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1. Set entfernen a Set hinzufuegen Set entfernen Figure 2 Picking options in ZSS8Aurora V2 During the pre processing qualities can be assigned this set like materials loads boundary conditions meshing rules etc The last entries in the respective menus stored in the file SETACTIVE TXT control afterwards the calculation Z88 Aurora V2 is planned in the shape that the pre processing is carried out interactively by the user in a graphical surface interface i e a GUI Though the files are clear and built up logically nevertheless the production of hand is difficult This is not the key feature of Aurora but from Z88 V14 OS The use of the Pickings and the set management is found in the user s handbook 97 LIB on Theorie Manual 4 2 1 SURFACE LOADS Although the entering of the boundary conditions is not required by hand in Aurora you need some knowledge on the peculiarities regarding surface loads With distributed loads and sur face loads like pressure loads and tangential shear some specific features are to be followed Seldom a load is in a few points on a body mostly loads reflect surface loads For the distri bution of these loads on the component there are several possibilities Directions Rotations L X direction C X Axis C Y direction C Y Axis OZ direction E Type O Displacements O Pressure Force uniformly distributed Surface load O Projected surface load O Line load O Projec
2. If you find a 3D model totally flat You ve defined a coordinate system CSO in Pro ENGINEER which does not fit Z88 s needs Simply define a new correct coordinate sys tem in Pro ENGINEER and define it as datum when outputting the model Keep in mind that those exchange file formats and their Pro ENGINEER output are subject to change every some months You may create the following Z88 element types with Z88G e Tetrahedron No 16 Tetrahedron parabolic in Pro ENGINEER e Tetrahedron No 17 Tetrahedron linear in Pro ENGINEER e Plane stress No 14 Shell triangle parabolic in Pro ENGINEER e Plane stress No 7 Shell quadrangle parabolic in Pro ENGINEER e Plate No 18 Shell triangle parabolic in Pro ENGINEER e Plate No 20 Shell quadrangle parabolic in Pro ENGINEER e Torus No 15 Shell triangle parabolic in Pro ENGINEER e Torus No 8 Shell quadrangle parabolic in Pro ENGINEER e Shell No 23 Shell quadrangle parabolic in Pro ENGINEER e Shell No 24 Shell triangle parabolic in Pro ENGINEER Please keep in mind that Z88G is capable to deal directly with pressure loads from Pro ENGINEER only with NASTRAN files In this case the file for surface and pressure loads Z88I5 TXT is generated This is not possible for COSMOS files Here you are to enter pressure loads via nodal forces 92 Da 56 Aurora Theory Manual Choose element type before start Pro ENGINEER makes no distinction between volume elements pla
3. Z8811 TXT 2 37 8 740 AS Z88GEN Z88KNR Z88NET PPPRP TE A E A E E E a 5555544 F BERR Invert filter lt lt All 7 layers displayed of 7 total layers Id 4 PI Model_ Layout 1 or Autodesk licensed application Command Specify opposite corner vr Command p Ela Hafmena Aae 7th step Store your model or drawing in the DXF file format Choose AutoCAD R12 DXF format if in doubt but AutoCAD 2011 DXF works too For precision of decimal positions take the default value which the CAD program suggests You may import this DXF file into Aurora by DXF import DXF structure to Z88Aurora structure Later in Aurora you may enter the boundary conditions and surface loads 83 LIB on Theorie Manual EXAMPLE 2 FOR Z8S8 amp X SUPER ELEMENTS STRUCTURE This example is very similar to the first one but now we will generate a super structure This super structure will be loaded into Z88Aurora by DXF import and then automatically meshed by the mapped mesher Z88N resulting in a finite elements structure Consider a pipe under internal pressure of 1 000 bar 100 N mm Inside diameter of the pipe is 80 mm outside diameter of the pipe is 160 mm The length is 40 mm If one chooses the supports cleverly a quarter of the pipe is enough to reflect the problem Ist step Design your component in the CAD system as usual 80 00 40 00 2nd step We ll only use 2 super elements No 11 with 12 nodes
4. AUTOCAD DXF import and export You have the possibility to import 2D and 3D FE structures which were generated AutoCAD and to process For this a bit of groundwork is needed c f Chapter 4 1 5 STL import Z88 processes stereo lithography data which contain a triangulated 3D structure This format is also typically used as input data for CAM programs This is why most CAD programs can generate this file type NASTRAN import The CAD system Pro ENGINEER and other commercial programs can write FE data continuum elements and boundary conditions as nas file These can be directly imported into Z88 Aurora ABAQUS import Similar to the NASTRAN case the input files inp of the program ABAQUS can be loaded ANSYS import Direct transformation of ANS YS PREP7 data into data for Z88Aurora V2 COSMOS import The import of COSMOS files known from previous versions is still supported IV THE MAPPED MESHERS amp There are three possibilities in Z88Aurora V2 to improve the mesh super element generator for hexahedrons axisymmetric elements plain stress ele ments plates and volume shells tetrahedron improver shell thickener for 2D shells Depending on which element is used different adjustments have to be done 24 66 Aurora w Theory Manual 2 3 WHICH Z688 ELEMENTS CAN BE PRODUCED AUTOMATI CALLY Table 1 Automatically producible element types element type function hexahedron hexahedron No 1 ftimear f o o o
5. SIG TE stress in peripherical direction tangential stress Optional von Mises or principal or Tresca stresses Nodal forces in R X and Z Y for each element and each node 142 66 Aurora 86 Theory Manual 5 16 TETRAHEDRON NO 16 WITH 10 NODES amp This is a curvilinear Serendipity volume element with quadratic shape functions The trans formation is isoparametric The integration is carried out numerically according to Gauss Legendre Thus the integration order can be selected in Z88INT TXT The order 4 is good The quality of the displacement and stress calculations are far better than the results of the tetrahedron element No 17 but less precise than hexahedron No 10 This element type is implemented for use with automeshers The converter functionality in ZS8Aurora offers the possibility to import and process files with this element type For further information see chapter 4 1 8 Tetrahedron No 16 also applies well for thick plate elements if the plate s thickness is not too small compared to the other dimensions Pay attention to pressure loads when using forces cf chapter 3 4 It 1s easier to enter pressure loads via the surface and pressure loads file Z88I15 TXT X The nodal numbering of the element No 16 must be done carefully and must exactly match the sketch below Pay attention to the location of the axis system The possible error message Jacobi determinant zero or negative 1s a hint for incorrect
6. Theory Manual la fz Z88Aurora Version 2 0 3D view 29E 001 69E 001 38E 001 41E 002 87E 002 34E 002 81E 002 28E 002 75E 002 21E 002 68E 002 A 3 A A w 4 9 1 1 File View Pre processor Solver Post processor Tools Help O 5 i Linear mechanical CEARR Oss bekte SyYZ SFY OPED FF RNR SF T a Eea Bai xa a Flea IE Ir 69E 001 38E 001 41E 002 87E 002 2 2 3 3 4 4 5 STRESSES AT CORNER NODES 34E 002 81E 002 28E 002 75E 002 21E 002 68E 002 15E 002 io 2000 aera View O Undeflected Defected O Both Scaling 14 0 Em Max scaling factor 27 Filter Jv Apply Results Displacements X Displacements Y Displacements Z Total displacements Stresses per element Stresses at Gz Version V2 An easily operated Finite Elements Program for Windows LINUX and Mac OS X computers This Freeware Version is the literary property of the Chair for Engineering Design and CAD University of Bayreuth Germany composed and edited by Professor Dr Ing Frank Rieg In collaboration with Dr Ing Bettina Alber Laukant Dipl Wirtsch Ing Reinhard Hacken schmidt Dipl Math Martin Neidnicht Dipl Ing Florian Niitzel Dr Ing Bernd Roith Dipl Ing Alexander Troll Dipl Ing Christoph Wehmann Dipl Ing Jochen Zapf Dipl Ing Markus Zimmermann Dr Ing Martin Zimmermann
7. 1 10 16 17 possibly Choose solver Lanczos X Solver parameters amp Open Calculation 7 Solver parameters Lanczos Number of frequencies fis Number of iterations 20000 Residuum 1 000000E 008 Delta between 2 frequencies 1 000000E 006 Kappa 50 Help Figure 36 Parameters of the vibration solver Care is necessary concerning the boundary conditions While fixing boundary conditions movement is zero can be raised as usual on any nodal sets also in single degrees of free dom forces pressures as well as inhomogenous movements are ignored The aim of the nat ural frequency simulation is the calculation of free natural frequencies any dynamic sugges tions or external loads do not fall under it On the other hand a component must be statically defined for the vibration analysis by no means It can be also carried out totally without boundary conditions a free from problems calculation 106 66 Aurora 56 Theory Manual This time mathematically no equation system is to be solved but to carry out an eigenvalue calculation of a system matrix which contains information about the stiffness distributions as well as about mass distributions with regard to the FE mesh The eigenvalue calculation is considerably costlier numerically than the solution of the equation system and demands in practice according to more arithmetic time The procedure can be split up basically in two phases First
8. All rights reserved by the editor Version 2 July 2012 56 Aurora wo is a registered trademark No 30 2009 064 238 of Professor Dr Ing Frank Rieg LEB roc Theory Manual WELCOMES TO Z88 AURORA 788 Aurora is a software package for solving structural mechanical linear and nonlinear static problems eigen problems and thermal problems by the Finite Element Method FEM and is developed by a team of ten under the supervision of Professor Frank Rieg since 2009 Z88 Aurora is based on Z88 OpenSource V14 and is available for Windows 32 Bit and 64 Bit LINUX 64 Bit and Mac OS X for free download as executable file In addition to Z88 OpenSource V14 Z88Aurora offers a graphical user interface a completely new pre processor and an extension of the approved post processor Z88O along with four multi core solvers for static linear problems Z88R vibrations Z88EI thermal problems Z88THERMO and nonlinear static problems Z88NL Z88Aurora was developed with great care for easy and intuitive operation This Z88Aurora V2 is an extended development of the extremely successful version V1 of 788 It has even more features for managing a structure resulting in an even more straight forward import of STL and STEP files along with applying boundary conditions and materi als easily The new and outstanding online help SpiderHelp is especially designed for FEM rookies and leads you from the beginning to end through the complete workflow
9. O No reduced stresses von Mises stresses Rankine principal stresses resca stresses Solver parameters Calculation std PARDISO F Solver parameters sover output Solution procedure Newton Raphson procedure O Arc length procedure Riks Automatic switching Automatic switching Results O On O On O After 100 load Off Off After every load step After every iteration at every load step C Backup of Pardiso fields Number of iterations 20000 Residuum 1 000000E 008 Omega 1 000000E 000 Strategy of abort Norm lt TOL Also for increasing norm Number of load steps foo Max iterations i000 ts Residuum TOL 1 000000E 007 Arc length 1 0000006 000 X Abbrechen 2 abbrechen Figure 42 Adjusting the non linear solver 113 Theorie Manual The start of the calculation causes the call of the equation solver Z88NL which works with the following input files and output files Input files o Z88il TXT general structure data e Z8812 TXT mechanical boundary conditions o Z88I5 TXT mechanical surface loads or O in the first line e Z88NLI7 TXT adjustment of special parameters or 0 in the first line e Z88MAT TXT material defini and one or more material files in TXT format e TXT material file e Z88ELP TXT element parameters e Z88INT TXT integration orders e Z88MAN TXT solver parameters for Z88NL Output files e Z88NL LOG hints warnings and errors of Z88NL
10. Step 1 Write out the input deck as a inp file 2 In Z88Aurora you select from the menu File gt import gt ABAQUS data In the following choice dialog you can select automatically only inp files Select the desired file 3 The converted structure is plotted and you may show constraints and loads in Z88 Aurora 96 66 Aurora w Theory Manual 4 2 PICKING amp THE SET MANAGEMENT Boundary conditions material definitions surface loads all these qualities of a FE analysis which are controlled in the Open Source version by the input files Z88I1 TXT to Z88I5 TXT are tied together in Z88AuroraV2 with the set management In principle the action is always the same In the Picking menu nodes element or surfaces groups can be marked ne Knotenanwahl R Elementanwahl Flachenanwahl amp amp Ors Ansicht Ansicht Ansicht 2 R R 3 Schliessen Fy Schliessen L RQ 3 Schliessen Knoten Elemente Flaeche Einzelknoten Einzelelement Winkel Nr J OK Nr J OK 20 0 FEW Winkel Oberflaeche Alle Elemente 20 0 Flaeche Alle Flaechen BB vertauschen Abwaehlen BH Vertauschen Abwaehlen Flaeche J kante Markierungen V Marki a ertauschen amp Abwaehlen dh Hinzufuegen Entfernen d Hinzufuegen Entfernen Markierungen a Hinzufuegen Entfernen aa aa ap Set hinzufuegen Set entfernen gt o a Set hinzufuegen
11. Y and Z for each element and each node 129 LIB on Theorie Manual 5 5 SHAFT ELEMENT NO 5 WITH 2 NODES The shaft element is a simplification of the general beam element No 2 It has always a circular cross cut The element lies concentrically to the X axis consequently local and global coordinates have the same direction Thus inputs and calculations are simplified strongly Like with the beam element the results are exact according to Bernoulli s bend theory and Hooke s law and not approximate solutions like with the continuum elements Z U Algebraic sign Y U2 Input CAD see chapter 4 1 4 Line from node 1 to node 2 Z88STRUCTURE TXT gt Set KFLAG to 0 for Cartesian coordinates gt 6 degrees of freedom in a node Attention DOFS not right hand rule see below gt Element type is 5 gt 2 nodes per element Element parameters L Section Bd Thickness enter here the diameter for the elements Z88ENVIRO DYN gt Integration order INTORD for displacement calculation any order has no influence gt Integration order INTOS for stress calculation any order has no influence Z88CONTROL TXT gt Radial Tangential stress flag KDFLAG has no meaning gt Reduced stress flag ISFLAG has no meaning Results Displacements in X Y and Z and rotations around X Y and Z Attention DOF5 not right hand rule see below Stresses SIGXX TAUXX Normal stress shear stress SIGX
12. Your choice 1 ata ate ate ate ata ate ata ate ata ata ate ata ate ata ate ale ale ate ale ate ale ale ate al investigating 1st line of z88i1 txt dimension 3 detected 17801 nodes detected 11209 elements detected ibflag 0 ipflag 0 11209 elements of type 16 detected element infos may be okay z88i1 txt checked no errors detected all checks done no errors detected c puffer gt 4 Figure 1 ZSSVRY console application 62 66 Aurora 86 Theory Manual 4 1 2 THE STEP CONVERTER ZSSGEOCON What is the basic idea and which are the features The present STEP converter is based on the parsing and output routines of the Open Source 3D Suite OpenCASCADE Therefore the relevant sources stepread cpp and geocon cpp as well as a copy of the GPL license accompany Z88Aurora Most 3D CAD systems feature the possibility to store models in files according to the interna tional standard DIN ISO 10303 STEP STandard for the Exchange of Product model data In most of these cases the application logs AP203 and AP214 are used These store the 3D ge ometry described in highly accurate form in text files At the moment only few CAD pro ducers accommodate the fact that STEP could transfer a lot more notes parameters materi als and a lot more according to the definition The geometry however can mostly be used well also in FE programs if a few points are taken into account e Any STEP converter of a CAD pr
13. e Z88NLKV LOG convergence of Z88NL e Z88NL DYN memory parameters automatically computed e Z88NLO2 TXT displacements e Z88NLO3 TXT stresses Cauchy stresses 1f chosen e Z88NLOH TXT special parameters All input files except the files Z88NLI7 TXT and Z88MAN TXT are named identically with the input files of Z88R But the parameters file Z88MAN TXT of the solver contains an addi tional section which would be briefly described in the following The new section becomes limited by the wrench words NONLINEAR START and NONLINEAR END NONLINEAR START NLELAG 1 NLAERH 25 MAXNLIT 1000 EXIT 1 TOL 1E 7 AUTOGAUSS 0 OUTPUTFLAG 1 OUT CAUCHY 1 OUT INT9OFFS 1 PARSP 1 BGLAENG 1 0 NONLINEAR END The parametres are adjusted by the settings in the solver menu They have the following meanings e 1 value Solution processes NLFLAG Newton Raphson method 1 or arc length method according to Riks 2 e 2 value Number of the load steps NLAERH says in how many steps the whole load is applied e 3 value maximum iteration number MAXNLIT says in how many steps the non linear solution process is carried out at most e 4 value Control of the break criterion EXIT break of the non linear solution pro cess only if the norm is smaller than the break criterion TOL 1 or break even if the norm increases 2 114 66 Aurora 86 Theory Manual 5 value Break criterion or residuum TOL The norm must be smaller than TOL so that the so
14. 12 7 quit LINE function 1 7 quit LINE function 2 8 quit LINE function 3 9 quit LINE function 73 8B on Theorie Manual 6th step Define the layer Z88GEN and switch it active Write with the TEXT function into any place of your drawing the general information i e the first input group of the general structure data Z88I1 TXT or the mesh generator file Z88NILTXT In case of Z8811 TXT i e FE mesh ZSS11 TXT Dimension of the structure Number of nodes Number of finite elements Number of degrees of freedom DOF Coordinate flag 0 or 1 Write into one line separate each item by at least one blank Definitely write in the layer Z88GEN Example 3 dimensional FE structure with 150 nodes 89 finite elements 450 degrees of freedom Input with cylindrical coordinates Thus ZSSI1 TXT 3 150 89 450 1 In case of Z88NI TXT i e super structure ZSSNI TXT Dimension of the structure Number of nodes Number of super element Number of degrees of freedom DOF Coordinate flag for super elements 0 or 1 Trap radius header flag mostly 0 Coordinate flag for finite elements O or 1 Write into one line separate each item by at least one blank Example 2 dimensional super structure with 37 nodes 7 super elements 74 degrees of free dom Polar coordinates for the super elements use default for trap radius and use default cartesian coordinates for coordinate flag for the finite elements Thus ZSS
15. Input CAD see chapter 4 1 4 5 2 6 3 7 4 8 1 Z88STRUCTURE TXT gt In principle cylindrical coordinates are expected KFLAG must be 0 R coordinate X always positive Z coordinate Y always positive gt 2 degrees of freedom for each node DOF R and Z X and Y gt Element type is 8 gt amp nodes per element Z88ENVIRO DYN gt Integration order INTORD for displacement calculation 3 is usually good gt Integration order INTOS for stress calculation 0 Calculation of stresses in the corner nodes 1 2 3 4 Calculation of stresses in the Gauss points Z88CONTROL TXT gt Radial Tangential stress flag KDFLAG any has no meaning gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the Gauss points INTOS not 0 2 principal or Rankine stresses in the Gauss points INTOS not 0 3 Tresca stresses in the Gauss points INTOS not 0 Results Displacements in R and Z X and Y Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations It is SIGRR stress in R direction radial stress X direction SIGZZ stress in Z direction Y direction TAURZ shear stress in RZ plane XY plane SIGTE stress in peripherical direction tangential stress Optional von Mises principal or Tresca stresses Nodal forces in R X and Z Y for each element and each node 133 LIB on Theorie Manu
16. KDFLAG l ISFLAG l Example2 A structure featuring plane stress elements no 7 may calculate only default stress es thus KDFLAG 0 No reduced stresses calculation ISFLAG 0 Thus KDFLAG 0 ISFLAG O In the menu Solver under Solver options the parameters of the different solvers may be edited For further information on the use of the solver menu see User Manual 42 66 Aurora wos Theory Manual 35 Choose solver Failure theory pan PARDISO No equivalent stress GEH von Mises Rankine O Tresca Solver parameter sIcceG sorce F Solver parameters F Solver parameters SICCG Number of iterations to00c Residuum 1 000000E 006 Alpha 1 000000E 004 Help rA SORCG Number of iterations 10000 Residuum 1 000000E 006 Omega 1 200000 000 Help one Figure 6 Solver options menu for the control of the solver parameters of the four integrated solver types 3 2 7 SOLVER CONTROL FILE ZSS8SCONTROL TXT General settings such as memory needs or the appearance of Z88Aurora are defined in the two definition files Z88 DYN and Z88ENVIRO DYN The user can influence their control via the option menu under Help gt Options For further information about the settings in the option menu see the Z88Aurora User Manual The files are located in the working directory of Z88Aurora which is depending on the plat form in z88aurorav2 bin Selection operating sy
