFT ROLL PITCH SCFACT SCLEN SCMASS SCDRAG SCFOR Even though these items are called options the first three of them are necessary to properly define the database The PERIOD option defines the periods sec for which the database will be defined and HEADING defines the headings deg for Rev Page 376 MOSES REFERENCE MANUAL which the exciting forces will be defined The CONDITION option defines the vessel condition for which the database is defined and DRAFT ROLL and PITCH are the draft feet or
394. ly one can specify a default value for this data using the DEFAULT syntax after the optional data When MOSES parses the picture it will associate any excess tokens with the last variable in the picture As an example suppose that a macro was defined as amp MACRO COW A B OPT OPT C amp ENDMACRO and that it was executed by COW C D E OPT THIS IS AN OPTION The results of this would be that the variable OPT would be set to TRUE A would be set to C B would be set to D E and C would be set to THIS IS AN OPTION The same result can be obtained through the use of defaults Consider the following macro defined as amp MACRO COW A CB D E OPT OPT C THIS IS AN OPTION amp ENDMACRO and executed by COW OPT This operation would behave the same as the previous example but with fewer keystrokes Notice the use of the single quotes to delimit data containing blanks By definition a macro will be executed whenever the user specifies the macro name Rev Page 74 MOSES REFERENCE MANUAL as a command One may restrict when a macro can be executed by the following command amp M_ ACTIVE NAME COMNAM After this command has been issued macro NAME will only be executed from menus which have COMNAM as a valid command This command should be used when one creates a macro containing commands which must be executed from a specific menu Sometimes one will define a macro with a name which conflicts with a c
395. lysis of a structure in a single data file with each analysis using the same data There are two general rules here to which one must adhere The dimension cannot be changed during the analysis One must use a barge which conforms to conventions By a barge conforming to conventions we simply mean that all of the basic variables have been set A library of vessels is provided which conform If one of these is not suitable you can prepare a model of your own In preparing this model you should use the data file SAMPLE DATA in the vessels library and which is discussed here To use this system you should first read the documentation and then copy files install dat and install cif from ultra hdesk tools install to your working directory or by clicking here and then modify them to suite your problem Most of the work is involved with changing install dat and we will discuss it first Most of the data required is defined in this file The exceptions are the basic model data of the structures to be analyzed and the barge data The structures data is assumed to be in other files which are inserted The barge data is also inserted but it is assumed to be in a special directory which contains all of the barge models Basic Data The data required here is broken down into sections The first section contains basic Rev Page 328 MOSES REFERENCE MANUAL data required for any analysis and is basically self explanatory The line amp DIMEN S
396. mainder is global heading of the connector FRICTION the remainder is the friction in the connector T_MULT the remainder is the current trust multiplier for the connector T_ANGLE the remainder is the current body angle of the thrust of the connector R_ANGLE the remainder is the current angle of the rudder for the connector e HP_ANCHOR the remainder is the horizontal pull on the anchor for the connector VP_ANCHOR the remainder is the vertical pull on the anchor for the con nector and L_ON_BOTTOM the remainder is the line on bottom for the connector Since there are many different situations that MOSES can analyze there is a command that allows one to change many of the properties of connectors as different situations arise Rev This command is discussed in the section on altering connectors Page 310 MOSES REFERENCE MANUAL XIII A Defining a Pulley Assembly A pulley assembly is simply a set of connectors connected with pulleys Such an assembly is defined by the command ASSEMBLY PULLEY PUL_NAME EL 1 EL i Here PUL_NAME is the name you wish to give to the pulley assembly and EL i are previously defined connector element names The connector elements must be either H CAT without the exact option or BLCAT elements If one has a BL CAT element then it must be the last element of the assembly In essence a ASSEMBLY PULLEY assembly is a single line which passes through n 1 pulleys
397. mand file or macro will terminate execution Similarly one can conditionally terminate execution of the program by amp FINISH LPHRASE which terminates the program if LPHRASE is TRUE Rev Page 72 MOSES REFERENCE MANUAL IX C Macros MOSES allows a user to execute a series of commands with the input of a single name This is accomplished by allowing the user to define a macro Macros allow the user to conditionally execute commands repeat blocks of commands and set both local and global variables These capabilities provide the user with a true high level language in which he can actually write a program to accomplish common tasks One defines a macro as follows amp MACRO NAME ARG 1 ARG 2 ARG n OPTION 1 OPTVAR 1 CARG 1 DEFAULT 1 OPTION 2 OPTVAR 2 CARG 2 DEFAULT 2 COMMAND 1 COMMAND 2 amp ENDMACRO Here COMMAND i is any command which is either an internal command or a valid program command The data following amp MACRO is called the picture of the macro and NAME is the name of the macro and ARG i are the valid arguments to the macro While there are no restrictions on the names for macros one should be careful not to choose a name which will conflict with a valid program command If the valid arguments are specified as above then MOSES will parse the command for you and check for syntax errors In some cases however one neither knows nor cares pr
398. mand instructs MOSES to change the elevation of the hook in equal verti cal increments DZ feet or meters until one of the termination criteria defined by the NUMBER SHEIGHT SHOOK or STENSION options is satisfied MOSES will increment the hook height until either NUM changes have been made a specified point reaches a height of HSTOP feet or meters above the waterplane Rev Page 413 MOSES REFERENCE MANUAL the hook reaches a height of HOSTOP feet or meters above the waterplane or a specified hookload TSTOP is reached The point for which HSTOP is checked is defined by using the SP_HEIGHT option on the amp DESCRIBE BODY com mand When the lift increment is negative the specified heights and tension are lower bounds and when the increment is positive they are upper bounds In other words when lifting HSTOP HOSTOP and TSTOP are maximum values while when low ering they are minimum values At each increment in height MOSES will move the hook iterating pitch and roll angles and a hookload which result in equilibrium During the lifting process the lifting sling is treated as an assembly of elements which are rigid in tension but can carry no compression Thus the hook attachment point is first found assuming all sling elements to be rigid The load in each sling element is then computed assuming a distribution which will minimize the sum of the squares of the deviations if the problem is indeterminate If any of the sling
399. may wish to override the automatic joint classification This can be accomplished with the JNTCLASS option Here PRCK PRCT and PRCX are the percentages of K T and X joint types used to classify a joint When this option is used the specified classification for all load cases In Joint Crushing MOSES treats the joint as a two dimensional ring Two basic assumptions here are that the braces do not alter the stresses in the ring and that an effective length of the chord is used to distribute the load The BBC MUL option allows a factor of the bending stress under a brace to be used In other words if one believes that the brace will prevent any bending stress in the chord under its footprint then he should specify a value for 0 with the BBC_MUL option The opposite conservative view is that the brace has no effect in the bending of the chord where one specifies a value of 1 for MULT Of course one can specify any value between these two The EFF_CHD_LEN option is used to change the effective chord length for Joint Crushing from the default behavior computed according to API RP2A for both joints with and without rings The remainder of the options control the computation of SCFs for tubular joints Rev Page 206 MOSES REFERENCE MANUAL These options were discussed in the section Associating SCFs with Tubular Joints Rev Page 207 MOSES REFERENCE MANUAL XII L 2 Geometry String Functions The string function for points is one o
400. mbers are simply specified With VALUES the records considered are defined with the values of a column of data Here CV is the column number for which the values will be obtained and VAL_MIN and VAL_MAX are two numbers VAL_MIN is less than VAL_MAX BEG_REC is then the largest record number which the values of column CV is less than or equal VAL_MIN and END_REC is the greatest record number where the value of this col umn is greater than VAL_MAX If neither VALUES nor RECORD are specified all records will be considered The form of the first of these commands is SPECTRUM CS 1 CS 2 OPTIONS and the available options are RECORD BEG RNUM END_RNUM VALUES CV VAL_MIN VAL MAX When issued MOSES will compute a spectrum for the columns selected by CS 2 CS N assuming that CS 1 is the independent variable The form of the second one is FFT CS 1 CS 2 22 OPTIONS and the available options are RECORD BEG RNUM END RNUM Rev Page 108 MOSES REFERENCE MANUAL VALUES CV VAL MIN VAL MAX These two commands are very similar the only difference is that with FFT a Fourier transform of the data is produced instead of a spectrum The last of these special commands is CULL CS EXL 1 EXU 1 EXL n EXU n This command creates a new set of data from the original by excluding specified parts Here CS defines a column and other values define ranges of values of the selected column which will be
401. ments have a yield stress of 42 ksi As a second example consider LONG W18X40 BEAM LONG A B This defines 1 beam as a wide flange beam 18 x 40 This is a prismatic beam as only one LONG command is given The example below uses a string of nodes for a beam description which can sometimes be quite useful TUBE TUBE 42 1 625 BEAM TUBE GOl1 10 10 10 1 2 3 GO2 12 12 12 4 5 In the above example there are five nodes used and four individual beam elements created Each of the beam elements has a name assigned to it by MOSES The options apply in the order the beam is defined For instance 1 is the A end of the beam joining nodes 1 and 2 and the GO1 is a global offset at 1 2 is the A end of the beam joining nodes 2 and 3 with 3 as the B end of the beam This sequence continues for as many nodes as there are to define the entire series of beams For the last beam of this series 5 is the B end of the beam joining node 4 and 5 and the GO2 option is a global offset at 5 The backslash used above is for a Rev Page 249 MOSES REFERENCE MANUAL continuation of the same command on the next line In many instances one needs to define beam load attributes other than those defined via the element description Three mechanisms for this are provided two commands and the T_ PRESSURE option on the amp ENV command and a T PRESSURE command This option allows one to specify the temperature intern
402. mes that the slam events are Raleigh distributed In this case one simply computes the number of times in a given time that the probable motion will exceed the mean This gives us a slam velocity or number of slams per hour The second question is not so clear Suppose that we write the velocity as a multiple of the RMS V f Fmax Vrms Here V is the velocity which will be used Fmax is the multiplier which gives the maximum event from the RMS and f is a factor If the slam velocity is low then the slam events are associated with extreme events and the multiplier f should be 1 so that the velocity used is the maximum velocity If on the other hand the slam velocity is high then slams are not rare events and the multiplier should be one appropriate to a normal event such as 1 Fmax MOSES uses an linear interpolation for f with the points in the table defined by the SLA MULTIPLIER option This option defines a table of slam velocities S VEL k vs multipliers S MUL k By default the table consists of three points If the slams per hour are lt 1 then f is 1 if the slams per hour are 10 then f 1 1 86 and if they are gt 360 then f HTO Rev Page 184 MOSES REFERENCE MANUAL XII I Forces In MOSES forces on the system are separated into nineteen named categories WEIGHT This is the weight of a portion of the system CONTENTS The weight of ballast in compartments or fluid in an element BUOYANCY The
403. meters roll deg and pitch deg defining the condition The option SCFACT defines a set of scale factors which can be used to convert to the units required In other words all of the quantities input via the commands discussed below will be multiplied by the scale factors prior to being stored in the database The manner in which these factors will be combined with the input num bers will be discussed with each command After the I TOTAL command the database is defined by a sequence of the following commands H_ORIGIN OX OY OZ H_EULERA EROLL EPITCH EYAW H_PERIOD T H_AMASS AM 1 1 AM 2 1 AM 6 6 H DAMP DAMP 1 1 DAMP 2 1 DAMP 6 6 H_FORCE H RFKX RFKY RFKYAW IFKX IFKYAW RDIX RDIY RDIYAW IDIX IDIYAW The HLORIGIN and H EULERA commands define a change of coordinate system from the one being input to the one employed by MOSES Here OX OY and OZ are the components of a vector in the MOSES body system from the origin in the local body system to the origin of the system in which the input quantities are computed Likewise the quantities EROLL EPITCH and EYAW are three Euler angles deg These angles when applied as a yaw followed by a pitch followed by a roll define the direction cosine matrix which transforms the system in which the quantities are computed to the local body system If either of these two commands is omitted the corresponding transformation will be assum
404. mputed they are checked against the product of Fx and MU i e we compute Fh sqrt Fy Fy Fz Fz Fm MU abs Fx Fh Rev Page 229 MOSES REFERENCE MANUAL FACT min Fm 1 and then actually apply FACT Fy and FACT Fz If both lateral stiffnesses are zero then the lateral force applied will be Fm and it will be applied in the direction opposite the relative velocity Three classes are used to define the constituents of slings and pipe assemblies CLASS SLING OD LEN L OPTIONS CLASS DAVIT OD LEN L OPTIONS CLASS ROLLER SENSE DF 1 SPV 1 AF 1 DF n SPV n AF n OPTIONS Slings and davits are similar in that they are really lines whose force depends only upon the distance between the ends The cross sectional area of these elements is computed from OD inches or mm assuming that the section is circular The stiffness is then given by AE and L feet or meters The only other option available for this class is EMODULUS A ROLLER is a limited GSPR element It is limited in that all of the options discussed above are not available Here the available options are YPY P 1 Y 1 P 2 Y 2 P n Y n ZPY P 1 Y 1 P 2 Y 2 P n Y n Y_ROLLER Y Y Z ROLLER Z Z If neither the Y ROLLER nor the Z ROLLER is specified then the roller will automatically restrain lateral motion and prevent the pipe from going below the roller The values Y Y
405. n will be considered If no values are given for TYPE i then results for all TYPEs will be produced Here a TYPE of STRESS will produce the average stress in the element LOADS will produce the membrane tractions acting on the faces of the element and the aver age bending stresses FATIGUE will produce spectral fatigue results and COUNT will produce the number of cycles of the stresses in bins With the exception of COUNT the extent of the reports which will be produced is controlled by which of the three report types DETAIL STANDARD or SUMMARY were selected and the report limits With a STANDARD ob SUMMARY report L i and T i are used to specify a range of values for which a given report will be printed The value used for determining the range is the Von Mises stress divided by yield stress except for FATIGUE where the value is the CDR One can specify as many ranges as he desires or he can omit all data following the option If no ranges are specified one report for all ranges of value will be printed An option of STANDARD will result in a report of the results for the maximum unity ratio over all selected load cases for Rev Page 464 MOSES REFERENCE MANUAL each member selected If one specifies an option of SUMMA RY this report will be reduced to the results for only the selected element in each class which has the greatest unity ratio Finally if one specifies DETAIL as an option the original report will be expand
406. n a point is first located at the intersection of the two lines which connect RPA and RPB and RPC and RPD The X Y and Z coordinates then define the vector from this point to point NNAM Remember that if one changes the coordinates of a point being referenced then the coordinates of the defined point will also change Some examples of using reference points are Rev Page 205 MOSES REFERENCE MANUAL shown below PT3 10 REFERENCE PT1 PT2 This will create a point 10 feet or meters from PT1 along a line formed by PT1 and PT2 This example is handy for defining points along a battered jacket leg PT5 REFERENCE PT1 PT2 PT3 PT4 This will create a point at the intersection of the lines formed by points PT1 and PT2 and PT3 and PT4 which is useful for defining points at the middle of X braces If one wished to temporarily override the current system he may do so by specifying any of the options RECT CYLINDER SPHERICAL or LOCATION which were discussed with the amp DEFAULT command The option DEL is used to delete the degrees of freedom of a point which specified by DOF i which must be either X Y Z RX RY or RZ If no DOFs are specified then all degrees of freedom will be fixed Notice that this option only has meaning if the point is also a node All of the remaining options define the joint behavior of points MOSES auto matically classes joints based on the load path In some rare cases one
407. n effect until it is changed with a new C_SCALE or C_SHIFT command or until the Disposition Menu is exited Rev Page 101 MOSES REFERENCE MANUAL X A Reporting Viewing and Storing Data Three commands are available which allow one to select portions of the data and write it to a post processing file an output file or to the screen There are several options which can be used on more than one command HARD BOTH HEADING HEAD RECORD BEG RNUM END RNUM VALUES CV VAL MIN VAL MAX MAG_USE FIGURES COL SEL RIGHT They will be defined here and then listed for the commands for which they are applicable By default the results for commands that produce reports except for the REPORT command discussed above is to write the results to the terminal The HARD option instructs MOSES to produce a report on the OUTPUT channel and the BOTH option writes the results to both the OUTPUT channel and the terminal When these reports are written they have a single line generic heading The HEADING allows one to replace the generic heading with one you specify You can specify as many of these options as you wish The will appear on the page in the order you specify them The RECORD and VALUES options defines the records which will be con sidered Here a RECORD is simply a row of the matrix of data With the RECORD option the beginning and end record numbers are simply specified With VALUES the records consider
408. n specifies the wave spectrum of the environment ENV_NAME which will be used to linearize the equations spectrally Here any nonlinear de pendence will be replaced by the RMS value times SMULT where SMULT can be specified with the SPE MULTIPLIER option of an DESCRIBE BODY command If SPECTRUM is omitted then an equivalent linearization will be performed where the drag is linearized by either constant wave steepness or constant wave height The default is to use constant wave steepness for roll damping and Morison s drag on bodies and constant wave height for drag on rod elements These assumptions can be altered by using the STEEP option for roll damping and body drag and ROD_STEEP for rod drag When either of these options is used the wave steepness will be held constant at 1 ST for periods less than PBCHEI seconds and a constant wave height of CHEI feet or meters will be used for larger periods If neither PBCHEI nor CHEI are specified then constant steepness will be used for all periods During the RAO computation the dependence of drag coefficient with Reynolds Number is not considered Instead the drag coefficient corresponding to the value specified with the F_CD_TUBE option of amp DEFAULT command is used During the computation of nonlinear damping the computed value is multiplied by a factor to obtain that which is used in the computation For a rod a drag multiplier can be defined with amp DEFAULT FM_ROD For bodies t
409. n the STATIC_PROCESS command is re issued the last event of the previous process will be displayed In either case a process is now available for modification When in the Static Process Menu the quantities reported for roll and pitch have a different meaning than elsewhere Here pitch and roll are defined as angles which two vectors make with the waterplane These two vectors are defined using the SP_ORIENT option of the amp DESCRIBE BODY command The initial position generated by the BEGIN command normally corresponds to the floating position with no applied hookload and no water in any of the compart ments One can alter the situation by using either of the options PERFUL or CHEIGHT For the PERFUL option TANK_NAME i is the name of the ith tank to be initially flooded and PER i is the initial percentage full of tank i If the CHEIGHT option is specified MOSES will set the location of the hook at the position it has in the initial configuration and keep the hook height constant Otherwise the hook height will be allowed to change and the hook will have zero load When the BEGIN command is issued MOSES takes the initial configuration of the system as the starting point for finding equilibrium Since the process of finding equilibrium is expedited if the starting point is reasonably close to an equilibrium position it is a good idea to issue an amp INSTATE command to set a reasonable guess for an equilibrium position prior
410. n the beginning and end record numbers are simply specified With VALUES the records considered are defined with the values of a column of data Here CV is the column number for which the values will be obtained and VAL_MIN and VAL_MAX are two numbers VAL_MIN is less than VAL_MAX BEG_REC is then the largest record number which the values of column CV is less than or equal VAL_MIN and END_REC is the greatest record number where the value of this col umn is greater than VAL_MAX If neither VALUES nor RECORD are specified all records will be considered The MAG_USE option instructs MOSES to add a second heading line based on the definition of magnitude defined with the MAG_DEFINE option The EXTREME command offers the user the opportunity of obtaining a report on the extremes of the data The form of this command is Rev Page 110 MOSES REFERENCE MANUAL EXTREME CS 1 CS 2 OPTIONS and the available options are HARD BOTH HEADING HEAD 1 HEAD 2 RECORD BEG_RNUM END_RNUM VALUES CV VAL_MIN VAL_MAX MAG USE With this command one will obtain a report of the extremes of the data selected Here the first value entered will become the independent variable and the remain der the dependent ones MOSES will search through the results from BEG RNUM to END RNUM to find the minimum and maximum value of each type of data selected It will then issue a report for each value of the independent variabl
411. nalysis of the system in the frequency domain At any point one may perform a time domain simulation of the current system This is accomplished by issuing a command to define the environment and a second to initiate the time domain simulation MOSES then takes the hydrodynamic forces computed via the proper hydrodynamic theory combines them with the other forces which act on the system and integrates the nonlinear equations of motion in the time domain At the conclusion again a menu of post processing commands are available to assist the analyst in deciphering the results trajectories of points forces on elements connector forces etc As before a stress analysis at events during the simulation requires only a few additional commands To simulate the process of lifting a structure off of a barge lowering it into the water and bringing it upright MOSES offers a menu of alternatives One can interactively ballast compartments and move the hook up or down to assess the results of any field action These results are stored by event so that they can be reviewed and the action changed until the desired outcome is attained As with other simulations at the conclusion the results can be post processed and used for a stress analysis A specialized type of time domain simulation is a jacket launch Here a single body is moved until it comes free of other bodies upon which it was towed to location Traditionally a jacket was launched from a
412. nd TOLERANCE Here MAX_ITER is the maximum number of iterations to be taken default is 50 and TOL is the acceleration convergence tolerance in G s for translational motion default is 0 001 The IGNORE option can be used to ignore specified degrees of freedom only for the current equilibrium search In other words amp EQUI IGNORE BARGE X Y RZ is the logical equivalent of amp DESCRIBE BODY BARGE IGNORE X Y RZ amp EQUI IGNORE BARGE X Y RZ amp DESCRIBE BODY BARGE IGNORE Here B_LNAME is the name of the body and DOF i must be either X Y Z RX Rev Page 402 MOSES REFERENCE MANUAL RY or RZ To find equilibrium MOSES simply hunts for a configuration where F 0 This is a deceptively simple equation the exercise of finding an equilibrium configu ration is one of the most difficult things that MOSES does One of the complicating factors is that since the equations may be nonlinear there may be more than one equilibrium configuration When one finds an equilibrium configuration care should be used it may not be the one that occurs in real life To solve for the configurations which satisfy the equilibrium condition a modified Newton method is used The modifications deal with two problems the main one being that in many cases the stiffness matrix is singular For example consider a freely floating ship Here one has stiffness in heave roll and pitch but none in surge sway and yaw Blindly applying a Newton metho
413. nditions for a stress analysis and the constraints on the bodies for a simulation In most cases the body system of a body will be coincident with the part system of all parts belonging to the body When certain types of connections launch legs are defined however the body system will be altered as described later Also the user can alter a part system using the MOVE option Here NX NY and NZ are the location feet or meters of the origin of the part system with respect to the reference and NRX NRY and NRZ are a set of Euler angles which defines the new orientation Rev Page 197 MOSES REFERENCE MANUAL of the part system Alternately if the second form of the command is used the four points define the orientation of the part system Here the part X axis will be from the midpoint of the segment connecting PT 4 and PT 2 to the midpoint of the segment connecting PT 3 and PT 1 The part Z axis is defined by the cross product of the X axis with the vector from PT 4 to PT 2 and the Y axis is given by the right hand rule This option can be used both in defining a model and when editing one but one can move a body part a part with the same name as a body only while editing Moving a body part is equivalent to changing the orientation of all of the parts of the body When one is moving a part the above data defines the part system with respect to the body part system and when moving a body part it defin
414. ne or more barges Time or frequency domain simulation of a structure on a system of vessels Time or frequency domain simulation of moored vessels Time or frequency domain simulation of a tension leg platform Docking simulation of a jacket and a pile Upending of a jacket Ballasting and stability of a vessel and cargo Laying of pipe from a lay vessel Lifting a structure from a barge Lowering a structure into the water Loadout of a structure onto a vessel Stress analysis of any of the above or Inplace analysis of a jacket Rev Page 6 MOSES REFERENCE MANUAL MODEL CONNECTORS STIFFNESS ATTRIBUTES ENVIRONMENT HYDROSTATIC ATTRIBUTES HYDRODYNAMIC ATTRIBUTES WIND ATTRIBUTES MASS ATTRIBUTES SIMULATOR PROCESS TRAJECTORY REACTIONS PROCESS POST REPORTS GRAPHS PICTURES STRUCTURAL SOLVER REACTIONS DEFLECTIONS STRUCTURAL POST STRESSES CODE CHECKS ANALYSIS FLOW FIGURE 1 Rev Page 7 MOSES REFERENCE MANUAL HI OVERVIEW OF MOSES Perhaps the easiest way to describe MOSES is that it is not very smart but it has a good memory In other words MOSES must be told to do everything but remembers almost everything that it has been told As definition the things MOSES is told to do are called commands while the place the results are stored is called the job database While all instructions to MOSES are called commands it helps to separate instruc tions into the categories commands d