17. NAS BDF ANS INP and FE export INP context sensitive online help and video tutorials simplest installation with Microsoft Installer MSI Z88Aurora can load input files from the OpenSource Z88 V 14 directly Z88Aurora is compatible with Z88 V13 and Z88Aurora Vla Existing files and projects can be migrated easily 66 Aurora 56 Theory Manual Note Always compare FE calculations with analytical rough calculations results of ex periments plausibility considerations and other tests without exception Keep in mind that sign definitions of Z88 and also other FEA programs may differ from the usual definitions of the analytical technical mechanics from time to time The file formats of the three Z88 versions Z88 Aurora V2 Z88 Aurora V1 and Z88 V13 are quite similar but especially Z88Aurora V2 uses more and different input files than former versions for better operation of the GUI Proper migration tools are added to the Z88Aurora V2 software package How Z88 deals with other programs and utilities etc is not predictable It is the aim of this research version to give you an understanding of the fundamental operating concept The de velopers of Z88Aurora are interested in constantly improving this software Proposals sug gestions and remarks can be sent to aurorasupport z88 de In addition FAQs are available on the homepage www z88 de and users can exchange experiences in a forum The present version Z88Aur
18. Select the LINE command and select the proper snap options e g points intersection points and if necessary end points Start at the first element For Z88 the first element is the element with which you start now that means the one which you have chosen for your first element FE Select the node you want to be the first node of this element and draw a line to the node which shall be the second node of this element From there draw a line to the third node of this element Connect all required nodes with lines and draw at last a line to the starting point the first node and then quit the LINE function Thus we might draw this line P1 P2 P3 P7 P11 P10 P9 P6 P1 quit LINE However these lines would do fine too P9 P6 P1 P2 P3 P7 P11 P10 P9 or P3 P7 P11 P10 P9 P6 P1 P2 P3 or P11 P10 P9 P6 P1 P2 P3 P7 P11 Then do the same with the second element Remember You determine with this order which of the elements will be the real second element now In the previous 4th step you have only defined what kind of element the second element is You determine here how the element is defined topologically Thus we might draw this line P3 P4 P5 P8 P13 P12 P11 P7 P3 quit LINE Let the other elements follow This procedure sounds strange and complicated but be assured that it will work much more easily and quickly than one can describe it For these 8 elements you will finish work in less than two minutes 81 Theorie Manual re 032D Draftin
19. Shell Flag IHFLAG ZS8MAN TXT Not applicable Z8811 TXT Z881 TXT 28 66 Aurora 86 Theory Manual Radial tangential Flag ZSSMAN TXT ZSSCONTROL TXT ZSSMANAGE TXT ZSSI3 TXT KDFLAG here KSFLAG here KFLAG Comparison stress Flag ZSSMAN TXT ZSSCONTROL TXT ZSSMANAGE TXT ZSSI3 TXT ISFLAG 3 2 FILE LAYOUT IN ZSSAURORA V2 Basically Z88Aurora V2 reflects the file structure of Z88 V14 OS and Z88Aurora V1 but the input is divided into more structure files to guarantee an optimal operation and expansion pos sibilities The input files of Z88 Aurora V2 are e ZSSSTRUCTURE TXT general structure data coordinates coincidence e ZSSMARKS TXT data sets of nodes or elements which can be used to create SETs ZSSSETS TXT node and element allocation for boundary conditions and applying a mate rial ZSSSETSACTIVE TXT properties of the SETS valid for the current calculation 1 TXT TXT material data files ZSSNI TXT input file of mesh generator ZSSN ZSSCONTROL TXT control parameters for solver ZSSDYN TXT control file Z88 ZSSENVIRO TXT control file for ZSSAurora V2 3 2 1 GENERAL STRUCTURE DATA ZSSSTRUCTURE TXT In Z88STRUCTURE TXT the geometry data of the structure is entered 1 input group General data in the first line contain general structure data Write all numbers into a line sep arate them at least by one blank respectively All numbers here are of the type Long 1 number Dimension of the struct
20. Theory Manual Element No 2 4 5 9 13 Line from node 1 to node 2 Z X 1 Element No 3 14 15 18 and 24 1 4 2 5 3 6 1 Y Element No 6 1 2 3 1 71 ohh Theorie Manual Z Y 2 R X Element No 19 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1 16 _ 10 T n is y 4 GY vA 13 a a ew Element No 1 Upper plane 1 2 3 4 1 quit LINE function Lower plane 5 6 7 8 5 quit LINE function 1 5 quit LINE function 2 6 quit LINE function 3 7 quit LINE function 4 8 quit LINE function Element No 10 Upper plane 1 9 2 10 3 11 4 12 1 quit LINE function Lower plane 5 13 6 14 7 15 8 16 5 quit LINE function 1 17 5 quit LINE function 2 18 6 quit LINE function 3 19 7 quit LINE function 72 Theory Manual Element No 16 XY Plane 1 5 2 6 3 7 1 quit LINE function 2 8 4 quit LINE function 3 9 4 quit LINE function 1 10 4 quit LINE function Element No 17 XY Plane 1 2 3 1 quit LINE function 2 4 quit LINE function 3 4 quit LINE function 1 4 quit LINE function Element No 21 Upper plane 1 5 2 6 3 7 4 8 1 quit LINE function Lower plane 9 13 10 14 11 15 12 16 9 quit LINE function 1 9 quit LINE function 2 10 quit LINE function 3 11 quit LINE function 4 12 quit LINE function Element No 22 Upper plane 1 4 2 5 3 6 1 quit LINE function Lower plane 7 10 8 11 9
21. Yoho Theorie Manual gt Integration order INTOS for stress calculation 0 Calculation of stresses in the corner nodes 1 7 13 Calculation of stresses in the Gauss points Z88MAT TXT gt Define materials ref chapter 3 1 4 and 3 1 5 Z88MAN TXT gt Radial Tangential stress flag KDFLAG has no meaning gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the Gauss points INTOS not 0 2 principal or Rankine stresses in the Gauss points INTOS not 0 3 Tresca stresses in the Gauss points INTOS not 0 Z8815 TXT This file is only used see 3 1 3 if in addition to nodal forces edge loads are applied onto el ement no 15 otherwise enter a O into the first line gt Element number with surface and pressure load gt Pressure positive if pointing towards the edge gt Tangential shear positive in local r direction gt 2 corner nodes and one mid node of the loaded surface Mathematically positive in top view The local r direction is defined by the nodes 1 2 The local nodes 1 2 3 may differ from the local nodes 1 2 3 used for the coincidence Results Displacements in R and Z X and Y Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations It is SIGRR stress in R direction radial stress X direction SIGZZ stress in Z direction Y direction TAURZ shear stress in RZ plane XY plane
22. Z88Aurora easily by MITOO For the plotting of results the approved Z880 was extended and adjusted Furthermore for the further use of the results the files Z88O0 Z8804 TXT can be displayed and printed I THE SOLVERS de 2 2 1 THE LINEAR SOLVER Z amp 85R The linear solver Z88R is the heart of any FEA system It reads the general structure data the data for boundary conditions and surface and pressure loads along with the integration order the elements parameters and the material definitions Basically the Z88 input files can be cre ated by CAD converter Z88X by 3D converter Z88G by mesh generator Z88N by editor or word processor system or by a mixed procedure e g by CAD and editor The solver generates prepared structure data Z88O0 TXT and processed boundary conditions Z8801 TXT calcu lates the element stiffness matrices compiles the total stiffness matrix scales the system of equations solves the huge system of equations and stores the displacements in Z88O02 TXT Thus the main task of every FEA system the calculation of displacements is solved There upon the stresses are calculated and stored in Z8803 TXT afterwards the nodal forces are cal culated and stored in Z8804 TXT Furthermore the solver generates two files Z8805 TXT and Z8808 TXT which are used for the communication with Z88 Aurora ZSSR features three different solvers e A so called Cholesky solver without fill in It is easy to handle and very fast for sma
23. an FE analysis The following information has to be written FE Element number Element type 79 n Sdan AN Theorie Manual It might be a good idea to use another colour for the objects of layer Z88EIO here blue However you don t need to For better information the former layer Z88KNR is switched off 03 2D Drafting amp Annotation b6_4 dwg Type a keyword or phrase Insert Annotate Parametnc View Manage Output Express Tools 1 2 8 SSlOIA L les Bee as Line dit Move z amp dh i oes Last See Nn Block Properties Utilities Clipboard N amp 55 A Y of W zssE0 Draw v Modify v Search for layer q FP Ansichtsfe Definitions Z88EIO Z88KNR x 14 4 gt PL Model_ Layout 1 Autodesk DWG This file is a TrustedDWG last saved by an Autodesk application or Autodesk licensed Ei eons Command ae pe HOA oe Henog oleh Sth step Define the Layer Z88NET and make it the active layer You need concentration for this step because a firm and rigid work sequence must now be kept because of the topological information One of the most important information the coincidence is defined in this step that means which elements are defined or outlined by which nodes Choose a proper colour 80 66 Aurora ti Theory Manual which differs well from the colours used till now and remove all superfluous information by switching off unused layers
24. component in the CAD system as usual You do not need to maintain a definite order and you can use any layers It is highly recommended to put symbols on one layer edges on another layer dimensions on a third layer invisible lines and centre lines on a fourth layer and so on This enables you to remove all unnecessary information in the next Step 2nd step Plan your mesh subdivision that means suitable finite element types and their dis tribution Subdivide the FE structure or the super structure into elements by lines insert all points which are not yet existing for example intersection points or end points of lines are usable Any order and layer However it is recommended not to use the Z88 layers like Z88NET Z88GEN Z88PKT Z88KNR Z88EIO Z88FLA and Z88RBD Better define any new layer for this or use already available layers from step 1 3rd step Define the Z88 Layer Z88KNR and make it the active layer Catch or trap every FE node which were already defined in the Ist step by your construction or have been completed 67 LIB on Theorie Manual in the 2nd step and number them Write to every node P blank node number e g P 33 with the TEXT function of the CAD program Be very careful to snap exactly the node and attach the number exactly to the node s location Take your time With the snap modes of AutoCAD intersection point end point point etc this works well Choose any order of the work se quence as you like you can we
25. corner nodes very inaccurate Computing effort medium Size of element stiffness matrix 12 x 12 Z lt 1 Theorie Manual Tetrahedron No 16 A Quadratic Isoparametric Serendipity element Quality of displacements very good Stresses in the Gauss points very good Stresses in corner nodes good Computing effort very high Size of element stiffness matrix 30 x 30 18 LB coc Theory Manual 2 THE Z88 COMPUTING UNITS 2 1 OVERVIEW Z88Aurora always exclusively works on the tasks required at the moment Under the new user interface the established Z88 programs are launched Z88 is no gigantic monolithic pro gram but consists of several separate running modules according to the UNIX philosophy Small Is Beautiful They are loaded into the main memory according to your requirements execute their tasks and release the main memory again In this way Z88 achieves its enormous speed and faultlessness beating many other FE programs The Z88 modules communicate by files cf Chapter 3 2 2 ASHORT DESCRIPTION OF THE MODULES I THE PRE AND POST PROCESSOR i In addition to the established Z88 modules Z88Aurora possesses a graphic user interface All input which in Z88 V13 was made via the input files Z88I1 Z88I5 TXT is now directly made in Z88Aurora But of course input files from Z88 V14 OS may be loaded directly into Z88Aurora V2 while existing input files from Z88 V13 and Z88Aurora V1 may be migrated to
26. determine here how the element is defined topologically Thus we might draw this line P9 P10 P11 P12 P14 P16 P20 P19 P18 P17 P15 P13 P9 quit LINE This procedure takes less than half a minute 88 m 56 Aurora a i6320 Drafting amp Annotation E pe b6n_5 dwg rye a keyword or phrase Insert Annotate Parametnic View Manage Output Express Tools Filla et GOAR El es 4iy 2i4 ia _ Bir fl d amp dw Unsaved Layer State Line Move 4 amp oa gt O of W zener Modify v Theory Manual Block Properties Utilities Clipboard Draw Search for layer Q f FP 0 Ansichtsfe Definitions Z88EIO Z88KNR Z88 NET ld 41 gt bI Model Layout1 Rutodesk DWG This file is a TrustedDWG last saved by an Autodesk application or Autodesk licensed application Command P i i BR N Ton 5 ssena So KIO 4 4 aoa Ape oe 6th step Define the layer Z88GEN and switch it active Write with the TEXT function into any place of your drawing the general information i e the first input group of the general structure data Z88NI TXT ZSSNI TXT Dimension of the super structure Number of nodes Number of super elements Number of degrees of freedom DOF Coordinate flag for super elements 0 or 1 Trap radius header flag mostly 0 89 men 56 Aurora Theorie Manual Coordinate flag for finite elements 0 or 1 However here
27. each and this will do for a nice 90 arc because of the cubic interpolation functions of element No 11 Subdivide the super structure into elements by lines insert all points which are not yet existing for example intersection points or end points of lines are usable Any order and layer However it is rec ommended not to use the Z88 layers like Z88 NET Z88GEN Z88PKT Z838KNR Z88EIO Z88FLA and Z88RBD Better define any new layer for this or use already available layers from step 1 Take care to set nice looking points Use the AutoCAD command DDPTYPE 84 66 Aurora Yoi Theory Manual Now you may delete any auxiliary lines arcs etc to see the true super elements structure When working with super elements it is always a good idea to insert arrows to mark the local x axis for more easy operation later Thus you ll have the starting point for the multi line too 3rd step Define the Z88 Layer Z88KNR and make it the active layer Catch or trap every super node which were already defined in the Ist step by your construction or have been completed in the 2nd step and number them Write to every node P blank node number e g P 33 with the TEXT function of the CAD program Be very careful to snap exactly the node and attach the number exactly to the node s location Take your time With the snap modes of AutoCAD intersection point end point point etc this works very well Choose any order of the work sequence as you li
28. either plane stress elements or 3D elements but neither beam elements nor cam ele ments Plot of stresses The kind of plotting the stresses within FEA programs 1s truly of philosophi cal character As a matter of fact numerous experiments and computer studies at the Institute of Engineering Design and CAD of the University of Bayreuth Germany showed that some very expensive and well known professional FEA programs produced incorrect stress plots in some situations The best way is the computation of stresses directly in the Gauss points However this is odd for OpenGL in some modes so I decided for the following way after a lot of experiments 123 IB on Theorie Manual 1 von Mises principle Tresca stresses in corner nodes In fact the stresses are computed not really in the corner nodes which would lead to very wrong results especially for very tapered elements sic but in Gauss points lying near the current corner nodes Stresses are computed for just the same number of Gauss points like the number of corner points Because often a node is linked to more than one element the stresses are computed to a mean value from the corner node stresses of all linked elements This results in pretty balanced stress shadings which are mostly somewhat lower than the maximum stresses in the Gauss points however The value of the order of integration INTOS in the header file Z88EN VIRO DYN has no meaning but INTOS should be greater than 0 2
29. gt Element number with surface and pressure load gt Pressure positive if pointing towards the edge gt Tangential shear positive in local r direction gt 2 corner nodes and one mid node of the loaded surface Mathematically positive in top view The local r direction is defined by the nodes 1 2 The local nodes 1 2 3 may differ from the local nodes 1 2 3 used for the coincidence Results Displacements in X and Y Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations For KFLAG 1 the radial stresses SIGRR the tangential stresses SIGTT and the accompanying shear stresses SIGRT are computed additionally makes only sense if a rotational symmetric structure is available For easier orientation the respective radiuses and angles of the nodes points are printed Optional von Mises or principal or Tresca stresses Nodal forces in X and Y for each element and each node 140 66 Aurora 86 Theory Manual 5 15 TORUS NO 15 WITH 6 NODES UO This is a curvilinear Serendipity torus element with quadratic shape functions The transfor mation is isoparametric The integration is carried out numerically according to Gauss Le gendre Thus the integration order can be selected in Z88INT TXT The order 7 is mostly sufficient This element calculates both displacements and stresses very exactly The integra tion order can be chosen again for the stress calculation The stresses
30. in the Gauss points INTOS not 0 Z8815 TXT This file is only used see 3 1 3 if in addition to nodal forces pressure loads are applied onto element no 19 otherwise enter a O into the first line gt Element number with pressure load gt Pressure positive if pointing towards the edge Results Displacements in Z i e w and rotations 0 around X axis and O around the Y axis Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations The following results will be presented e plate bending moments M and Myy unit force x length length e plate torsion moments Mxy Myx unit force x length length e the shear forces Qy and Q x unit force length e the true stresses resulting from plate bending moments and plate torsion moments Optional von Mises or principal or Tresca stresses Nodal forces in X and Y for each element and each node 153 ohh Theorie Manual 5 21 HELL NO 21 WITH 16 NODES This is a curvilinear Serendipity volume shell element The transformation is isoparametric The integration is carried out numerically in all axes according to Gauss Legendre The ele ment can be arbitrarily curved it is actually a hexahedron with square shape functions on the surface and linear shape functions in the thickness direction The integration order can be se lected in Z88INT TXT The order 3 i e 3x3 Gauss Points is mostly sufficient This element c
31. mm The second surface load is applied tangentially and positive in local r direction with 200 N mm The third surface load is applied tangentially and positive in local s direction with 300 N mm Thus gt 456 100 200 300 51 34 99 12 102 ISI 166 191 Tetrahedron No 17 Element number with pressure load Long Pressure positive if pointing towards the surface Double 3 nodes of the loaded surface 3 x Double Example The tetrahedron 356 features surface loads The load should be applied onto the surface defined by the corner nodes 51 34 and 12 The surface load is pressure with 100 N mm pointing towards the surface 1 e positive Thus gt 356 100 5I 34 12 Tetrahedron No 16 Element number with pressure load Long Pressure positive if pointing towards the surface Double 6 nodes of the loaded surface 6 x Double Example The tetrahedron 888 features surface loads The load should be applied onto the surface defined by the corner nodes 51 34 and 12 and the mid nodes 65 66 and 67 The sur face load is pressure with 100 N mm pointing towards the surface 1 e positive Thus gt SSS 100 51 34 12 65 66 67 Tetraeder with pressure load on one element side Plate elements No 18 19 and 20 Element number with pressure load Long Pressure positive if pointing towards the surface Double Shell No 21 gt Element number gt Pressure positive if pointing towards the surface gt Tangential shear in local r direct
32. not possible because this will make no sense Use plates No 20 for the mapped mesher ZSSN Because plates No 20 compute both the deflections and the stresses more ex actly than the curvilinear triangle plates No 18 you should prefer always plates No 20 Input CAD 4 2 5 3 6 1 ref Chap 2 7 2 Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt set plate flag IPFLAG to I or 2 if you want to reduce the shear influence gt 3 degrees of freedom for each node w O O gt Element type is 18 gt 6 nodes per element Z88ELP TXT gt Cross section parameter QPARA is the element thickness 147 LIB on Theorie Manual Z88INT TXT gt Integration order INTORD for displacement calculation 3 is usually good Possible is 3 for 3 Gauss points 7 for 7 Gauss points and 13 for 13 Gauss points For easy combination with plate elements No 20 function SPLASS of Z88 uses internally these values integration order I or 2 3 Gauss points integration order 4 7 Gauss points Example ZSSINT TXT uses an entry of 2 for INTORD Thus plate element No 20 use 2X2 4 Gauss points and plate element No 18 use 3 Gauss points for integration gt Integration order INTOS for stress calculation 0 Calculation of stresses in the corner nodes 1 7 13 Calculation of stresses in the Gauss points Z88MAT TXT gt Define materials ref chapter 3 1 4 and 3 1 5 Z88MAN TXT gt set plate flag IPFLAG to 1 gt Ra