415. ness Here the letter following the defines the element degree of freedom to which the extra stiffness will be applied All of these options define points on the force deflection curve of a spring Here P i is the force in bforce and Y i is the resulting deflection in feet or meters The curve defined must have the deflection being a function of the force In other words there can be no two points with the same P and the points must be defined in increasing P Also MOSES assumes that the tension compression behavior of the spring is the same so that the values should all be positive Also to avoid mathematical difficulties Y should be a monotone increasing function of P The X_DAMPING Y_DAMPING and Z_DAMPING options defines a nonlinear dashpot at the end of the element As with the PY options discussed above the letter following the defines the degree of freedom in which these dashpots act Here the force is given by F Co Cy Ex for F lt Fo bforce Here v is the relative velocity and Co is in bforce sec ft or bforce sec meter This dashpot is only active when the spring will have a force in it The FRICTION option can be used to limit the force in the element y and z directions based on the element x force and the precise behavior depends on the stiffness data If either of the Y or Z stiffnesses are non zero then friction is used as follows After the force components Fx and Fz have been co
416. ness in 1 16s of an inch Double angles are named sLddwwtt where s is the spacing between the two angles in 1 8 of an inch dd is the depth in 1 10s of an inch ww is the width in 1 10s of an inch and tt is the thickness in 1 16s of an inch Square and rectangular tubes are named TSddwwtt where dd is the depth in inches ww is the width in inches and tt is the thickness in 1 16s of an inch Here exceptions are made for dd and ww values for some of the smaller sizes For these tubes dd and ww are in 1 10s of an inch For British shapes names UdddBmmm are used for Universal Beams with depth ddd millimeters and mass mmm kilograms per meter Likewise UdddCmmm is used for Universal Columns UdddPmmm is used for Universal Bearing Piles and JdddSmmm for Joists The remaining shapes are named CdddBwww for channels SHddttt for Square Hollow Sections RHddwwtt for Rectangular Hollow Sections LEdddttt for Equal Angles and LUddwwtt for Unequal Angles Here dd denotes the depth in centimeters ww the width in centimeters and tt the thickness in millimeters The French shapes in the table are denoted HEAZddd HEAYddd HEBZeddd HEBYeddd HEMZddd HEMYddd IPEZddd IPEYddd IPEZddd and IPEYddd Here the shapes with the Z in their name are defined with the strong axis in the normal direction while those with the Y in their name are rotated 90 degrees Here ddd is the depth of the section in millimeters The shape type of TUBE is special in that
417. ng form of the REPORT command is REPORT REP_NAMES 1 REP_NAME 2 OPTIONS Here REP_NAMES i is a set of report names which may be selected and will depend on the command issued The only option available for reporting is again EVENTS The MAG DEFINE option defines how the Magnitude is computed You can have one two or three A i and each on must be either X Y or Z If you specify all three the default then the magnitudes will be the length of the vectors Alterna tively the magnitude will be the length of the vector projected on to either a line if one is specified or a plane For example MAG DEFINE X Y will give you the length of the vector projected onto the X Y plane The command SENSOR DNAME OPTIONS instructs MOSES to compute the sensor signals of all sensors who s names match SNAME and there is no DATA for the report command MOSES is instructed to compute the draft readings along the draft marks selected by DNAME with the command Rev Page 420 MOSES REFERENCE MANUAL DRAFT DNAME OPTIONS and there is no DATA for the report command The POINTS command instructs MOSES to compute the location velocity motion and acceleration of the points selected by PNT_NAME Here motion is the vector from the global location of a point the last time the command amp DESCRIBE IN TEREST was issued to the current position of the point The form of this command is POINTS PNT_NAME OPTIONS An add
418. nks or compartments he wished to flood Next he would issue the EQUI command to find the floating damaged position and then issue a RARM command to examine the stability of the damaged system Rev Page 354 MOSES REFERENCE MANUAL XVIII A Tank Capacities To compute tank capacities the user should issue a command of the form TANK CAPACITY TNAME INC OPTIONS Where the options available are ROLL ROLL_ANGLE PITCH PITCH_ANGLE When this command is issued MOSES will compute the weight volume and center of the compartment name TNAME in increments of INC feet or meters Normally it is assumed that the vessel has zero roll and pitch This can be changed however with either of the two options The angles one specifies here are in degrees At the conclusion of the command the user is again placed in the Disposition Menu so that he can dispose of the results Rev Page 355 MOSES REFERENCE MANUAL XVITII B Curves of Form Perhaps the most primitive hydrostatic results are those which normally comprise the curves of form To generate this type of result with MOSES one should issue the CFORM command After the properties have been computed MOSES will place the user in the Disposition Menu so that he can dispose of the results as he desires This command produces two hard copy reports in the Disposition Menu BASIC and COEFFICIENT The first of these contains the condition displacement center of buoyancy waterplane area cent
419. no plate can be attached to a tube This shape also allows for having a tube inside of a tube with the inside tube being specified by the dimensions C and D If one has an inside tube then he should not specify contents for this element within this class This is useful for defining piles inside of legs Rev Page 223 MOSES REFERENCE MANUAL XII M 3 Pile Classes A pile class is simply a beam class with a soil defined and some extra options available The extra options for CLASS PILE classes are REFINE NUM REFINE PYMULT PMUL YMUL TZMULT TMUL ZMUL QWMULT QMUL WMUL SOIL SOIL NAME The REFINE option defines the number of segments into which the pile segment will be broken to solve the nonlinear pile soil interaction problem If it is omit ted a single element will be used The options PYMULT TZMULT and QWMULT define multipliers for the basic soil properties If they are omitted values of 1 will be used The option SOIL defines the name of the soil in which the pile will be embedded Here SOIL_NAME is the name of a soil which has been previously defined in the amp DATA Menu This is accomplished by first entering the menu with the command amp DATA SOIL SOIL NAME and when the definition is complete exit the menu with END_ amp DATA In the menu one uses the following DEPTH ZDIS PY P 1 Y 1 P n Y n QW Q 1 W1 Q n W n TZ T 1 Z 1 T n Z n MPY MULP MUL
420. ns will appear to be lost They are however not really lost To recover them one should issue another DESCRIBE PROCESS command to change the current process back to the name under which the results are stored Thus the process concept allows one to have many different sets of results Rev Page 326 MOSES REFERENCE MANUAL available for further processing If one wishes to have the events of the previous process available in the new one he can specify the EVENTS option when he created the process Now the new process is a true copy of the old process and it can be altered as desired Most processes will have events defined by either a time domain simulation the results of a TDOM or LAUNCH command or an upending sequence At the con clusion of a time domain or launch simulation MOSES will revert to the situation at the beginning Thus issuing amp STATUS after a time domain simulation will produce the same result as issuing it before the simulation In some cases however one may wish to construct a series of events which correspond to a set of equilib rium configurations with different ballast conditions This can be accomplished by computing an equilibrium configuration and storing the results with a given event number via the command amp EVENT STORE EVE NUMBER The results of this simulation can be post processed as any other simulation in the Process Post Processing Menu Notice if this command is used when
421. nsidered Here EVE_BEGIN and EVE_END are the beginning and ending event numbers for which the results will be computed and EVE_INC is the increment for computing results After the results have been computed MOSES places the user in the Disposition Menu so that he can dispose of the data The corresponding form of the REPORT command is REPORT REP_NAMES 1 REP_NAME 2 OPTIONS Here REP_NAMES i is a set of report names which may be selected and will depend on the command issued The only option available for reporting is again EVENTS The MAG DEFINE option defines how the Magnitude is computed You can have one two or three A i and each on must be either X Y or Z If you specify all three the default then the magnitudes will be the length of the vectors Alterna tively the magnitude will be the length of the vector projected on to either a line if one is specified or a plane For example MAG DEFINE X Y will give you the length of the vector projected onto the X Y plane For the FORCE option FORCE_NAME i is a selector which selects forces from the list WEIGHT CONTENTS BUOYANCY WIND V DRAG R DRAG WAVE SLAM W DRIFT CORIOLIS DEFORMATION EXTRA AP PLIED INERTIA A_INERTIA CINERTIA FLEX CONNECTORS RIGID_CONNE and TOTAL If this option is omitted only the total force will be computed The meaning of these forces can be found in the section of FORCES The command ELMFORCE ELE_NAME OPTIONS i
422. nto global ones The TYPE VECG2L transforms a vector in global coordinates to local ones and VECL2G performs the inverse Here Q is a direction cosine matrix there are nine numbers for Q VG is a vector in global coordinates and VL is a vector in local coordinates Rev Page 82 MOSES REFERENCE MANUAL IX D 3 The amp STRING String Function Another function for dealing with strings is amp STRING ACTION STRING 1 STRING 2 STRING n Here ACTION defines what you want the function to do and STRING i are the strings STRING 1 is the basic string and the others may be used for additional operational data depending on ACTION Here the valid forms of the function are amp STRING SUBSTR STRING 1 BCN ECN amp STRING BEFORE STRING 1 DELIM amp STRING AFTER STRING 1 DELIM amp STRING MATCH STRING 1 STRING 2 amp STRING NULL STRING 1 amp STRING O_NUMBER STRING 1 NUMBER amp STRING OVERLAY STRING 1 STRING 2 amp STRING REVERSE STRING 1 STRING 2 amp STRING N EXTRACT WORD NUMBER STRING 3 amp STRING REPEAT WORD NUMBER For SUBSTR the result will be the characters BCN through ECN of the input string STRING 1 For BEFORE the result will be the characters of STRING 1 starting at the beginning of the string through the character before the character DE LIM For AFTER the result is the last portion of STRING 1 beginning with the character after the last occ
423. ntrol only yaw and the thrust is not altered by the control system In other words one sets the thrust with a amp CONNECTOR xxx SET PROPULSION command and the control sys tem will control the rudder to achieve a given heading Rev Page 319 MOSES REFERENCE MANUAL XIIILF Defining a Winch Assembly A winch assembly is simply a set of connectors connected to a winch Such an assembly is defined by the command ASSEMBLY WINCH WINCH_NAME EL 1 EL i OPTIONS Here WINCH_NAME is the name you wish to give to the winch assembly and EL i are previously defined connector element names The connector elements must be either BL CAT H_CAT SL_ELEM ROD GSPR LMU elements or the SLING element connecting the boom to the hook on a tip hook assembly Here the available option is WINCH FULL_WEIGHT MAX TORQUE S MOMENT D MOMENT TOT_LENGTH FULL_GYRADIUS FULL RADIUS This option is used to define the mechanical properties of the winch and alterna tively the second defines the velocity of the winch as a function of time Here FULL WEIGHT is the weight feet or meters of the drum plus the wire The next three values define either the maximum applied torque MAX_TORQUE maximum applied torque or two moments applied by a brake S MOMENT is the static mo ment due to the brake and DLMOMENT is a factor which when multiplied by the square of the angular velocity is the dynamic moment due to the brake All three of these are in bforc
424. nu and select Preferences It is possible to select preferences you actually did not want For instance if you choose a proportional font for the log file none of the reports coming to the screen will look correct the titles and columns will be misaligned The easiest way to solve this is to select a fixed pitch font using Customize Edit Preferences from the MOSES tool bar If you want to return to the original defaults shipped with MOSES delete moses ini from your HOME and data local directories use Customize Edit Preferences and click OK without changing anything Two other selections are available in this menu REGISTER and UNREGISTER REGISTER will register the software with the operating system This provides the ability to click the MOSES icon to run the software as well as associate certain file types with particular software For instance clicking on root ans gdv00001 eps can open the Ghost View Postscript viewer Clicking on root cif root dat root ans log00001 txt or root ans out00001 txt can open the VI text editor Also a right click on root log can invoke the TIDY utility which cleans up a MOSES database Of course if one prefers the command prompt method of starting MOSES less typing is required if the path is set to where the software is installed Using UNREGISTER will remove all these file associations Rev Page 21 MOSES REFERENCE MANUAL V MOSES DIMENSIONS One of the interesting features of MOSES is that al
425. nventions for arithmetic In other words a number can be defined as a series of numbers combined by primitive numerical operations As an example consider the number 64 The following representations would all yield the same value 6143 8 2 6 2 8 35 1 2 4 2 While this ability may appear to be of limited utility it proves to be quite powerful Rev Page 15 MOSES REFERENCE MANUAL when combined with the more advanced language features To simplify the operation and documentation of the program MOSES employs the concept of menus A menu as used here is an available list of commands which can currently be executed If an attempt is made to execute a command which is not contained in the current list a message to that effect will be reported and a prompt for another command will be made There are several menus in MOSES When an END command is issued MOSES will return to the next higher menu To terminate execution of MOSES one simply inputs an amp FINISH command which is a valid command in any menu In a window environment the key Alt F can be used instead of typing in amp FINISH There are several commands within MOSES which can be executed regardless of the current menu These commands are called Internal Commands In general they control the operation of the program set basic variables which effect the analysis and can be distinguished by the fact that they all begin with the character amp An example is the am
426. o define the sea body interaction forces on things for which Morison s Equa tion is not applicable and e To define ballast in the interior of a body In essence compartments are used to model the exterior of bodies and the interior compartmentation of bodies Thus we have two types of compartments interior and exterior The distinction between interior and exterior compartments is made when the com partment is named Whenever a body is defined MOSES will automatically define a compartment with the same name as the body This compartment is an exterior compartment Any other compartment defined whose name is not also the name of some part is an interior compartment Only exterior compartments can attract hydrodynamic loads and only interior compartments can be flooded or ballasted Compartments are a collection of two basic entities pieces and tube tanks A tube tank is used to model the interior of a tube and pieces are used to model everything else In essence a piece is a ship like part of the compartment When a piece is part of an exterior compartment it creates buoyancy drag force wind force and behaves according to either Strip Theory Three Dimensional Diffraction Theory or attracts no hydrodynamic load at all When part of an interior compartment it can be damaged flooded or ballasted and defines part of the inertia of the system The way to define pieces and tube tanks will be discussed below Compartments are de
427. o immer sion in the water Since all computations involving these forces have the correct phase relationship between the acceleration and the angular motion they will be less conservative than adding the two components after an irregular sea computation The commands here are essentially the same as those discussed previously for the motions of a point except that the results will be forces instead of motions Again if the original data was obtained with an RAO command then all of the data discussed here can be specified If instead the original results were obtained with a SRESPONSE command then no environment nor options can be specified The FR FCARGO command is used to produce the frequency response of the dynamic forces acting on a rigid body whose CG is located at the last position specified on a FR POINT command The form of this command is FR_FCARGO WEIGHT RX RY RZ where WEIGHT is the weight bforce of the body and RX RY RZ are the X Y Z radii of gyration feet or meters of the body When placed in the Disposition Menu the results for all headings are available The names of the variables are prefixed by HEDXXX where XXX is the heading angle in degrees When using the REPORT command in the Disposition Menu one can selectively report the response If there is no data on the REPORT command all headings will be reported To report data for only some headings one should specify the angles of the heading to be reported on
428. ods If this option is omitted then a single period of PERIOD will be consid ered With the option periods of PERIOD EP 1 EP 2 will be produced If CSTEEP is specified with a YES NO of YES then the height of the wave will be altered so that all seastates have the same steepness as the initial one Otherwise the wave height will remain constant To compute statistics of responses in irregular seas one should issue ST_FCARGO ENV_NAME OPTIONS where the available options are SEA SEA_NAME THET HS PERIOD GAMMA SP_TYPE TYPE SPREAD EXP E_PERIOD EP 1 EP 2 CSTEEP YES NO and the options are defined above The statistics here are of the forces which resulted from the last FR FCARGO command If one is computing statistics of G forces the angular accelerations should be the same as the angular accelerations produced from statistics of the motions They may however differ due to numerics The ones produced from the motions are computed better If the difference is too large to suit you need more periods When dealing with irregular seas it is often of interest to know the variation of the sea and response spectra with frequency or period To obtain results of this nature Rev Page 394 MOSES REFERENCE MANUAL one should issue SP_FCARGO ENV_NAME OPTIONS where the available options are SEA SEA_NAME THET HS PERIOD GAMMA SP_TYPE TYPE SPREAD EXP The results pro
429. of many commands the user is placed into the Disposition Menu In this menu data may be processed and written to either an output file a post processing file the terminal a graphics device or to a global variable When dealing with data in the Disposition Menu it is best to think of it as being a matrix The columns of the matrix are called variables and the rows are called records Each variable is identified by its column number or name and one can obtain a list of the names of the variables and their column numbers by issuing the command VLIST Throughout this menu one selects columns with column selectors These selectors can be a single number a colon separated pair of numbers or a name selector e g 5 7 8 x The colon pair selects all columns from the first number to the second one In many cases only a limited number of columns can be selected In this case the first one selected will be used For example suppose that you can select six values and you use 1 12 for the column selector then only 1 6 will be used Sometimes one may wish to alter the values of the data available This can be accomplished by using either of the commands C_SCALE SCALE F CS 1 CS 2 C_SHIFT SHIRT_F CS 1 CS 2 The C_SCALE command defines a multiplier by which a variable will be scaled and the C_SHIFT defines a constant which will be added to the variable Once of these factors are established they will stay i
430. of solution is controlled by the type of loads generated When a structural analysis has been performed the results can again be combined in the post processor If the problem is linear combining the deflections in the post processor or combining the loads prior to solution produce the same results For a nonlinear problem however this is not the case For the linear problem in the frequency domain either options 1 or 2 defined above are available Of these two methods the frequency domain allows the user more flexibility while the time domain can offer some savings in computational effort The frequency domain method must be used if one wishes to compute the cumulative fatigue damage for the system If one wishes to use nonlinear elements the structural system of equations will be nonlinear In this case the frequency domain solution method will not really yield the proper results since the solution will be for unit wave Here it is better to combine loads to form the total load on the system prior to solution Thus one cannot correctly assess cumulative fatigue damage using nonlinear elements When the structural analysis is complete one should issue END_STRUCT Rev Page 433 MOSES REFERENCE MANUAL XXVI A Extracting Modes Of Vibration If one wishes to investigate the vibration modes of a body he should issue the com mand MODES BODY_NAME OPTIONS and the options are NUM EVAL NEV NO FIX Here BODY NAME de
431. ollection of load attributes is associated together as a group For simulations the load due to each of the attributes is computed and applied to the proper body A load group also has a list of points associated with it This list is given a name normally the name of the load group and is called a load map When a stress analysis is performed the total load on the group will be distributed to the nodes associated with the points by a least squares technique Thus if there is only one node associated with the group it acts as a nodal load There are two primary differences between a load group and a nodal load First load groups allow for the association of not only loads but also load attributes with nodes Secondly the load attributes of a load group can be distributed to more than one node In addition to the obvious advantages of using attributes instead of loads the load group allows one to define gross properties to entire bodies when he is not interested in the structural details The load map may be either defined with a set of selectors as described below or MOSES will define it for you In particular if one has not defined a map explicitly the loads will be mapped to the points where load attributes have been defined Whenever a body or part is defined MOSES will automatically define a load group with the same name as the body or part Load groups are defined in much the same manner as bodies and parts In other words one is
432. olution is controlled by the type of loads generated When a structural analysis has been performed the results can again be combined in the post processor If the problem is linear combining the deflections in the post processor or combining the loads prior to solution produce the same results For a nonlinear problem however this is not the case For the linear problem in the frequency domain either options 1 or 2 defined above are available Of these two methods the frequency domain allows the user more flexibility while the time domain can offer some savings in computational effort The frequency domain method must be used if one wishes to compute the cumulative fatigue damage for the system If one wishes to use nonlinear elements the structural system of equations will be nonlinear In this case the frequency domain solution method will not really yield the proper results since the solution will be for unit wave Here it is better to combine loads to form the total load on the system prior to solution Thus one cannot correctly assess cumulative fatigue damage using nonlinear elements When the structural analysis is complete one should issue END_STRUCT Rev Page 445 MOSES REFERENCE MANUAL XXVIII STRUCTURAL POST PROCESSING At the conclusion of the Structural Menu the deflections and element loads are stored in the database To obtain reports of these results or any results which can be derived from them one must
433. ommand name If this occurs it can be rectified by changing the name of the macro This is accomplished via the KM CNAME command Its form is amp M_CNAME OLD_NAME NEW_NAME Also if one defines a macro which does not work properly and he wishes to change it he can delete the macro and start over This is accomplished as amp M_DELETE MACRO_NAME Rev Page 75 MOSES REFERENCE MANUAL IX D String Functions Perhaps one of the more useful concepts MOSES employs is the String Function A string function converts an input string into another string and the general syntax of a string function is amp FUNCTION ARG 1 ARG 2 There are quite a few things which can be accomplished with string functions In the next several sections specific string functions will be discussed but some examples are a string function is o check if a variable has been defined The function amp V_EXIST VARNAM will return the string TRUE if the variable VARNAM has been defined If VAR NAM has not been defined a value of FALSE is returned Another useful string function is amp FORMAT which is used for formatting and its form is amp FORMAT FMT STRING Here FMT is a formatting instruction and STRING is the string to be formatted If STRING is a number then FMT can be a FORTRAN format e g F10 2 13 etc Otherwise FMT must be either UPPER LOWER FIRST or COMMA For UPPER the entire string will be made into upper ca
434. on graphics along with a figure number The default here is gt FIGURE The FIG_NUM option instructs MOSES whether or not to put figure numbers on plots and perhaps what number to use If YES NO is YES then Figure XX will be placed in the lower left corner of all plots not directed to the screen Here XX is a number which will be 1 for the first plot 2 for the second etc If YES NO is NO no figure numbers will be plotted If gt NUMBER is specified then the next figure plotted will have the number specified The next option is used to alter the destination of graphic output There are two places where graphics can be deposited the primary place and the secondary one When a PICTURE or PLOT command is issued the results are automatically written to the primary place and when a SAVE is issued the results are written to the secondary place The G_DEFAULT option defines the default logical device for graphics Here GLDEVICE must be either SCREEN or FILE which will define either the SCREEN or GRA_DEVICE logical device to be the device where default graphics is written The next class of options controls the type of output which is received The OECHO option is used to control the listing of output If the YES NO following this option is YES then each record from the input file is written to the output file as the record is read Conversely if YES NO is NO the echo will not occur The MECHO option will instruct MOSES
435. on the element definition command or by specifying WTPLEN to be zero when defining the stiffener class The weight is computed by the weight per length of the stiffener times its length times the number of stiffeners If one does not specify a class for the stiffeners then the stiffeners are magic in that they are weightless and automatically pass any checks on their properties While these are conceptually simple one can easily become confused by the details While the form of the options used to define stiffeners is the same for all elements the details differ Thus let us begin by considering stiffeners on generalized plates Here the options used to define stiffeners are T_ STIFF SPACE STIF_CLASS WHERE Rev Page 219 MOSES REFERENCE MANUAL L_STIFF SPACE STIF_CLASS WHERE The option which begins with T defines transverse stiffeners and that beginning with L defines longitudinal ones Here longitudinal stiffeners are parallel to the element X axis and transverse ones are perpendicular to the X axis For both of these options STIF_CLASS is the class name which will be used to define the stiffener and have been defined previously WHERE defines the vertical position of the stiffener WHERE may be either Z or Z If Z is used the stiffeners will be connected to the top size of the plate and for Z the bottom side If WHERE is omitted INTERNAL or Z will be used Longitudinal stiffeners