33. pressure load gt Pressure positive if pointing towards the edge Results Displacements in Z i e w and rotations Ox around X axis and O around the Y axis Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations The following results will be presented 150 66 Aurora 56 Theory Manual e plate bending moments M and My unit force x length length e plate torsion moments Mxy Myx unit force x length length e the shear forces Qyz and Q x unit force length e the true stresses resulting from plate bending moments and plate torsion moments Optional von Mises or principal or Tresca stresses Nodal forces in X and Y for each element and each node 151 LIB on Theorie Manual 5 20 PLATE NO 20 WITH 8 NODES 8 This is a curvilinear Serendipity Reissner Mindlin plate element with quadratic shape func tions The transformation is isoparametric The integration is carried out numerically in both axes according to Gauss Legendre Consequently the integration order can be selected in Z88INT TXT The order 2 2x2 points is mostly sufficient reduced integration This ele ment calculates both displacements and stresses quite good The integration order can be cho sen again for the stress calculation The stresses are calculated in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly For this element you need to s
34. pressure loads in contrary to Z88 V13 and ZS8Aurora V1 And here s why After the import of commercial input decks you may define the material data the element parameters and the integration orders very comfortable in Z88Aurora even if some of these information are included in the input decks however because only in this way a proper use of Aurora s own material data base is possible This will give you a clean data base for ZSSAurora V2 projects Which ANSYS files systems can be imported by Z88Aurora ANSYS PREP7 data in ASCII format can feature very different structures and contents de pending on their origin That is why accurate statements about compatibility cannot be made Especially integrated scripts can cause problems This converter was developed and tested for Pro ENGINEER Wildfire 4 Data generated by ANSYS Workbench cannot be imported Which elements are supported by the converter You can use tetrahedrons as linear or as quadratic type Conversion gt from TET 4 to element type 17 and vice versa Conversion gt from TET 10 E 92 to element type 16 and vice versa 94 66 Aurora 86 Theory Manual Which functions does the converter offer Import functions of the converter Z88ASY Generation gt of ZSSI1 TXT from an ANSYS file Generation gt of ZSSI2 TXT from an ANSYS file Generation gt of ZSSI5 TXT from an ANSYS file Generation gt of MAT TXT from an ANSYS file How to proceed 1 Construct your model accor
35. straight lines Especially illuminated scenes need a huge amount of computational power If a part renders pretty fast in your CAD system Pro ENGINEER for example and the same part renders quite slowly in Z88O this is normal business because CAD systems are drawing only some outline curves In contrast FEA system have to render every finite element i e compute the normal vectors for any element surface compute light effects for every tetrahedron etc Hidden line scenes put very heavy load on the CPU This can be solved by applying Surface Solid View and Quick View which can be found in the view menu Here only the outer solid edges are calculated and completely displayed but this procedure is not suitable for all functionalities What can I plot Nearly everything if a solver was run which stored the deflection file Z880O2 TXT and the three stress files Z8803 TXT for you to check the stresses Z880O5 TXT for Z880 internally and Z8808 TXT for Z88Aurora internally Even for trusses you may plot the von Mises stresses 1 e tensile stresses with different colours on ly beams No 2 and No 13 and cams No 5 allow only the plotting of deflections and nothing more Why Because you must compute for beams and cams also the stress concentration factor which is impossible for a FEA system which deals with a whole structure of beams Of course you may compute the stresses in a chamfer by putting an FE mesh around it But this needs
36. stress calculation 0 Calculation of stresses in the corner nodes 1 2 3 4 Calculation of stresses in the Gauss points Z88CONTROL TXT gt Radial Tangential stress flag KDFLAG has no influence gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the Gauss points INTOS not 0 2 principal or Rankine stresses in the Gauss points INTOS not 0 3 Tresca stresses in the Gauss points INTOS not 0 Results Displacements in X Y and Z Stresses SIGXX SIGYY SIGZZ TAUXY TAUYZ TAUZX respectively for corner nodes or Gauss points Optional von Mises or principal or Tresca stresses Nodal forces in X Y and Z for each element and each node 126 66 Aurora 86 Theory Manual 52 BEAM NO 2 WITH 2 NODES IN SPACE Y Beam element with any symmetric profile no slanting bend with the restriction that the local y y axis must be parallel to the global X Y coordinate system The profile values are provided in the GUI Thus you can use any symmetric profile in contrast to other FEA programs which incorporate a variety of different special beam and profile subroutines without matching all symmetric profiles as necessary The element matches exactly Ber noulli s bend theory and Hooke s law It uses no approximate solution as for the continuum elements ZU 3 Algebraic sign Y U 2 Y Us i J l U UW Us f parallel to h A i Ue x y plane T T TN N A A A
37. the Gauss points substantially more exactly Pay attention to edge loads when using forces cf chapter 3 4 It is easier to enter edge loads via the surface and pressure loads file Z88I5 TXT You may combine this element with elements no 3 not recommended or ele Plane Stress Elements No 7 can be generated by the mesh generator Z88N from super elements Plane Stress Elements No 7 or No 11 Thus the Plane Stress Element No 7 is well suited as super element Input CAD see chapter 4 1 4 5 2 6 3 7 4 8 1 Z88STRUCTURE TXT gt KFLAG for Cartesian 0 or polar coordinates 1 gt 2 degrees of freedom for each node gt Element type is 7 gt amp nodes per element Element parameters F Section Ht Thickness Z88ENVIRO DYN enter here the thickness of the elements gt Integration order INTORD for displacement calculation 3 is usually good gt Integration order INTOS for stress calculation 0 Calculation of stresses in the corner nodes 1 2 3 4 Calculation of stresses in the Gauss points Z88CONTROL TXT gt Radial Tangential stress flag KDFLAG 0 Calculation of SIGXX SIGY Y and TAUXY gt Radial Tangential stress flag KDFLAG 1 Additional calculation of SIGRR SIGTT and TAURT gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the Gauss points INTOS not 0 2 principal or Rankine stresses in the Gauss points INTOS not 0 3 Tresca stresses i
38. von Mises principle Tresca stresses as a mean value for each element The stresses are computed in the Gauss points of the current element added and then divided by the cur rent number of Gauss points This results in a mean value for the von Mis es principle Tresca stress per element The value of the order of integration INTOS in the header file Z88MAN TXT is important and INTOS must be greater than 0 3 von Mises principle Tresca stresses directly in Gauss points This is most accurate but does not deliver as pretty pictures as 1 and 2 INTOS must be greater than 0 Z88Aurora may show the following reduced stresses but only one at a time depending on the previous computation run von Mises stresses Rankine 1 e principal stresses Tresca stresses Thus if you have computed the von Mises stresses previously Z88Aurora will show them If you want to show the Tresca stresses now you have to run the solver again in this case with the setting Tresca see Figure This looks awkward but don t you know before starting the FE computations which type of stresses is suitable and correct for your task The choice of the appropriate reduced stresses hypothesis is not a matter of trial and error sss Menu Solver Choose solver PARDISO v Failure theory No reduced stresses von Mises stresses Rankine principal stresses Tresca stresses Solver parameters amp Open Calculation 4 Start calculation F
39. with Z88NL computed Cauchy stresses nonlinear calculation with Z88NL computed process variables nonlinear calculation with Z88NL rotocol file in Z88 Aurora rotocol file in Z88 Aurora oO p COSMOS FE file for converter Z88G NASTRAN FE file for converter Z88G ABAQUS FE file for converter Z88AINP ANS YS PREP7 FE file for converter Z88AS Y AUTOCAD CAD file for converter Z88X import of geometry for internal mesh generator import of geometry for internal mesh generator Input file for mesh generator Z88N Dimensions 1 e measurement units are not used explicitly You may work in optional meas urement systems e g in the Metric or Imperial measurement system Use inches Newton s 26 66 Aurora 56 Theory Manual pounds tons millimetres meters and yards whatever you prefer But make sure to keep the one chosen measurement unit throughout all computations of this structure Example You want to work with mm and N thus Young s modulus must be used in N mm Why working with files Is that not old fashioned and isn t working interactively better In Z88Aurora you have both possibilities Any kind of pre processing and post processing is possible without restrictions You can generate the input files by small self written pre programs such a pre program is the mesh generator Z88N or leave the job of processing the output data to other programs You can quite easily load Z88 output files because it s pure ASCII into E
40. 0 EPS 0 0000001 ALPHA Standard value without significance OMEGA 0 9 Example 2 You want to use the Iteration Sparse Matrix Solver and you want to stop positively after 10000 iterations the limit shall be 10 and the convergence acceleration factor a for SIC shall be 0 001 because you want to use the SICCG Solver SICCG sparse iterative Thus MAXIT 10000 EPS le 9 ALPHA 0 001 OMEGA Standard value without significance Example 3 You want to use the direct Sparse Matrix Solver with fill in Paradiso sparse direct and you have two double core CPUs installed in your computer Thus MAXIT Standard value without significance EPS Standard value without significance ALPHA Standard value without significance OMEGA Standard value without significance ICORE4 Example 4 You want to use the Cholesky solver Thus The control values MAXIT EPS ALPHA OMEGA and ICORE can be arbitrary and are without significance VIBRATION SOLVER ICFLAG 5 is the Lanczos solver Z88EI MAXIT is the first termination criterion When reaching this number of iterations the Lanczos solver is terminated in any case The values of the solution vector reached up to this point are printed however EPS is a termination criterion It s a measurement to determine that the calculated eigenval ues won t change significantly anymore EIGDIFF is the difference between two eigenvalues that determines that the two eigenvalues are handled as two diff
41. 00E 006 ALPHA 1 00E 004 OMEGA 1 20 THERMOMODE 1 THERMOMECHANIC 0 TMSOLVER END STRESS START 66 Aurora 86 Theory Manual KDF LAG 0 ISFLAG 1 STRESS END DYNAMIC END Explanation GLOBAL SIMCASE 11 linear static mechanical analysis 19 nonlinear static mechanical analysis 66 steady state thermal analysis 37 natural frequency analysis ICORE is a control parameter for the calculation of constraints and for the PARDISO solver It determines the number of CPUs on multi core computers LINEAR SOLVER ICFLAG 1 Cholesky solver ICFLAG 2 SIC solver ICFLAG 3 SOR solver ICFLAG 4 PARDISO solver MAXIT is the first termination criterion When reaching this number of iterations the itera tion solvers SICCG and analogously SORCG are terminated in any case The values of the solution vector reached up to this point are printed however EPS This value is compared to a norm of the residual vector When this value is reached for the iteration solvers SICCG and SORCG the solution reached should have a good precision This is the second termination criterion Enter a relatively small value e g 0 00001 or 0 0000001 Note that there is no absolute truth in this field No matter which norm of the re sidual vector is compared against this limit you can never be sure that all elements of the solution vector are precise The choice of EPS influences the iteration count and thus the computing speed enormously Remember this when comparing Z8
42. 345 55555 0 Wrong 1 345 S5555E 0 no entry Floating point numbers Z88 uses internally double precision floating point numbers Double Right l 345 5 5555E 10 0 Wrong 1 345 O letter O no entry Z88 input files may have comments in every line if all corresponding data has been entered before Separate the last data and the comment at least by one blank Lines in Z88 input files can include 250 bytes really needed are noticeably less than 80 Blank lines and pure com ment lines are not permitted 27 Yoho Theorie Manual Problems which often occur when editing text files Are the files really pure text files in ASCII format Have hidden control characters been added by your text processor without being noticed Is the last line of an input file terminated by at least one RETURN Is the coincidence list defined properly Especially Hexahedrons No 10 are very sensitive to wrong numbering Z88Aurora V2 input files for UNIX and Windows have the same structure You may load without restriction Z88 UNIX files i e LINUX and Mac files into Windows and vice versa As a matter of principle the user can generate the desired calculation model completely in Z88Aurora Users who already know Z88 however are supposed to get the possibility to edit the input files with an editor or word processor as usual These edited files may be loaded directly for subsequent use in Z88Aurora In case of word processor systems you have to pay attentio
43. 40 mm If one chooses the supports cleverly a quarter of the pipe is enough to reflect the problem Such structures are best suited for polar coordinates The internal pressure of 1 000 bar corre sponds to a force of 251 327 N while the edge load is ga 2 E 251327 6 ro 407 4000 N mm Ist step Design your component in the CAD system as usual You do not need to maintain a definite order and you can use any layers It is highly recommended to put symbols on one layer edges on another layer dimensions on a third layer invisible lines and centre lines on a fourth layer and so on This enables you to remove all unnecessary information in the next step For this example you may enter the main data by command line Recall AutoCAD s numeric data formats e absolute cartesian coordinates X Y e relative cartesian coordinates DeltaX DeltaY e absolute polar coordinates Radius lt Angle e relative polar coordinates Radius lt Angle co 40 00 75 Yoho Theorie Manual 2nd step Plan your mesh subdivision that means suitable finite element types and their dis tribution Subdivide the FE structure or the super structure into elements by lines insert all points which are not yet existing for example intersection points or end points of lines are usable Any order and layer However it is recommended not to use the Z88 layers like Z88NET Z88GEN Z88PKT Z88KNR Z88EIO Z88FLA and Z88RBD Better define any new layer
44. 6 WITH 10 NODES QP ooo eee 143 517 TETRAHEDRON NO 17 WITH 4 NODES amp Y ooo ooo 145 5 18 PLATE NO 18 WITH 6 NODES fj 147 5 19 PLATE NO 19 WITH 16 NODES CV j 149 5 20 PLATE NO 20 WITH 8 NODES fj 152 5 21 SHELL NO 21 WITH 16 NODES f 154 5 22 SHELL NO 22 WITH 12 NODES ff 157 6 5 23 SHELL NO 23 WITH 8 NODES FR 5 24 SHELL NO 24 WITH 6 NODES FR Theory Manual Yoho Theorie Manual 1 THE FINITE ELEMENTS PROGRAM Z88 AURORA a Z88Aurora Version 2 0 Jun 21 2012 20 38 19 File View Pre processor Solver Post processor Tools Help O i Linear mechanical vi Bt wee A Cear OS kt tk SP SE CF SAO FF RR ES Tayga FIANS MlA 3D view 1 29E 001 4 69E 001 9 38E 001 1 41E 002 1 87E 002 2 34E 002 2 81E 002 3 28E 002 3 75E 002 4 21E 002 4 68E 002 4 68E 002 5 15E 002 STRESSES AT CORNER NODES 3 75E 002 4 21E 002 Z88Aurora started 4 C Z88AuroraV2 docu de Beispiele Projekt b1 Fall_1 1 1 GENERAL OVERVIEW ON ZSSAURORA THE Z88 PHILOSOPHY IS ALSO TRUE FOR Z88AURORA Fast and compact Developed for PC no ported mainframe system full 64 Bit support for Windows LINUX and Mac native Windows LINUX and Mac OS X programs no emulations Windows LINUX and Mac OS X versions use the same computing kernels full data exchange from and to CAD systems DXF STP STL FE structure import COS
45. 8Aurora to the big com mercial solvers you do not know which termination criterions are internally used anyway The limit you can adjust there may have absolutely nothing to do with EPS of Z88 However extensive tests proved that the deflections of different nodes compared quite well to those from the commercial solvers if EPS was between 0 00001 and 0 0000001 with similar compu ting time Please note When computing large FEA structures with different solvers you will never know which solver delivers the best result anyway ALPHA is the convergence acceleration parameter a With this parameter for the SIC_pre conditioner you choose the shift factor a for the iteration solver SICCG from 0 to 1 good values may vary from 0 0001 to 0 1 0 0001 is a good initial value OMEGA 1s the convergence acceleration parameter With this parameter for the SOR pre conditioner you choose the relaxation factor w for the iteration solver SORCG from 0 to 2 good values may vary from 0 8 to 1 2 Which value to choose for Good question Try with 1 which will never lead to totally bad results and then try other values for further runs with this structure 39 LIB on Theorie Manual Example 1 You want to use the Iterations Sparse matrix Solver and stop after 5000 iterations the limit is 0 0000001 and the convergence acceleration parameter for SOR is 0 9 since you want to use the SORCG Solver SORCG sparse iterative Thus MAXIT500
46. Aurora and can be processed The same functionalities are available when you access the STEP import via the toolbar f2 Choose STL file A Z88AuroraV2 docu de Beispiele Import b29 fame ett Anero f B loeffel stl 20 04 2012 amp Lokaler Datentrager C gt Daten D amp DVD RW Laufwerk E Z8 stl ox _Masorecnen Figure 22 Importing STL files 4 1 4 THE DXF CONVERTER Z58X What is the basic idea and which are the features 2D CAD systems like AutoCAD offer a simple possibility to transfer complex 2D or 2 2D structures into Z88Aurora without an expensive 3D system For this purpose the layer based structure of the DXF files is perfectly suited 65 maY 56 Aurora Theorie Manual Which CAD systems can cooperate with Z88X Any CAD systems which can import read and export write DXF files However we can not guarantee any success Z88Aurora V2 has been tested together with different AutoDesk AutoCAD and AutoCAD LT versions and AutoDesk s DXF guidelines have been regarded as the inventor of the DXF interface 1 e according from AC1009 to AC1024 Choose AutoCAD R12 DXF format if in doubt but AutoCAD 2011 DXF works too Sp X 288 dxf 23 04 2012 amp Lokaler Datentrager C gt Daten D s DVD RW Laufwerk E Z8 68 Hinzuf gen s Entfernen DXF structure to Z88Aurora structure DXF structure and constraints to Z88Aurora DXF super struc
47. CALCULATION cecseccccccsssseecceccesseeeccccsseseeceee 104 4 3 3 SOME NOTES ON NODAL FORCE CALCULATION cocecccccsccecccccsseeeeceee 105 4 4 THE VIBRATION SOLVER Z88EI E 106 45 THE THERMAL SOLVER Z88THERMO oosscccccssssssccccsssessceseeseseececesseseececesseeeeeeee 109 4 6 THE NONLINEAR SOLVER Z88N occcccssssssccccssesescsccssesceseesesceesestteeeeeseseeeeeees 113 4 7 THE MAPPED MESHERS 8 jj 116 4 7 1 Z88N FOR 2D AND 3D ELEMENTS E 116 4 7 2 THE TETRAHEDRON REFINER oosssssccccsssessccccsseeseceessssesececceseeeeeecesseeeeeeees 118 4 7 3 THE SHELL THICKENER o 120 4 8 THE POST PROCESSOR E 122 5 DESCRIPTION OF THE FINITE ELEMENTS cccccssssccccccssesseccecssescececccsseeeeceessssece 126 51 HEXAHEDRON NO 1 WITH 8 NODES Score 126 52 BEAM NO 2 WITH 2 NODES IN SPACE oocccccccccccccccssccccccccccccccccecccesessesssssees 127 53 PLANE STRESS TRIANGLE NO 3 WITH 6 NODES CO ooo 128 5 4 TRUSS NOAIN SPACE n 129 5 5 SHAFT ELEMENT NO 5 WITH 2 NODES T a 130 5 6 TORUS NO 6 WITH 3 NODES CS k 131 57 PLANE STRESS ELEMENT NO 7 WITH 8 NODES CP occ 132 5 8 TORUS NO 8 WITH 8 NODES D ooo 133 5 9 TRUSS NO 9 IN PLANED cece 134 5 10 HEXAHEDRON NO 10 WITH 20 NODES SE cocoon 135 5 11 PLANE STRESS ELEMENT NO 11 WITH 12 NODES CP a 136 5 12 TORUS NO 12 WITH 12 NODES CS ooo coooooooooeeeseeeeeeeesee 137 5 13 BEAMNO 13 IN PLANED ccccccccecseeeeeeeeeeeeo cc 138 5 14 PLANE STRESS ELEMENT NO 14 WITH 6 NODES CP ooo 139 5 15 TORUS NO 15 WITH 6 NODES D 5 16 TETRAHEDRON NO 1
48. ESS TRIANGLE NO 3 WITH 6 NODES EP This is a simple triangular plane stress element with complete quadratic shape functions This element is obso lete and kept in Z88 only for studies Elements No 7 11 or 14 are much better Pay attention to edge loads cf chapter 3 4 No entries into the surface and pressure loads file Z88I5 TXT 3 Input CAD see chapter 4 1 4 4 2 5 3 6 1 Z88STRUCTURE TXT gt KFLAG for Cartesian 0 or polar coordinates 1 gt 2 degrees of freedom for each node gt Element type is 3 gt 6 nodes per element Element parameters k Section Ht Thickness enter here the thickness of the elements Z88ENVIRO DYN gt Integration order INTORD for displacement calculation any order has no influence gt Integration order INTOS for stress calculation any order has no influence Z88CONTROL TXT gt Radial Tangential stress flag KDFLAG 0 Calculation of SIGXX SIGY Y and TAUXY gt Radial Tangential stress flag KDFLAG 1 Additional calculation of SIGRR SIGTT and TAURT gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the center of gravity 2 principal or Rankine stresses in the center of gravity 3 Tresca stresses in the center of gravity Results Displacements into X and Y Stresses The stresses are calculated in the element s centre of gravity The coordinates of the centre of gravity are thus printed For KDFLAG 1 the radial stre