436. oncentrated at the point specified by PT In contrast to AREA a PLATE command defines a distributed area and load attraction does not depend on the location of the center of area The form of this command is PLATE PNT 1 PNT 2 aeaaee OPTIONS and the available options are CATEGORY CAT NAME NUM_APPLIED NUMBER WIND WINMUL DRAG DRGMUL AMASS AMSMUL WAVE_PM WAVMUL BUOY THICK BTHICK TOT WEIGHT WT MULT WEIGHT WMULT Here one specifies up to four vertices of a polygon by points PNT i These vertices Rev Page 270 MOSES REFERENCE MANUAL must be input in the order of one tracing the outline of the plate MOSES will compute the portions which are submerged and those which are above the water surface applying the proper forces in each regime The level of detail used in the force calculation is defined by the MAXAREA and MAXREFINE and the method of computing drag are defined with options of the amp PARAMETER command The options for PLATE function in the same manner as they do for AREA with one exception When the submerged portion of a plate is computed an aspect ratio is also computed The added mass for the plate is that computed for a rectangular plate according to DNV Classification Notes 30 5 Occasionally it is convenient to describe a load attribute as a tubular but without actually adding a tubular element to the model This can be performed with the command TUBE OD T
437. ontrast to the time statistics the statistics are derived assuming a Raleigh distribution Rev Page 114 MOSES REFERENCE MANUAL X E Plotting In MOSES a graph consists of one or more dependent variables plotted on one or two ordinate vertical axes all against an independent variable which is plotted using the abscissa horizontal axis Two ordinate axes a left and an optional right axis are available in order to graph variables which differ greatly in magnitude but which the user wishes to present on the same graph If two or more dependent variables are graphed MOSES differentiates the curves by adding symbols to several points in each curve and a legend is placed on the graph which defines these symbols In addition the title for the abscissa is set to the name of the independent variable and for the left and right axes each title is set to the name of the first dependent variable defined for that axis To produce a graph one issues the command PLOT IVAR L 1 L 2 OPTIONS and the available options are RAX R 1 R 2 LIMITS X 1 X 2 SMOOTH SM_TOL ADD NUM_ADD POINTS LEGEND X 1 Y 1 X 2 Y 2 CLEAN LINE CROP _FOR LEGEND NO EDIT T MAIN TITLE T_SUB TITLE AR TITLE T LEFT TITLE T_RIGHT TITLE LEGEND NUMBER TITLE Here IVAR is the column selector of the independent variable and L 1 L 2 L n are the column selectors of the dependent variables to be pl
438. ope with both understanding the program and with the details of a large problem Rev Page 9 MOSES REFERENCE MANUAL IV MOSES BASICS In order to perform any task with MOSES one must be able to communicate with the program in a language understandable by both the user and the program In this section the rules of grammar and syntax of the language employed and the general operation of MOSES will be discussed In discussing the various types of commands some of the words are set off By set off we mean the words are either underlined or printed in bold type depending on the method used to print this manual These words are keywords either commands or options and must be input exactly as written The characters not set off represent the data which takes on the appropriate numeric or alphanumeric value In some cases an underline is part of an option or command For example END_DISPOSE is a command In keeping with the format of this manual these commands are set off and possibly underlined and the user needs to remember that the underline exists as part of the command MOSES provides many features of a programming language In MOSES one can alter the flow of either command or description input make logical checks define variables create macros etc All of these features operate on both commands and descriptions so that with this language one can automate the definition of a model as well as build a s
439. operate on the pov00001 pov file by executing something like the following povray ipov00001 pov w1024 h768 This would take input file pov00001 pov and render it at 1024x768 For further options see the POV Ray documentation Rev Page 67 MOSES REFERENCE MANUAL IX ADVANCED LANGUAGE FEATURES In addition to the basic command structure outlined above MOSES provides many features of a programming language In MOSES one can alter the flow of either command or description input make logical checks define variables create macros etc All of these features operate on both commands and descriptions so that with this language one can automate the definition of a model as well as build a set of specific commands he needs to perform repetitive tasks The language described here is an interpreted string based language In other words all of the functions described here are performed before control is passed to the command interpreter Rev Page 68 MOSES REFERENCE MANUAL IX A Variables MOSES has two types of variables global and local The difference between the two is the extent of their lives A global variable lives forever as long as the database for a given root exists while a local variable vanishes once the procedure which defined it ceases to exist The scheme employed here is similar to that used elsewhere in that if one defines a local variable with the same name as a global one then the global variable will be
440. otate the vessel NUM times adding INC to the roll angle For each increment the program will iterate an equilibrium position for the other degrees of freedom and then compute the righting and wind heeling arms Since the righting arm is based on the equilibrium of the buoyancy and weight of the vessel the vessel weight must have been previously defined either in the model itself or via an amp WEIGHT command For this command only roll is defined as a rotation about an axis which can be changed The default is of course the vessel X axis The YAW option is used to compute righting arms about a skewed axis YAW_ANGLE is the angle of the axis for computing the arms from the vessel X axis If this option Rev Page 359 MOSES REFERENCE MANUAL is used then the axis for the roll is yawed to the angle specified Here the angle is measured positive from the X axis positive toward Y If one uses a angle of 90 degrees the roll axis will be moved 90 degrees toward Y and the righting arms will be about the Y axis In other words here a roll of 2 degrees will make the vessel stern go down In addition to computing the righting arms of the vessel MOSES will compute the wind heeling arms when the WIND option is used Here any load attributes which attract wind AREA PLATE TABLE TANKER structural elements or pieces will be used with WIND_SPEED knots to compute a wind force A heeling moment is computed from this force
441. otted using the left axis If two ordinate axes are needed then the variables to be plotted on the right axis are added by using the option RAX The LIMITS option is used to limit the range of the X axis of a plot Here X1 and X2 define the allowable range of the independent variable Normally each curve is drawn by merely connecting the data points with a series of straight lines If however one uses SMOOTH the program will fit a set of Rev Page 115 MOSES REFERENCE MANUAL cubic splines to the original data so that the root mean square of the fit is less than SM_TOL Additionally one can use the option ADD so that NUM_ADD points are added between the original points and the result plotted Notice that a quite small value of SM _TOL 1E 7 with NUM_ADD 0 will essentially reproduce the original plot while the same value of SM_TOL with NUM_ADD greater than zero will produce a graph which passes through the original points with the additional ones added using the spline fit The POINTS option adds the points specified as centered symbols to the plot No lines will be drawn connecting these points Here LEGEND is the name given for the legend of the new points The X values will be scaled the same as the independent variable and the Y values will be scaled with the left axis This option is useful for adding information to the plot from external sources such as model test data The option CLEAN_LINE instructs MOSES to use color
442. p FINISH command which is valid regardless of the current menu The primary importance of an internal command is that it can be issued from either the INPUT or COMMAND channel therefore it can be set once in the INPUT channel and later reset interactively MOSES uses minimum uniqueness to identify a command in the current list By this we mean that only enough of the command need be specified so that the program can uniquely define the intended command If the command issued is not unique all valid commands which match the one issued will be printed and a prompt for a unique response will be given If one issues a null command a simple carriage return MOSES will print a list of all the currently valid commands For Internal Commands minimum uniqueness in not employed Instead one need only specify the first five characters of the command name Also notice that MOSES uses minimum uniqueness for commands but not for modeling language commands In other words commands which enter through the INPUT channel must be specified completely with the exception of internal commands MOSES has the notion of an escape character This character is used to remove any special meaning associated with the following character Here the escape character is the An example of the use of this character was shown previously with the continuation of a command line In this context the character is used to escape the end of the line If one actually wis
443. p SURFACE menu quite valuable since dealing with the intersections between pieces is provided Once a diffraction mesh has been defined it can be exported to a file for later use with the command amp EXPORT MESH Rev Page 287 MOSES REFERENCE MANUAL XII P 2 Defining Surfaces with Polygons MOSES provides a method for combining closed surfaces in space using simple closed surfaces called blocks These blocks can then be combined in a variety of ways to produce more complex shapes This block combining is accomplished in a menu which one enters with the command amp SURFACE and exits using an END_ amp SURFACE command At this menu level one can proceed to build blocks with the command BLOCK BLOCK_NAME OPTIONS and the available options are LOCATION X Y Z ROLL PITCH YAW STBD PORT BOTH Here BLOCK NAME is the block name and is optional If this name is not sup plied MOSES will provide one Once at the BLOCK menu level building blocks can be generated using any of the commands for describing planes found in the sec tion describing pieces The BLOCK menu can be exited with the END BLOCK command If one has an existing mesh description it can be entered into the program through the MESH menu by typing the command MESH In this menu the valid commands are the same ones used to define panels also found in the section describing pieces The sole purpose of this menu is to accept previously defined me
444. pe of data must be unique A special reserved packet name is NONE If this name is associated with a body for a given type of data then it has the same effect as null data The data in the Hydrodynamic database is used in both frequency and time domain computations Since the database consists of frequency domain quantities its use in the frequency domain is easily inferred For a time domain simulation use of this data is not obvious Here three things happen First an excitation force is created as a cosine series of the frequency domain forces The periods for the series are those specified with the S_PERIOD option on the ENV command The amplitudes are chosen to conform to the specified sea spectrum and a set of phases are chosen Next a mean drift force is computed from the drift force RAOs and the sea spectrum A time varying drift force is created as a cosine series at periods specified with the MD_PERIOD options of the amp ENV command and amplitudes which conform to the drift spectrum and a set of phases Finally the frequency domain added mass and damping matrices are transformed by an inverse Fourier transform into a convolution kernel or retardation function and the equations of motion are integro differential equations Thus any time domain simulation in a seaway first requires the basic data discussed above The basic method of computing mean drift force from the hydrodynamic pressures is to integrate the resul
445. pecifying fixed positions in space there is a part which does not belong to any body GROUND Therefore to define fixed locations in space one can specify that the following points will be fixed by issuing amp DESCRIBE PART GROUND before the fixed points are defined The part system of GROUND is the global system Points to which one attaches structure have a special name nodes Each point which is not a node will have a node associated with it Any load associated with a point is ultimately applied to the structure at the associated node The associated node is the node closest to the point which is in the associated node set Normally this set will be the set of all nodes In some situations however one wishes to exclude certain nodes for being associated and thus from attracting loads This is accomplished with the command amp DESCRIBE NODE_NAS PART_NAME 1 PNT_SEL 1 where PART_NAME i is a part name and PNT_SEL i is a selection criteria which defines the nodes which will not be associated Points which have both a chord a single tubular member with the same outside diameter and at least one other tubular element are called tubular joints Tubular joints are not true parts of a model since they inherit the most of their properties from the elements which intersect to form the joint The concept of a joint is really only used in checking the codes which are applicable to joints and in computing fatigue at the
446. pes of analysis This database can be input directly in this menu or it can be computed from the model The menu is entered with HYDRODYNAMICS and when one has completed his task here he exits with END_HYDRODYNAMICS In order to fully understand the implications of the pressure database it helps to have some information about what the program computes and how it uses the intermediate results Basically the primitive quantity is a set of velocity potentials on each panel which results from the interaction of the panel with the sea The first six of these velocity potentials arise due to unit motion of the body at a given frequency in each of the degrees of freedom These are called radiation velocity potentials The remaining potentials result from a wave being stopped by the body These are called diffraction potentials The diffraction potentials depend not only on wave frequency but also on wave heading All of the potentials are complex numbers a real and an imaginary part for each potential Collectively we will refer to these potentials as diffraction results since they are normally computed via some type of diffraction analysis The forces on Morison s Equation elements are not a part of the pressure database are computed whenever they are needed and are not considered in this Menu In addition to the diffraction potentials the incident wave potentials are also required but since they are easy to compute they are not
447. ple connectors are defined with the following command in the MEDIT menu CONNECTOR CNAME OPTIONS CLASS NODE 1 NODE 2 and the available options are GOi X Y Z ANCHOR THET DTA EULER E_DATA NUM_APPLIED NUMBER TUG ANG DIST and restraints are defined with REST CLASS NODE 1 NODE 2 Here CLASS is a previously defined class and NODE 1 and optionally NODE 2 are the nodes to which the connector will be attached The details of the options and the number of nodes required depends on the category of connector class The GOi options are used to define offsets at the ith vertex of the element Here GO1 defines offsets at the first end etc The values X Y and Z define the coordinates of the offset inches or mm and are defined in the part system If only GO is specified then all vertices will have the same offsets In all cases an offset is defined as the vector from the node to the vertex of the member To connect a body to ground Rev Page 308 MOSES REFERENCE MANUAL either the second node should be omitted or it should be a fixed node Fixed nodes are nodes which belong to a special part GROUND The ANCHOR option is applicable only to connectors which have a class type of ROD or B_CAT and must be used to define the location of the ground attachment for these classes Here the location is defined relative to NODE 1 by a heading and a distance THET is the heading deg from the ves
448. pressure ksi or mpa INP i measured at a global height GH i feet or meters and SC i is the specific gravity of any fluid contained inside the element If OBJECT i is two node names they may include wild characters but must begin with a the attributes will apply to all beams between those two nodes If OBJECT i is an attribute class name begins with a then the attributes will apply to all elements which belong to classes which match OBJECT i If OBJECT i does not begin with either an or a then the attribute will be applied to all members whose names match OBJECT i The command ENVIRONMENT ENV_NAME OPTIONS stores a complete environment in the database The options for this command are the same as those for amp ENV described earlier The command S GRID GRID_NAME GRID_TYPE DEPTH HEIGHT PERIOD is used to define a wave grid Here GRID_TYPE is the type of wave used to gen erate the grid and it must be either REGULAR STOKES STREAM or IN PUT For this command GRID_NAME is the name of the wave grid and DEPTH HEIGHT and PERIOD are the water depth feet or meters wave height feet or Rev Page 166 MOSES REFERENCE MANUAL meters and period sec used in generating the wave as shown in Figure 3 If one of the first three values is specified MOSES will automatically generate a wave grid using either a regular wave a Stokes fifth order wave or a wave generated by a stream function algorithm If I
449. ption keyword TYPE and a set of strings which are normally numbers Here the valid forms of the function are amp NUMBER STRING amp NUMBER REAL RN amp NUMBER INTEGER RN amp NUMBER SIN RN amp NUMBER SIND RN amp NUMBER COS RN amp NUMBER COSD RN amp NUMBER TAN RN amp NUMBER TAND RN amp NUMBER ACOS RN amp NUMBER ASIN RN amp NUMBER ATAN RN amp NUMBER ATANZ X Y amp NUMBER SQRT RN amp NUMBER LN RN amp NUMBER EXP RN amp NUMBER ABS RN amp NUMBER MIN RN 1 RN 2 amp NUMBER MAX RN 1 RN 2 amp NUMBER MEAN RN 1 RN 2 amp NUMBER SORT RN 1 RN 2 amp NUMBER INTERPOLATE X X 1 Y n amp NUMBER NORM RN 1 RN 2 amp NUMBER DOT RN 1 RN 2 amp NUMBER UNIT_VEC RN 1 RN 2 amp NUMBER CROSS RN 1 RN 2 amp NUMBER SCALE SF RN 1 amp NUMBER ADDV SF RN 1 amp NUMBER 3PTS2Q P1 1 P1 2 P3 3 amp NUMBER VECG32L Q VG 1 VG 2 VG 3 amp NUMBER VECL2G Q VL 1 VL 2 VL 3 The result produced depends of course upon the value of TYPE The first option is different from the others in that it returns a value of TRUE if the string is a Rev Page 80 MOSES REFERENCE MANUAL valid number or FALSE if it is not All of the others return a set of numbers As an example of how these functions operate consider the following amp NUMBER REAL 2 3 8 2 This function will re
450. quired The following amp STRING D2M amp DIMEN D METERS amp GET PICK 1 FORCE UNIT TONNES KN END amp ENDSTRING amp MENU ADD T BAR DIM2M D2M Now when one pushes the DIM2M button it will execute the amp STRING macro D2M In here the user is asked to choose the force unit he wants to use The entire Tool Bar structure used in MOSES can be investigated in the file ul Rev Page 92 MOSES REFERENCE MANUAL tra data progm moses mac Rev Page 93 MOSES REFERENCE MANUAL IX G Using Files Normally the user does not have to worry about the files that MOSES is using In some circumstances however the user wants to change the file associated with a given type or to write information to a file of his choice These things can be accomplished with the string function amp F_READ TYPE VAR and command amp FILE ACTION DATA OPTIONS The string function amp F READ is used to read a file and the command amp FILE is used for a variety of tasks When reading or writing files are referred by type and TYPE is this type A TYPE is associated with a file when the file is opened The string function will read a record from the file and store it in the variable VAR The value returned by the function is TRUE if there is no more data to read and FALSE if there is more to read To check to see if a file exists you can use the string function amp INFO FILE_EXISTS filename which returns TRUE if the file exists or FALSE if
451. quired in each tank listed in CMP_SEL to achieve the specified draft and trim If the EQUI option is used MOSES will consider all the information in the barge and cargo input files and find an equilibrium condition The DAMAGE option defines DAM_CMP which is a list of compartment names which are damaged If this is omitted only intact stability will be computed The option S_COND defines the sea states to be considered Here specify several sea triples These three tokens are first a character sea state identifier next a wave height and finally a period The options PERIOD and HEADING define the periods and headings at which the response operators will be computed If they are omitted then headings of 0 45 90 135 180 225 270 and 315 and periods of 4 5 5 5 6 6 5 7 7 5 8 8 5 9 9 5 10 10 5 11 13 15 and 20 seconds are used The option WIND defines the wind speeds used in the analyzes Here W INTACT is the wind speed for intact stability W DAMAGED for damaged stability W_VORTEX for vortex shedding and W_STRUCTURAL for structural analysis The defaults are 100 50 100 and 100 knots respectively If WSTRUCTURAL is zero then wind load is not included in structural load cases The option MO POINTS will provide statistics of motions for the point names specified with PLNAMES This is an easy way to determine the motion accelerations at specified locations on the cargo Control of the spectral motions computation is
452. r the automated launch analysis is shown below INST LAUNCH OPTIONS And the available options are DRAFT L DRAFT1 L_DRAFT2 TRIM L_TRIM1 L_TRIM2 BALLAST BAL SEL AMOUNT BAL AMT CMP BAL CMP SEL EQUI FRICTION FRICT MAXANGLE MAX ANGLE MAXTIME MAX TIME STOP SEP MAXOSC MAXOSC WINCH WINCH NO REPORT NO_ STRUCT FLEXIBLE NONLINEAR ALL POINT FLX RIG AMOD L AMOD This command assumes that an equal number of drafts have been specified with the DRAFT option and trims have been specified with the TRIM option It will perform a launch for each draft and trim pair If no draft and trim are specified a single launch will be performed with a trim of 3 degrees and a draft so that the Rev Page 341 MOSES REFERENCE MANUAL tilt pin is at the water surface The draft specified on this command is measured at midships The data expected after the BALLAST AMOUNT CMP BAL and EQUI options are the same as for the INST_TRANSP command defined above The skidway friction is specified via the FRICTION option Likewise the max imum angle of tilt for the primary tilt beam is specified with the MAXANGLE option Normally a launch will proceed until the maximum time specified with MAXTIME is reached or until 5 oscillations of the jacket have been made How ever if the STOP SEP option is used the simulation will stop when the jacket separates from the barge The MAXOSC option is used to speci
453. r the environment When the system is altered the changes are again remembered until the system is altered again Thus one can perform numerous simulations on the same basic system without rereading the model When one issues a simulation command the simulation is performed the results stored in the database and control is returned to the user No reports are automatically produced and no questions are asked so that simulations can easily be performed in the background To obtain reports of the results one must enter one of the sections of commands which were designed to answer questions about the results of simulations These sections of commands are called Post Processing Menus or Disposition Menus In these sections of the program one may be asked questions himself so it is best if these tasks are performed interactively The database structure of MOSES allows for seamless restartability One can terminate the program at almost any point and resume execution later with no loss of information This structure and the root file concept discussed later free the user Rev Page 8 MOSES REFERENCE MANUAL from having to worry about naming reconnecting and remembering the names of restart files and provide superior performance to previous systems Since nothing is necessary to restart the program nothing further will be said about it but the capability is one of the primary features of MOSES While MOSES is initially not very
454. r zeroth moment you can use any units you wish e F_ SPECTRUM defines either a wind or wave spectrum as a function of fre quency Here DATA is F 1 S 1 F m S m F i is a Period sec and S i is the spectral value Since the spectral values will later be scaled to get the proper zeroth moment you can use any units you wish e M_GROWTH defines the marine growth for elements Here the DATA is Z 1 ADD 1 Z m ADD n where Z i is the depth and ADD i is the increase in element outside diameter inches or mm due to marine growth e W HISTORY defines a wind history Here DATA is a set of three n numbers T 1 V 1 ANG 1 T a V n ANG n Here T i is the time V i is the wind speed knots and ANG i is the direction from which the wind comes degrees Now what MOSES does is to compute the mean wind speed of the history you input and subtract the mean from the input values Now at each computation step the deviation history speed is added to the mean This Rev Page 154 MOSES REFERENCE MANUAL speed and the history wind heading are then used to compute a wind force LT MULTIPLIER is used to define load multipliers which vary with time Here DATA is T 1 V 1 T n V n where T i is the time and V i is the multiplier at that time The TYPE of curve accepts the option PERIODIC If this option is specified then the defined values will be repeated with a period of the last
455. ral loads on the panel PANEL_NAME will be mapped to all points matching PNT_SEL i The command FPANEL PANEL_NAME AREA XC YC ZC NX NY NZ WLLEN defines a panel Here PANEL_NAME is the name of the panel XC YC and ZC are the coordinates feet or meters of its centroid NX NY and NZ are the components of its normal and WLLEN is the length of the intersection of the panel with the waterline feet or meters After a panel has been defined the pressures acting on it are defined through a set of velocity potentials with commands FPPHI PER RPRX IPRX RPRY IPRY Rev Page 375 MOSES REFERENCE MANUAL RPRRZ IPRRZ RPDH 1 IPDH 1 Here PER is one of the periods T i and the remainder of the data are velocity potentials per unit wave amplitude feet or meters These commands must be in decreasing order of period In other words the value of PER for a given command must be less than the value of PER for the previous one and greater than PER for the next one The velocity potentials are pairs of real and imaginary numbers The first six pair twelve numbers are the radiation potentials and the remainder are diffraction potentials The diffraction potentials correspond to the headings H i and are in the same order The final type of data for a panel is defined with FDELP PER RPRXX IPRXX RPRXY IPRXY RPRRZZ IPRRZZ RPDHX 1 IPDHX 1 These quantities are the gradients of the potentia
456. ral nodes To eliminate many of these difficulties MOSES has a command available in the MEDIT menu Rev Page 284 MOSES REFERENCE MANUAL M PAN FIX TOL_OP TOL_B OPTIONS where the available options are BOUNDARY NODES YES NO COMPART CMP_SEL PIECE PIECE SEL PANEL PAN_SEL POINTS PNT SEL X X_BOX1 X_BOX2 Y Y_BOX1 Y_BOX2 Z Z BOX1 Z BOX2 DIRECTION DIR The purpose of this command is to change the nodes to which the loads will be mapped for selected panels The details of the options will be addressed later The two numbers TOL_OP and TOL B control the remapping To see how these work consider the situation discussed above In particular suppose that you have large panels and small plates so that there are several plates which are inside a panel By default there will be no load applied to the nodes at the vertices of the interior generalized plates M PAN FIX will solve this problem by adding points on the boundary and interior of the panel to the list of points which will receive the load Here TOL_OP feet or meters defines an out of plane tolerance Only points within TOL_OP distance along the normal of the plane will be considered Likewise TOL_B feet or meters defines a boundary tolerance and only points with a distance of TOL_B of the boundary will be considered to belong to the boundary These two tolerances define what is meant by on the boundary and inside the panel If a point is w
457. rce on a stationary tanker Instead of simply using the current velocity in the formulae MOSES uses the relative current tanker velocity so that viscous damping is obtained as well as applied force This approach works quite nicely for the basic forces and yaw moment but produces zero moment for a tanker which has zero velocity about the center of pressure regardless of the yaw angular velocity To overcome this problem an additional term has been added which depends on the lateral coefficient and the yaw angular velocity The YAW FACTOR option specifies a multiplier for this extra term A value of zero for YF means that the term will not be used while a value of one means that it will be used with no modification Here SIZE is the size of the tanker in thousands of deadweight tons e g a SIZE of 100 would denote a 100 000 DWT tanker If all of the other dimensions are omitted they will be interpolated from an internal database The other data are length depth beam extra frontal area extra lateral area and distance from the origin to the longitudinal center of the tanker Here the units are feet or meters for distances and ft 2 or m 2 for areas MOSES uses the major dimensions to compute the wind and current areas and the extra areas are for wind only There is an internal database of default extra areas for AEX and AEY These values are replaced when a non zero value is used for AEX or AEY In particular the lateral wind area is given
458. re one should issue SP_POINT ENV_NAME OPTIONS where the available options are SEA SEA_NAME THET HS PERIOD GAMMA SP_TYPE TYPE SPREAD EXP The results produced here are based on the results of the last FR POINT command and the options were discussed above The results obtained with the ST POINT command consist of motions measured from a point in vessel coordinates Often one desires a global motion measured from a specified reference Results of this type can be obtained via the command PMOTION PNT_SEL ENV_NAME OPTIONS where the available options are SEA SEA NAME THET HS PERIOD GAMMA SP TYPE TYPE SPREAD EXP E_PERIOD EP 1 EP 2 CSTEEP YES NO Here PN T_SEL is a selector for the points whose motion will be computed and the other options are the same as for the ST POINT command When this command is issued statistics for the global dynamic motion of the Interest Points selected by the selector PNT_SEL will be computed In addition MOSES will compute the mean global position of the point and the mean motion of the point The mean motion is the vector from the global position of the point the last time the amp DESCRIBE INTEREST command was issued The mean motion is added to the dynamic motion with the sign of the mean to produce a total motion away from the marked global position of the point The options were discussed above A command similar to the above is
459. re root of the area for generalized plates In particular to define the effective length multipliers for beams one uses the option KFAC Here KZ is used for bending about the Z axis while KY is used for bending about the Y axis If this option is not used both factors will be set to 1 Element lengths for beams include the effect of any offsets invoked by either the GO Rev Page 247 MOSES REFERENCE MANUAL Node 21 Node 22 762X25 762X19 762X25 3m 2m L 2m L 4m amp DEFAULT FY 290 TUB762 TUBE 762 25 LEN 2 TUB762 TUBE 762 19 TUB762 TUBE 762 25 LEN 2 BEAM TUB762 LOA 3000 LOB 4000 21 22 DESCRIPTION OF BEAM FIGURE 8 and LO options on the BEAM card or the OFFSET option on the INMODEL command The BLENG or BLY and BLZ options can be used to alter the buckling lengths about each axis Here the dimensions are feet or meters The BLENG BELE_NAME construct offers a way to bind the buckling length of an element to the load state of another element Here BELE_NAME is the name of the brace element If this option is exercised then the KL factors of the basic element will be those input if the brace element is in compression If the brace element is in tension then the factor for out of plane will be the same as for inplane When this option is used the compression lengths will be used in any report or computation outside of the Structural Post Processing Menu An alternative way of defin
460. red by a forgotten selector There is a string function amp str_pst ACTION OPTION which gives information about the results obtained in the STRPOST Menu Here ACTION should be chosen from E CHECK E_FATIGUE E_LOADS E_STRESS J_CHECK J_FATIGUE C_CHECK C_LOADS C_FOUNDATION or DU Rev Page 446 MOSES REFERENCE MANUAL RATION and the only option is INITIALIZE MOSES saves a set of data about the worst situation encountered for each type of report in the STRPOST Menu This information is initialized for all sets of data each time the menu is entered or for a particular set when the INITIALIZE option is used The prefix stands for the type of data to be returned E_ for elements J for joints and C_ for connectors The word following the _ is the type of command for which the data will be returned CHECK for a code check FATIGUE for CDRs LOAD for internal loads and STRESS for stresses The ACTION DURATION is different from all of the others It returns information about the duration data used in computing fatigue In particular it will return 4 numbers The number of spectra used to define the duration The length of time of the duration in days The length of tow in in feet or meters and The average speed of the tow in feet or meters per second The data returned for the other values of ACTION vary in detail but in general will be The name of the element joint which was the most severe The value w
461. rns the CM factor used in the AISC and API code checks KFAC results the K factor used in the code checks and LAMBDA returns the strong and weak axis values of the slenderness param eter HAS_P D returns YES of the element includes p delta loads NO otherwise FLOODED returns YES if the element is flooded NO otherwise The last set of options return non empty values only for generalized plate elements WIDTH AREA CENTROID and THICKNESS Here width and length are Rev Page 241 MOSES REFERENCE MANUAL the maximum distance feet or meters across the Y and X element axis respectively The area is returned in ft 2 or m 2 and the centroid in feet or meters The thickness is returned in inches or mm SUBELEMENT returns the subelement names for the specified element excluding the base element itself In other words this action will return a null value for a triangular plate The string function which returns information about a subelement is amp SUBELEMENT ACTION NAME Where ACTION must be either RATIO STRESS CDR NODES RELEASES E_COORDINATES or OFFSETS and NAME is the name of the subelement The options here return the same data as the same one for the ELEMENT string function Rev Page 242 MOSES REFERENCE MANUAL XII N 1 Element System Both beams and generalized plates have a special direction along the length for a beam and normal for a generalized plate Thus for a beam the local X axis will be from the first end to
462. ro to this time The simulation will still begin at zero but the environment at time equal zero will have the same as that at the specified time If TTRA_SET and CYCLES are omitted a translation of zero will be used If however TTRA SET is FIND then MOSES will attempt to find a time so that during the synthesis a peak will be found which corresponds to the probable maximum during a simulation with NCYCLES In essence the following algorithm is used e Compute the wave amplitudes e If the amplitude is within 85 percent of the desired value keep it as a viable peak e Keep finding peaks until there are 10 candidates e Pick the candidate which is closest to the desired value It is possible that a good solution to this problem will not be found In particular if NCYCLES is too large then no peak greater than that specified may be found The other extreme is if NCYCLES is too small in comparison to the observation time Here it may not be possible to get a time interval in which a peak will not be too large The above scheme will however normally yield a result which is larger than that requested The option T REINFORCE is used to pick the phases of the frequency compo Rev Page 163 MOSES REFERENCE MANUAL nents If the sea was defined as a regular wave then the phase is zero If however the sea was specified via a spectrum another method is used Here the phases are chosen as phi i TB w i Here phi i is
463. rst two cases both the load cases and the portion of the system to be considered must be defined before the commands to compute the results are issued With vibration modes a single command suffices The remainder of this discussion is applicable only to structural analysis and applied loads Before proceeding however it is best to make a distinction between load cases and load sets A load set is either one of the intrinsic load sets that the program generates or a user defined load set Load sets are combined to form load cases It is these cases that are used to obtain the results When emitting applied loads or when performing a structural analysis it is the load cases which will be used It is beneficial to think of the solution as being performed in one of four types Frequency Domain Time snap shots of a frequency domain Events during a MOSES generated process or At events in a user defined process Rev Page 444 MOSES REFERENCE MANUAL Here the types refer to the type of loadings which will be applied to the structure MOSES is different from most programs in that the structural dynamics is included directly in the analysis via generalized degrees of freedom Thus if generalized degrees of freedom are included during an analysis the deformation inertia is automatically included when the load case is generated The result is a true load case which accurately describes the static as well as the dynamic behavior The type of s
464. s A TYPE of LONG_STRENGTH produces a summary of the vessel longitudinal strength properties To produce reports for selected bodies and parts for load groups selected by the load Rev Page 130 MOSES REFERENCE MANUAL group selector one issues the command LOADG_SUM TYPE 1 TYPE 2 OPTIONS where TYPE i must be chosen from ATTRIBUTE UD_FORCE or MATRI CES and the available options are those of the amp REP_SELECT command A TYPE of MATRICES is used for reporting the mass added mass and damping matrices for the group A TYPE of ATTRIBUTES is used for the buoyancy and area contributions to the group Finally a TYPE of UD_FORCE is used for re porting user defined loads for the group The next command is used to obtain summaries of the properties of beams It returns reports for elements selected with the element selector for classes selected by the class selector and with end nodes which match the node selectors The form of the command is BEAM_SUM TYPE 1 TYPE 2 OPTIONS where TYPE i must be chosen from LOADS PROPERTIES UD FORCE CLEARANCE SCF TUBE ENDS or VORTEX and the available options are those of the REP_SELECT command and for a type of VORTEX W_VELOCITY WIND_VELOCITY C_VELOCITY CURRENT_VELOCITY BRIEF A TYPE of PROPERTIES reports the location offsets length etc of beams A TYPE of LOADS reports the intrinsic load attributes weight and diameters for elements and UD_FORCE r
465. s TRUE then the commands which follow will be executed until the amp ELSE is encountered If LPHRASE 1 is FALSE then MOSES will evaluate LPHRASE 2 If it is TRUE then the commands following amp ELSEIF will be executed until amp ELSE is encountered otherwise the commands between amp ELSE and amp ENDIF will be executed Both amp ELSEIF and KELSE may be omitted and more than one amp ELSEIF can be placed between an amp IF and amp ELSE but amp IF and amp ENDIF must always be present There is virtually no limit on the nesting of amp IF blocks In MOSES the concept of repetition is implemented via the constructs amp LOOP INDEX BEGVAL ENDVAL INCR amp LOOP VAR LIST 1 LIST n amp NEXT LPHRASE amp EXIT LPHRASE amp ENDLOOP The amp LOOP command marks the beginning of a set of commands which will be repeated and the amp ENDLOOP command marks the end When this construct is encountered MOSES will continue to execute the commands delimited until a termination criteria is satisfied Termination can occur in one of two ways depending upon the form of the amp LOOP command itself The parameters on the first form of the amp LOOP command allow for an indexed loop In other words INDEX is the name of a local variable which will be set to the integer BEGVAL at the beginning of the loop and it will be updated to its current value plus INCR at each repetition Loops of this type will terminate when
466. s and define connections The restriction to MEDIT will be made explicit when these commands are defined Within either of these menus the model is defined with a set of commands defining the primitives upon which MOSES will operate Each of these will be discussed in detail below During this discussion we will also define the commands which alter the settings of some of the primitives It should be remembered that even though one can issue these commands within a model defining menu they are internal commands Rev Page 136 MOSES REFERENCE MANUAL it normally does not make sense to alter something until it has been completely defined Also remember that MOSES was designed to be an integrated program for both simulating a process and performing a stress analysis of the system during the process To accomplish this integration the model which one prepares for MOSES is conceptually different than one would prepare for a program designed for either of the two tasks alone Thus a model for MOSES is not simply a model of the structure of the system Instead it is a model from which MOSES can compute not only the stiffness of the system but also the loads which act on the system The basic idea behind the modeling language is to convey as much of the needed information as possible with the minimum amount of description Thus we have modeling commands which define the physical components of the system instead of defining only some aspect
467. s are given by the stability criteria of the different regulatory bodies All angles except the equilibrium angle defined below are relative to the equilibrium position First let us define the symbols R a The righting arm at the angle a a The wind heeling arm at the angle a RA a The area under the righting arm at the angle a HA a The area under the wind heeling arm at the angle a DWT The smallest angle at which a WT point goes below the water DNWT The smallest angle at which a NWT point goes below the water The angles are shown in the figure below Now Rev the macros compute GM The distance from the metacenter to the center of gravity DOWN H The down flooding height at equilibrium ZCROSS The equilibrium angle without wind THETA1 The first angle T at which R T H T THETA2 The second angle T at which R T H T RANGE of stability Is the second angle T at which R T 0 R_M_EQUI The RANGE FACTOR ZCROSS Here FACTOR is specified on the option DANG DNWT DANG_T1 DNWT THETA1 DWT_T1 DWT THETA1 ANG_DIFF THETA2 THETA1 ANG MARM The angle at which the RA peaks AR_RATIO The ratio of the RA HA with both measured at the minimum of DANG and THETA2 ARR 30 The ratio of the RA HA with both measured at the minimum of THETA2 DANG or 30 degrees AR_RESID RA T RA THETA1 HA T HA THETAL1 where T is the smallest of the down flooding
468. s corresponding to the angles specified with ANGLE Notice that VDM 1 corresponds to ANGL 1 VDM 2 with ANGL 2 etc The units for VDM are bforce sec feet or meters R TANAKA refers to roll damping coefficients while P_TANAKA is for pitch This menu is exactly the same as the one you have before with TANAKA The final command which can be used for defining load group attributes is different from the others Here instead of defining specific load attributes one defines the Rev Page 273 MOSES REFERENCE MANUAL wind and current load attributes of an entire vessel The particular form of this command is TANKER SIZE TLEN TDEP TBEAM AEX AEY LCP OPTIONS and the available options are CATEGORY CAT_NAME CBOW YAW FACTOR YF WAVE PM WAVMUL This command causes wind and current forces to be computed for a tanker of the specified size according to the data presented in Prediction of Wind and Current Loads on VLCCs by the Oil Companies International Forum OCIMF NOTICE these curves assume that the vessel is defined so that the X axis goes from bow to stern and that the keel of the vessel is at the origin of the part These forces will be added to any other forces computed for the load group The option CBOW should be used if the tanker has a bulbous bow and the option YAW FACTOR controls the yaw viscous damping during a time domain simulation The OCIMF formulae were derived for computing the wind and current fo
469. s of it Of course one must have a method of overriding the built in assumptions and in some cases there is no easy way to model what one desires The basic ingredients for performing a simulation are bodies which are considered rigid and composed of parts Bodies are connected with special elements called connectors A part is the smallest entity upon which a structural analysis can be performed In essence a part is simply a named connected subset of the model Most properties of the system are described by the attributes of the parts In other words every attribute of the system must be an attribute of some part of the system Therefore everything except bodies belong to some part There is a special part which does not belong to any body and it is in this part that elements which connect bodies reside These elements called connectors are quite important They define both the boundary conditions for a stress analysis and the constraints on the bodies for a simulation To avoid confusion elements which connect parts elements which are connected to nodes in different parts must belong to a part with a type of PCONNECT Thus the only elements which can span parts are restraints connectors or PCONNECTors A PCONNECT part should not have any nodes which belong to it The geometry of the model is defined by quantities called points Points all have names beginning with a The subset of the points to which structural elements are conn
470. s of the EL i must belong to the same body The INITIAL option instructs MOSES to initialize the set If this option is specified and this is the first tip hook set defined the body will be moved so that the hook point is directly below the boom point If the option is selected and this is not the first tip hook set then the length of the tip hook elements will be changed so that there is no sag in the lines The DEACTIVATE option instructs MOSES to to deactivate all previously de fined tip hook sets The ORIENT option can be used to alter the definition of the body system of the body to which the EL i are connected With this option the order of the sling nodes is used to define the local body system The origin of this system is defined as the midpoint of the vector connecting the first two sling nodes The local Y axis is in the direction of the first node toward the second the local Z axis is from the Rev Page 315 MOSES REFERENCE MANUAL second node to the third and the local X axis is given by the right hand rule During static processing the configuration of the body is defined by the height of the hook attachment point above the waterplane and two angles These two angles are called pitch and roll The two angles are defined by vectors which can be defined via a amp DEFAULT command The VERTICAL option can be used to automatically define these three quantities Here pitch is the angle which the normal to t
471. s product of the SAV1 vector and the generalized plate Z axis e If the generalized plate Z axis is parallel to the SAV1 vector then the generalized plate Y axis is determined by the cross product of the SAV2 vector with the local Z axis For both beams and generalized plates the default behavior can be changed with two options on the element definition command REFN REFNOD DIR LOC SAV1 1 SAV1 2 SAV1 3 SAV2 1 SAV2 2 SAV2 3 The REFN option replaces the default SAV1 vector with a unit vector from the element origin first point specified to the point defined by REFNOD The Rev Page 243 MOSES REFERENCE MANUAL DIR_LOC option can be used to completely redefine both the SAV1 and SAV2 vectors If less than 4 numbers are specified with this option then only SAV1 will be redefined The local system definition described can be altered again for both beams and gen eralized plates In particular for generalized plates the DIR_LOC option can be used with only the string NODES following This instructs MOSES to use the vec tor from the local origin to the second node as the SAV1 vector For beams one can specify the option CA CHANG This option rotates the local system about the local X axis an angle of CHANG degrees The rotation of the system is about the beam x axis positive towards the beam negative Y axis right hand rule If for a beam one wants the strong axis of beams to be horizontal the SA
472. s the first number as the desired X value the next N 2 numbers as an array of Xs and the last N 2 numbers as an array of Ys It returns the Y values which corresponds to the first number input Of course the X values must be in increasing order The next remainder of TYPEs allow one to treat strings as vectors of numbers For a type of NORM MOSES will return a string which is the square root of the sum of the squares of the numerical arguments For a TYPE of DOT the number of numerical arguments must be divisible by two and it returns the inner product of two vectors represented by the 2 n numbers With UNIT_VEC the value returned is the input vector scaled by its length With SCALE the first number is a multiplier and the function will return N numbers which represent the remaining numbers multiplied by the first ADDV takes the first number and uses it as a scalar multiplier for the first N 2 numbers and it vectorially adds the result to the second N 2 numbers The last three functions deal with matrices and vectors The TYPE 3PTS2Q returns Rev Page 81 MOSES REFERENCE MANUAL a direction cosine matrix Here P1 P2 and P3 are the coordinates of three points You need nine numbers here The origin of the local system is at P1 The vector from P1 to P2 points in the direction of the local X axis and the vector from P1 to P3 points in the direction of the local Z axis This direction cosine matrix will transform local vectors i
473. s the kernel of the convolution by CONV_FACTOR before it is applied If CONV_FACTOR is zero the convolution will not be added and if CONV_FACTOR is one all of the convolu tion will be added The PERI_USE option allows one to replace the convolution terms in the equations of motion with single added mass and damping matrices The matrices used will be the frequency domain matrices at the specified period PER This eliminates any numerical problems with the convolution The defaults here CONV_FACTOR 1 and PER 0 i e use all of the convolution in the time domain In the time domain the buoyancy is computed correctly at each time step Since the frequency domain forces already include the effects of the wave elevation this buoyancy is computed assuming that the water surface is flat If WAVE_RUNUP is used with a YES NO of YES then a different algorithm is used Here the water surface is assumed to be adequately described by the incident potential and the correct Froude Krylov force computed When this option is used the Froude Krylov force is not included in the frequency domain forces applied The string function which returns data for bodies is amp BODY ACTION BODY_NAME OPTION Here BODY_NAME is the name of the body for which data is desired and ACTION Rev Page 195 MOSES REFERENCE MANUAL must be either CURRENT E NODES P_NAME EXTREMES DRAFT LOCATION VELOCITY MXSUBMERGENCE BOTCLEARANCE NWT_DOWN
474. s the maximum of the x coordinates of the vertices Additionally the y and z coordinates must be between the minimum values of the vertices minus TOL_OP and the maximum values plus TOL_OP Finally the MEDIT command MAP MAPNAM MAP_SEL 1 MAP_SEL 2 can be used to completely define the map for a panel Here MAPNAM is the name of the panel map and MAP_SEL i are a set of selectors which define the map One can look at the maps with the commands amp STATUS MAP and amp STATUS N_MAP If Strip Theory is used to compute hydrodynamics the planes defined in a PGEN piece are used for the Two Dimensional hydrodynamic computation Thus for these Rev Page 286 MOSES REFERENCE MANUAL pieces one needs a reasonable longitudinal distribution and several over 10 planes even if two would suffice hydrostatically In contrast to most programs the mesh used for Three Dimensional Diffraction is the same as that used for hydrostatics Whenever one asks for hydrodynamic pres sures to be computed MOSES will convert this mesh to one which describes the submerged portion of the body in the initial configuration Thus one can analyze different drafts and trims without changing the mesh definition MOSES has an au tomatic refinement capability controlled by the two options M DISTANCE and M_WLFRACTION of the amp PARAMETER command When the mesh is be ing used for hydrodynamic computations MOSES will automatically refine the mesh so
475. s the minimum bottom clearance and TOP_OF_LEG specifies the distance from the waterline to the top of leg in the final installed position If this option is used the jacket will be lowered to this location In this position the reported hookload would also be the on bottom weight The FIRST FLOOD option provides input for the names of the tanks to be flooded first along with a description of these tanks Tank names used here would normally use the wild character as shown FIRST_FLOOD B Row B Legs In this example all tanks beginning with B would be flooded and tank names would normally be defined as BlLeg and B2Leg for instance In a similar fashion the second stage flooding is described using the SECOND FLOOD option The DAMAGED_LEG option is used to define the tank assumed to be damaged With this option MOSES will return to the original undamaged floating position and Rev Page 343 MOSES REFERENCE MANUAL compute a new floating position assuming the specified tank to be open to sea This macro is designed to perform a simulation and a corresponding structural analysis by default If the structural analysis is not required simply use the NO STRUCT option The final command in this sequence of simulations and structural solutions provides structural post processing for all the load cases previously created and has the fol lowing syntax INST SPOST OPTIONS And the available options are RESIZE UP_
476. s the tube diameter and the option SLA COEFFICIENT defines S COE is the slam coefficient nominally 3 and V is the relative velocity be tween the beam and the water and Vv is the relative velocity vertically Now the maximum bending moment in the beam assuming that the load is uniformly applied over the length can be written as M SFIXITY W L L Here the SLA_FIXITY is used to define S FIXITY which is a number that depends on the fixity of the beam It is 1 8 if the beam is simply supported and 1 12 if it is Rev Page 183 MOSES REFERENCE MANUAL built in This in turn gives a maximum stress in the beam of s S_DAF SCF R M I Where R is the beam radius I is the section inertia SCF is the stress concentration factor and the option SLA DAF defines S_DAF is the dynamic amplification factor which is nominally 2 After the impulse is applied and released the beam will freely vibrate with decreasing amplitude s k s k 1 exp 200 pi S CDAMP Here S CDAMP is the percentage of critical damping defined with the SLA_CDAMP option Now the total damage due to a single impulse is CDR SUM 1 N s k Here N is the number of allowable cycles at the stress s k and the sum continues until there is no further damage There remain two unanswered questions the first is how many slam events do we have and what are the velocities associated with each slam event The first question is easily answered if one assu
477. s to map to points which are not nodes then they should use the NODES option with a value of NO for YES NO With the options X Y or Z the first dimension defines the beginning of the box minimum di mension and the second one defines the end of the box maximum dimension For example if one issues M_PAN_FIX X 0 50 then only panels which have the average of their vertices in the x direction between 0 and 50 will be remapped The POINTS option defines the set of points which will be used for the mapping By default PNT_SEL is set to so that all points will be used The last option DIRECTION completely alters the behavior of the remapping This option is useful for remapping meshes that are connected to beam models In this case the concepts of closeness used above are changed to measures along a single axis Here DIR which must be chosen from X Y or Z defines the direction of the mapping Here the remapping works as above except that now in the panel means that a point has its selected coordinate between the extremes of the selected coordinates of the panel By selected coordinate we mean either the x y or z coordinate depending on the value of DIR Thus suppose that we specified X for DIR A point will be used for the mapping if its x coordinate is between X_MIN TOL_B and X MAX TOL_B where X_MIN is the minimum value of the x coordinates of the vertices of the panel and X MAX i