49. G must be 0 R coordinate X always positive Z coordinate Y always positive gt 2 degrees of freedom for each node DOF R and Z X and Y gt Element type is 12 gt 12 nodes per element Z88ENVIRO DYN gt Integration order INTORD for displacement calculation 3 is usually good gt Integration order INTOS for stress calculation 0 Calculation of stresses in the corner nodes 1 2 3 4 Calculation of stresses in the Gauss points Z88CONTROL TXT gt Radial Tangential stress flag KDFLAG any has no meaning gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the Gauss points INTOS not 0 2 principal or Rankine stresses in the Gauss points INTOS not 0 3 Tresca stresses in the Gauss points INTOS not 0 Results Displacements in R and Z X and Y Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations It is SIGRR stress in R direction radial stress X direction SIGZZ stress in Z direction Y direction TAURZ shear stress in RZ plane XY plane SIGTE stress in peripherical direction tangential stress Optional von Mises or principal or Tresca stresses Nodal forces in R X and Z Y for each element and each node 137 LIB on Theorie Manual 5 13 BEAM NO 13 IN PLANEX Beam element with any symmetric profile Enter the element parameters into the GUI Thus you can u
50. GZZ2 Bending stress around z z for node 1 and node 2 Nodal forces in X and Y and nodal moments around Z for each element and each node 138 66 Aurora 86 Theory Manual 5 14 PLANE STRESS ELEMENT NO 14 WITH 6 NODES This is a curvilinear Serendipity plane stress element with quadratic shape functions The transformation is isoparametric The integration is carried out numerically according to Gauss Legendre Consequently the integration order can be selected in Z88INT TXT The order 7 7 Gauss points is mostly sufficient This element calculates both displacements and stresses very exactly The integration order can be chosen again for the stress calculation The stresses are calculated in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly Pay attention to edge loads when using forces cf chapter 3 4 It is easier to enter edge loads via the surface and pressure loads file Z88I5 TXT This element type is implemented for use with automeshers Thus a mesh generation with ZSSN is not possible Use plane stress elements No 7 for Z88N Use plane stress element No 7 whenever possible It is substantially more precise than this isoparametric triangle Y Input CAD see chapter 2 7 2 1 4 2 5 3 6 Z8811 TXT gt KFLAG for Cartesian 0 or polar coordinates 1 gt 2 degrees of freedom for each node gt Element type is 14 gt 6 nodes per element Z88ELP TXT gt Cros
51. In the previous 4th step you have only defined what kind of element the second element is You determine here how the element is defined topologically The third element follows and so on If you should make a mistake at the outlining of an ele ment then delete all previous lines of this element e g with an UNDO function and start again at the first point of the element in question But if you notice now just outlining element 17 that you have made a mistake at element 9 then you must delete all lines of the elements 9 to 17 and restart with element 9 For your comfort you must Keep the following outline orders which partly differ from the orders shown at the element descriptions when entering the coincidence by hand 788X then sorts internally correctly Example The coincidence for the element type 7 is as follows in the element description First the corner nodes then the middle nodes reads 1 2 3 4 5 6 7 8 The coincidence list must look like this in the Z88 input files However for Z88X use for comfortably outlining the elements the order is 1 5 2 6 3 7 4 8 1 left picture respectively A B C D E F G H A right picture 69 8B on Theorie Manual 7 Figure 24 Example for correct outline orders Following the CAD outline orders for all elements Element No 7 No 20 and No 23 1 5 2 6 3 7 4 8 1 a3 Element No 8 1 5 2 6 3 7 4 8 1 R X Element No 11 1 5 6 2 7 8 3 9 10 4 11 12 1 70 66 Aurora 56
52. L OVERVIEW ON Z88AURORA coccccssscccsssesccsseseccsstiecestteeceesteecessttecestteeee 8 1 2 SUMMARY OF THE Z88 ELEMENT LIBRARY a 10 2D PROBLEMS PLANE STRESS PLATES BEAMS TRUSSES ccccccccccccccccsseeeece 10 AXISYMMETRIC PROBLEMS an 13 SHELL PROBLEMS oocccsesscccosssccsssecccseseeeseieecssteestteestteestieestteeetiseesttecessitecese 14 SPATIAL PRODL ME kfin 16 2 THE Z88 COMPUTING UNITS cosccccccsccccossecccssescccsssececsiseccestisescsticecsttcesssteceesiteeeese 19 21 OVERVIEWS a 19 2 2 A SHORT DESCRIPTION OF THE MODULES u 19 L THE PRE AND POST PROCESSOR FEE 8 ooo 19 IL THE SOLVERS f jj 19 2 2 1 THE LINEAR SOLVER Z88R oossccsssssccssssececseseceseseeestteeestbeeesetesstteeestteesee 19 2 2 2 THE VIBRATION SOLVER Z88EI occcscsccccssseccsesseccseseseeseseesstteesesteecestteeesee 21 2 2 3 THE THERMO SOLVER Z88TM aau 22 2 2 4 THE NONLINEAR SOLVER 7S cecsssccccsssccsssssccseseeessssscessteeesssseccesseeeesee 23 II THE INTERFACES TO CAD amp FEA SYSTEMS BLOM O V THE MAPPED MESHERS kj 24 23 WHICH Z88 ELEMENTS CAN BE PRODUCED AUTOMATICALLY 25 3 THE INPUT AND OUTPUT OF Z88AURORA V2 ecccccsssccccsssecccsssecccsssececssteceeseseecese 26 3 1 COMPARISON OF Z88 FILE FORMATS a 28 3 2 FILE LAYOUT IN Z88AURORA V2 a 29 3 2 1 GENERAL STRUCTURE DATA Z88STRUCTURE TXT eeseeccseecccceeseecceseeces 29 3 2 2 GROUP DATA Z88MARKS TXT amp ZSIS ETT AT an 31 3 2 3 CHARACTERISATION FILE Z88SETACTIVE TXT vocecscccccccccccccsseccce
53. LAG INTOS TYP 1 2 FLAG INTOS TYP 7 3 FLAG INTOS TYP 8 FLAG INTOS TYP 10 3 FLAG INTOS TYP 11 3 FLAG INTOS TYP 12 3 FLAG INTOS TYP 14 7 FLAG INTOS TYP 15 7 FLAG INTOS TYP 16 4 FLAG INTOS TYP 17 4 FLAG INTOS TYP 18 3 FLAG INTOS TYP 19 4 FLAG INTOS TYP 20 2 47 ZSS Aurora Theorie Manual 56 FLAG INTOS TYP 21 FLAG INTOS TYP 22 FLAG INTOS TYP 23 FLAG INTOS TYP 24 J GO sy Go o0ath to extern programs PATH P01 ACROBAT Ga PATH P02 PLAYER UG PATH P03 BROWSER Ore ta PATH P04 PROJECT ere ad BUeCCONS OF bOOLDars TOOLBAR 1 1 28 4 ODO 8S 6 bs 7 oO 9 IU VaL l TOOLBAR 2 1 OO O41 O2 0 54 55 27 0 2e 224 Zo Zo i TOOLBAR 3 1 I2 d3 14a Q oO 0 50 1g 49 0 21L V 28 27 P 20 3L G2 33 TOOLBAR 4 1 41 42 43 44 45 46 47 48 0 35 0 36 37 U 39 O 40 1 Figure 10 Example ZSSENVIRO DYN Lines which are preceded by are ignored by Z88Aurora They are comment lines Behind PATH there is the directory of extern programs The paths have to be written in uppercase letters otherwise blinds cannot be imported correctly The flags listed in Table are marked by the preceding keyword FLAG They can be changed under Help gt Options in the tab View see figure 11 Behind PATH you find the paths of external programs which can be automatically ac cessed If no path is present C is used as standard These paths as well as all other settings of Z88ENVIRO DYN can be modified under Options in the menu Help see figur
54. LINUX or Mac OS X along with the 64 bit version of Z88 and about 6 GByte of memory The largest processed structure up to now in Z88R featured 12 million DOF using an ordinary PC This very stable and approved solver works always thus you may use it as your standard solver Note The following explanations for the manual launch of the solver are only meant for a deeper understanding if necessary Z88Aurora takes care of everything for you The solver Z88R runs in console mode and requires two control flags z88r mode solver mode means t Test mode Z88R determines the required memory and enters these settings into the memory definition file Z88R DYN c Computing mode Z88R DYN is imported Run the solver in test mode first and then a second time in computing mode using the same setting of the second parameter solver solver means Chie Launch the simple Cholesky solver without fill in with Jennings storage parao Launch the direct sparse matrix solver with fill in and solver PARDISO 0 1000 Launch the iteration solver conjugated gradients with SIC preconditioning Ore Launch the iteration solver conjugated gradients with SOR preconditioning Explanations to the sparse matrix iteration solvers SICCG and SORCG An iteration solver uses only the so called non zero elements which results in an absolute minimum of storage requirements It builds the following pointers for the lower part of the total stiffness matri
55. NILTXT 2 37 7 74 100 Write into one line separate each item by at least one blank Make sure to write in the layer Z88GEN 9th step Store your model or drawing in the DXF file format Choose AutoCAD R12 DXF format if in doubt but AutoCAD 2011 DXF works too For precision of decimal positions take the default value which the CAD program suggests Caution Use the Z88X keywords P number FE values SE values FLA RBD Z88NLTXT Z8801 TXT Z88I2 TXT and Z8si5 TXT only where they are really needed 74 66 Aurora 86 Theory Manual Take care that they do not appear in other drawing captions Please note The import of DXF ABAQUS ANSYS NASTRAN and COSMOS input decks is positively limited for this version ZSSAurora V2 to the FE geometry boundary condi tions forces and surface and pressure loads in contrary to Z88 V13 and ZSSAurora V1 And here s why After the import of commercial input decks you may define the material data the element parameters and the integration orders very comfortable in ZSSAurora even if some of these information are included in the input decks however because only in this way a proper use of Aurora s own material data base is possible This will give you a clean data base for ZSSAurora V2 projects EXAMPLE I FOR Z88X FINITE ELEMENTS STRUCTURE Consider a pipe under internal pressure of 1 000 bar 100 N mm7 Inside diameter of the pipe is 80 mm outside diameter of the pipe is 160 mm The length is
56. No addi tional adjustments have to be done for a thermo mechanical calculation The solver Z88TM automatically runs the desired simulation if thermal and mechanic boundary conditions have been applied If only thermal boundary conditions are applied a steady state thermal calcula tion is conducted lt Static thermal pan PARDISO Failure theory No equivalent stress GEH von Mises Rankine Tresca Solver parameter Calculation Stat calculation Qsicce sorce F Solver parameters Solver parameters SICCG Number of iterations 0000 Residuum 1 000000E 006 SORCG Number of iterations t0000 Residuum 1 000000E 006 Omega 1 200000E 000 Help Alpha 1 000000E 004 Help ok X Cancel Figure 3 solver menu of the thermo solver ZS8STM 22 66 Aurora 2 2 4 THE NONLINEAR SOLVER ZSSNL Theory Manual The module Z88NL represents an equation solver which is designed for nonlinear calculation Only the geometric model can be nonlinear the stress strain correlation remains linear Re garding the material properties Young s modulus and Poisson s ratio are required a Non linear mechanical Dd ag O SORCG Choose solver PARDISO PARDISO v rFailure theory O No reduced stresses von Mises stresses Rankine principal stresses Tresca stresses Calculatiog gt stgrt calculation PARDISO Solution procedur
57. OS for stress calculation any order has no influence Z88CONTROL TXT gt Radial Tangential stress flag KDFLAG has no influence gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the center of gravity 2 principal or Rankine stresses in the center of gravity 3 Tresca stresses in the center of gravity Results Displacements in R and Z X and Y Stresses The stress are internally computed in the corner nodes but plotted in the centre of gravity It is SIGRR stress in R direction radial stress X direction SIGZZ stress in Z direction Y direction TAURZ shear stress in RZ plane XY plane SIGTE stress in peripherical direction tangential stress Optional von Mises stresses Nodal forces for each element and each node 131 Theorie Manual 5 7 PLANE STRESS ELEMENT NO 7 WITH 8 NODES C 7 ments no 14 good This is a curvilinear Serendipity plane stress element with quadratic shape functions The transformation is isoparametric The integration is carried out numerically in both axes according to Gauss Legendre Consequently the integration order can be selected in Z88ENVIRO DYN The order 3 is mostly sufficient This element calculates both displacements and stresses very exactly The integration order can be chosen again for the stress calcu lation The stresses are calculated in the corner nodes good for an over view or calculated in
58. T in cylindrical coordinates Thus 237774101 NIFLAG In order to identify already defined nodes the mesh generator needs a trap radius The defaults are 0 01 for EPSX EPSY and EPSZ if NIFLAG is 0 These values can be modified at ex tremely small or large structures To initiate this change set NIFLAG to 1 The new trap radi uses of EPSX EPSY and EPSZ are then defined in Z88NI TXT as the 5th input group Example Super structure 2 dimensional with 37 nodes 7 super elements 74 degrees of freedom cartesic coordinates trap radius default value 0 output into ZSSI1 TXT in car tesic coordinates Thus 237 774 100 0 34 66 Aurora 86 Theory Manual KFLAG Internally Z88N works with natural or Cartesian coordinates Sometimes though you might want to store the output of Z88N as polar or cylindrical coordinates With this flag 1 the output takes place in polar or cylindrical coordinates This is independent from the flag KFLAGSS for the input file Z88NI TXT Example Super structure 2 dimensional with 37 nodes 7 super elements 74 degrees of freedom Cylindrical coordinates 1 trap radius default value 0 Coordinate flag KFLAG for the finite elements l output into ZSSI1 TXT in cylindrical coordinates Thus 237774101 2 input group Starting in line 2 contains coordinates of nodes one line per node node numbers strictly as cending Ist number Node number Long 2nd number Number of the degrees of fre
59. X 1 Z 7 X 2 J 4 Input CAD see chapter 4 1 4 Line from node I to node 2 Z88STRUCTURE TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt 6 degrees of freedom in a node Attention DOFS not right hand rule see below gt Element type is 2 gt 2 nodes per element Element parameters L Section 14 Thickness enter here the parameters for the elements gt Cross sectional area OPARA gt Second moment of inertia I bending around y y axis gt Max distance e from neutral axis y y gt Second moment of inertia l bending around z z axis gt Max distance e from neutral axis z z gt Second moment of area torsion Ir gt Second modulus torsion Wr Z88ENVIRO DYN gt Integration order INTORD for displacement calculation any order has no influence gt Integration order INTOS for stress calculation any order has no influence Z88CONTROL TXT gt Radial Tangential stress flag KDFLAG has no meaning gt Reduced stress flag ISFLAG has no meaning Results Displacements in X Y and Z and rotations around X Y and Z Attention DOF5 not right hand rule see below Stresses SIGXX TAUXX Direct stress shear stress SIGZZ1 SIGZZ2 Bending stress around z z for node 1 and node 2 SIGYY1 SIGY Y2 Bending stress around y y for node and node 2 Nodal forces in X Y and Z and nodal moments around X Y and Z for each element and each node 127 OS brscoxa Theorie Manual 5 3 PLANE STR
60. XCEL and analyse them there Or you use Z88Aurora and manually adjust the input in the text editor later 1f neces sary because only few boundary conditions have changed or you want to use a different ma terial for calculation Very often input files are produced much faster than by any interactive queries Many input lines are similar to prior lines Use the block operations of your editor for copying and pasting Every FEA program can and so does Z88Aurora produce a huge amount of data junk from time to time You are very often interested only in very specific results e g of special nodes The output files are simple ASCII files You may edit and shorten them as you like and print only the really interesting results Downward compatibility Z88 V13 and Z88Aurora V1 files may be migrated to Z88Aurora V2 by our external migra tion tools MITOO Z88 V14 OS files can be opened directly This is why we do not want to refrain from explaining the input and output of the program Z88 Aurora is Supposed to be as transparent to experienced users as Z88 V 14 Rules for entering values within the files There is no need for special rules or field divisions only the usual C rules apply All values are to be separated by at least one blank Integer numbers may not contain any points or exponents For floating point numbers no points need to be provided Numerical values which are 0 zero have to be entered explicitly Integer numbers Right l
61. XT This file must always exist If you do not have any surface and pressure loads enter a 0 zero into the first line add a RETURN and skip the second input group Mind the following formats Long 4 bytes or 8 bytes integer number Double 8 bytes floating point number alternatively with or without point 1 input group Ist number Number of surface and pressure loads Long 57 LIB on Theorie Manual ON 2 input group Surface and pressure loads one line per load Of course an element may have more than one load applied The following entries depend from the element type with surface and pressure load to avoid unnecessary data entries As for the local directions Define the local r and s directions by the nodes and their sequence These local directions for the surface loads may differ from the local r and s coordinate sys tem of the finite element The numbering has to conform to the element numbering see chap 5 Plain stress element No 7 and 14 and Torus elements No 8 and 15 Element number with surface load Long Pressure positive if pointing towards the edge Double Tangential shear positive in local r direction Double 3 nodes of the loaded edge 3 x Double Example The plain stress element 97 features surface load The load should be applied onto the edge defined by the corner nodes 5 and 13 and by the mid node 51 One surface load is applied normally to the edge with 100 N mm and the other surfac
62. Y1 SIGXY2 Bending stress in X Y plane for node 1 and node 2 SIGXZ1 SIGXZ2 Bending stress in X Z plane for node 1 and node 2 Nodal forces in X Y and Z and nodal moments around X Y and Z for each element and each node 130 66 Aurora 86 Theory Manual 56 TORUS NO 6 WITH 3 NODES D This element is implemented only for historical reasons and possible data exchange to other FEA systems Much better Torus No 8 or Torus No 12 3 or No 15 No entries into the surface and pressure loads file Z88I5 TXT Z Y This is a simple triangular torus element with linear shape functions for axisymmetric structures The displacement results for this very simple element are quite useable but the stress calculation results are inaccurate The stresses are calculated in the corner nodes internally and then distribut ed as average value in the centre of gravity However the use of the torus elements No 8 or No 12 or No 15 is highly recommended especially for accurate stress calculations R X 2 Input CAD see chapter 4 1 4 1 2 3 1 Z88STRUCTURE TXT gt In principle cylindrical coordinates are expected KFLAG must be 0 R coordinate X always positive Z coordinate Y always positive gt 2 degrees of freedom for each node DOF R and Z X and Y gt Element type is 6 gt 3 nodes per element Z88ENVIRO DYN gt Integration order INTORD for displacement calculation any order has no influence gt Integration order INT
63. Z88 does not want to compete with professional FEA programs which can do really every thing but are hardly payable and complicated to operate While you are still puzzling about installation and start of some programs of this genre you will already have calculated the first examples with Z88Aurora And the online help is always only one keystroke or mouse click away The Z88 system may operate with English or German language depending on your set ting ENGLISH or GERMAN in the options menu In addition to this Theory Manual there are a User Manual an Example Manual an Installa tion Manual and video sequences available If you already have FEA experiences you may start at once If you are a beginner in this ar ea I would recommend secondary literature Here are a few choices e Zienkiewicz O C Taylor R L The Finite Element Method Volumes l 3 a edition But terworth Heinemann and John Wiley amp Sons 2000 e Bathe K J Finite Element Procedures Prentice Hall 1995 o Rieg F Hackenschmidt R Alber Laukant B Finite Elemente Analyse fiir Ingenieure Carl Hanser Verlag Munich Vienna 2012 4th edition in German language The Z88 website www z88 de Give us your feedback Professor Dr Frank Rieg Bayreuth July 2012 Lehrstuhl Konstruktionslehre und CAD Chair for Engineering Design and CAD Faculty of Engineering Science University of Bayreuth Germany frank rieg uni bayreuth de www uni bayreuth de departme
64. Z88NI TXT 2 20 2 40 0 0 1 Thus the resulting FE structure will be written by the mapped mesher Z88N in pone coordinates re 332 Drafting amp Annotati Insert Annotate Parametnc View Manage Output Express Tools Y ro b n _6 dwg Type a keyi word or p phrase Eka st WA ek El 4 3 22 i6 lt al A X es al U d La St t Line Move Al i iimas ini Ann Block Properties Utilities Clipboard fF Be Al 9 of BB Zsscen v Draw v x Search for layer Qi FP n a o o ce eee ete ES Al 6 All Used Layers Ansichtcfe Definitions Z88EIO Z88NI TXT 2 20 2 40001 788GEN Z88KNR Z88NET ososooklo 55555564F EEHEEHE ET id lt gt PIi Model _ Layout1 Autodesk DWG This file is a TrustedDWG last saved by an Autodesk application or Autodesk licensed application Command aM OO 2 Le Ea ef open CO A it 2 TS ne Tor 7th step Store this drawing as a DXF file In Z88Aurora we import it by DXF Import with the option DXF super structure to ZSSAurora structure Thus Z88Aurora interprets the DXF file as a super structure and launches immediately the mapped mesher Z88N resulting in this FE structure 90 EE Aurora is Theory Manual Now you may add in Aurora comfortably boundary conditions materials integration orders and element thickness 4 2 THE NASTRAN amp COSMOS CONVERTER Z58G Som