478. s used for elements with two vertices and the Rev Page 424 MOSES REFERENCE MANUAL LDGFORCE LG_NAME NODE_NAME 1 NODE_NAME n OPTIONS LDGFORCE command is used for generalized plate elements or load groups For an ELMFORCE command forces will be computed at the two end nodes of all elements which are selected by the selector ELE NAME The LDGFORCE command operates somewhat differently Here one can select only a single group LG_NAME The other data on this command is a set of node names NODE_NAME i If this data is specified then the forces will be computed at the specified nodes The computation of force at the specified nodes is accomplished by first computing a force applied to the element A least square fit is then performed to reduce this total force and moment to forces at the specified nodes Rev Page 425 MOSES REFERENCE MANUAL XXV E Post Processing Connector Forces MOSES has several commands available for post processing connector forces All of these commands make the results available in the Disposition Menu and have a common option EVENTS E_BEG E_END E_INC Here E BEG and E_END are the beginning and ending event numbers for which the results will be computed and E_INC is an event increment The corresponding form of the REPORT command is REPORT REP_NAMES 1 REP_NAME 2 OPTIONS Here REP_NAMES i is a set of report names which may be selected and will depend on the command issued T
479. se characters and for LOWER the converse will occur FIRST transforms only the first character in the string into upper case Finally COMMA adds a comma after each token in the string and an and between the last two tokens FMT can have at most 8 characters To compress a logical phrase one can use the function amp LOGICAL LPHRASE Here a logical phrase is a string of numbers characters and logical variables com bined by logical operators Here numbers are any string which can be converted to a number and logical variables are strings with values of either TRUE or FALSE Any two tokens can be compared by the logical operators EQ and NE For num bers four additional operators are available LT LE GT and GE These six operators denote respectively equal not equal less than less than or equal greater than and greater than or equal A single logical variable can be modified by the operator NOT and two logical variables can be combined by the two operators AND and OR As examples Rev Page 76 MOSES REFERENCE MANUAL consider amp LOGICAL amp LOGICAL amp LOGICAL amp LOGICAL A EQ A NOT A EQ A AND B EQ B 5 LE 4 5 GT 4 OR A EQ B _ The strings resulting from these functions would be respectively TRUE FALSE FALSE and TRUE Rev Page 77 MOSES REFERENCE MANUAL IX D 1 The amp INFO String Function Often one wishes to know the current se
480. se of the results MOSES then returns to the simulation as if the RARM_STATIC had not been issued Rev Page 416 MOSES REFERENCE MANUAL XXV POST PROCESSING OF A PROCESS By entering the command PRCPOST the user can enter the Process Post Processing Menu to obtain results of a process In this menu one can select certain aspects of the process for further investigation MOSES then places him in the Disposition Menu to either view results find the extremes or statistics of the results graph the results store the results or report the results The precise commands available in this menu depend on the type of process being considered and the detail of the model MOSES checks the database to see if infor mation for a given command is available If it is not then the user will not see the command in the command list After obtaining all desired results the user should issue the END_PRCPOST command to return to the Main Menu This menu offers extreme flexibility However at times the user may wish to receive a fixed body of information Two commands LAUP_STD and STP STD are available The LAUP_STD command is used for fixed reports and graphs of a launch It will produce a report of the trajectory velocity acceleration and constraint forces as well as pictures of the launch and graphs of the tiltbeam reactions versus position The STP_STD command is for post processing a static process Here the reports of position stabilit
481. sed At each position the X and Y components of the restoring force and the magnitude of the restoring force are reported Also the tension the horizontal force and ratio will be reported for the lines with maximum and minimum tensions During this process all other bodies are held fixed in their position in the initial configuration Rev Page 348 MOSES REFERENCE MANUAL XVI D Obtaining the Results for a Pile To aid in designing or checking a pile MOSES has the command PILE DESIGN PILE_NAME OPTIONS where the options are FORCE FX FY FZ MX MY MZ DISPLACEMENT DX DY DZ RX RY RZ When this command is issued MOSES will take the pile defined by PILE NAME and apply either a force or a displacement at the top of the pile A force is specified by the FORCE option where forces and moments are specified in the global coor dinates in bforce and bforce blength An imposed displacement is specified via the DISPLACEMENT option and is defined in the global system inches or mm and deg When this command is issued MOSES will iterate a solution for the pile with the conditions specified At the conclusion of the computation the user is placed in the Disposition Menu where he may dispose of the results as he sees fit When reporting these results three different reports are available LOCATION FORCE and STRESS Rev Page 349 MOSES REFERENCE MANUAL XVI E Designing a Lifting Sling To aid in the design of a lifting s
482. sed to give you information during a program session This information is also written to a file the log file so that you can review it later The information is scrollable so that you can look at any portion of it any time a command is expected Rev Page 12 MOSES REFERENCE MANUAL As you will see below the display can be toggled back and forth between the log the user manual and for a window interface a picture The tools bar can be used to change settings and obtain reports without actually inputing the commands to do so At the moment it does not entirely suffice in place of the command line but in the future it will When you push one of the buttons on the tool bar a menu will drop down In this new menu buttons which are plane will immediately do what the title says Those which end in a gt will drop down another level of menu To clear a menu you should push the top area which is blank except for a lt A large tree of menus can be cleared by simply hitting an Enter Keyboard Shortcuts There are special keys that are mapped to commands or which move one about in the display They are in either display amp FINISH Ctl F amp PICTURE Ctl P amp PICTURE RENDER GL Ctl G amp PICTURE RENDER WF Ctl W TOP the home key BOTTOM the end key P the page up key P the page down key i the up cursor key the down cursor key The first of these command terminates
483. sel X axis in the current configuration positive toward Y to the anchor line and DTA is the horizontal distance feet or meters from the attachment point to the anchor The vertical coordinate is not defined since it is given by the depth of the anchor on the class definition The EULER option is applicable only to connectors which have a class type of GSPR LMU or FOUNDATION and it is used to change the element system of the connector By default the element system is aligned with the body system of the body to which the first node belongs E DATA can be a set of Euler angles which changes this orientation There are three angles a roll a pitch and a yaw These are rotations about the element system In particular suppose that the element system is in its default position Now give it a yaw a rotation about the element Z axis and then a pitch a rotation about the new element Y axis and finally a roll a rotation about the new element X axis to put it into the desired position As a quick way of defining these angles MOSES will also accept values of X X Y Y Z or Z These align the element X axis with the body axis specified In other words a value of Y is the same thing as an value of 0 0 90 The option NUM_APPLIED allows one to have a multiplier NUMBER for a connector The results for a connector are first computed based on the specified properties and then all results are multiplied by NUMBER In particu
484. selected element in each class which has the greatest unity ratio Finally if one specifies DETAIL as an option the original report will be expanded to include checks of all members for all selected load cases at all load points Notice that DETAIL STANDARD and SUMMARY may all be used on the same command to produce reports of all three types If no options are specified STANDARD is assumed For a TYPE of DISPLACEMENT three additional options are available REPORT FILE and LOCAL The first two of these options are used to control whether or not the results are written to a post processing file or to the standard output file The default is to write them only to the output file If FILE YES is specified then the results will be written to both places If FILE YES REPORT NO is speci fied then the results will only be written to the post processing file By default the displacements are reported in the body part system If one uses the option LOCAL NO then the displacements will be reported in the current global system Notice since the structural results can come from many different processes at many different events the current global system may not be a good system in which to view the deflections produced at events with a different configuration The type of unity ratio which will be computed for types of CRUSH and CODE_CHECK depends upon the last CODE option The type of code which will be used depends upon the las
485. shes The mesh generation commands from prior versions of the program are accepted here For these earlier meshes the vertices must be defined before the panels Commands are also available for defining a plate mesh In fact the term mesh now refers to a structural plate mesh a hydrostatic mesh and a hydrodynamic Rev Page 288 MOSES REFERENCE MANUAL mesh The differences between these types of mesh are discussed later Remember to exit from the MESH menu by typing END_MESH The BLOCK and MESH menus basically serve to describe the polygons that make up a surface When these have been described one returns to the SURFACE menu to complete the building process Blocks can be manipulated using the following commands LIST _ BLOCK MOVE_BLOCK BLOCK_NAME ANSNAM X Y Z RX RY RZ DELETE BLOCK BLOCK_NAME 1 BLOCK_NAME n REFLECT BLOCK BLOCK NAME ANSNAM AXIS The LIST_BLOCK command will provide a list of all blocks currently defined MOVE_BLOCK will create a new block ANSNAM based on BLOCK_NAME moved from its original location to that specified by X Y Z RX RY RZ To delete an existing block use the DELETE BLOCK command and specify the block name or names to delete Remember that wild characters are valid here Finally the REFLECT_BLOCK command will take an existing block BLOCK_NAME and create a reflection of the specified AXIS X Y or Z The new block created by the reflection will be named ANSNAM Blocks can be com
486. sical devices e DOCUMENT can only be connected to DEFAULT TEX POSTSCRIPT or PCL physical devices e TABLE can only be connected to HTML or CSV physical devices e PPOUT can only be connected to DEFAULT physical devices Rev Page 31 MOSES REFERENCE MANUAL e MODEL can only be connected to DEFAULT physical devices With the exception of the SCREEN channels are connected to files For example the results for channel OUTPUT will be written to the file OUTXXXXX TXT in the ROOT ANS directory In general the file name is the first three characters of the channel names followed by a five character number and having a suffix which corresponds to the physical device Here the physical device suffixes are DEFAULT txt POSTSCRIPT eps TEX tex PCL pel DXF dxf JPG jpg PNG png UGX ugx HTML htm CSV CSV If you want to change the directory where the answer files are stored you can use the command amp FILE USE discussed below If you want to change the location of the file for a given channel you can use the FILE can be used Normally all of the graphics for a given run will be stored in a single file except for types of JPG or PNG This can be changed with the SINGLE option where a YES NO of YES will result in each frame of graphics being written to a separate file Each time a amp CHANNEL is issued the file currently connected to the channel will be closed and a new file will be used For example suppose GRA00001 eps is the
487. single value This is done with the remainder of the data S DESIRED is the desired value of the signal and may be omitted It is used when sensors are connected to a control system Here S_VAL is either NORM or VALUES and S_B and S_N are integers What the last three things do is to tell MOSES how to take the general data and Rev Page 156 MOSES REFERENCE MANUAL transform it into a single number to monitor For example NORM 1 3 says to take a vector signal and to take the norm of the first three values as the signal This may be useful when monitoring C_FORCE connector force Likewise VALUE 3 Says to select the third component of the vector signal This could be useful for monitoring the height of a point If the CONVOLUTION option is selected then the raw signal is processed by the convolution before it is monitored Also the DERIVATIVE option can be used to define a signal which is the velocity relative velocity or change in length of a connector instead of the default position and length LIMITS is used to define a lower and upper bound of the signal If These bounds are exceeded then an alarm is sounded During a time domain simulation ac tion is then taken based on the ACTION option Here A TYPE must be cho sen from NONE STOP SIMULATION STOP_WINCH DEACTIVATE or CHANGE PROP and the action will be applied to RECEIVER For example suppose one specified amp DESCRIBE SENSOR M_LINE1 SIGNAL C_FORCE LINE1 NORM 1 3
488. smart it can learn In other words the user can teach the program how to perform many commands when a single one is issued This capability is implemented by allowing users to define macros These are really sets of commands which the program associates with a single name and any time the name is issued as a command the entire set will be executed thus freeing the user from the tedious task of issuing many commands The flexibility of MOSES may at first overwhelm a new user but with a little experience one quickly learns to enjoy the power of the system In the sections which follow all of the features of MOSES will be discussed In many cases the utility of a feature may not be apparent when it is discussed The primary reason is that there are many facets of the MOSES language which are not really necessary but are quite useful once one has mastered the basics Thus instead of worrying about how each feature is to be used one should proceed throughout the manual briefly to get a general feel of what one can accomplish and how to do it The next step is to carefully look over the samples supplied with this installation to see how typical problems may be attacked The next step in solving a problem is to create a simple problem which has all of the attributes of the real complex one to be solved and to use it as a prototype in understanding It is always easier to use small problems to complete ones understanding than it is to c
489. specified with TOB the results will be adjusted to reflect a 3 hour simulation Note that the time domain results used here come from a time domain synthesis where the waterplane is assumed to remain constant If only the DO_TIME option is used only time domain cases will be created To provide the frequency domain and time cases in the same run use both the DO_FREQ and the DO_TIME options It is prudent to make a quick preliminary run to check the position of the structures on the barge before investing in the longer duration run that performs the entire analysis For these types of runs use of the various NO_ options will turn off the specified computation If the FLEXIBLE option is exercised the flexibility of the barge will be consid ered Otherwise the barge will be considered as rigid If tiedowns are included in the model a sequential structural analysis will be performed The first pass through the structural solver will create a dead load case without tiedowns while the second pass will create dynamic load cases including tiedowns The default action regarding tiedowns is to assume that a tension connection does not exist at the barge end of the tiedown Another way to say this is the footprint of the tiedown brace lands on a doubler plate and the welding of the barge deck plate to the web frames under neath is not sufficient to develop tension For these situations the load cases for the tiedowns are conservatively multipli
490. sponse operator solutions into some thing more meaningful MOSES associates a process name with each set of response operator loads cases The PROCESS option tells MOSES to use the response op erators associated with process PRC_NAME for all options which follow Normally one wishes to combine the response operators with the mean to obtain the results Without any other action MOSES will use the frequency mean load case for this process in the combination Use of the MEAN option instructs the program to use the case MLCNAME instead of FRQMEAN i for all cases defined after the MEAN option is encountered until a new MEAN is encountered The FATIGUE option can be used to alter the total time of exposure to a given environment or the process to which it is applied If this option is used then whenever the duration DURATION_NAME is used to compute fatigue the actual exposure for a given component will be WTIME TOTTIME SUMTIME where TOTTIME days is that specified with the option WTIME is the time specified when the component was defined and SUMTIME is the sum of WTIME i for the duration If TOW_VEL is specified the length of the tow will be computed as the tow velocity Rev Page 450 MOSES REFERENCE MANUAL times the duration of the tow where TOW_VEL is in ft sec or m sec and the duration of the tow is determined by summing the durations When this option is used the process associated with the duration is also changed to be t
491. ssel and jacket instead of a linear one If this option is selected the TIME option should also be selected This option is used to select a time domain solution of the structural system Here SEANAME is the name of a seastate which was previously defined by a amp ENV command CASE i is the name which the user wishes to give to the case and T i is the time at which the loads will be combined to produce the snapshot If this option is omitted the solution will be in the frequency domain Rev Page 435 MOSES REFERENCE MANUAL XXVI C Defining Load Cases The loads which will be generated by MOSES are determined by the LCASE com mand This command has different forms to generate different loads One can input as many of these commands as desired and each one will define at least one load case If two of these commands are used which specify the same load case name then the results of both of them will be combined Also one can change the current process name when defining load cases in order to perform a single analysis for several different physical situations In general the form of this command is LCASE OPTION DATA The next option is used for analyzing fixed structures subjected to an environment It uses the options STATIC ENV_ NAME LCNAME CHECK PERIODIC This will produce a set of loads which result from the environment ENV_NAME and the resulting load case name will be LCNAME Here the system will be assumed
492. st processing information and MOSES model data respectively The options serve to define the ap pearance of the results The CHANNEL option associates a channel with the logi cal device More will be said about channels later but the valid values for CHANAM are exactly the same as for LDVNAM The STYLE option defines a style which will normally be used when writing things to this logical device For graphics devices three styles can be specified with T_STYLE defining the style for text on the graphics N STYLE the numbers and A_STYLE the axes The MARGIN option defines the margins for a page in points IM and OM define the inside and outside margins and TM and BM define the top and bottom margin The LANDSCAPE option can alter the orientation of the print on the paper If YES NO is NO the results are placed on the paper so that they should be read with the long edge of the paper on the left If YES NO is YES then the page will be rotated 90 degrees The margins are a property of the paper itself with the program taking care of the details when landscape and double sided printing are performed The PSOURCE option selects the current paper tray Here TRAY must be either UPPER or LOWER and this option only works for certain physical Rev Page 30 MOSES REFERENCE MANUAL devices Channels are defined with the command amp CHANNEL CHANAM OPTIONS where the available options are PAGE_DIMEN WIDTH HEIGHT
493. st node belongs For both DF i is the name of the degrees of freedom which will be restrained and must be chosen from the list X Y Z RX RY RZ A FIX class will fix the specified degrees of freedom of the element nodes If all degrees of freedom are to be restrained then one can simply specify FIX with no other values The SPR class is used to define linear springs Here SPV i is the value of the spring bforce blength for degrees of freedom X Y and Z and bforce blength radian for degrees of freedom RX RY and RZ These classes are used for defining both restraints and connectors During a stress analysis the behavior of a restraint and a connector with the same class is identical During a simulation however a connector will behave differently than one may expect During a simulation rigid constraints are capable of restraining only translation Thus if one selects a rotational connector it will only be applied during the stress analysis Also the connector applied during a simulation will be the same regardless of whether FIX or SPR was used to define the connection The difference however will appear during the stress analysis where the specified flexibility will be applied A GAP connector is a rigid connector between two nodes It will produce a force between the two nodes acting from the second node to the first to keep the distance between them greater than or equal to the distance between them when the gap was def
494. stion can be answered by issuing the following command EQUI H OPTIONS and the available options are ECHO YES NO FIX DOF 1 DOF N NUMITER ITER MAX TOLERANCE HE RO PI WAVE WLENGTH STEEP CREST When this command is issued MOSES will iterate until equilibrium is found The program simply iterates until the center of buoyancy is above or below the center of gravity and the buoyancy equals the weight If one wishes to see the details of the resulting position he should issue the amp STATUS command afterward The ECHO option controls the trace of iterations which is printed at the terminal If YES NO is YES then the trace will be printed otherwise it will not The option FIX fixes the specified degrees of freedom during the iteration Here DOF i can be HEAVE ROLL and or PITCH The option NUMITER is used to override the default 20 number of iterations and TOLERANCE is used to override the default closure tolerances for heave roll and pitch respectively The values are a percentage of weight for heave and arms for the angular motions The defaults are 0 0001 0 01 0 01 Finally the WAVE option controls the static wave as discussed previously Rev Page 357 MOSES REFERENCE MANUAL XVIII D Longitudinal Strength To produce longitudinal strength results the user should issue the command MOMENT OPTIONS where the available options are WAVE WLENGTH STEEP CREST ALLOW ALLOW STRESS ALL
495. stored in the pressure database Also for some computations MOSES needs to have not only the potentials but their gradient so they are included in the database From these basic ingredients MOSES then computes a new or Total database which includes e The forces which unit amplitude regular waves exert on a stationary body e The bodies added mass and damping matrices e The mean drift force which a regular wave exerts on a stationary body e The change in mean drift force with a motion of the body and e The damping on a body due to time variation of the mean drift force Rev Page 370 MOSES REFERENCE MANUAL These results are a function of wave heading forward speed and encounter frequency The Hydrodynamic database actually consists of two different types of data for each body Pressure data and Mean Drift Force Data Also the data is stored by Packet Name Thus it is possible to have several different sets of hydrodynamic data avail able for each body For example one can have different sets for different draft and trim conditions or different sets computed with different methods A packet of data is associated with body whenever the packet is Generated or Imported In general the user is free to define the packet name for the data when it is created but if the name already exists then a new name will be created The same name can exist for each of the different types of data but all names for a given ty
496. sued If no REP_NAMEs are supplied all reports will be printed The only option available for reporting is EVENTS The first of these commands R_DETAIL ROD_NAME OPTIONS allows one to look at the situation at all points in the rod at a single event EVENT NUMBER defined by the option EVENTS EVENT_NUMBER and the valid REP_NAMES i must be either FORCE or STRESS The command R_ENVELOPE ROD_NAME OPTIONS yields the minimum and maximum values at all points in the rod over all events Rev Page 429 MOSES REFERENCE MANUAL selected by the option EVENTS E_BEG E_END E_INC and the valid REP_NAMES i must be either FORCE STRESS or LOCATION Finally the command R VIEW ROD NAME OPTIONS gives the maximum absolute values of the values over the points in the rod as a function of time The available option is EVENTS E BEG EEND E_INC and the valid REP_NAMES i must be either FORCE STRESS or LOCATION Most of the quantities are self explanatory except with stresses Here you get the normal axial bending torsion and shear stresses Also you get a column for the maximum axial normal force This is just the combination of the axial and bending at the extreme fibers Finally there are three utilization ratios the maximum normal stress divided by the yield stress the Von Mises stress divided by the yield stress and a code check of the interaction of hoop stress with normal stress according to RP2A working stress e
497. sues amp DESCRIBE LOAD_GROUP LG_NAME NODE SEL 1 NODE SEL n OPTIONS where the options are DAMP FUSE YES NO AMASS_FUSE YES NO and all load group attributes which follow belong to the specified load group Here LG_NAME is the name which one wishes to give to the following load group and NODE_SEL i are a set of selectors defining the points to which the loads will be mapped The force from a load group is automatically distributed to the specified nodes as if the nodes were connected to the point of application by a rigid structure Note however the rigid structure is not required since the force is distributed by a least squares technique as shown in Figure 21 The options DAMP_FUSE and AMASS FUSE control the use of matrices defined with FAMASS and DRAG Rev Page 265 MOSES REFERENCE MANUAL commands in the frequency domain By default they are not used If YES NO is set to YES the matrices will be included Rigid structure not required NOD3 NOD2 LOAD DISTRIBUTION FIGURE 21 E NOD1 One can obtain the values of some of the present attributes of a load group with the string function amp LOADG LSEL OPTION the valid options are PERCENT W EIGHT RADII and CG The string returned here is the name of the load group followed by the applicable values for each load group which matches the selector LSEL This value is multiplied by the load group multiplier and m
498. sults are scaled by the ratio of duration time to simulation time The results are summed over the selected durations so one can compute fatigue in both domains and over all lifetime situations If a duration environment is defined with more than one spectrum then MOSES provides two ways to compute the average period The choice is governed with the T AVERAGE option of the amp PARAMETER command In the following we specifically discuss the role of the REP_SELECT command but any of the options discussed for this command can be issued on the option which requests fatigue or cycle information In other words amp REP_SELECT SN X JOINT POST FATIGUE produces the same result as JOINT POST FATIGUE SN X The same can be said of the BEAM _ POST or PLATE POST commands Rev Page 172 MOSES REFERENCE MANUAL XII H 1 Defining SN Curves Before any fatigue can be computed an SN curve must be defined This is accom plished with the command amp REP SELECT OPTIONS and the available options are SN CURVE TYPE 1 N 1 S n N n THICK SN TO POWER MAXCOR FLAG S_IMP FACTOR SFACTOR F STRESS MULT Once a curve has been defined one need only specify SN CURVE to select CURVE for use in computing cumulative damage ratios MOSES has a set of curves automatically generated and hence these do not need to be defined to be used The automatic ones are the e API_X and API_XP curves from API