65. a so called tridiagonal matrix is calculated iterative which is able to approximate eigenvalues of the system matrix just the smallest and technically most interesting Never theless the regulation of these approximated eigenvalues occurs not in every step but 1s car ried out in the interest of enhanced speed only in agreed step sizes As soon as the eigenvalues do not change almost any more the iteration is finished The second phase contains the search for the eigenvectors and their transformation to the so called form vectors To every eigenvalue defines the frequency an accompanying vector is calculated by a single solution of the equation system For the control of the computing kernel the following five values are usable Number of frequency Here it is fixed which number of the smallest natural frequencies should be determined However although one is interested often only in one or some frequen cy the number should not be selected too small Often so called rigid body modes are for numerical reasons under the oscillations of the slightest frequency The calculation time rises with bigger number even a little because the iteration is done furthermore only once Then merely the part of the eigenvalue approximation demands more time A good default value is ID Number of iterations Alike to the parameter MAXIT with iterative equation solvers a limit after which the iterative phase I of the Lanczos solver is stopped can be entered h
66. abeled nodes and elements For more information please refer to the user manual Z88MARKS TXT works like the marker function in a word processing program Z88MARKS TXT is composed as follows 1 value number of markers 1 input group identifier NODES for nodes or FHELEMENTS for elements 2 value consecutive number of the marker 3 value number of nodes elements in the marker 4 name of the marker 2 input group list of nodes elements of the respective marker Explanations The markers are written in the files consecutively How many markers can be imported is controlled by the first value in the file Example There are two markers The first left contains the nodes no 2174 2175 2176 2177 2179 The second right contains the nodes no 1929 1931 1932 1933 1934 1935 1936 gt gt 2 NODES 1 5 left 2174 21 15 2176 2177 2179 NODES 2 7 right 1929 1931 1932 1933 1934 1935 1936 With boolean operations these markers can be used to create sets Sets defined the allocation of nodes and elements to their application as boundary conditions material Z88MARKS TXT is composed as follows 1 value number of sets 1 input group identifier NODES for nodes or HELEMENTS for elements 2 keyword e g CONSTRAINTS MATERIAL MESH ELEMENTGEO UN KNOWN 3 consecutive number of the set 4 number of nodes elements in the set 5 name of set 2 input group list of nodes elements o
67. acement and stress calculations are far better than the results of the hexahedron element No 1 Hexahedron No 1 also applies well for thick plate elements if the plate s thickness is not too small compared to the other dimensions Or use shell elements No 21 and No 22 The element causes heavy computing load and needs a large amount of memory because the element stiffness matrix has the order 60x60 The nodal numbering of the element No 10 must be done carefully and must exactly match the sketch below Pay attention to the location of the axis system The possible error message Jacobi determinant zero or negative is a hint for incorrect node numbering Hexahedron No 10 can be generated by the mesh generator Z88N from super elements Hexahedron No 10 Thus the Hexahedron No 10 is well suited as super element Hexahedron No 10 can also generate 8 node Hexahedrons No 1 Input CAD see chapter 4 1 4 Upper plane 1 9 2 10 3 11 4 12 1 quit LINE function Lower plane 5 13 6 14 7 15 8 16 5 quit LINE function 1 17 5 quit LINE function 2 18 6 quit LINE function 3 19 7 quit LINE function 4 20 8 quit LINE function Z88STRUCTURE TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt 3 degrees of freedom for each node gt Element type is 10 gt 20 nodes per element Z88ENVIRO DYN gt Integration order INTORD for displacement calculation 3 is usually good gt Integration order INTOS for
68. al 5 9 TRUSS NO 9 IN PLANEX The truss element No 9 can take any location in the X Y plane It is the simplest element in Z88 and is calculated extremely fast The truss elements match Hooke s law exactly Hint Trusses No 9 are very suitable for model ling spring supports or oblique angled supports Y 2 1 Input CAD see chapter 4 1 4 Line from node I to node 2 Z88STRUCTURE TXT gt KFLAG for Cartesian 0 or polar coordinates 1 gt 2 degrees of freedom for each node gt Element type is 9 gt 2 nodes per element Element parameters L Section Hi Thickness enter here the cross section area for the elements Z88ENVIRO DYN gt Integration order INTORD for displacement calculation any order has no influence gt Integration order INTOS for stress calculation any order has no influence Z88CONTROL TXT gt Radial Tangential stress flag KDFLAG has no meaning gt Reduced stress flag ISFLAG has no meaning Results Displacements in X and Y Stresses Normal stresses Nodal forces in X and Y for each element and each node 134 66 Aurora 86 Theory Manual 510 HEXAHEDRON NO 10 WITH 20 NODES This is a curvilinear Serendipity volume element with quadratic shape functions The transformation is isoparametric The integra tion is carried out numerically in all axes according to Gauss Le gendre Thus the integration order can be selected in Z88ENVIRO DYN The order 3 is good The quality of the dis pl
69. alculates both displacements and stresses very exactly The integration order can be chosen again for the stress calculation The stresses are calculated in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly The three degrees of freedom are the global displacements in X Y and Z However there are no rotational degrees of freedom because Type 21 is in fact a volume element The element can be generated by the mapped mesher Z88N Type 21 gt Type 21 Input CAD upper plane 1 5 2 6 3 7 4 8 1 lower plane 9 13 10 14 11 15 12 16 9 Lines 1 9 2 10 3 11 4 12 see chapter 4 1 7 Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt 3 degrees of freedom for each node gt Element type is 21 gt 16 nodes per element Z88ELP TXT gt Cross section parameter QPARA is insignificant Z88INT TXT gt Integration order INTORD for displacement calculation 3 is usually good gt Integration order INTOS for stress calculation 0 Calculation of stresses in the corner nodes 154 66 Aurora 56 Theory Manual 1 2 3 4 Calculation of stresses in the Gauss points Z88MAT TXT gt Define materials ref chapter 3 1 4 and 3 1 5 ZT88MAN TXT gt Radial Tangential stress flag KDFLAG has no influence gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the Gauss points INTOS not 0 2 principal or Rankine str
70. also be edited without previous memory overflow alert For this purpose select the function Options in the menu Help The tab Memory contains all memory parameters MAXK for the maximum node numbers and MAXE for the maximum number of elements After closing the dialog box Aurora has to be rebooted The file Z88 DYN can also be edited manually by experienced users The important thing 1s that certain keywords remain in any case Blank lines or comments are optional only the up percased keywords are recognized After the keyword follows an integer value separated by at least one blank The order of the keywords is optional There are no limits for the size of the structures for ZS8 The maximum size is limited only by virtual memory of your computer and your imagination However for very large structures you may use Z88 with 64 Bit integers and pointers i e the 64 Bit versions for Windows and Mac OS X to avoid overflows of internal loop counters paths view Structure Number of nodes MAXK 450000 Number of elements MAXE 1300000 ok X Cancel Figure 8 Memory settings in the options menu 44 66 Aurora 86 Theory Manual In the 32 bit versions Z88 Aurora uses e Floating point numbers with doubles 8 Bytes and e Integers and pointers with longs 4 Bytes In the 64 bit versions Z88 uses e Floating point numbers with doubles 8 Bytes and e Integers and pointers with longs 8 Bytes Figure 9 shows
71. an example for a file Z88 DYN with the mentioned keywords DYNAMIC START COMMON START MAXE 500000 MAXK 500000 COMMON END DYNAMIC END Figure 9 Example of control file ZS8 DYN The file must start with the keyword DYNAMIC START and end with the keyword DY NAMIC END By entering GERMAN German is selected as language for English select ENGLISH Between the lines COMMON START and COMMON END there are the memory parameters MAXK Maximum number of nodes in the structure MAXE Maximum number of elements in the structure 3 2 8 DEFINITION FILE ZSSENVIRO DYN Z88Aurora includes a project folder management While working with Z88Aurora a project directory must be selected All input and output files are stored here The main directory con tains the protocol data Apart from that several other paths are stored here as well They per mit for example the automated access to text viewers like Adobe Reader Furthermore some control flags for the configuration of the user interface are stored here e g a flag for the defini tion of the number of processors set by default CPU_NUM Table 4 List of flags of file Z88ENVIRO DYN Possible values Controls if after starting the pro 8 SHOW_SURFACE gram all elements are shown 8 or only surface elements 7 56 Aurora Theorie Manual ao SCROLLER Atay of scroll wheel for view dis 1 to 299 ROTATOR Speed of rotation for view display 0 1 to 2 0 TRANSLATOR Speed of displace
72. ane Stress Element 12 nodes Element No 12 Isoparametric Serendipity Torus 12 nodes Element No 20 Isoparametric Serendipity Plate 8 nodes Element No 21 Isoparametric Serendipity Shell 16 nodes Example An Isoparametric Serendipity Plane Stress Element No 7 has element number 23 The coincidence has the global nodes 14 8 17 20 38 51 55 34 locally these are the nodes 1 2 3 4 5 6 7 8 see chapter 4 7 Thus resulting in two lines 23 7 14 8 17 20 38 51 55 34 amp 4 input group Starting after last coincidence line contains the descriptive details for the mesh generation process 2 lines for every super element Ist line Ist number Super element no Long 2nd number Finite element type types I 7 8 10 19 20 21 to be generated Long 2nd line Ist number Number of finite elements in local x direction Long 2nd number Type of subdivision of CMODE x Character 3rd number Number of finite elements in local y direction Long 4th number Type of the subdivision CMODE y Character 5th number Number of finite elements in local z direction Long 6th number Type of the subdivision of CMODE z Character The two values for Z are skipped at 2 dimensional structures Explanations CMODE can accept the following values e E Subdivision equidistant e is also permitted e L Subdivision increasing geometrically in local coordinate direction e l Subdivision decreasing geometrically in local coordinate direc
73. angential stress flag KDFLAG has no influence gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the Gauss points INTOS not 0 2 principal or Rankine stresses in the Gauss points INTOS not 0 3 Tresca stresses in the Gauss points INTOS not 0 Z8815 TXT This file is only used see 3 1 3 if in addition to nodal forces surface and pressure loads are applied onto element no 23 otherwise enter a O into the first line gt Element number gt Pressure positive if pointing towards the surface gt 4 corner nodes and 4 mid nodes of the loaded surface Mathematically positive in top view The local r direction is defined by the nodes 1 2 the local s direction is defined by the nodes 1 4 The local nodes 1 to 8 for the surface load may differ from the local nodes 1 to 8 used for the coincidence Z Results Displacements in X Y and Z and global Rotations around X and Y axis Ox u Oy Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations The stresses SIGXX SIGYY and TAUXY as well as optionally von Mises or principal or Tresca stresses are output Nodal forces first for each element then for each node 160 658 Aurora 86 Theory Manual 5 24 SHELL NO 24 WITH 6 NODES This is a curvilinear Serendipity shell element with quadratic shape functions The transfor mation is isoparametric The integration i
74. appropriate equation solver In the post processor the plots are extended by the thermal results temperature and heat flux as well as by the thermo mechanical results thermal strains and thermal force For a thermal or thermo mechanical calculation there are as usual also furthermore the input and issue data in the form of txt files possible Input files e Z88I1 TXT Z8812 TXT Z8815 TXT Z88TI2 TXT Z88TI5 TXT Z88MAT TXT TXT Z88INT TXT Z88MAN_TH TXT Output files e Z88TH LOG e Z88AG2THI LOG e Z88TH DYN general structure data mechanical boundary conditions mechanical surface loads or 0 in the first line thermal boundary conditions temperature heat flux thermal surface loads heat flux density or O in the first line material defini and one or more material files in TXT format material file integration orders solver parameters for Z88 THERMO hints errors and warnings of Z88 THERMO hints errors and warnings of the Z88 THERMO converter memory parameters automatically computed 111 Theorie Manual Z88 TOO TXT Z88TO1 TXT Z88TO2 TXT Z88TO3 TXT Z88TO4 TXT Z88TO6 TXT Z88TO7 TXT temperature results heat flux results thermal strains results thermal forces results displacements results forces results stresses results As you may see the files of the structure and the mechanical boundary conditions are identi cally to those of the linear mechanical analysis In the thermal solver file Z88MAN_TH TXT th
75. are calculated in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly Pay attention to edge loads when using forces cf chapter 3 4 It is easier to enter edge loads via the surface and pressure loads file Z88I5 TXT This element type is implemented for use with automeshers Thus a mesh generation with ZSSN is not possible Use torus elements No 8 for ZS8N Use torus element No 8 whenever possible It is substantially more precise than this isopara metric triangle Z Y Input CAD see chapter 2 7 2 1 4 2 5 3 6 1 Z8811 TXT gt In principle cylindrical coordinates are expected KFLAG must be 0 R coordinate X always positive Z coordinate Y always positive gt 2 degrees of freedom for each node DOF R and Z X and Y gt Element type is 15 gt 6 nodes per element Z88ELP TXT gt Cross section parameter QPARA is 0 or any value no influence Z88INT TXT gt Integration order INTORD for displacement calculation 7 is usually good Possible is 3 for 3 Gauss points 7 for 7 Gauss points and 13 for 13 Gauss points For easy combination with torus elements No 8 function ISODSS of Z88 uses internally these values integration order l or 2 3 Gauss points integration order 4 7 Gauss points Example ZSSINT TXT uses an entry of 2 for INTORD Thus torus elements No 8 use 2X2 4 Gauss points and torus elements No 15 use 3 Gauss points for integration 141
76. cally only three matrix values because all previously calculated entries preserved In the second stage the eigenvalues of the matrix are determined starting at zero and sorted in ascending order F Free vibration ag Choose solver Lanczos v Solver parameters amp Open Calculation 2 Start calculation Lanczos Number of frequencies Number of iterations 20000 sits Residuum 1 000000E 008 Delta between 2 frequencies 1 000000E 006 Kappa so Help Figure 2 Solver menu of the solver for natural freqgencies 21 Habj Aurora Theorie Manual 86 2 2 3 THE THERMO SOLVER Z88TM For the calculation the modul for thermo mechanical simulation resorts to the solver types Paradiso SORCG and SICCG The number of values used in the system of equations is de creased by using the finite elements for pure thermal analysis hexahedrons tetrahedrons because of the reduction of the DOF to one instead of three so the system of equations itself is reduced In contrast there are no changes in the thermo mechanical calculation the usual three DOF have to be regarded The thermal conductivity is the only material property that is necessary for determining the steady state thermal conduction If a thermo mechanical simu lation is to be conducted the coefficient of thermal expansion is also needed in addition to the material properties used in elastostatic problems Young s modulus Poisson s ratio
77. ccuracy CAUTION In the following paragraphs the range of functions of the converters are listed as well as the programs with which they were tested In spite of intensive tests we cannot guar antee the compatibility of files from other programs or newer versions Please note the respec tive support in the explanations There are two possibilities to access the import and export functions of files 1 Via the text menu figure 12 2 Via the toolbar figure 13 fz Z788Aurora Version 2 0 May 2 2012 17 31 18 JCJ View Preprocessor Solver Postprocessor Tools Help 5 New echanically gt Bt ae 30 t mi opoo pae wee amp Close project H Save project as ev re E E RR iP 42 Wt 4 A SE Geometry STP STEP 2 STL files STL DY AutoCAD DXF files DXF NASTRAN files BDF NAS F ABAQUS files INP ANSYS files ANS COSMOS files COS 4 Z88 files TXT BZ Remove project data Import Figure 12 Import in the text menu 50 66 Aurora Gis Theory a ora Version un 21 12 20 3 File View Pre processor Solver Post pr i Tools Help O O WM Kunearmechanicai vi o W ES wee A Seer Oss itt ETI H ESY DEYO ESFE RR FF SB amp SeQeneou PAR HW 4 30 view Import Figure 13 Import and export via the toolbar Depending on the range of functions of the converter a multitude of FE model data can be imported or exported You have the possibility
78. cording to Gauss Legendre Consequently the integration order can be selected in Z88INT TXT The order 4 4x4 points is very good This element calculates both dis placements and stresses very precisely The input amount is heavy you should use the mesher Z88N The integration order can be chosen again for the stress calculation The stresses are calculat ed in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly For this element you need to set the plate flag IPFLAG to 1 Attention In con trary to the usual rules of the classic mechanics Z88 defines O the rotation around the X axis and 0 the rotation around the Y axis Mesh generation with ZSSN Use plates No 20 for super elements resulting in finite elements of type 19 plates No 20 may generated by AutoCAD or Pro ENGINEER ref the chapters of ZS8X and ZS8G A bit tricky but works quite fine For example some lines from a mesh generator input file ZSSNI TXT 5 20 super element 5 of type 20 20 25 27 22 24 26 26 2I 5 19 generate from super element 5 which is of type 20 is see above finite elements of type 19 3E 3E _ and subdivide them three times equidistant in X direction and three times equidistant in Y direction 16 Input CAD 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1 ref chap 2 7 2 Usually you will not work in this way It s much easier to build within a CAD program a super elements mesh with 8 node plates N
79. ction points and if necessary end points Start at the first element For Z88 the first element is the element with which you start now that means the one which you have chosen for your first super element SE 1 Select the node you want to be the first node of this element and draw a line to the node which shall be the second node of this element From there draw a line to the third node of this element Con nect all required nodes with lines and draw at last a line to the starting point the first node and then quit the LINE function Thus we might draw this line P1 P2 P3 P4 P6 P8 P12 P11 P10 P9 P7 P5 P1 By the two corner nodes P1 and P4 the local x axis is defined and this we ve already marked by an arrow This auxiliary arrow has no meaning for Z88X it was only a hint for us This fits fine with our definition SE 1 11 75 L5 E What would have happened if we would have drawn this line P4 P6 P8 P12 P11 P10 P9 P7 P5 P1 P2 P3 P4 Basically nothing You are only to change the super element s definition to SE 1 11 7 5 E 5 1 small letter L And here s why By drawing the line P4 P6 P8 you did define the local x axis by the nodes P4 and P12 and thus the local y axis from node P4 to node P1 Then do the same with the second element Remember You determine with this order which of the elements will be the real second element now In the previous 4th step you have only defined what kind of element the second element is You
80. culated process variable nonlinear calculation with ZSSNL The files Z8805 TXT Z8808 TXT Z88TOS TXT and Z88TO8 TXT are no regular Z88 out put files They are internally used for the postprocessor and stored as ASCII files so that ex perienced users can use them for their own routines if necessary 49 Yoho Theorie Manual 4 THE Z88 MODULES Note Always compare FE calculations with analytical rough calculations results of exper iments plausibility considerations and other tests without exception 4 1 CAD amp FE INTERFACES Z88Aurora offers the possibility to import a multitude of established file formats from com mercial simulation programs pure geometry data or super structures as well as to load existing FE data from Version 14 of the Open Source program Z88 Each of these converters offers an individual range of functions and its own setting options 1f necessary Z88V13 and Z88Aurora V1 files can be migrated with the external migration tool MITOO into the Z88V 14 file format But since especially the actual proprietary data formats of simulation programs do not meet any national or international standards the respective producers can conduct changes in the files when issuing a new version which may influence the converters When using neutral formats for geometry or product data STL or STEP some appropriate adjustments might have to be made in the CAD programs in order to generate a functioning FE model in the desired a
81. data base is possible This will give you a clean data base for ZSS8Aurora V2 projects Which ABAQUS versions can cooperate with Z88Aurora The converter at hand was tested with ABAQUS 6 8 4 therefore the full range of functions is available in this case Since the ABAQUS format is proprietary modifications may occur at any time resulting in malfunction of the converter Older versions of ABAQUS e g 6 6 or 6 7 also do not write any version information into the files Therefore a version dependent conversion is difficult as well Which elements are supported by the converter You can use any Tetrahedrons and Hexahedrons from ABAQUS but since normally no acoustic or thermal simulation data are exchanged between ABAQUS and Z88Aurora the following element transformations will occur Conversion gt from C3D4 to element type 17 and vice versa 95 8B on Theorie Manual Conversion gt from C3D10 to element type 16 and vice versa Conversion gt from C3D8 to element type 1 Conversion gt from C3D20 to element type 10 Which functions does the converter offer Import gt of ZSSSTRUCTURE TXT ZSSSETSACTIVE TXT and ZSS8SETS TXT from an ABAQUS input file How to proceed You can use files from ABAQUS CAE as well as your own input decks Please look for the corresponding keywords in the ABAQUS documentation which you may enter into the file INPENVIRO Z88 and pay attention to upper and lower case characters For ABAQUS 6 8 4 is enclosed
82. des in one plane good calculation of both displacements and stresses Stresses in the corner nodes good for an overview or in the Gauss points substantially more exact Computing effort average Size of element stiffness matrix 36x36 SPATIAL PROBLEMS Truss No 4 T Linear function Quality of displacements exact Hooke s law Quality of stresses exact Hooke s law Computing effort Minimal Size of element stiffness matrix 6 x 6 Z gt X 1 Beam No 2 F Linear function for tensile stress cubic function for bending stress Quality of displacements exact Hooke s law Quality of stresses exact Hooke s law Computing effort Low Size of element stiffness matrix 12 x 12 parallel to x y plane lA 16 66 Aurora 86 Theory Manual Hexahedron No 1 ve Linear shape functions Quality of displacements average Stresses in the Gauss points useable Stresses in corner nodes inaccurate Computing effort very high Size of element stiffness matrix 24 x 24 Z Hexahedron No 10 iy Quadratic Isoparametric Serendipity element Quality of displacements very good Stresses in the Gauss points very good Stresses in corner nodes good Computing effort extremely high Size of element stiffness matrix 60 x 60 2 4 1 f 8 Tetrahedron No 17 gt Linear shape functions Quality of displacements bad Stresses in the Gauss points inaccurate Stresses in
83. dial Tangential stress flag KDFLAG has no meaning gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the Gauss points INTOS not 0 2 principal or Rankine stresses in the Gauss points INTOS not 0 3 Tresca stresses in the Gauss points INTOS not 0 Z8815 TXT This file is only used see 3 1 3 if in addition to nodal forces pressure loads are applied onto element no 18 otherwise enter a O into the first line gt Element number with pressure load gt Pressure positive if pointing towards the surface Results Displacements in Z i e w and rotations Ox around X axis and O around the Y axis Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations The following results will be presented e plate bending moments M and Myy unit force x length length e plate torsion moments M My unit force x length length e the shear forces Qy and Q x unit force length e the true stresses resulting from plate bending moments and plate torsion moments Optional von Mises or principal or Tresca stresses Nodal forces in X and Y for each element and each node 148 66 Aurora 86 Theory Manual 5 19 PLATE NO 19 WITH 16 NODES amp 8 This is a curvilinear Lagrange Reissner Mindlin plate element with cubic shape functions The transformation is isoparametric The integration is carried out numerically in both axes ac
84. ding to the instructions for the NASTRAN converter Z88G 2 Take care to select the ANSYS format when outputting the simulation data 3 Import the simulation model into Z88Aurora as described in figure 26 For this pur pose select File gt Import gt ANSYS file 4 1 7 THE ABAQUS CONVERTER ZSSAINP What is the basic idea and which are the features Today ABAQUS has become a wide spread simulation tool in the industrial field offering a large range of performance as well as simple operation Due to the extensive range of func tions the following restrictions were made with regard to the functions of the converter One solid 1 instance with one material linear elastic can be converted The solid must consist of one element type Optional Cartesian boundary conditions forces Concentrated Force and pressure can be applied You do not need to define any material in ANSYS be cause Please note The import of DXF ABAQUS ANSYS NASTRAN and COSMOS input decks is positively limited for this version ZSSAurora V2 to the FE geometry boundary condi tions forces and surface and pressure loads in contrary to Z88 V13 and ZS8Aurora V1 And here s why After the import of commercial input decks you may define the material data the element parameters and the integration orders very comfortable in ZSSAurora even if some of these information are included in the input decks however because only in this way a proper use of Aurora s own material
85. e Newton Raphson procedure i O Arc length procedure Riks p pEr After every iteration at every load step Norm lt TOL O Also for increasing norm Number of load steps jho tt S Max iterations 1000 Residuum TOL 1 0000006 007 Arc length 1 0000006 000 f C Backup of Pardiso fields Number of iterations 20000 Residuum 1 000000E 008 Omega 1 000000E 000 Figure 4 Control of the non linear solver ZSSNL 23 LIB on Theorie Manual IIL THE INTERFACES TO CAD amp FEA SYSTEMS 2 EED Z88Aurora offers the possibility to import a multitude of established file formats from com mercial simulation programs pure geometry data or super structures as well as to migrate ex isting files from Z88 OpenSource V13 or Z88Aurora V1 by the use of our migration tools MITOO Each of these converters offers an individual range of functions and its own setting options if necessary In chapter 3 2 the functions of the auxiliary programs as well as the pro cedure when using them is explained in detail You have the following possibilities ce Import of Z88 files from Z88 V14 OS to Z88Aurora V2 Import of data decks from previous Z88 releases i e Z88V13 and Aurora V1 files may be converted first by MI TOO into Z88V 14 OS data decks STEP import You may import 3D geometry data in the STEP data format according to DIN ISO 10303 AP 203 and AP 214 This format is supported by most 3D CAD sys tems
86. e 11 Experienced users can edit them directly in the file The path P04 changes dynamically because it contains the last project directory which is used as basis to open the project folder Additional programs Mouse configuration Media player wmplayer exe paa Browser amp iexplore exe Sow es _ sy Fe Acrobat reader amp iexplore exe is Rotate 1 0 Translate 1 0 Resolution 1280 x 1024 v Advanced settings C Enable culling Start with SPIDER Help Figure 11 Flags for the standard view left and the path settings right 48 66 Aurora 56 Theory Manual 3 2 9 OUTPUT FILES ZS amp 8O TXT The following list is an overview of the Z88Aurora output files ZS8OO0 TXT prepared input data ZSSO1 TXT prepared boundary conditions ZS8O2 TXT calculated displacements ZS8SO3 TXT calculated stresses ZS8O4 TXT calculated nodal forces ZSS8TOO TXT calculated temperature ZSSTOL TXT calculated thermal flow ZS8TO2 TXT calculated thermal expansion ZS8TO3 TXT calculated thermal forces ZS8TO4 TXT calculated displacements ZS8TOS5 TXT calculated nodal forces ZSS8TO6 TXT calculated forces thermo mechanical ZSSTO7 TXT calculated stress thermo mechanical ZSSNLO2 TXT calculated displacements nonlinear calculation with ZSSNL ZSSNLO3 TXT calculated Cauchy stress nonlinear calculation with ZSSNL ZSSNLOH TXT cal
87. e 3D CAD programs include so called automeshers which divide a CAD model into fi nite elements This generated mesh can be stored in some output format to fit the needs of the various FEA programs Typical output formats are the COSMOS and the NASTRAN format for the COSMOS or the NASTRAN FEA program DIO f linear mechanical vii o BB 2A ae A Geometry STL file STEP file FE structure Bi aoco ore nastran fle gt F Abaqus file Ansys fie Choose Nastan fll 12 zssauroreve win bin Name Moe Recently Used Remove nas dead Tetrahedrons ww Figure 25 Accessing the 3D converter Z88G and import options in ZSSAurora 91 8B on Theorie Manual Z88G is developed and tested for Pro ENGINEER by Parametric Technology USA Pro ENGINEER must include the option the additional module Pro MECHANICA Then you may activate FEM in the Pro ENGINEER program after designing your 3D model define a coordinate system which must be in harmony with Z88 and add forces and boundary con ditions to single points Create these single points with Feature gt Datum gt Point For plates the direct entry of the pressure load is allowed Do not forget to define an analysis Otherwise no boundary conditions are filed Modify the mesh control values if necessary Create the mesh with Make Model and choose the element type e g Tet Mesh Store the mesh with Out put Model choose NASTRAN or COSMOS M and lin
88. e load is applied tangentially and positive in local r direction with 300 N mm defined by the two corner nodes Thus gt 97 100 300 5 13 5I X Plane stress element with surface loads Hexahedron No 1 Element number with surface and pressure load Long Pressure positive if pointing towards the surface Double Tangential shear positive in local r direction Double Tangential shear positive in local s direction Double 4 nodes of the loaded surface 4 x Long Example The hexahedron 356 features surface loads The load should be applied onto the surface defined by the corner nodes 51 34 99 and 12 The first surface load is pressure with 100 N mm The second surface load is applied tangentially and positive in local r direction with 200 N mm The third surface load is applied tangentially and positive in local s direction with 300 N mm Thus gt 356 100 200 300 51 34 99 12 Hexahedron No 10 Element number with surface and pressure load Long Pressure positive if pointing towards the surface Double 58 66 Aurora 56 Theory Manual Tangential shear positive in local r direction Double Tangential shear positive in local s direction Double S nodes of the loaded surface 8 x Double Example The hexahedron 456 features surface loads The load should be applied onto the surface defined by the corner nodes 51 34 99 and 12 and the mid nodes 102 151 166 and 191 The first surface load is pressure with 100 N
89. e stresses are calculated in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly For this element the shell flag IHFLAG should be set to 1 in Z88MAN TXT In case of thin shells set IHFLAG to 2 or 3 In case of very thin shells set it to 4 The first three degrees of freedom are the global displacements in X Y and Z The degrees of freedom 4 and 5 are the global torsions on the respective node thus quite useless degree of freedom 6 is a pseudo DOF without practical significance Only the global displacements in X Y and Z are practically useful and of interest for mechanical engineers Input CAD 5 2 6 3 7 4 8 1 see chapter 4 1 7 Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt 6 degrees of freedom for each node but only DOF 1 3 are of interest gt Element type is 23 gt 8 nodes per element Z88ELP TXT gt Cross section parameter QPARA is the element thickness Z88INT TXT gt Integration order INTORD for displacement calculation 3 is usually good gt Integration order INTOS for stress calculation 0 Calculation of the stresses in the corner nodes 1 2 3 4 Calculation of the stresses in the Gauss points 159 ohh Theorie Manual Z88MAT TXT gt Define materials ref chapter 3 1 4 and 3 1 5 Z88MAN TXT gt Set shell flag IHFLAG to I or to 2 or 3 in case of thin shells and to 4 in case of very thin shells gt Radial T
90. ear or parabolic the option toggle fix elements is not bad for this purpose Enter filename nas for NASTRAN files or filename cos for COSMOS files for the output file name Then the converter Z88G is launched automati cally if you load either a NASTRAN file or a COSMOS file see figure 25 Specify the element type to be generated Of course both must correlate with what you have previously designed in Pro ENGINEER The background especially of the selection of the element type is that the output of Pro ENGINEER is the type shell even if we deal with plane stress elements axisymmetric elements or plates The converter produces the Z88 input files Z88I1 TXT Z8812 TXT and Z88I5 TXT automatically Then you may enter the materi al data element parameters and integration orders directly in Z88 Aurora V2 Please note The import of DXF ABAQUS ANSYS NASTRAN and COSMOS input decks is positively limited for this version ZSSAurora V2 to the FE geometry boundary condi tions forces and surface and pressure loads in contrary to Z88 V13 and ZS8Aurora V1 And here s why After the import of commercial input decks you may define the material data the element parameters and the integration orders very comfortable in ZSS8Aurora even if some of these information are included in the input decks however because only in this way a proper use of Aurora s own material data base is possible This will give you a clean data base for ZSSAurora V2 projects
91. eason is the data exchange with 3D CAD systems Use tetrahedrons No 16 hexahedrons No 1 and best choice hexahe drons No 10 Tetrahedron No 17 cannot be generated by the mapped mesh generator Z88N Input Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt 3 degrees of freedom for each node gt Element type is 17 gt 4 nodes per element Z88ELP TXT gt Cross section parameter QPARA is 0 or any other value has no influence Z88INT TXT gt Integration order INTORD for displacement calculation 1 is usually good Allowed are 1 for I Gauss point 4 for 4 Gauss points and 5 for 5 Gauss points gt Integration order INTOS for stress calculation 0 Calculation of stresses in the corner nodes 145 Yoho Theorie Manual 1 4 5 Calculation of stresses in the Gauss points Z88MAT TXT gt Define materials ref chapter 3 1 4 and 3 1 5 ZT88MAN TXT gt Radial Tangential stress flag KDFLAG has no meaning gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the Gauss points INTOS not 0 2 principal or Rankine stresses in the Gauss points INTOS not 0 3 Tresca stresses in the Gauss points INTOS not 0 Z8815 TXT This file is only used see 3 1 3 if in addition to nodal forces pressure loads are applied onto element no 17 otherwise enter a O into the first line gt Element number with pressure load gt Pressure positive if poin
92. edom for this node Long 3rd number X coordinate or if KFLAG is 1 R coordinate Double 4th number Y coordinate or if KFLAG is 1 PHI coordinate Double Sth number Z coordinate or if KFLAG is I Z coordinate Double The Z coordinate may be skipped for 2 dimensional structures Example The node no amp has 3 degrees of freedom and the coordinates X 112 45 Y 0 Z 56 75 Thus 83 112 45 0 56 75 3 input group Starting after the last node contains coincidence 1 e the allocation of the element type and the corresponding nodes of every element Edit two lines for every super element The ele ment numbers like the node numbers must be entered strictly ascending 1 line Ist number Element number Long 2nd number Super element type 1 7 8 10 11 12 20 21 Long 2nd line Depending on element type Ist number Ist node number for coincidence Long 2nd number 2nd node number for coincidence Long 20 number 20th node number for coincidence Long Write all numbers into a line separate at least by one blank respectively All numbers here of the type Long 35 Yoho Theorie Manual These are the mesh generator suitable elements Element No 1 Isoparametric Hexahedrons 8 nodes Element No 7 Isoparametric Serendipity Plane Stress Element 8 nodes Element No 8 Isoparametric Serendipity Torus 8 nodes Element No 10 Isoparametric Serendipity Hexahedron 20 nodes Element No 11 Isoparametric Serendipity Pl
93. effort Low Size of element stiffness matrix 12 x 12 U SHELL PROBLEMS Shell No 21 R curvilinear isoparametric Serendipity volume shell element isoparametric transformation arbitrary curvature of element possible good calculation of both displacements and stresses Stresses in the corner nodes good for an overview or in the Gauss points substantially more exact Computing effort high Size of element stiffness matrix 48x48 14 66 Aurora Yoi Theory Manual Shell No 22 FR curvilinear isoparametric Serendipity volume shell element isoparametric transformation arbitrary curvature of element possible good calculation of both displacements and stresses Stresses in the corner nodes good for an overview or in the Gauss points substantially more exact Computing effort average Size of element stiffness matrix 36x36 Shell No 23 AR curvilinear isoparametric Serendipity shell element Shape functions quadratic isoparametric transformation all nodes in one plane good calculation of both displacements and stresses Stresses in the corner nodes good for an overview or in the Gauss points substantially more exact Computing effort high Size of element stiffness matrix 48x48 15 Yoho Theorie Manual Shell No 24 FR curvilinear isoparametric Serendipity shell element Shape functions quadratic isoparametric transformation all no
94. ence is already reached An enlargement of the value leads at the same time to a stricter break criteri on vice versa a small value weakens his influence The start of the calculation causes the call of the Solvers Z88EI which works with the follow ing input and output files 107 Theorie Manual Input files Z88I1 TXT Z8812 TXT Z88I2ZELTXT Z88MAT TXT TXT Z88INT TXT Z88MAN TXT Output files Z88O02 TXT general structure data boundary conditions the Lanczos solver parameters material defini and one or more material files in TXT format material file integration orders solver parameters Displacements for all frequencies 108 66 Aurora Yoi Theory Manual 4 5 THE THERMAL SOLVER ZS8THERMO In the new module Z88 THERMO of Z88Aurora a purely thermal conduction simulation as well as a thermo mechanical simulation can be carried out The first step to select the module and therefore the solver to the temperature calculation is to change the rider in the menu fillet from linear mechanical to steady state thermal see figure 37 b ee 4 5 as Ef EJ CL Static thermal Figure 37 Choosing the steady state thermal calculation mode The first small difference to the linear mechanical calculation is the import of components In general it is possible to load a pure geometry structure by the known interfaces However with FE structures only the element types tetrahedron and hexahedron linearly or squarely eithe
95. ent with the TEXT function SE 19 10 1 3 E 5 L 4 E eorE for equidistant is equivalent Sth step Define the Layer Z88NET and make it the active layer You need concentration for this step because a firm and rigid work sequence must now be kept because of the topological information One of the most important information the coincidence is defined in this step that means which elements are defined or outlined by which nodes Choose a proper colour which differs well from the colours used till now and remove all superfluous information by switching off unused layers Select the LINE command and select the proper snap options e g points intersection points and if necessary end points Start at the first element For Z88 the first element is the element with which you start now that means the one which you have chosen for your first element SE or FE 1 Select the node you want to be the first node of this element this can be e g globally the node 150 and draw a line to the node which shall be the second node of this element this can be e g global ly the node 67 From there draw a line to the third node of this element this can be e g globally the node 45 Connect all required nodes with lines and draw at last a line to the start ing point the first node and then quit the LINE function Then you do the same with the second element Remember You determine with this order which of the elements will be the real second element now
96. er Z88R includes internally three different solvers The so called Cholesky solver without fill in with so called Jennings storage It is easy to handle and very fast for small and medium structures Z88R choly is your choice for small and medium structures up to 20 000 30 000 degrees of freedom In Z88AuroraV2 can be calculated only truss and beam frameworks with this solv er A so called direct sparse matrix solver with fill in It uses the so called PARDISO solver Z88R parao This solver is very fast since it is multi CPU compliant but it uses very much dynamic memory therefore the program is likely to quit with an error message if the main memory is exhausted This solver is your choice for medium structures up to 150 000 degrees of freedom on ordinary 32 bit PCs However we ve computed structures with 1 million of DOF very fast using a computer featuring 32 Gbyte of memory 4 CPUs 64 bit Windows version of Z88 100 66 Aurora 56 Theory Manual e The so called sparse matrix iteration solver It solves the system of equations by the method of conjugate gradients featuring SOR preconditioning Z288R sorcg or pre conditioning by an incomplete Cholesky decomposition Z88R siccg depending on your choice This solver needs a minimum of storage This is your choice for large structures with more than 150 000 200 000 DOF FE structures with 5 million DOF are no problem for it if you use a 64 bit operation system Windows