499. system The orientation of the new frame is defined by either three Euler angles RX RY and RZ or by up to four nodes When using the Euler angles the new frame orientation is determined by three successive rotations about the Z Y and X axes respectively When using nodes the location and orientation both depend upon the number of nodes specified For one node the orientation of the frame is the same as the part frame but the new origin is at the specified node For two nodes the new origin is at the first node and the orientation is the same as that of the element system of a beam between the two nodes For three nodes the new origin is at the midpoint between the first two nodes the new X axis is perpendicular to the plane formed by the nodes and the new Y axis points from the first node to the second one specified Finally for four nodes the origin is at the midpoint between the second and the fourth nodes and the Y axis points from the fourth node toward the second one and the X axis goes from the origin to the midpoint of the line segment connecting the first and third nodes The options BBC_MUL MULT CO_SCF SCF_TYPE LEN FACTOR FRACHOL MAX CHD LEN MAXCHOL CHD _FIXITY CHD FIX MIN SCF MIN SCF establish defaults for the same options on the point definition command and are discussed there The options COLOR NAME COL TEXTURE NAME TEX X_ SCALE Y_SCALE define the default color and texture for
500. systems or systems with tensions only element equilibrium may fail because steps which are too large are being taken Here MOSES thinks it needs to move a good bit but once it gets there it finds it has gone too far Here the way to help is to use MOVE_MAX to make the maximum step size change smaller Rev Page 403 MOSES REFERENCE MANUAL This option sets two additional parameters MAX TRANSLATE and MAX_ANGLE which limits step size The defaults are 1 foot 3 meters for MAX TRANSLATE and 2 degrees for MAX_ANGLE The advice given here may appear contradictory but there are two distinct cases If you have problems you first need to find out the cause The best way to eliminate difficulties is to begin with a good guess This eliminates several problems you no longer need big steps to find equilibrium and you are much more certain that the configuration you have found is in fact the one you want Rev Page 404 MOSES REFERENCE MANUAL XXII TIME DOMAIN SIMULATION To initiate a time domain simulation use the command TDOM OPTIONS where the available options are NO_CAPSIZE YES NO EQUI NEWMARK YES NO BETA ALPHA CONVERGE NUMB TOL RESTART RESTART TIME RESET RESTART_TIME STORE STORE INCREMENT When a time domain simulation is requested MOSES will convert the frequency domain hydrodynamic pressure data for use in the time domain This will results in a constant added mass a convolution kerne
501. t CODE option Here TYPE may be either AISC API NOR SOK or ISO The value CCAT defines the class of check for AISC or API type checks It should be omitted for ISO or NORSOK type checks and it must be either WS or LRFD for AISC or API checks If it is omitted for these checks WS will be assumed If one wishes to use an LRFD check it is his responsibility to build load cases which include the proper multipliers This option is remembered Rev Page 467 MOSES REFERENCE MANUAL between BEAM code checks and JOINT checks Thus if one has previously used the CODE option he need not be re issued EDITION defines the edition of RP2A which will be used checked for the check If it is OLD then the first supplement of the 21st edition will be used otherwise the new method will be used If one wishes to use an LRFD check it is his responsibility to build load cases which include the proper multipliers For a type of CRUSH the results computed consist of the force and moment in the chord due to the braces stresses in the chord as a function of angle around the chord and a unity ratio The unity ratio is the larger of the stress unity based on an allowable of 6Fy and the shear unity based on an allowable of 4Fy The stress reported is the stress which produced the unity ratio This angle is measured clockwise from the first brace For the options STANDARD and SUMMARY only the results at the angle which corresponds to the highest unity check
502. t Thus if you use things without a prefix they probably should be defined first The INITIALIZE and SUFFIX options defines initial values and suffixes for the widget If an initial value is specified then this will be the value displayed in the box as if the user input it A suffix will not normally be needed but if it is specified then what is emitted by this widget will be the concatenation of the prefix the value and the suffix Ideally the words in the list should suffice to tell the user what he is selecting Some time this is not the case and you need to add a L DESCRIPTION option which defines a long description This description is written in a pop up window when on mouses over the description The ACTIVATE option is complicated When this option is used the widget is initially hidden Here KEY_TO is an option on the previous widget and when the previous widget selects KEY_TO the hidden widget is shown giving choices which only make sense for the chosen value For example WIDGET BOX DEFLECTION Show Deflected Shape YES NO Rev Page 90 MOSES REFERENCE MANUAL WIDGET BOX DEFLECTION Deflection Multiplier ACTIVATE YES Here the second widget is hidden unless YES is selected by the first one Rev Page 91 MOSES REFERENCE MANUAL IX F Programming the Tool Bar The MOSES Tool Bar is a set of buttons at the top of the display area which when pushed drop down another set of buttons Each of th
503. t To proceed consider two coordinate systems a local system used in this menu only and the part system The local X axis lies along the length of the piece positive aft The local Z axis is perpendicular to the local X axis and is positive up The local y axis is defined by the local X and Z axes and the right hand rule positive to starboard The surface of the piece is now defined by its intersection with a set of planes These planes have constant local X values and the intersection is defined by a set of local points Yi Zi The options define how the points will be interpreted The default is to define only the positive Y portion of the plane allowing MOSES to automatically produce the negative half If one specifies STBD no reflection will be performed If PORT is specified then the plane is reflected and the positive portion is deleted Finally if BOTH Rev Page 282 MOSES REFERENCE MANUAL is specified one must define both halves of the plane In this case one first defines the positive portion and proceeds around the contour to define the negative portion In all cases one starts at the bottom of the station minimum z and zero y and proceeds around counter clockwise point 2 is has non decreasing z from point 1 If using Strip Theory the user should set TYPE to be STRIP and the STBD PORT and BOTH options cannot be used The CS options work exactly the same as described above The TOL_OFF option allows
504. t Mean Av of 1 1000 Lowest Mean Maximum Mean Minimum Mean Pred Max Mean Pred Min Mean of the variables selected These quantities are calculated for the It will also compute averages for the peaks encountered Notice these peaks are computed from the sam ples themselves and not by assuming any type of probability distribution Extreme values of the maximum and minimum are also predicted This prediction is controlled by the EXTREMES option Here TIME is the time in seconds for the extreme If for example TIME is 3600 then the predicted value will be the probable maximum in one hour The default is three hours In general the predicted extreme is of the form PE MEAN DEVIAT FACTOR here MEAN is the mean and the plus is used for the maximum and the minus for the minimum Traditionally the standard deviation is used for DEVIAT and FACTOR Rev Page 112 MOSES REFERENCE MANUAL is given by FACTOR sqrt 2 Log r Np where Np is the number of peaks in the sample and r is the ratio of the length of the sample to TIME The values of DEVIATION and MULTIPLIER can be used to change this behavior In particular the value of DEVIATION is used to change DEVIAT Here a value of STANDARD will use the standard deviation while a value of PEAKS will use the largest peak and smallest peak values minus the mean PEAKS is the default and normally gives better predictions than the traditional method The final value MU
505. t computed at the same end by joint fatigue but it is not excessively conservative for slamming fatigue Rev Page 182 MOSES REFERENCE MANUAL XII H 5 Beam Fatigue Due to Slamming If one is computing fatigue in the time domain then the damage due to slamming is correctly included When fatigue is considered in the frequency domain however the situation is quite different Here an element which is out of the water in the mean position occasionally enters the water and a slam event occurs MOSES has a special algorithm to compute fatigue due to these slamming events This computation depends on the parameters specified on either the BEAM_POST command or the amp REP SELECT OPTIONS and the options applicable here are SLA COEFFICIENT S_COE SLA _FIXITY S_FIXITY SLA_DAF S_DAF SLA _CDAMP _CDAMP SLA MULTIPLIER S VEL 1 S MUL 1 S VEL n S MUL n The data will be discussed below and only beams that are out of the water in the mean position and of which are allowed to have forces due to added inertia will be considered for beam fatigue First notice that here we do not have the normal frequency domain phenomenon Instead we have an occasional impulsive load which acts on the beam and when the load is removed then beam experiences a free vibration decay Thus according to DNV the force per unit length on a beam due to slamming is W 5 rho D S_COE abs V Vv Where rho is the water density D i
506. t of selectors S_ NAME i define a set of names which will be selected The second set ELNAME i define a set of names which will be excluded The objective of the selection process is to take a set of values and to apply a selection rule which will result in a selected subset The selector SEL_NAME operates on the admissible set in two steps The first is to search the entire list of values for a match with any of the SNAMEs This results in a subset which is then subject to exclusion by the second step In other words the results of the first step are checked for a match against any of the ELNAMEs If a match is found that item is removed from the selected set A special menu is provided to define and examine selection criteria This menu is entered via the command amp SELECT and the valid commands are END_ amp SEL NAME SEL_NAME OPTION Rev Page 40 MOSES REFERENCE MANUAL SELECT _NAME 1 S NAME 2 S NAME n EXCEPT E_NAME 1 ENAME 2 ENAME n INFO_SEL SEL_NAME OPTION LIST_SEL OPTION The first of these commands define the current selection criteria name All of the commands which follow will deal with the current name until it is redefined If no option is included then the action which follows will be added to the existing defini tion of the selection criteria To start over one should use the option DELETE on the NAME command This will remove any previous data
507. t rests on the barge skidway An illustration of the node arrangement is shown in Figure 23 BODY_NAME 1 is the body name assigned to the barge where the tiltpins are attached and XB YB and ZB are the coordinates in the BODY_NAME 1 body system of the beginning of the skidway on body BODY _NAME 1 Here the skidway should be considered to be at the height of the jacket launch leg centerline above the barge origin Also B1 i are selectors for the nodes in BODY_NAME 1 which will be used for connecting the jacket to the barge BODY_NAME 2 is the name of an optional second body over which the skidway may pass and B2 i are again node selectors The dynamic coefficient of friction for the launchway is specified with the FRIC option as DYNFRC The tiltbeam geometry for the launchway is specified via the TPIN option Here XP YP and ZP are the body coordinates of the primary tiltpin feet or meters TPRIDEP is the height of the primary tiltbeam feet or meters MAX_ANGLE the maximum angle the tiltbeam is allowed to rotate until the secondary tiltbeam becomes active deg TSECDEP is the height of the sec ondary tiltbeam feet or meters and DIST is the distance along the skidway from the primary tiltbeam to the secondary one feet or meters Here again the depth of the beams should be considered to be the vertical distance from the tiltpin to the centerline of the jacket leg If there is no secondary tiltbeam one should omit the val
508. t system and the options that control it are considered in the next section All of the structural elements have additional attributes that can be associated with them and which are defined with options Most of these options can be used with any type of structural element and these are considered in a section below Options which are specific to a given type of element are considered with the element definition While one can alter existing elements by issuing a new BEAM or PLATE command this is often cumbersome since all of the data must be redefined An alternative is offered by the command ED_ELEMENT OBJECT OPTIONS where OBJECT is the name of the object to which the options will apply If OBJECT is two node names they may include wild characters but must begin with an the attributes will apply to all beams between those two nodes If OBJECT is an attribute class name begins with a then the attributes will apply to all elements which belong to classes which match OBJECT If OBJECT begins with neither an nor a then the attribute will be applied to all members whose names match OBJECT Here any option which is valid for the elements being edited can be specified The ED ELEMENT command works in the input channel through INMODEL or under the MEDIT menu The string function which returns information about an element is amp ELEMENT ACTION DATA Where ACTION must be either EN_NODES CLASS CATEGORY ELE_TYPE STRW_USE
509. ta must be omitted In other words with spectral results no environmental data will be allowed With RAOs these commands not only initiate the computation of quantities in an irregular sea but are also amp ENV commands Thus when one issues one of these commands with a non blank ENV_NAME he is altering the definition of this environment within the database If ENV_NAME is omitted then the environment used will be totally defined by the options specified To produce a time domain process from the frequency response and and an environ ment one should issue FR_2TIME ENV_NAME OPTIONS where the available options are SEA SEA_NAME THET HS PERIOD GAMMA _SP_TYPE TYPE SPREAD EXP TIME TOBSERV DELTA TIME TTRA SET NCYCLES T REINFORCE TB This command generates a set of configurations of the system and the connector forces by summing the frequency response with the sea One is not put into the Disposition Menu Instead one can enter the Process Post Processing menu where on can look at the position of points the relative motion of points connector forces etc You cannot however use the TRAJECTORY POSITION STABILITY TANK FLD TANK BAL HOLE FLOODING R VIEW R ENVELOPE or R DETAIL commands because data for them is not generated Also notice that this command creates events for a process and it will overwrite any existing events you may have Finally this command is not only useful for looking at a true sample
510. te there is only one value DCOSINES returns the 3X3 direction cosine matrix which transforms vectors in the element sys tem into the part system The next three option return element length and element buckling length and the length of each segment in feet or meters respectively No value is returned for SEG_LENG when the element is a generalized plate The next three set of options are valid for beams and plates The SN option returns N values of SN where N is the number of segments plus one for a beam and one for a plate The SCF option returns the SCFs used for beam fatigue There are three time the number of segments plus one for a beam and one number for plates The J_SCF option returns the eight SCFs used for joint fatigue at each end of the beam if both ends are parts of tubular joints If an end is not part of a tubular joint the NOT_A_TUBULAR JOINT will be returned for that end If the end is part of a tubular joint but has the default values then TUBULAR_JOINT_DEFAULTS will be returned The next set of options are again valid for all types of elements The next four options NODES RELEASES E COORDINATES and OFFSETS return the nodes the releases six values of YES or NO the coordinates three values in feet or meters and the offsets three values in inches or mm at each vertex of the element The next set of the actions return values only for beam elements CFB returns the compression flange bracing in inches or mm and CM retu
511. ted before starting If the NO_EQUI option is used the basic position is used Notice that the GM may not be defined when using this option The results of this command are plots of the righting arm heeling arm area ratio curves and two reports The first report is the standard stability report The second presents the condition the allowables and the results for each stability criterion along with a statement of PASS or FAIL We apologize for the complexity here but we tried to make these commands applica ble to as many rules as possible Only the checks which are specified will be checked and reported We compute the maximum allowable KG for a set of drafts intact wind speed and Rev Page 367 MOSES REFERENCE MANUAL a damage wind speed with the command KG_ALLOW where the options are WIND I WIND D WIND YAW Y_ANGLE 1 DAMAGE DAM_CMP 1 DRAFTS D1 D2 KG_TOL KG_TOL KG MIN KG MIN KG MAX KG MAX CEN_LATERAL XC YC ZC U_CURRENT COEF_WIND W_COEF WIND MAC any of the options discussed above The options here are the same as those for the STAB_OK command except that one should specify wind speeds for both intact and damaged cases with WIND and one can specify more that one thing with YAW and DAMAGE The only new options are KG_TOL which define the tolerance feet or meters for the compu tation of the allowable KG DRAFTS which defines the dr
512. tem The precise distribution generated depends on whether or not the jacket has tipped off the barge Before tipping a single distribution will be generated After tipping the distribution will be composed of two trapezoidal distributions each TBLEN feet or meters long which are symmetric about the tiltpin The relative intensities at the pin and at the ends of each distribution are governed by two parameters QBEG and QMID Here QMID is the relative load intensity under the tiltpin percent QBEG is the relative load intensity at the ends of the tiltbeam percent and TBLEN is one half the tiltbeam length feet or meters Notice that QMID QBEG should equal 100 and that they only describe one half of the loading on the tiltbeam This load condition is illustrated in Figure 27 For a uniform loading values of 50 and 50 should be used for QMID and QBEG respectively For a trapezoidal loading with twice the load at the pin compared to the ends values of 66 and 34 should be used QMID QBEG en ROCKER ARM LOAD DISTRIBUTION FIGURE 27 If either SSOLVE NONLINEAR or BODSOLVE is used for solving a launch MOSES will create connections modeling the launchway at each load case The type of restraint supplied in the area of the tiltbeam is dependent on the use of the BEAM option of the LLEG command This option defines a bending stiffness and length for the beam Before tipping all jacket nodes between the aft end of the
513. ter will flow into the compartment or contents will flow out depending on the location of the valves internal pressure and amount of ballast in the compartment This change of fluid in the compartment occurs statically and can be observed using amp STATUS COMPARTMENT The maximum volume of fluid in the compartment is artificially limited by that specified using the add ballast options The DOWN_FLOOD option instructs MOSES to fill the compartment up to the waterline whenever the lowest vent point goes below the water Here no maximum Rev Page 298 MOSES REFERENCE MANUAL need to be specified This option is particularly useful for hydrostatic stability and capsizing studies Down flooding points on tanks that have been marked with DOWN FLOOD are not used when computing down flooding during a RARM command Thus this option can be used to get a correct picture of the stability No tice that when this command is issued water may be drained from the compartment The DYNAMIC option defines tanks which will be flooded dynamically when a time domain simulation is performed In essence this option opens the valves of all holes with a type of F_VALVE at the beginning of a time domain simulation Using this option is reasonably delicate It should be the last item specified on the command Any reference to dynamic compartments after they are selected will turn off the dynamic behavior There are three options which influence this floo
514. th will be altered and the method of specifying the new length is controlled by the options If one uses LENGTH he is simply defining each line which matches the selectors to have a length of the first segment of LEN feet or meters Using L_DELTA is similar to the above except that DLEN feet or meters is added to the existing length Alternately one could specify either LLHORIZONTAL or L_TENSION With these options a new length of the first segment will again be defined but here the new length is calculated so that either the tension or horizontal force has the value FORCE in the initial configuration To alter the location of the anchor use the options ANCHOR XA YA ZA A HORIZONTAL FORCE Rev Page 321 MOSES REFERENCE MANUAL A TENSION FORCE Here CONN SEL i j are the selectors for lines whose anchor location will be al tered and the method of specifying the new location of the anchor is controlled by the options If one uses ANCHOR he is simply defining the global x y and z coordinates feet or meters of the anchor of each line which matches the selectors The z coordinate specified here is honored for all flexible connectors except a type of H_CAT where it is ignored Alternately one could specify either A TENSION or A HORIZONTAL which instructs MOSES to compute the location so that either the tension or horizontal force has the value FORCE in the initial configuration The force of H CAT conn
515. the commands amp TYPE MESSAGE amp CTYPE MESSAGE amp CUTYPE MESSAGE These commands will write MESSAGE to the terminal whenever they are executed The difference between the commands is that the amp TYPE command left justifies the output line while the other two center the line on the screen The amp CUTYPE command not only centers the line but also underlines it If one is writing macros it is often necessary to report to the user an error or warning This is accomplished with the command amp ERROR CLASS MESSAGE Here CLASS is the class of warning and can be either WARNING ERROR or FATAL and MESSAGE is the message you wish to have printed along with the class If CLASS is FATAL then the program will terminate after printing the message In addition there is a menu which can be used to define reports amp REPORT HEAD 1 HEAD 2 OPTIONS and the available options are HARD BOTH The report generated will have a primary heading of HEAD 1 and a secondary heading of HEAD 2 If no options are specified it will be written to the terminal If Rev Page 37 MOSES REFERENCE MANUAL HARD is specified it will be written to the output file and if BOTH then it will be written to both devices The menu is exited with an END_REPORT command Inside this menu the commands TYPE MESSAGE CTYPE MESSAGE CUTYPE MESSAGE are available These commands are exactly the same as those discussed above Rev Page 3
516. the definition itself serve to alter the settings defined by those from amp DEFAULT The options defined above allow one to effectively define which elements are exposed to different environments To give the user even more control there is an additional concept the Category Each load attribute in MOSES has a category name associated with it and each category name has a set of multipliers for each load type The category name is associated with a load attribute when it is defined in a manner similar to the load type flags The amp DEFAULT command accepts two options BAS_CAT BASE_CAT_NAME EXT_CAT EXTRA_CAT_NAME the BAS_CAT option defines a Category name BASE CAT NAME to the load at tributes defined with the structural elements themselves EXT_CAT defines a Cat Rev Page 187 MOSES REFERENCE MANUAL egory name EXTRA_CAT_NAME for any additional load attributes those which belong to Load Groups or those defined with a ELAT command Now when a element or load attribute is defined the default Category either BASE CAT_NAME or EXTRA CAT NAME will be associated with it This default association can be changed with the option CATEGORY CAT_NAME which associates CAT_NAME with the attribute This option is availableon BEAM or PLATE commands and any command which begins with a Reports are available which produce sums of weight and buoyancy by Category As an example consider BEAM BODY_NAME CATEGORY INSIDE N
517. the model Here NAME_COL is any color which has been previously defined See the section on Colors for a discussion on defining colors The NAME_TEX value for TEXTURE is the name of a file in either X data textures or X data local textures here MOSES is store in X The X_SCALE and Y_SCALE are scale factors which will be applied to the texture The NAME_TEX of NONE will yield a null default texture The options BAS CATEGORY NAME_BAS Rev Page 145 MOSES REFERENCE MANUAL EXT CATEGORY NAME EXT define the default Category for structural element and additional load attributes re spectively NAME_BAS will be the category for all load attributes directly associated with a structural elements and NAME_EXT will be the category for all additional load attributes unless they are specifically defined on the element or load attribute command The default scheme is also used for defining default properties of element classes The material properties are set via the options SPGRAVITY SPGR DENSITY RHO EMODULUS EMOD POI RAT POIRAT ALPHA ALPHA FYIELD FYIELD SN TYPE 1 SN1_A SN1_B SN1_R TYPE 2 SN2_A SN2_B SN2_R Here SPGR is used to define the material density by the ratio of its density to that of standard water RHO is the material density pounds ft 3 or newtons m 3 EMOD is the Young s Modulus ksi or mpa POIRAT is the Poisson s Ratio ALPHA is the coefficient of thermal expansion
518. the obvious choices except for connectors where their BODY and PART is GROUND The ENDS of a string are simply the points at the ends of the string PARENT and PIECE are a bit more abstract and the definition depends on the type of string For structural elements with load attributes the PIECE is SLAT and for those without load attributes it is SELE The PARENT for all structural elements is the element class For connectors the piece is CONNECTOR and the parent is the element class For panels the piece is the piece name and the parent is the compartment name For load group attributes the piece is either BUOY 7 TUBE AREA PLATE WEIGHT or LSET depending upon how it was defined and the parent is the load group name If one is viewing pictures from the SURFACE MENU then block names replace compartment and piece names in the above scheme To obtain pictures of the panels which will be used in a three dimensional diffraction analysis one should use the TYPE MESH With this TYPE one can use the option DETAIL and MOSES will generate a refined mesh for plotting which corresponds to current settings of the M_DIST option of the PARAMETER command In addition to these names the strings have numbers associated with them In general these numbers are a ratio a cdr a stress and a deflection Only nodes will Rev Page 57 MOSES REFERENCE MANUAL have a deflection associated with them These numb
519. the original x axis must be rotated to yield the new x axis This rotation is positive toward the original y axis As with all output operations in MOSES the amp UGX commands are performed according to a style To establish the current style here one issues the command STYLE C_ STYLE Where C_STYLE is the style which will be used for all subsequent drawing One can also change the color by issuing the command COLOR COLOR_NUM where COLOR_NUM is a line color number The association of line color numbers and colors was discussed previously Pictures are created by combining lines and text and for each primitive drawing begins at the current cursor position The current cursor position can be defined Rev Page 44 MOSES REFERENCE MANUAL by the command MOVETO X Y To draw a generalized line one issues LINE X 2 Y 2 X n Y n This command will draw n 1 straight line segments beginning at the current cursor location and ending at the coordinates X n Y n At the conclusion of the drawing the current location will be at X n and Y n To fill a polygon in the current color one uses FILL X 2 Y 2 X n Y n which works the same way as LINE does Three other primitives are available for drawing lines To draw a rectangle one can issue BOX X_DIM Y_DIM The resulting rectangle will have the upper left corner at the current location and it will have a width of X_DIM and a height of
520. the phase for the ith component w i is the frequency rad sec of the ith component and TB is a time By using this scheme you always get the same sea and two time domain simulations will yield identical results The time TB has an interesting interpretation it is a time at which all of the components reinforce i e at this time the amplitude of the sea is the sum of all of the Fourier coefficients Depending on the number of components you use this sum is unreasonably large and this time is to be avoided during the simulation Thus by default it is set to be a large number If you need to change it to perform Monte Carlo simulations use T_REINFORCE Finally if TB is negative then the phases will be chosen randomly using the absolute value of TB as the seed The wind is defined with the options WIND W PROFILE W PERIOD W DESIGN W SPECTRUM W_HISTORY and W_MD_CORRELATION options The WIND option defines the wind speed WIND SPEED which is the mean wind speed in knots and WIND DIRECTION is the direction from which the wind blows The W PROFILE option defines how the wind will vary with height Here WP_TYPE can be ABS API NPD or POWER If TYPE is ABS then height coefficients will be computed according to the ABS rules If WP_TYPE is API or NPD the wind variation with height will be according to the specified code If however WP_TYPE is POWER then EXP is the power which defines the power law for wind variat
521. the structure G s and rad sec 2 Normally however one will use one of the other forms of the LCASE command Rev Page 439 MOSES REFERENCE MANUAL 1 1 Ks ps 1 SS 3El Ko Barge Node a Structural Element Barge Node Nearest the Rocker Pin JACKET SUPPORT CONDITION FOR LAUNCH AFTER TIPPING FIGURE 29 Rev Page 440 MOSES REFERENCE MANUAL XXVI D Obtaining Applied Loads If the goal of entering the Structural Menu was to generate a set of applied loads one should first issue the appropriate LCASE commands and then select the portion of the model for which he wishes to generate the loads If the loads for the entire model are desired then no further action is necessary If however loads on only a portion are desired the loads generated can be limited by the commands S_PART PART_NAME 1 PART_TYPE 1 PART_NAME n PART TYPE n S BODY BODY_NAME 1 BODY_NAME n Here PART NAME i and BODY _NAME i are the part and or body names to be selected and PART_TYPE is the type of the part and all can contain wild characters When using S_PART a part will be selected only when both part name and type match that of a PART_NAME i and PART_TYPE i After the load cases and the model have been defined one then exports the loads by simply issuing the command EXP_ALOAD and MOSES will write the loads applied to the selected system to a file for use elsewhere By default this file will be named
522. they are not blank One important aspect of the MOSES language is the string function Most of the string functions discussed previously performed simple tasks such as arithmetic There is another class of function which returns information about the current model or configuration These are extremely useful in automating certain tasks Each of these functions will be discussed later but one which is useful in generating loops is amp NAMES QUANT SELE which returns the names of database quantities Here QUANT is the category for which names is desired This valid categories is defined in the section Obtaining the Names of Quantities or you can obtain it by issuing either amp NAMES NAMES or amp STATUS NAMES The amp STATUS gives not only the list of names but also a brief description The behavior here depends on if SELE is omitted If specified then all names of QUANT which match SELE will be returned If SELE is not specified then most of the time all of the names for QUANT will be returned to the command line For PARTS EL EMENTS COMPARTMENTS LOAD GROUPS POINTS and NODES however the results are returned only for the current body and part With the power of the MOSES language users often want to emit the commands used to build a model to a separate file for later use This can be achieved elegantly using amp EMIT which has the following syntax Rev Page 139 MOSES REFERENCE MANUAL amp EMIT O
523. this option One can however turn off the force due to a load group using this option For example amp APPLY PERCENT LOAD_GROUP A NAME 50 FRACTION B_NAME 0 50 will apply 50 percent of load group A NAME and one half of load group BLNAME The TIME option define multipliers which vary with time Here NAME is the name of either a LOAD GROUP or a user defined load set and C_NAME is the name of a curve which has been previously defined with a amp DATA CURVE TIME command At each event during a time domain simulation MOSES will interpolate a multiplier from the specified curve If NAME is later specified with LOAD GROUP or FORCE options the time variation will be turned off The last two options control the load type multipliers for Categories The CATEGORY option allows one to control the multipliers for all load types while the MARGIN option sets only the DEAD or weight multiplier Here VAL i are the same as for the load group and load set options while VAL_INC i are increases i e the multi plier is really 100 or 1 plus VAL_INC depending upon PERCENT or FRACTION option in effect Here CAT i is a selector for the Categories for which multipliers will be set and NAME i are selectors for the load types For example amp APPLY PERCENT CATEGORY STR_MODEL 0 DEAD 105 will set the multipliers for category STR MODEL to all zero except for the weight which will be applied with a multiplier of 1 05 There
524. tic specified with the last PROBABILITY option on a amp DEFAULT command The remainder of the commands available for connector forces have a similar syntax in that the final portion of the command is identical to that of the amp ENV com mand In fact these commands not only initiate the computation of quantities in an irregular sea but are also amp ENV commands Thus when one issues one of these commands with a non blank ENV_NAME he is altering the definition of this envi ronment within the database If ENV_NAME is omitted then the environment used will be totally defined by the options specified The options SEA SPREAD and SP_TYPE are used to define the sea state to which the vessel will be subjected The E_PERIOD option can be used to generate results for seas of several different periods If this option is omitted then a single period of PERIOD will be considered With the option periods of PERIOD EP 1 EP 2 will be produced Rev Page 388 MOSES REFERENCE MANUAL XX B Motion Post Processing The commands discussed in this section all deal with the frequency response of a point or relative motion of two points and they allow one to obtain the frequency response of the point statistics of this response and a time realization of the motion Basically one first finds the frequency response at a given point and then the other commands discussed here deal with this response until the response at another point is
525. tics of pressures in irregular seas one should issue ST_PANPRESS PAN_SEL ENV_NAME OPTIONS where the available options are SEA SEA NAME THET HS PERIOD GAMMA SP_TYPE TYPE SPREAD EXP E_PERIOD EP 1 EP 2 CSTEEP YES NO Here the statistic of the pressure on panels selected by PAN_SEL will be returned and the user will be placed in the Disposition Menu Here there is no limit on the number of panels selected and the statistical result is the statistic specified with the last PROBABILITY option on a amp DEFAULT command and If the original response data was produced with the SRESPONSE command then no additional sea data can be specified The remainder of the options have a similar syntax to those of the amp ENV command In fact commands using these options not only initiate the computation of quantities in an irregular sea but is also an amp ENV command Thus when one issues one of this command with a non blank ENV_NAME he is altering the definition of this Rev Page 400 MOSES REFERENCE MANUAL environment within the database If ENV_NAME is omitted then the environment used will be totally defined by the options specified The options SEA SPREAD and SP_TYPE are used to define the sea state to which the vessel will be subjected The E PERIOD option can be used to generate results for seas of several different periods If this option is omitted then a single period of PERIOD will be consid
526. ties are desired for each connector specified The results of this command will be a table of distance from anchor horizontal force and tension at the attachment the derivative of horizontal force with respect to distance from anchor the vertical and horizontal pull on the anchor the active length of the connector the height of the first con nection and the applied force on this connection If there is a spring buoy at the first connection the last two entries will of course be the height of the buoy and its displacement An illustration of some of these quantities is shown in Figure 25 i i P Distance i 1 Tension 7 i Lineon 1 Bottom Fairlead Horizontal Force Height to Vert pull first connecti on on anchor 1 SSRs A IAN ANNIE NN NN IEA IE NS IES IE NN IZ pu on anchor PROPERTIES OF MOORING LINES FIGURE 26 Rev Page 346 MOSES REFERENCE MANUAL XVI B Obtaining Connector Geometry The GEOMETRY command is used to obtain the current geometry of a connector The form of this command is GEOMETRY LNAME Here LNAME is the name of the connector for which the geometry is desired The results of this command will be a table of the distance along the connector from end 2 to the point in question the horizontal distance from end 2 to the point and the X Y Z coordinates of the point After the properties are computed the user is placed in the Disposition Menu Rev Page 347
527. tiltbeam and the bow of the barge will be restrained After tipping only jacket nodes between the two ends of the tiltbeam will be restrained In cases where this criteria does not yield at least two nodes the node furtherest forward yet aft of the pin and the node furtherest aft yet forward of the pin will be added to the others The selected nodes are then connected with compression only springs to the closest Rev Page 438 MOSES REFERENCE MANUAL barge nodes For nodes in contact with the barge proper a nominal stiff spring is used For those in contact with the tiltbeam this stiff spring is put in series with the bending stiffness of the tiltbeam at the proper location In some cases the compression only springs will be allowed to carry tension This happens when less than two nodes remain during the iterative process The stiffness of the restraints and the number of restraints in the tiltbeam area are further explained in Figure 28 Ko Ko Ko Ko k L WHERE THE SUPPORT NODES ARE ALL NODES BI 0 ALL NODES 0 L 2 NODE WITH MIN X gt 0 NODE WITH MAX X lt 0 JACKET SUPPORT CONDITION FOR LAUNCH BEFORE TIPPING FIGURE 28 and Figure 29 The final option of LCASE is DEAD CNAME INT 1 INT 6 which instructs MOSES to create the load case named CNAME by multiplying the inertia of the system by various intensities i e the values are the six components of the accelerations which act on
528. time in the list If the option is not used the last value in the list will be used for times larger than the last The next two curve TYPEs are used with connectors CT_LENGTH is used to define the rate of change of the length of a connector Here DATA is T 1 V 1 T n V n where T i is the time and V i is the rate of change of length ft sec or m sec at T i EFFICIENCY is used to define the propeller efficiency as a function of water particle velocity Here DATA is V 1 E 1 V n E n where V is the water particle velocity ft sec or m sec and E is the efficiency The type CS_VELOCITY is used to define a drag coefficient which varies with the relative speed Here the DATA is pairs of velocities and drag coefficients The last curve TYPE AM_PRESSURE is used to define added mass pressures as a function of submergence Here DATA is a set of four n numbers S 1 AP_SURGE 1 AP_SWAY 1 AP_HEAVE 1 S n AP_SURGE n AP_SWAY n AP_HEAVE n Here S i is the submergence feet or meters and AP_SURGE AP_SWAY and AP_HEAVE are the surge sway and heave added mass pressures feet or meters of water Rev Page 155 MOSES REFERENCE MANUAL XII F Sensors Sensors are things which monitor conditions and when certain values are exceeded alarms are set Sensors are defined with the command amp DESCRIBE SENSOR SENSOR_NAME OPTIONS and the available options are ON SEL 1 SEL 2 OFF SEL
529. ting at the node FX FY FZ MX MY MZ The nodal loads are continued for this load case until an ELMAPL command is encountered Element loads have three lines per element The first line begins with ELMAPL followed by the element name the class name the begin and end nodes and the begin and end distance from the end of the beam over which the load acts If the begin and end distances are equal then the load is concentrated The next two lines define the load distribution For concentrated loads the two lines are the same and each one define the total load i e one of these lines should be ignored For distributed loads the first line defines the load intensity at the beginning distance from the start of the beam and the second line at the end distance There are six numbers on each line corresponding to force intensities in the X Y and Z directions and moment intensities in X Y and Z directions These loads are trapezoidally distributed loads defined by the intensity at each end and the portion of the beam over which it acts as shown in Figure 30 Normally there will be more than one ELMAPL command for each element These come from a variety of sources and there is no way to ascertain their origin The ELMAPL commands are repeated for all the elements in the model that have load for this load case The sequence of load case name nodal loads and ELMAPL commands is then repeated for each load case specified Rev Page 442 MOSES REFER
530. ting blocks of data MOSES provides for loops Instead of having different sets of data for slightly different situations MOSES provides for conditional execution Instead of having the same data defined in different places MOSES allows one to define variables and use them later Instead of repeating com mands with minor alterations MOSES allows the user to create his own commands called macros The MOSES language is built upon a proprietary database manager specifically de signed for its purpose the storage and retrieval of scientific models and the results of their simulations By storing all data in a database MOSES is totally restartable One can perform some tasks interactively stop then seamlessly restart the program to perform other tasks in the background The database even allows different types of simulation with the same model and a stress analysis to be performed for all types concurrently Before MOSES most marine problems were considered in two steps a simulation followed by a stress analysis Two different programs were required Since MOSES performs both of these analyses one needs only a single program to investigate all Rev Page 1 MOSES REFERENCE MANUAL aspects of the problem Also with MOSES one is spared the agony of transferring files and of learning the idiosyncrasies of several programs Since it must cope with the demands of both simulation and stress analysis the MOSES modeling language is richer th
531. tion The primary strength here is that the user is free to issue the commands in any order that makes sense In other words once a basic system has been defined the user can alter it in many different ways to change the initial conditions for similar simulations or perform different types of simulations without altering the basic definition of the system Also after a simulation has been performed he can analyze the deflections stresses etc at different phases of the simulation In general the things with which MOSES performs simulations are called bodies During a simulation bodies have N degrees of freedom The first six of these are the traditional rigid body degrees of freedom and any others represent deformation of the body Bodies are composed of smaller pieces called parts with each part having all of the characteristics of a body itself MOSES is capable of considering four types of forces which act on bodies those which arise from water wind inertia and those which are applied Thus to MOSES a body is a collection of attributes which tell it how to compute loads and how to compute deflections MOSES can deal with up to 50 bodies In computing the forces on a body due to its interaction with the water the user can choose from three hydrodynamic theories Morison s Equation Three Dimensional Diffraction or Two Dimension Diffraction the particular method used being con trolled by the manner in which the body is modeled A
532. tion Information is obtained via a REP_TYPE of S CASE R_CASE or AMOD AMOD yields a status of the current allowable stress modifiers S CASE yields all available cases to post process and R_CASE yields a status of the cur rently defined R CASE cases The report obtained with R CASE lists the names of the cases and the constituents of each case If the BRIEF option is used then only the names of the cases will be displayed Rev Page 129 MOSES REFERENCE MANUAL XI C Obtaining Summaries of the Model To obtain summaries of the database one must enter a sub menu devoted to this purpose To enter this menu one need only issue the command amp SUMMARY At this point numerous commands are available When finished with summaries the user must exit the report sub menu by issuing the END_ amp SUMMARY command which returns the user in the menu where he entered amp SUMMARY To restrict the quantity of information received one can employ the options for the previously discussed amp REP_SELECT command thereby limiting the reports to subsets based on the selectors In general all reports are separated by body and part an exception being summaries based on connectors and classes which have no body or part Thus most reports can be obtained for only selected bodies and parts For all of the commands in this menu one can request different types of data to be reported If no type selection is made reports for all of the available types will be
533. tivating elements when they are not present with the command EL_ACTIVE OPTIONS OBJECT 1 OBJECT 2 OPTIONS OBJECT 3 Here OBJECT i is as described above and the available options are ACTIVE and Rev Page 304 MOSES REFERENCE MANUAL INACTIVE All elements selected with OBJECT i will have the activity defined by the option immediately preceding the object The command GEN_OFFS It serves the same purpose as the OF FSET option on the INMODEL command Thus if a model is defined entirely in the MEDIT menu member end offsets can still be generated by issuing this command after the model has been defined As with all things in MEDIT GEN_OFFS only generates offsets on elements which have been defined before the command is issued The command CL_D T_RESIZE C_SELECT D T_MIN D T_MAX D INCREMENT will change the diameter and thickness of tubular members with classes which match the selector C_SELECT It will take the original area and compute a new diameter and thickness which produces d D T ratio between the two limits and which has the same area as the original sizes The new dimension will be changed to the nearest D_INCREMENT By default all classes will be checked D T_MIN is 30 D T MAX is a huge number and DINCREMENT is 1 8 inch or 2 mm depending on the units being used With the defaults the new dimensions will be multiples of either 1 8 inch or 2 mm A simple way to define element dependent bucklin
534. tive for predicting the connector forces as it will be for predicting the motions Fixing the tensions is a partial remedy for this problem If the option is used with a value of YES NO of YES then MOSES will compute the value of the tension at the maximum position and compute a ratio of this maximum to that predicted by the force response The force response is then scaled by the ratio so that the predicted maximum will be that computed for the extreme position After obtaining frequency response results one can examine them with other com mands in this Menu Some of the commands produce response operators others produce statistics for irregular seas and others produce equation force data At the conclusion of most of these commands the user is placed in the Disposition Menu where he is given the option of reporting viewing or graphing the results of the command The behavior of the commands in this menu differ with the type of frequency response data to be examined With response operators obtained with an RAO command one must specify an environment to obtain statistical or time synthesis results while for nonlinear spectral results obtained with a SRESPONSE command an environ ment cannot be specified With RAOs the commands in this menu which deal with sea states have a final syntax which is identical to that of the amp ENV command Rev Page 384 MOSES REFERENCE MANUAL With nonlinear spectral results the environment da
535. to issuing BEGIN Now suppose that the process is good up to some point but it is desirable to change it after that event Here one instructs MOSES to move the last good event and delete the remainder of the process from the current work process This is accomplished by Rev Page 412 MOSES REFERENCE MANUAL GOTO LGEVENT OPTIONS and the available option is POST If LGEVENT is positive it is the event number which will become the last event in the process Alternately if LGEVENT is negative it is the number of events back from the current event Thus if one currently has a process with 20 events and he wishes to reconsider action at event 18 he can accomplish this by either GOTO 18 or GOTO 2 When a GOTO command is issued some information will be lost To save this information one can use an option POST on the command so that he is placed in the Process Post Processing Menu before the old work process is truncated Here the user can either report the results graph them or save them on a post processing file MOSES simulates two types of field operations altering the amount of water in compartments or lifting with a crane vessel Each action is invoked by one of two commands the first one being LIFT DZ OPTIONS where the available options are NUMBER NUM SHEIGHT HSTOP SHOOK HOSTOP STENSION TSTOP CLOSURE TOL 1 TOL 2 DISPLAY OLD 1 NEW 1 OLD 6 NEW 6 This com
536. ts over each submerged panel If however one has used strip theory then this results in zero surge drift force the surge diffraction potential is ignored In this case a representation by Salvesen which employs an assumption of the body being a weak scatterer is used to estimate a surge component There are basically two types of data considered in this menu pressure and mean drift Each of these will be considered in detail later but as a general rule commands which generate data begin with G_ those which post process with V_ those which import with I_ and those which export with E_ The commands for importing hydro dynamic data are designed to allow the user to completely describe a hydrodynamic data base Although the commands for doing this are documented in the following sections the user is encouraged to examine the samples of data provided with this Rev Page 371 MOSES REFERENCE MANUAL software release To input your own data it is helpful to first export a hydrodynamic data base to get an understanding of the MOSES file format Then modify this file as desired and import it to the program Rev Page 372 MOSES REFERENCE MANUAL XIX A Pressure Data To compute the sea pressures on the vessel the program must know the form of the vessel below the water This is communicated to MOSES by a set of vessel description data defined earlier and the current condition of the body To initiate the pressure computations
537. ts the nodes releases and offsets for each vertex To obtain a summary for RESTRAINTS one should issue RESTRAINT SUM OPTIONS and the available options are those of the amp REP_SELECT command This com mand will produce a report of the location of the ends of each element which is not neither a beam nor a plate and is not a connector The next command produces a report of the weight center of gravity buoyancy and center of buoyancy of each class and each load group by category Only those selected Rev Page 132 MOSES REFERENCE MANUAL elements and load groups belonging to selected parts will be considered The form of the command is CATEG_SUM OPTIONS and the available options are those of the amp REP_SELECT command In particular if the option BRIEF is used then only the total for each category will be reported To obtain information about the property classes selected by the class selector one issues the command CLASS_SUM TYPE 1 TYPE 2 OPTIONS where TYPE i must be chosen from DIMENSION SECTION MATERIAL or SOIL and the available options are those of the amp REP_SELECT command A TYPE of DIMENSION reports the information about the section type and size SECTION reports section and stiffener properties MATERIAL provides information about the redesign and material properties of the class such as yield strength and Young s Modulus Finally SOIL will produce a report of the soil properties for the
538. ttings To accomplish this task MOSES provides the string function amp INFO NAME DATA In general there are four classes of information available Information about Error information Run information Unit information File information Program information Current output device information and Graphics information Error information is obtained with a NAME of SEVERITY When using macros or loops it is sometimes useful to know if an error or warning occurred during execution If so appropriate action can be taken The string function amp INFO SEVERITY FLAG is used to determine if an error or warning has occurred Here FLAG is either ERROR or WARNING The function will return a value of TRUE if FLAG is set to WARNING and either an error or a warning occurred during the previous command Likewise a value of TRUE is also returned if FLAG is ERROR and an error occurred during the previous command Otherwise a value of FALSE is returned Consider the following example amp IF amp INFO SEVERITY ERROR amp THEN amp TYPE LOST BEYOND HOPE amp FINISH amp ELSE amp INFO SEVERITY WARNING amp THEN amp TYPE FIXING SITUATION FIXUP amp ENDIF In this example a message is typed to the screen and a fixup macro is executed if a warning resulted from the previous command If an error occurred a different message is typed and the program is exited Run information is obtained with either MENU DATE T_OF
539. tween the ends and acts in the direction of the vector from one end to the other By default an SL ELEM can have both tension and compression If however a value of TENSION is specified for FLAG then is can have only tension A B CAT is a catenary to ground and a H CAT is a hanging catenary Both of the catenaries employ restrictions and assumptions and FLAG controls a second level of approximation e The only force which is assumed to act is the weight in air weight for a H CAT and in water weight for a B CAT e A B_CAT can only connect a body to ground and DEPTH is the depth at the anchor e By default a B CAT tabulates the force vs horizontal distance at the initial depth If one uses a value of EXACT for FLAG then the table will not be used This should be done when changes in depth are important e A H_CAT ignores both the bottom and the water line so a spring buoy cannot be used here e By default a H CAT ignores the weight of the element so that it is really a tension only SL_ELEM A value of EXACT for FLAG considers the weight The following are in general available REFINE N IG_STIFF SEND KE 1 KE 2 X_PY P 1 Y 1 P 2 Y 2 P n Y n X_DAMPING Co Ex Fo SPGRAVITY SPGR DENSITY RHO CONVOLUTION CVL_NAME Rev Page 231 MOSES REFERENCE MANUAL EMODULUS EMOD POL RAT POIRAT ALPHA ALPHA FYIELD FYIELD WTPLEN WTPFT DISPLEN DPFT PISTON TYPE LT LD VLO
540. ues are less than or equal to zero the program computed value will be used Normally MOSES determines critical points at which to compute stresses Some times one wishes to define these points himself Stress points are defined with the POINTS option Here Y n and Z n are the beam system Y and Z coordinates of the point and AY n and AZ n are the values of alpha for that point These are the same alphas discussed above except that instead of computing the stresses at the neutral axis do it at the nth point The option P _FY allows one to define the yield stress at the critical points If one uses this option he really should define his own points so that he is certain of the physical location of each point The options M_P and P_N define the plastic moments and the nominal axial strength of the section NOTICE If you use the SECTION option to change the properties you probably will also need to use the M_P and P_N options as well The option ETA defines the exponent eta in the interaction formulae of the AISC LRFD code check Fi nally the option F_TYPE defines the fabrication type of the section Here TYPE must be either FABRICATED or COLD_FORGED The next class of Structural Class options are LEN L PERL PCLEN REFINE NUM REFINE RDES NAME KL R_LIM D T_LIM In general MOSES allows for an element to have different properties along its length To define such an element one should have a Cl
541. ues for MAX_ANGLE TSECDEP and DIST An illustration of the tiltbeam is shown in Figure 24 The stiffness of a tiltbeam is input using the BEAM option Here LENP is the Rev Page 312 MOSES REFERENCE MANUAL yj Launch Direction X PLANE VIEW SHOWING JOINTS USED ON LLEG COMMAND FIGURE 23 Rev Page 313 MOSES REFERENCE MANUAL XB YB ZB at ls 6 go eT I Q N DIST z SS XAxis TILTBEAM GEOMETRY FIGURE 24 length of the primary tiltbeam feet or meters and EIP is the stiffness bforce ft 2 or bforce meters 2 LENS and EIS are the length and stiffness values for the secondary tiltbeam respectively If there is no secondary tiltbeam these values should be omitted The order of input of the ASSEMBLY LLEG commands is important as it is used to establish the launch coordinate system of the jacket The axes of this coordinate system are set as follows The X axis is parallel to a line connecting J 1 and J n and is directed towards J 1 The jacket is launched in the positive X direction The origin of this system is midway between the trailing joints given on the first and last ASSEMBLY LLEG commands and the Y axis is along the line connecting the J n on the last ASSEMBLY LLEG input with J n on the first one input The Z axis is determined from the right hand rule At the conclusion of the MEDIT Menu the orientation of the body systems will in general change