97. er edge in Y direction see figure 2 Incorrect 1 000N 7 142 86 N per node Not correct for elements with square shape function Correct 2 x 1 6 2 x 1 6 1 6 3 x 2 3 18 6 3 corresponds to 1 000 N 1 6 points 1 000 18x1 55 55 2 6 points 1 000 18x2 111 11 2 3 points 1 000 18x4 222 22 Control 2x55 55 2x111 11 3x222 22 1 000 N o k Here s why 1 4 1 4 1 2 1 2 1 4 1 4 1 4 1 4 1 4 ua Figure 32 Elements with linear shape functions e g Hexahedron No 1 99 LIB on Theorie Manual 1 12 1 33 1 12 1 6 1 6 1 12 2 3 1 3 1 3 1 3 1 3 1 12 1 12 1 3 1 3 1 12 1 3 1 12 1 12 Figure 33 Elements with quadratic shape functions e g plane stress element No 3 and 7 Torus No 8 Hexahedron No 10 1 8 3 16 3 16 1 8 1 8 3 8 3 8 1 8 3 16 3 16 3 16 3 16 1 8 3 16 3 16 1 8 Figure 34 Elements with cubic shape functions e g plane stress element No 11 torus No 12 plate No 19 The choice surfaces projected surface load and projected line load take the fact into account that meshing with Free Meshern very often means irregular node distributions par ticularly with curved surfaces If a surface contains more nodes on her right half than in the left the load application occurs one sided This effect is weakened by the projection Further details to the application of boundary conditions see user s handbook 4 3 THE LINEAR SOLVER Z88R The linear solv
98. ere This serves primarily to be able to check with test calculations already after a short time whether the model is computable as desired As usual with iterative processes the results which were generated after the maximum iteration number should be taken with care In these cases can not be spoken yet of a convergence against the correct solution The statement helps that at the latest after that iteration number which corresponds to the degree of freedom number of the model the maximum accuracy is reached Difference b 2 frequency Particularly with symmetrical components it often seems that two successive natural frequencies differ only very little Then the oscillation forms are often turned around the symmetric axis and are absolutely the same otherwise Besides mathemati cally it concerns so called multiples of the accompanying eigenvalues To exclude this in phase I a least difference in Hz can be stopped from two frequencies should be also con sidered really as different The value must be really greater as zero quite small values like 1 0E 6 cause the desired results Kappa This value determines after which fixed number of Lanczos iterations an eigenvalue approximation should be done If for example the default 50 is used an approximation occurs only after 50 100 150 iterations All 49 intermediate steps are run in the interest of short er arithmetic time without a complex check of the break criterion even if the converg
99. ere are on the other hand beside the settings for the iterative solver two new Flags The first Flag THERMOoMODE must always be 1 The second Flag THERMomEcHANIC must be o for a purely thermal simulation and for a thermo mechanical simulation 1 TMSOLVER START MAXIT EPS RALPHA ROMEGA THERMOMODE THERMOMECHANIC TMSOLVER END 10000 O0O0000E 006 JO0000E 004 200000E 000 PRP RE 112 Mah Aurora 86 Theory Manual 4 6 THE NONLINEAR SOLVER ZSSNL The module Z88NL is an equation solver which is designed for non linear calculations Be sides non linearities are limited to such of geometrical origin thus the stress strain relations are linear Concerning the material parameters are necessary therefore here like with the linear solver Z88R Young s modulus and Poisson ls ratio IN en A iai Figure 41 Choosing the non linear solver Figure 41 shows how Z88Aurora is switched to non linear calculations For the import and the pre processing no differences arise in comparison to the linear mechanical calculation except that merely the elements 1 4 7 8 10 16 17 can be used In the menu cf figure 42 the settings can be adjusted in three different tabs for the non linear solution process the linear sub equation solver and the result issue A reduced stress calculation by Z88NL is only for v Mises stresses possible KB Non linear mechanical M ag O SORCG Choose solver gt PARDISO PARDISO v Failure theory
100. erent values EIGNUM is the number of frequencies that are determined Only the lowest frequencies are calculated EIGSTEP determines the number of iterations after which is checked if EPS is reached 40 66 Aurora 86 Theory Manual THERMAL SOLVER ICFLAG 2 gt see Linear Solver ICFLAG 3 gt see Linear Solver ICFLAG 4 gt see Linear Solver MAXIT see Linear Solver EPS gt see Linear Solver ALPHA see Linear Solver OMEGA see Linear Solver THERMOMODE is an internal control flag For steady state thermal analysis and thermo mechanical analysis it has to be set to 1 THERMECHANIC is required for thermo mechanical analysis It has to be set to 1 0 steady state thermal analysis NONLINEAR SOLVER ICFLAG 2 gt see Linear Solver ICFLAG 3 gt see Linear Solver ICFLAG 4 gt see Linear Solver MAXIT gt see Linear Solver EPS gt see Linear Solver ALPHA gt see Linear Solver OMEGA gt see Linear Solver NLFLAG determines the method Newton Raphson 1 or the arclength method by Riks 2 NLAERH determines how many steps are used to apply the total load MAXNLIT determines the maximum number of iterations of the nonlinear solver EXIT quits the solver if the norm is smaller than TOL 1 or if the norm is still rising 2 TOL termination bound value of the norm must be smaller than TOL so that the solution is found AUTOGAUSS controls the automatic change of the solver If the flag is activated 1 the cha
101. es SIGRR the tangential stresses SIGTT and the accompanying shear stresses SIGRT are computed additionally makes only sense if a rotational symmetric structure is available For easier orientation the respective radiuses and angles of the nodes points are printed Optional von Mises or principal or Tresca stresses Nodal forces in X and Y for each element and each node 136 66 Aurora 86 Theory Manual 5 12 TORUS NO 12 WITH 12 NODES UE This is a curvilinear Serendipity torus element with cubic shape func tions The transformation is isoparametric The integration is carried out numerically in both axes according to Gauss Legendre Thus the integration order can be selected in Z88ENVIRO DYN The order 3 is mostly sufficient This element calculates both displace ments and stresses with outstanding precision The integration order can be chosen again for the stress calculation The stresses are calcu lated in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly Torus elements No 8 can be generated by the mesh generator Z88N from super elements torus elements No 12 Thus the torus element No 12 is well suited as super element However torus elements No 12 cannot be generated by the mesh generator Z88N from super elements torus elements No 12 Input CAD see chapter 4 1 4 5 6 2 7 8 3 9 10 4 11 12 1 Z88STRUCTURE TXT gt In principle cylindrical coordinates are expected KFLA
102. es stresses in the Gauss points INTOS not 0 2 principal or Rankine stresses in the Gauss points INTOS not 0 3 Tresca stresses in the Gauss points INTOS not 0 Z8815 TXT This file is only used see 3 1 3 if in addition to nodal forces surface and pressure loads are applied onto element no 22 otherwise enter a O into the first line gt Element number gt Pressure positive if pointing towards the surface gt 3 corner nodes and 3 mid nodes of the loaded surface Mathematically positive in top view Y Z Results Displacements in X Y and Z Stresses SIGXX SIGYY SIGZZ TAUXY TAUYZ TAUZX respectively for corner nodes or Gauss points Optional von Mises or principal or Tresca stresses Nodal forces in X Y and Z for each element and each node 158 66 Aurora 86 Theory Manual 5 23 SHELL NO 23 WITH 8 NODES This is a curvilinear Serendipity shell element with quadratic shape functions The transfor mation is isoparametric The integration is carried out numerically in all axes according to Gauss Legendre All nodes have to be on a common surface which may be placed arbitrarily in a space which is very useful for the data exchange with 3D CAD systems The integration order can be selected in Z88INT TXT The order 3 i e 3x3 Gauss Points is mostly suffi cient This element calculates both displacements and stresses quite good The integration order can be chosen again for the stress calculation Th
103. eshing with for example half this value 64 66 Aurora Yoi Theory Manual 3 Edge ratio The quotient of the longest and the shortest edge of a triangle is also a measure for its regularity Here you should select a value close to 1 Which CAD systems can cooperate with Z88GEOCON Any CAD systems which can export 1 e write STL files in ASCH format However we can not guarantee any success Which elements are supported by the converter Z88Aurora first generates a visualisation from the imported STL files This can be transferred into structures from elements No 16 or No 17 linear or quadratic Tetrahedrons by means of the existing meshers How to proceed 1 Construct the 3D geometry to be calculated in your CAD system In the process please keep in mind the above mentioned particularities 1f possible Export the geom etry as STL file It is recommended to check the original model and the interchange file with an integrated geometry check for defective and very small surfaces Have a closer look at the STL and search for triangles with very acute angles If they are lo cated in a part of the component which is important for the calculation it is recom mended to export the interchange file one more time with modified settings 2 In ZSS8Aurora select File gt Import gt STL data In the subsequent selection box you can only select STL files Therefore select the desired file figure 3 The geometry is visualised in Z88
104. esses in the Gauss points INTOS not 0 3 Tresca stresses in the Gauss points INTOS not 0 Z8815 TXT This file is only used see 3 1 3 if in addition to nodal forces surface and pressure loads are applied onto element no 21 otherwise enter a O into the first line gt Element number gt Pressure positive if pointing towards the surface gt Tangential shear positive in local r direction gt Tangential shear positive in local s direction gt 4 corner nodes and 4 mid nodes of the loaded surface Mathematically positive in top view The local r direction is defined by the nodes 1 2 the local s direction is defined by the nodes 1 4 The local nodes 1 to 8 for the surface load may differ from the local nodes 1 to 8 used for the coincidence Results Displacements in X Y and Z Stresses SIGXX SIGYY SIGZZ TAUXY TAUYZ TAUZX respectively for corner nodes or Gauss points Optional von Mises or principal or Tresca stresses Nodal forces in X Y and Z for each element and each node 155 Habj Aurora Theorie Manual eu 156 66 Aurora 86 Theory Manual 5 22 SHELL NO 22 WITH 12 NODES amp This is a curvilinear Serendipity volume shell element The transformation is isoparametric The integration is carried out numerically in all axes according to Gauss Legendre The ele ment can be arbitrarily curved it is actually a kind of pie segment with square shape functions on the surface and linear shape functions
105. et the plate flag IPFLAG to 1 Attention In contrary to the usual rules of the classic mechanics Z88 defines 0 the rotation around the X axis and 0 the rotation around the Y axis This element type is implemented for use with automeshers In addition a mesh generation with ZSSN is possible Super elements of type 20 can generate finite elements of type 20 and plates of type 19 with 16 nodes too Input CAD 5 2 6 3 7 4 8 1 ref chap 2 7 2 Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt set plate flag IPFLAG to I or 2 if you want to reduce the shear influence gt 3 degrees of freedom for each node w O 0 gt Element type is 20 gt 8 nodes per element Z88ELP TXT gt Cross section parameter QPARA is the element thickness Z88INT TXT gt Integration order INTORD for displacement calculation 2 is usually good gt Integration order INTOS for stress calculation 0 Calculation of stresses in the corner nodes 1 2 3 4 Calculation of stresses in the Gauss points Z88MAT TXT gt Define materials ref chapter 3 1 4 and 3 1 5 132 66 Aurora 86 Theory Manual Z88MAN TXT gt set plate flag IPFLAG to I gt Radial Tangential stress flag KDFLAG has no meaning gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the Gauss points INTOS not 0 2 principal or Rankine stresses in the Gauss points INTOS not 0 3 Tresca stresses
106. eters into the file Z88CONTROL TXT This is done via Solver parameters in the menu Solver for every solver e termination criterion maximum count of iterations e g 10000 e termination criterion residual vector lt limit Epsilon e g le 7 e parameter for the SIC convergence acceleration Shift factor Alpha from 0 to 1 good values may vary from 0 0001 to 0 1 start with 0 0001 For further information con sult the literature e Parameter for the SOR convergence acceleration Relaxation factor Omega from 0 to 2 good values may vary from 0 8 to 1 2 102 66 Aurora Zi Theory Manual Choose solver pak PARDISO Failure theory No equivalent stress GEH von Mises O Rankine Tresca Solver parameter sIcce sorce F Solver parameters Solver parameters SICCG Number of iterations ir DOC Residuum 1 000000E 006 Alpha 1 000000E 004 Help a SORCG Number of iterations 10000 Residuum 1 000000E 006 Omega 1 200000E 000 Help Figure 35 Options of the solver menu according to the chosen solver Explanations to the direct sparse matrix solver with fill in This solver does direct matrix decomposition but in contrary to the simple Cholesky solver this solver operates with fill in Fill in means allocating dynamic memory for the new matrix elements created by the decomposition process Thus the memory needs cannot be calculated before run
107. f a simulation system Who wants to revise their models every six months Therefore all input files from previous versions can be used in Z88AuroraV2 If necessary only a few small ad justments must be made Which Z88 versions can cooperate with Z88Aurora As a matter of principle every input file from every previous version can be imported The function is mainly intended for the import of files from Z88 V14 OS and via the migration tool MITOO Z88 V13 and Z88Aurora V1 Therefore older files must be updated to these versions For this purpose it is often sufficient to add some flags or values The Migration Tool MITOO S Files from Z88V14 OS can be imported directly to Z88AuroraV2 without MITOO MITOO may be used for an easy migration of Z88 V13 and Z88Aurora V1 files MITOO generates a Z88V14 OS data set Z88I1 TXT Z88I2 TXT Z88I5 TXT Z88MAN TXT Z88MAT TXT TXT Z88INT TXT Z88ELP TXT Path to inputdata Path to outputdata gt bin convert data Start Info quit older Z88 files F igure 14 migration tool MITOO for The executable MITOO can be found in the bin folder Double clicking opens the migration dialogue Selecting the respective folder and Start converts the data Afterwards the import menu and the import can be done as usual in Z88Aurora see fig 15 For complete projects the following import option can be chosen 32 ZSS Aurora wos E Theory Manual amp Lo
108. f the respective set Explanations 31 M liha Aurora Theorie Manual The sets are written in the files consecutively How many sets can be imported is controlled by the first value in the file Example There is a set Material which contains 22948 elements gt gt 1 ELEMENTS MATERIAL 1 22948 Material 1 2 3 4 Example 3 NODES CONSTRAINT 1 58 Constraints 86 87 88 89 90 91 92 93 94 95 96 125 126 127 132 133 134 135 136 137 138 139 140 141 142 143 144 172 173 466 467 468 469 470 471 472 473 474 475 476 4777 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 NODES CONSTRAINT 2 54 Pressure 174 s 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 321 322 er 324 325 326 327 328 329 330 331 332 335 334 225 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 ELEMENTS MATERIAL 3 2764 Material 1 2 3 4 5 6 7 8 9 10 11 12 13 14 wS 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 S 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 15 76 T 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 32 66 Aurora 86 Theory Manual 3 2 3 CHARACTERISATION FILE ZS8SS8SETACTIVE TXT Here the specific information and the applicati
109. file Z88I1 TXT and KFLAG is set to 1 in Z88I1 TXT 4 7 2 THE TETRAHEDRON REFINER With this functionality it is possible to refine existing tetrahedron meshes By means of pick ing a set with those tetrahedrons which should be refined can be selected The division of eve ry element occurs through 8 tetrahedrons 118 68 Aurora sets Set4 C All elements Li Minimal inner angle 2 5 00 00 Administration ee Add Create mesh m Delete Remove mesh Close K Mesh info Rules for mesh Theory Manual initial tetrahedron with all median lines 3 AN corner tetrahedron 4 octahedron 2A 2square based UN gt K 3 1 ps 4 tetrahedron Figure 46 entry field for tetrahedron refiner left method of tetrahedron refining right Afterwards the adjoining elements are adapted to the changed nodal numbers and are also divided On this occasion a minimum element angle is to be entered to prevent of a too strong distortion 119 ey 66 Aurora Theorie Manual Figure 47 Verlauf des Verfeinerungsalgorithmus mit Winkelkriterium Instead of the ideal internal angle of 60 a default of the angle is realistic by a FE meshing between 3 10 Further details to the application see user s handbook 4 7 3 THE SHELL THICKENER With this functionality it is possible to thicken existing flat shells from Nastran or DXF im port and thus to convert to
110. for this or use already available layers from step 1 Point Size 3 0000 Set Size Relative to Screen Set Size in Absolute Units OK J Cancel Hep O Now you may delete any auxiliary lines arcs etc to see the true FE structure 76 766 Aurora wos Theory Manual 3rd step Define the Z88 Layer Z88KNR and make it the active layer Catch or trap every FE node which were already defined in the Ist step by your construction or have been completed in the 2nd step and number them Write to every node P blank node number e g P 33 with the TEXT function of the CAD program Be very careful to snap exactly the node and attach the number exactly to the node s location Take your time With the snap modes of AutoCAD intersection point end point point etc this works very well Choose any order of the work sequence as you like you can well number the node 1 P then the node 99 P 99 and then node 21 P2 However the numbering of the nodes must make sense and must be meaning ful for an FE analysis You define which node is node 99 and which other node is 21 AQ Drafting Settings x Snap and Gid Polar Tracking Object Snap 3D Object Snap Dynamic Input Quic V Object Snap On F3 V Object Snap Tracking On F11 Object Snap modes O F Endpoint Cy E insertion Select Al A V Midpoint Hh _ Perpendicular Clear All O Center Tangent i V Node X E Neare
111. g 4th number Value of the load or displacement Double Example The node I shall be fixed at his 3 degrees of freedom respectively Node 3 features a load of 1 648 N in Y direction i e DOF 2 the degrees of freedom 2 and 3 are supposed to be fixed for the node 5 This will result in 6 boundary conditions gt Thus oOo amp NAUNA Bo NNUNN bo Nh BD NW LO l S A Co OSO It is a good idea to define surface and pressure loads in the file ZSSI5 TXT Only forces and constraints should entered here into Z88I2 TXT Of course it 1s possible too to convert surface loads into concentrated forces manually and to enter these forces into Z88I2 TXT which is the classical way but somewhat cumbersome 55 M lh Aurora Theorie Manual For the elements with linear shape function e g Hexahedrons No 1 and Torus No 6 edge loads and surface loads are distributed to the elements simply and straight forward onto the respective nodes However for elements with higher shape functions 1 e square Plane Stress No 3 No 7 To rus No 8 Hexahedron No 10 etc or cubic Plane Stress No 11 and Torus No 12 edge and surface loads have to be put onto the elements according to certain rules which are not always physically obvious but mathematically absolutely correct Amazingly some load components can have negative values Though these facts are not obvious nevertheless they lead to cor rect results which is not the case for int
112. g amp Annotation vil b6_5 dwg Type a keyword or phrase Annotate Parametnc View Manage Output Express Tools BOR w Ele amp CACIK BE SAD O F D 1 the d Layer Stat NSINVOG ByE ee Block Properties Utilities Clipboard a Go cr 9 of IP ZENET Modify v yer Q oe g6 Filters Tm Ansichtsfe Definitions Z88EO Z88KNR Z88NET O 9 9 9 9 9 9 14 4 gt Pi Model_ L Rutodesk DWG This file is a TrustedDWG last saved by an Autodesk application or Autodesk licensed application Command SO 12 ee alone lt a 6th step Define the layer Z88GEN and switch it active Write with the TEXT function into any place of your drawing the general information i e the first input group of the general structure data Z88I1 TXT ZSS11 TXT Dimension of the structure Number of nodes Number of finite elements Number of degrees of freedom DOF Coordinate flag 0 or 1 82 mn 56 Aurora Thus here Z88I1 TXT 2 37 8 74 0 Theory Manual ma 0 2D Drafting amp Annotation v ia b6_6 dwg Type a keyword or phrase Insert Annotate Parametnc View Manage Output Express Tools r o wesohes Blse zd i O g Gt Als Unsaved Layer State Line Move S F4 ao H AA i 9 gf HE Zsscen Block Properties Utilities Clipboard Draw v Modify v Search for layer R lt a GH e amp Filters B all 6 All Used Layers T TERETE RR o 9 a J