542. urrence of DELIM MATCH returns a value of TRUE if STRING 1 matches STRING 2 and FALSE if it does not The function NULL returns a value of TRUE if STRINGI is null and a value of FALSE otherwise The function O NUMBER overlays the integer NUMBER on the string STRING 1 starting at the end For example if STRING 1 is NO0000000 and number is 3333 then the returned string will be N00003333 The function OVER LAY works in a similar fashion except the values here are characters The command amp STRING OVERLAY 12345678 ABCDE will return a value of 123ABCDE for in stance Both of these functions are useful for building names which can be used to automate the creation of various analytical models The function REVERSE will reverse the tokens of STRING N EXTRACT will return NUMBER numbers from STRING 3 starting at the token immediately following the word WORD If there are not NUMBER numbers zeros are returned i e first WORD is found in the string and the next token is checked If it is not a number or if WORD is not found then NUMBER zeros are returned If this token is a number then the first value returned is set to the number and the next token is checked This pro cess is repeated until either NUMBER numbers have been found or a non number terminates the process Finally the function REPEAT will return a string with Rev Page 83 MOSES REFERENCE MANUAL NUMBER occurrences of STRING Rev Page 84 MOSES R
543. used a rigid barge is assumed and the reactions between the jacket and barge are applied to the jacket as distributed loads To perform an Automated Upend analysis one uses the INST_UP command Which Rev Page 342 MOSES REFERENCE MANUAL assumes a typical upending sequence which includes lifting the jacket to provide the specified minimum bottom clearance flooding the bottom side legs and then flooding the top side legs The flooding is performed with a constant hook height Two upending simulations are actually performed to determine the proper lifting height needed to obtain the minimum clearance The syntax of the command is INST_UP OPTIONS And the available options are LIFT INCREMENT LINCREMENT FILL_ INCREMENT F_INCREMENT VENTS _ CLOSED C_LEGS MIN_BOTTOM_CLEAR MIN BOT TOP _OF_LEG TOP_OF_LEG FIRST FLOOD FF_TANKS FF_DESC SECOND FLOOD SF_TANKS SF_DESC DAMAGED LEG DAMAGED LEG NO STRUCT The options of this command are used to convey the information needed to perform the upend analysis and the variable names used here are fairly obvious The variable L_INCREMENT is the lift increment for the lifting stage of the upend in the present big length units F INCREMENT is the flood increment for the flooding stages in percent C_LEGS refers to the names of tanks that have their vent valves closed during flooding and can be a list of tank names a selection criterion or a wild character MIN_BOT specifie
544. ute any commands found in this file and when the file is exhausted it will look for commands from the terminal In addition one execution of the program will result in two subdirectories ROOT DBA and ROOT ANS being created ROOT DBA contains the MOSES database for the root One should never delete any of these files while a given job is being done The ROOT ANS directory contains the answers associated with the root The files which begin with OUT are the output files which begin with LOG are the log files which begin with DOC are the files written during document formatting which begin with GRA are the files containing graphics which begin with PPO are the files containing data for further post processing which begin with TABLE are the files generated which a STORE command is issues in the Disposition Menu and e which begin with MOD are the files containing models which can be used in MOSES The initial three characters are followed by a five digit number which signifies the order in which the files of the various files were created e g LOG00001 TXT is the first log file that created and LOGO00003 TXT is the third The suffix of the file denotes the formatting of the file e g TXT is a text file htm is a HTML file EPS Rev Page 18 MOSES REFERENCE MANUAL is a postscript file etc The OUT files contains all of the hardcopy reports you requested and the LOG files contain the commands issued and and M
545. ve the water and a portion below The wind force on the out of water portion and the current force on the below water portion are computed as if the area was a PLATE Here however the components of the velocity are multiplied by the values of CSC_X CSC_Y and CSC_Z respectively In addition the current force is multiplied by a multiplier MULT that depends on the water depth to draft ratio DDR This value is obtained by interpolation from the table defined with the DD MULT option The default values for the CSs and the multiplier table are set with the amp DEFAULT command Several other things need to be said here First the current force actually depends on both the current velocity and the velocity of the panel so using the word current is really incorrect Second the results are quite dependent upon the setting of AF ENVIRONMENT option of amp PARAMETER If the option is set to NO and the above is used for round pieces the results may be surprising The force produced for a rectangular box is exactly the same as one would get by using a pair of PLATEs For a circular cylinder however one gets a force of 785 pi 4 times that of a square box This is simply a result of the recipe used to compute the force Thus to get the correct force on a cylinder one should specify CS_WIND 5 785 5 785 1 CS_CURRENT 5 785 5 785 1 If the setting is YES then this does not apply The option CS_VELOCITY can b
546. ve you the length of the vector projected onto the X Y plane The BODY option is used to specify the bodies for which results will be reported only bodies which match B SEL are considered The TRAJECTORY command instructs MOSES to compute the location velocity acceleration bottom clearance and displacement for each selected body and to place the user in the Disposition Menu The form of this command is TRAJECTORY OPTIONS The available options are EVENTS EVE BEGIN EVE_END EVE_INC MAG_DEFINE A 1 A n BODY B_ SEL Rev Page 418 MOSES REFERENCE MANUAL CG LOCAL YES NO Normally the location velocity and acceleration are computed for the body origin If one uses the CG option then the results will be computed for the body CG instead The final option is LOCAL If YES NO is NO MOSES will compute the velocity and acceleration in global coordinates instead of local body ones The opposite is true if YES NO is YES The other options are defined above The corresponding form of the REPORT command is REPORT NAME OPTIONS Here NAME is a selector which selects the available REPORTs LOCATION VELOCITY and ACCELERATION The only option available for reporting is EVENTS EVE_BEGIN EVE_END EVE_INC The BODY_FORCE command reports stored values of the force breakdown by type much as the other two commands but the report time increment has no effect on the results BODY FORCE OPTIONS The available
547. ves the radii of gyration while the report to file gives the actual terms of the matrix To obtain the exciting forces about the point specified on the last FR POINT command one uses EXFORCE OPTION When this command is issued the program will compute the forces operators at the specified location for every period and heading where response was computed Again if the option FILE option was used the forces will also be written to the PPO file In the file the forces will be real and imaginary parts instead of the magnitude and Rev Page 387 MOSES REFERENCE MANUAL phase elsewhere When placed in the Disposition Menu the results for all headings are available The names of the variables are followed by HEDXXX where XXX is the heading angle in degrees When using the REPORT command in the Disposition Menu one can selectively report the response operators If there is no data on the REPORT command all headings will be reported To report data for only some headings one should specify the angles of the heading to be reported on the REPORT command To compute statistics of the exciting forces in irregular seas one issues the command ST_EXFORCE ENV_NAME OPTIONS where the available options are SEA SEA_NAME THET HS PERIOD GAMMA SP_TYPE TYPE SPREAD EXP E_PERIOD EP 1 EP 2 Again the point where moments are referred is the last point specified on a FR_ POINT command The statistical result is the statis
548. vice is used to store MOSES graphics into DXF format The UGX device was designed as a page description language and is more completely defined later When this device is used the file can be read by MOSES and converted to a graph on the specified logical device In particular graphics saved in this format can be viewed on the screen by simply issuing the command amp INSERT GRAO0001 UGX Also if the primary graphics device is the GRA_DEV logical device then the above command will format the graphics for a hard copy device For any channel which has a physical device of PCL the results in the file contain escape sequences which control the device Thus files representing these channels should be sent to the device in raw form If MOSES is being run on a PC these files should be copied to the printer using the B option on the DOS COPY command This avoids the DOS spooler treating the printer escape sequences as end of line or end of file characters Rev Page 33 MOSES REFERENCE MANUAL VI D Controlling Execution The user also has the ability to control the various parameters which effect the exe cution of MOSES and the various files which will be used Perhaps the most useful of these commands is amp DEVICE OPTIONS and the available options are BATCH YES NO LIMERROR ERLIM US_DATE YES NO SET_DATE DATE CONT_ENTRY The Entry You Want NAME FIGURE NAME FIG NUM YES NO NUMBER G DEFAULT GLDEVICE O
549. vice such as a file In MOSES there are two concepts a channel and a logical device Basically channels can be thought of as either files or as directly connected physical devices Logical devices are different classes of output which are connected to a channel As data is written to a logical device it is formatted according to a set of instructions collectively called a style In the following pages each of these concepts will be defined in detail For most of the things defining device attributes the units required are points A point is 1 72 of an inch or 3527 mm The exception to the above rule is when one defines the pitch of a fixed pitch font which is defined in characters per inch Rev Page 24 MOSES REFERENCE MANUAL VI A Colors Colors in MOSES are treated by first defining a set of colors which may be used and then assigning individual colors to a color scheme Color schemes are then used by assigning them to styles which are discussed below or by special names which are used to draw the user interface window Both colors and color schemes are defined with the command amp COLOR NAME OPTIONS To define a color NAME should be omitted and the option COLOR_ADD C_NAME RVAL GVAL BVAL should be used Here CNAME is the name of the color to be defined and RVAL GVAL and BVAL are the intensities of red green and blue respectively These values are 0 for none of this color and 255 for the maximum of t
550. vity and buoyancy for each category Finally D_CATEGORY gives the weight and buoyancy multipliers the weight and the description of each category Element Information is obtained via a REP_TYPE of ELEMENT or F_ELEMENT The report obtained with REP_TYPE of ELEMENT gives a list of the currently selected elements and consists of the name of the element its class and a list of the nodes at its vertices The list of currently selected elements is controlled by the options of the amp REP_SELECT command Here for an element to be selected its class must match the class selector the element name itself must match the element selector and the nodes at the vertices must match the node selectors If an option of BRIEF is used for elements then only the element names will be displayed F_ELEMENT gives a breakdown of the force acting on the elements selected by SELE The option FORCE can be used to select the types of force reported If FORCE is not specified then only the total will be reported Map Information is obtained via a REP_TYPE of MAP or N MAP MAP produces a list of the load map names the part to which the map applies and the point selectors of the map N MAP provides the same information except that the point selectors are replaced with the structural nodes actually selected Both of these types accept the MAP option of the amp REP_SELECT command If this option is used only the maps selected will be printed Structural Solu
551. weight data supplied in the structural model and from currently active tanks weights etc This is necessary to insure that when structural loads are computed there will not be seriously out of balance in the loads It is therefore important to accurately model the weights not only from a local sense but also in a global one Another important thing to remember is that the response operators produced with the RAO command are not really independent of wave height For most cases nonlinear damping and perhaps forcing is important Thus some real wave amplitude must be used to linearize the system If post processing results are obtained for an environment which is radically different from that used in the linearization then the applicability of the results is open to question MOSES provides two ways to linearize the equations for RAO computations specified wave amplitudes and a spectral linearization With the specified wave height method one specifies a steepness a period and a wave height This is the default method MOSES will for each period and heading use a constant wave steepness to obtain a Rev Page 381 MOSES REFERENCE MANUAL real wave amplitude for linearization for periods less than the specified period For larger periods the specified height will be used The energy from the linear system and the real system over a period are set equal to obtain the linearized results For damping this appears to be a ration
552. which makes the specified configuration an equilibrium configuration This action occurs if FLAG is COMPUTE If FLAG is NO the extra force will be set to zero In addition to the weights which were defined for elements and load groups MOSES employs an additional weight which can be applied to any part This is called a defined weight and is controlled with the command amp WEIGHT OPTIONS where the available options are COMPUTE BODY NAME ZCG KX KY KZ DEFINE PART_NAME WEIGHT XCG YCG ZCG KX KY KZ TOTAL PART_NAME WEIGHT XCG YCG ZCG KX KY KZ The first of these options is restricted to bodies while the others can be used with parts For the first option all data given should be in the body coordinate system of the body BODY_NAME For the others all data should be in the part system of the part PART_NAME The COMPUTE option instructs MOSES to compute the weight so that in the initial condition the gravitational force will be equal to the sum of the other forces The local Z center of gravity of the computed weight will Rev Page 200 MOSES REFERENCE MANUAL be placed at the specified location ZCG Alternately a DEFINE option defines a load with the weight and center of gravity specified The option TOTAL creates an additional weight so that the total weight center and radii of gyration of the part will be that specified In either case the weight which is defined will have radii of gyration KX K
553. which are much easier to read and which have a smaller number of panels and points The final step in this process is to EMIT the results created This is accomplished with the command Rev Page 290 MOSES REFERENCE MANUAL EMIT BLOCK_SEL 1 BLOCK_SEL n OPTIONS where the options are PART PART_NAME PAROPT BODY BODY_NAME BODOPT USE NAME YES NO PERM PERM NAME NAME COMPARTMENT CMPOPT PIECE PIEOPT POINTS Here the PART or BODY option instructs MOSES to emit the points for the blocks matching the BLOCK SEL i selectors and to specify that they all belong to either body BODY_NAME or part PART_NAME This should normally be the first thing emitted After the points have been emitted one should then emit the panels for the exterior and any interior compartments Each one of these should have a single emit command Panel names will be used if YES NO is set to YES on the USE_NAME option If YES NO is NO no panel names will be provided The PERM option is used to specify the permeability of the piece being emitted When emitting panels both compartments and pieces will be generated one compartment is defined for each emit command and a piece for each block emitted Thus if there is on only a single block emitted one gets a compartment and a piece The NAME option specifies the name of the compartment If it is omitted then the compartment name will be the same as the first block emitted The
554. which define fatigue properties for the elements For a discussion of the SCF and SN options see the sections on associating SCFs and SN curves with fatigue points The next group contains the section options SECTION AREA IY IZ J ALPHAY ALPHAZ POINTS Y 1 Z 1 AY 1 AZ 1 Y n Z n AY n AZ n P_FY FY 1 FY 2 FY n M_P Zy Zz P_N Pn ETA ETA F_TYPE TYPE If one wishes to override the section properties computed from the dimensions then he should use the SECTION option Here AREA is the cross sectional area inches 2 or mm 2 TY and IZ are the moments of inertia inches 4 or mm 4 J is the polar moment of inertia inches 4 or mm 4 and ALPHAY and ALPHAZ are the shear area multipliers The ALPHAs are numbers which transform average Rev Page 215 TEE Rev MOSES REFERENCE MANUAL u J i a wW l PRI B A ae E r C C G_IBEAM F B B aP u 4G EZ Eg k A k A CATALOG OF SECTIONS FIGURE 5 Page 216 MOSES REFERENCE MANUAL et ES P T a B BOX B TUBE l i k A e o D Ez x s E a C WBOX B A o l T PLATE D_ANGLE B k b sie ce oes m A 4 CATALOG OF SECTIONS FIGURE 6 Rev Page 217 MOSES REFERENCE MANUAL shear stresses into the true shear stresses at the neutral axis i e TAU n ALPHA n SHEAR_FORCE AREA If any of these val
555. which has been defined via the amp DATA CURVE M_GROWTH command If one wishes to include internal pressure or temperature effects during a structural analysis he must specify the internal pressure and temperature distribution This is accomplished with the T_PRESSURE option with TMP NAME being a name which has been previously defined via the amp DATA Menu with a T PRESSURE command When an environment is used for computing forces or stresses spectrally one can either combine the deviation with the mean or omit the mean by using the USE_MEAN option depending upon whether or not YES NO is YES or NO Rev Page 165 MOSES REFERENCE MANUAL If this option is omitted then the mean will be used As mentioned previously some of the environmental data must be defined in a sepa rate menu This is accomplished by issuing amp DATA ENVIRONMENT One can then define basic environmental data At the conclusion of defining envi ronmental data one should then issue END_ amp DATA to exit the menu The command T_PRESSURE TMP_NAME OBJECT 1 TMP 1 INP 1 GH 1 SC 1 OBJECT 2 TMP 2 INP 2 GH 2 SC 2 defines a temperature and internal pressure distribution within the elements which can be referenced by the name TMP_NAME Here OBJECT is the name of the object to which the temperature TMP i degrees F or degrees C and internal pressure distribution will be applied The pressure distribution is defined by a given gage
556. wo major exceptions Here a process must have been defined previously with a TDOM or LAUNCH command within the Static_Process Menu or by issuing some amp EVENT STORE commands Also here the forces in the connections are explicitly taken into account since MOSES will generate a set of loads which will sum to the resultant of the rigid constraint loads i e MOSES will inertia relieve these load cases The form of the command is PROCESS CASE 1 T 1 CASE i T i When LCASE is issued with the PROCESS option MOSES will generate a load case for each event in the process which was specified Here again CASE i is the name which the user wishes to give to the case and T i is the event of the process for which the load case will be computed The final option for LCASE is used for generating a solution for a launch simulation as above but also approximating the loads that the launch barge applies to the jacket The form is LAUNCH QMID QBEG TBLEN CASE 1 T 1 CASE i T i The LAUNCH option is used only for generating load cases during the launch of a jacket where it provides an approximate way of subjecting the launch legs of Rev Page 437 MOSES REFERENCE MANUAL the jacket to a distributed load Caution one should never use LAUNCH in conjunction with BODSOLVE With this option a S PART command specifying only the jacket should be issued and some restraints should be selected to completely define the sys
557. wo other features A Click on the button resets the scene to the initial view in other words it is the same as amp PICTURE RESET The rotate button is the same as INC_VIEW ROTATE and the select button is the same as INC_VIEW SE LECT After selecting this tool press and hold down a mouse button in the picture window and move the mouse to rotate the scene Finally the GL button is used to change the render mode This is useful for getting higher quality rendering or to change to a faster render mode when dealing with large models Changing to Line Mode navigating to the location of interest and then changing to Normal Mode is a useful technique The mode changes in this order Normal gt Detailed gt Line gt Point gt repeat With a GUI interface each picture is placed in a separate frame so that you can look Rev Page 60 MOSES REFERENCE MANUAL at them again If you wish you can delete some of the frames with the option DELETE N M Where N and M are numbers With this option MOSES will delete frames N through M If M is omitted all frames greater than and equal to N will be deleted If only a single number is specified then only that frame will be deleted Rev Page 61 MOSES REFERENCE MANUAL VIII C Picture Selection There are quite a few options which can be used to paint only a portion of the data available They are XG_WIND X_MIN X_MAX YG_WIND Y_MIN Y_ MAX ZG_WIND Z_MIN Z MAX CONNEC
558. y and Gz are the X Y Z coordinates feet or meters of the CG in the part system The two flags INITIAL and ADDITIONAL define whether or not the compart ments will be emptied before adding or whether the following fluid will be added to that which exists For all of these flags CMP_SEL i is a selector which defines the compartments which will have their properties altered The FLAGS define how the amounts defined with PERCENT FRACTION AMOUNT or SOUNDING will be treated These options instruct MOSES to add ballast to the specified tanks the only difference is the manner in which the amount of ballast is specified With PERCENT one specifies the percentage full with FRACTION he specifies the fraction full with AMOUNT he specifies the amount of ballast bforce and with SOUNDING he specifies a sounding feet or meters SPGC is the specific gravity of the contents of a tank If it is omitted then the last specific gravity provided for a tank will be retained For new tanks the default is the specific gravity of ambient water If none of these flags is specified then all tanks mentioned will have a fill type defined by the FILL_TYPE option of the amp DEFAULT command The values CMP_SEL i which may follow these options allows one to change the type of filling without altering the amount of ballast in the tanks This command is quite complicated and a few examples are in order amp COMPARTMENT CORRECT ONE TWO S w
559. y height draft marks and sling tensions will be produced Pictures of the process and graphs of the metacentric heights are also generated Rev Page 417 MOSES REFERENCE MANUAL XXV A Post Processing Body Information Two commands deal with post processing information on bodies They are the TRAJECTORY and BODY_FORCE command The options common to both commands are EVENTS EVE_BEGIN EVE_END EVE_INC MAG_DEFINE A 1 A n BODY B SEL The EVENTS option selects the events which will be considered Here EVE_BEGIN and EVE_END are the beginning and ending event numbers for which the results will be computed and EVE_INC is the increment for computing results After the results have been computed MOSES places the user in the Disposition Menu so that he can dispose of the data The corresponding form of the REPORT command is REPORT REP_NAMES 1 REP_NAME 2 OPTIONS Here REP_NAMES i is a set of report names which may be selected and will depend on the command issued The only option available for reporting is again EVENTS The MAG DEFINE option defines how the Magnitude is computed You can have one two or three A i and each on must be either X Y or Z If you specify all three the default then the magnitudes will be the length of the vectors Alterna tively the magnitude will be the length of the vector projected on to either a line if one is specified or a plane For example MAG DEFINE X Y will gi
560. y not be open to the sea Interior compartments can also be ballasted in which case compartments define a part of the inertia of the system Since all of the model information in MOSES is stored by name the names are of importance in conveying to others what type of data is associated with the name Unfortunately the limited space of a name often does not allow one to adequately describe things Thus all of the modeling commands accept two options NOTE and TAG The first of these allows one to attach a 60 character description of the data This is a peculiar option in that it must be specified by all five characters One can then use an amp STATUS command to report the name and the notes for selected Rev Page 138 MOSES REFERENCE MANUAL types of data No quotes are needed for this option to include blank spaces but if you have a it must be escaped if it is not followed by a blank The TAG options allows one to define an eight character tag to the name Tags can be used to select reports for a given class of data to only that which matches its tag If a tag is not specified then one which is the same as the name will be given There are several commands in MOSES which exports portions of the model amp EMIT amp EXPORT amp CONVERT E_TOTAL and E PRESSURE Each of these com mands also accepts the NOTE option When the exported file is written the TI TLE SUBTITLE and the NOTE will be included in the exported file if
561. you must have load cases that are snapshots at times during a time domain simulation If so then you must tell MOSES to store the results so that you can use them for pictures One does this with the option FOR_ANIMATION on the Post Processing command commands BEAM POST CODE_CHECK JOINT_POST CODE_CHECK JOINT_POST DISPLACEMENTS If you use this option then e no output of the results will be generated e Results will be generated only for the current process If you have more than one process then you need to generate the data for each process i e use amp DESCRIBE PROCESS to change the current process e Once the data has been generated it will be used in place of the system wide data for all events greater than 0 e If you define a combination case then it will inherit the time association of the first member of the combination e If you have a combination case generated with the TIME option then it will have the event behavior of the time specified It will not however be useful unless you use the FR_2 TIME to associate a process with these events Perhaps it is good to look at some examples Suppose that you have a time domain simulation and that you generated load cases with amp loop t 1 1000 lcase process t amp string o number T0000 amp endloop Now suppose that you wanted to look at the deflections as a function of time You Rev Page 452 MOSES REFERENCE MANUAL can do this with strpost
562. your model MOSES supports exporting to a ray tracing program Ray tracing calcu lates the path of every beam of light in your scene making it a very computationally intensive process but one that can handle reflections refraction and transparency correctly as opposed to the approximations we make in the normal 3D display in order to give users a smooth interactive experience To export a scene for ray tracing it is recommended but not required that users first visualize the scene in MOSES s 3D viewer Once the scene is positioned correctly issuing the command amp PICTURE RENDER RAYTRACE SAVE will generate a file in the ans directory called povxxxxx pov which can be loaded and run by POV Ray by double clicking on it If double clicking on the file does not open POV Ray you need to download and install it from here The downloads are about half way down the page Once you have it installed double clicking the pov file should open it Hit the Run button in POV Ray to begin the render For better quality we recommend going to the menu and selecting Render gt Edit Settings Render and selecting the last option under Section 1280x1024 AA 0 3 For those looking for an even more realistic rendering you can use the amp PICTURE option W_FANCY YES NO This option with YES NO of YES will render realistic small waves when there is no sea specified After installing POV Ray command line users can directly

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