113. greich zu Verzeichnis C proe ge ndert _ Schattiertes Modell wird angezeigt amp Zoom Bereich durch Anklicken zweier Stellen definieren iv This is how torus elements are generated in Pro ENGINEER In case of plates and shells proceed correspondingly 93 Iah Aurora Theorie Manual 4 1 6 THE ANSYS CONVERTER ZSSASY What is the basic idea and which are the features Apart from NASTRAN and COSMOS Pro ENGINEER also supports the output of simula tion data as ANSYS file ans These data can subsequently be transmitted to ANSYS as well as to Z88Aurora Please keep in mind however that this data format can also be arbitrar ily altered by the producer which might lead to compatibility problems D LJ gt IZ Linear mechanical v s pt z i aK Si Geometry STL file BF STEP file FE structure DXF AutoCAD DXF Nastran file FS Abaqus file Cosmos file Z 788 file Figure 26 Accessing the ANSYS converter ZSSANS A solid with any number of materials linear elastic can be converted The solid must consist of one element type Optional Cartesian boundary conditions concentrated forces and forces on areas as well as pressures can be applied You do not need to define any material in AN SYS because Please note The import of DXF ABAQUS ANSYS NASTRAN and COSMOS input decks is positively limited for this version ZSSAurora V2 to the FE geometry boundary condi tions forces and surface and
114. heap graphic adapter will be sufficient To be on the safe side however check the system settings sometimes OpenGL hardware acceleration can be activated Your choice of colours screen size light features material properties the polygon offset etc can be defined in the file Z88 FCD But be careful with changes in Z88 FCD You must have some basic knowledge of how OpenGL works if you want to change light effects etc Other wise there will be long faces because nothing seems to work properly anymore Some hints are included in Z88 FCD in the form of remarks but we cannot give an introduction to OpenGL in this context Please consult for example Shreiner D OpenGL Programming Guide 7 edition Addison Wesley Pearson 2010 F Options Mouse configuration yx Zoom se Z Y 150 0 BE Rotate 1 0 Legend color Lights Translate Component color 10 Slow Resolution 800 x 600 v Advanced settings C Enable culling Start with SPIDER Help X Cancel Figure 50 Option menu View and the choice of lights labels and colors by the appropriate ICONS 122 66 Aurora 56 Theory Manual Features of rendering For fastest operation Z88 Aurora connects the nodal points in case of scenes with lighting and in hidden line mode and only the corner points with straight lines although for Serendipity elements the edges of the elements are square or cubic curves in wireframe mode all nodes are connected with
115. here are also systems in the area of Re verse Engineering which can generate STL data from a 3D capture This means that compo nents can also be simulated without using a CAD model In contrast to STEP which can describe the surface of the component very accurately by means of B zier curves or splines STL is always a discretisation of the component 1 e all surfaces are divided into straight edged triangles Therefore a loss of accuracy occurs espe cially at fillets roundings or holes However this occurs in the FEA anyway however after the meshing at the latest But you should take into account that a poorly generated STL leads to an even more extensive loss of quality in the meshing process Therefore you should check the following settings when generating STL data if your source system offers this possibility 1 Angle control If you can define the minimum angle in a surface triangle in your CAD system it is recommended to permit angles with at least 30 Very acute angles de pending on the mesher in most cases lead to acute angles in the elements of the FE mesh which inevitably either generates elements which cannot be calculated too small or negative Jacobian determinant or create bad results 2 Chord length A very small chord length also leads to triangles as equilateral as possi ble and to especially small triangles for the surface plot You should select the short est straight edge of your model and conduct the m
116. ian points is the right val ue For isoparametric elements Nr 14 15 18 22 and 24 3 7 or 13 i e N Calculation of stress in the Gaussian points 46 Theory Manual comparison stress calculation is possible A good value is 7 gaussian points For type 18 3 gaussian points may suffice For isoparametric elements Nr 16 and 17 1 4or5 i e N Calculation of stress in the Gaussian points comparison stress calculation is possible A good value is 7 for type 16 For type 17 1 gaussian point may suffice This value has no meaning for elements Nr 2 3 4 5 6 9 and 13 It s best to enter a 1 In figure 10 you ll find an example of the definition file Z88ENVIRO DYN Z88ENVIRO DYN is also located in the subdirectory z88aurorav2 bin Selection operating system KE LAGS CO Control different options FLAG SHOW SURFACE 8 FLAG SCROLLER o FLAG ROTATOR 10000 UU FLAG TRANSLATOR 1 000000 FLAG RESOLUTION 1024 x 768 FLAG MPC RIGID 1 000000E 012 FLAG MPC USER 1 000000E 002 FLAG MPC TYP 100 FLAG CULLING 8 FLAG SPIDER START 8 FLAG CPU NUM 4 FLAG INTORD TYP 1 2 FLAG INTORD TYP 7 3 FLAG INTORD TYP 8 3 FLAG INTORD TYP 10 3 FLAG INTORD TYP 11 3 FLAG INTORD TYP 12 3 FLAG INTORD TYP 14 7 FLAG INTORD TYP 15 7 FLAG INTORD TYP 16 4 FLAG INTORD TYP 17 4 FLAG INTORD TYP 18 3 FLAG INTORD TYP 19 4 FLAG INTORD TYP 20 2 FLAG INTORD TYP 21 2 FLAG INTORD TYP 22 7 FLAG INTORD TYP 23 3 FLAG INTORD TYP 24 7 F
117. igure 51 Setting options stress parameters in the menu Solver 124 66 Aurora 86 Theory Manual Plot of deflections You may plot the undeflected or the deflected structure or both of them overlaying The enlargement factor is adjustable normally the factor amounts to 10 of the biggest displacement amount In addition you may plot the deflections for X for Y or for Z with colour shading This is a pretty nice feature for large spatial structures You may plot the shaded colours for stresses or for the deflections or the hidden line display or the wire frame display with the deflected structure The background colours and legend display can be ad justed For further information consult the Z88Aurora User Manual By means of a scrollbar the deflection can also be scaled continuously The coordinate system OpenGL works with a Clipping Volume i e with a kind of cube defined by Xmin and Xmax in horizontal direction by Ymin and Ymax in vertical direction and Zmin points towards the user and Zmax points away from the user If you use a too large zoom factor or if you are panning the structure too near to you then the range of Zmin is ex ceeded and parts of the structure are lying outside the viewing volume This offers a nice chance to look into a structure also in order to see the internal stresses Otherwise change the value of Zmin default entry is 100 to lower values e g 1000 use the menu View gt Z limit towards y
118. in the thickness direction The integration order can be selected in Z88INT TXT The order 3 i e 3x3 Gauss Points is mostly sufficient This element calculates both displacements and stresses very exactly The integration order can be chosen again for the stress calculation The stresses are calculated in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly The three degrees of freedom are the global displacements in X Y and Z However there are no rotational degrees of freedom because Type 22 is in fact a volume element Input CAD upper plane 1 4 2 5 3 6 1 lower plane 7 10 8 11 9 12 7 Lines 1 7 2 8 3 9 see chapter 4 1 7 Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt 3 degrees of freedom for each node gt Element type is 22 gt 12 nodes per element Z88ELP TXT gt Cross section parameter QPARA is insignificant Z88INT TXT gt Integration order INTORD for displacement calculation 3 7 and 13 are possible 7 is usually good gt Integration order INTOS for stress calculation 0 Calculation of stresses in the corner nodes 157 Yoho Theorie Manual 3 7 13 Calculation of stresses in the Gauss points Z88MAT TXT gt Define materials ref chapter 3 1 4 and 3 1 5 ZT88MAN TXT gt Radial Tangential stress flag KDFLAG has no influence gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mis
119. ings e Calculation of the stresses at the Gauss points or at the corner nodes e Additional calculation of radial and tangential stresses for elements No 3 7 8 11 12 14 and 15 e Calculation of von Mises stresses for continuum elements No 1 3 6 7 10 11 12 14 15 24 104 66 Aurora 86 Theory Manual 4 3 3 SOME NOTES ON NODAL FORCE CALCULATION The results are presented in Z8804 TXT The nodal forces are calculated separately for each element If several elements meet a node one gets the complete nodal force for this node by adding the nodal forces of all accessing elements These results are presented further down in the nodal force file Z8804 TXT 105 Yoho Theorie Manual 4 4 THE VIBRATION SOLVER ZSSEI This eigen solver offers the possibility to examine components concerning her natural fre quencies as well as the oscillation forms caused from it The accelerating and damping nodal forces which are caused by dimension inertia or reset forces from stiffness qualities keep just the scales with this frequency As with the linear solver Z88R information to the modulus of elasticity and the across contraction becomes necessary In addition still the material density is required for the mass calculation All material data are deposited in the material data base Figure 36 shows the choice and control of the natural oscillation module The analysis is for tetrahedron and hexahedron with linear and square approach element model
120. ion 59 Yoho Theorie Manual gt Tangential shear in local s direction gt 4 corner nodes and 4 mid nodes of the loaded surface Mathematically positive in top view The local r direction is defined by the nodes 1 2 the local s direction is defined by the nodes 1 4 The local nodes 1 to 8 for the surface load may differ from the local nodes 1 to 8 used for the coincidence Shell No 21 with pressure load Shell No 22 gt Element number gt Pressure positive if pointing towards the surface gt 3 corner nodes and 3 mid nodes of the loaded surface Mathematically positive in top view Y Shell No 22 with pressure load Shell No 23 gt Element number gt Pressure positive if pointing towards the surface gt 4 corner nodes and 4 mid nodes of the loaded surface Mathematically positive in top view 60 66 Aurora wos Theory Manual Z Shell No 23 with pressure load Shell No 24 gt Element number gt Pressure positive if pointing towards the surface gt 3 corner nodes and 3 mid nodes of the loaded surface Mathematically positive in top view Y Shell No 24 with pressure load 6l LOO prscors Theorie Manual Checking of Z88V14 input data files by Z88VRY The file checker Z88VRY investigates input data sets for Z88 V14 and for Z88 Aurora V2 Z88VRY was written in Perl to have one universal program for all operating systems see docu Perl is always installed under LINUX and Snow Leopa
121. istantly Thus SE 1 11 75 LSE It might be a good idea to use another colour for the objects of layer Z88EIO here blue However you don t need to ma 932D Drafting amp Annotation b6n_4 dwg Type a keyword or phrase Insert Annotate Parametnc View Manage Output Express Tools a S x Thio et gont Aes saaa A E g Gt Al Unsaved Layer State Line Move x S 35 Ol1 9 of Mb zo x Modify v Ann Block Properties Utilities Clipboard Current layer Z88EIO EF All 6 All Used Layers Ansichtsfe Definitions Z88EIO Z88KNR hAban CE Invert filter All 5 layers displayed of 5 total layers 5 g 14 41 gt bi _Model_ Layout1 P Rutodesk DWG This file is a TrustedDWG last saved by an Autodesk application or Autodesk licensed application Command Sth step Define the Layer Z88NET and make it the active layer You need concentration for 87 LIB on Theorie Manual this step because a firm and rigid work sequence must now be kept because of the topological information One of the most important information the coincidence is defined in this step that means which super elements are defined or outlined by which nodes Choose a proper colour which differs well from the colours used till now and remove all superfluous infor mation by switching off unused layers Select the LINE command and select the proper snap options e g points interse
122. kaler Datentr ger C gt Daten D amp DVD RW Laufwerk E dP Hinzuf gen Entfernen Structural information z88i1 txt Meshing file z88ni bt Boundary conditions z88i2 txt Figure 15 Import of Z88 files Application of Z88AuroraV 2 files For further processing of files in Z88V14 OS you have to insert enable write only in Z88 EFCD With this the files are created as a complete data set for Z88V14 OS in the folder Z88V14O0Sdata in the bin directory This folder is overwritten If you want to use these files later you should move them to another folder 4 1 2 MANUALLY CREATING OF Z88 FILES Z88V14 files can be created manually and imported into Z88Aurora V2 For this the files are assembled by hand GENERAL STRUCTURE DATA Z88I1 TXT In Z88I1 TXT the geometry data of the structure is entered 1 input group General data in the first line contain general structure data Write all numbers into a line sep arate them at least by one blank respectively All numbers here are of the type Long 53 8B on Theorie Manual 1 number Dimension of the structure 2 or 3 2 number Number of nodes of the FEA structure 3 number Number of elements 4 number Number of degrees of freedom 5 number Coordinate flag KFLAG 0 or 1 Attention This position was in former ZS8 versions reserved for the number of materials NEG Explanations KFLAG On input of 0 the coordinates are expected Cartesian c
123. ke 85 56 Aurora Theorie Manual Pe 03 2D Drafting amp Annotation i b6n_3 dwg Type a keyword or phrase s A A x P a Annotate Parametnc View Manage Output Express Tools oS SOA Ble 4344 4 2a r fF o amp dls 8 s sees Leyes State soi Block Properties Utilities Clipboard 4 amp 5a C O Sof W zsexne Modify v Search for layer Definitions af Z88KNR x 14 4 gt b1 Model_ Layout1 Autodesk DWG This file is a TrustedDWG last saved by an Autodesk application or Autodesk licensed application Command ib S oiz Ee tamoe QO Aras o Oe 4th step Define the Layer Z88EIO and make it the active layer Write the super element information with the TEXT function anywhere of course it looks nicer with the element in fo s placed in middle of the respective finite element or super element The order of the work sequence is up to you The following information has to be written SE Element number Super element type Type of the finite elements to be produced by meshing Subdivision in local x direction Type of subdivision in local x direction 86 66 Aurora wog Theory Manual Subdivision in local y direction Type of subdivision in local y direction Suppose to mesh the first super element of type No 11 into finite elements of type No 7 Sub divide in local x direction 5 times ascending geometrically and subdivide in local y direction 5 times equid
124. lar to the layout of Z88I1 TXT or Z88S TRUCTURE TXT 1 e the input files for the linear FE solver Only the amp labelled data is required in addition Mind the following formats Long 4 bytes or 8 bytes integer number Double 8 bytes floating point number alternatively with or without point Character A letter 1 input group Ist number Dimension of the structure 2 or 3 2nd number Number of nodes of the super structure 3rd number Number of super elements 4th number Number of degrees of freedom Sth number Coordinate flag KFLAGSS for the super elements 0 or 1 amp 6th number Trap radius flag NIFLAG 0 or 1 amp 7th number Coordinate flag KF LAG for the finite elements 0 or 1 Write all numbers into a line separate at least by one blank respectively All numbers here of the type Long Explanations KFLAGSS On input of 0 the coordinates are expected Cartesian while on input of polar or cylindrical coordinates are expected The latter are then converted into Cartesian coordinates and there upon stored in this form in Z88I1 TXT if KFLAG see below is set to 0 Caution The ax isymmetric elements No 8 and 12 positively expect cylindrical coordinates set KFLAGSS to 0 here Example Super structure 2 dimensional with 37 nodes 7 super elements 74 degrees of freedom Cylindrical coordinates 1 trap radius default value 0 Coordinate flag KFLAG for the finite elements 1 output into ZSSI1 TX
125. ll and medium structures It is your choice for small and medium structures up to 20 000 30 000 degrees of freedom In Z88AuroraV2 the Cholesky solver can only be used for truss or beam structures 19 Yoho Theorie Manual e A so called direct sparse matrix solver with fill in It uses the so called PARADISO solver This solver is very fast but uses very much dynamic memory It is a good choice for medium structures up to 150 000 degrees of freedom on ordinary 32 bit PCs However we ve computed structures with 1 million of DOF degrees of fre dom very fast using a computer featuring 32 Gbyte of memory 4 CPUs 64 bit Windows version of Z88 e A so called sparse matrix iteration solver It solves the system of equations by the method of conjugate gradients featuring SOR preconditioning SORCG or precondi tioning by an incomplete Cholesky decomposition SICCG depending on your choice As our tests have shown this solver deals with structures with more than 100 000 DOF at nearly the same speed as the solvers of the large and expensive commercial FEA programs In addition a minimum of storage is needed This solver is your choice for large structures with more than 150 000 200 000 DOF FE structures with 5 mil lion DOF are no problem for it if you use a 64 bit operation system Windows or LINUX or Mac OS X along with the 64 bit version of Z88 and about 6 GByte of memory This very stable and approved solver works any time
126. ll number the node 1 P then the node 99 P 99 and then node 21 P2 However the numbering of the nodes must make sense and must be meaning ful for an FE analysis You define which node in node 99 and which other node reads 21 4th step Define the Layer Z88EIO and make it the active layer Write the element infor mation with the TEXT function anywhere of course it looks nicer with the element info s placed in middle of the respective finite element or super element The order of the work sequence is up to you You can describe element 1 first step to the attaching element 17 and then proceed with element 8 However your element choice and description must make sense for an FE analysis The following information has to be written For all finite element types from 1 to 24 FE Element number Element type Write into one line separate each item by at least one blank Example An Isoparametric Serendipity Plane Stress Element No 7 is supposed to get the element no 23 Write e g into the middle of the element with the TEXT function FE 23 7 For super elements 2 dimensional No 7 8 11 12 and 20 SE Element number Super element type Type of the finite elements to be produced by meshing Subdivision in local x direction Type of subdivision in local x direction Subdivision in local y direction Type of subdivision in local y direction Write into one line separate each item by at least one blank Example Subdivide an is
127. lution is found 6 value Automatic solver switching AUTOGAUSS If the Flag 1s activated 1 an automatic switching of the solver occurs with very small structures if it is deactivated 0 no switching occurs 7 value Output control OUTPUTFLAG Controls the output of the results Output only at the end of the solution process for the whole load 0 output after every load step 1 or output after every iteration step of every load step 2 8 value Stress calculation OUT_CAUCHY Stress calculation is carried out 1 or is not carried out 0 9 value Memory management for integration point sizes with 9 values OUT_INT9OFFS activates the supply of a special memory field which is necessary for example for the stress calculation with activated stress calculation this flag must be also activated active 1 or inactive 0 10 value Memory management PARSP If the flag is activated 1 additional memory is allocated for the backup of the sparse pointers IP and IEZ to speed up the calculation process if it is deactivated 0 an iterative new calculation occurs 11 value Arc length BGLAENG defines the arc length fixes for the method of Riks 115 LIB on Theorie Manual 4 7 THE MAPPED MESHERS The mesh generator Z88N from Z88 is integrated into Z88Aurora with enhanced functionali ties e Z88N for hexahedrons axisymmetric elements plane stress elements plates and vol ume shells e The Tetrahedron
128. lver parameters Output files in computing mode e Z88O00 TXT prepared structure data for documentation e Z880O1 TXT prepared boundary conditions for documentation e Z8802 TXT displacements e Z8803 TXT stresses e Z8804 TXT nodal forces 4 3 1 WHICH SOLVER TO TAKE Roughly spoken Use the simple and reliable Cholesky solver Z88R choly for small truss and beam structures The sparse matrix iteration solver Z88R siccg or sorcg always works even for very large structures under 32 bit operating systems For medium sized structures the direct sparse matrix solver with fill in Z88R parao is very suitable because of its tremendous speed Table 6 Overview of the integrated solvers and their efficiency Solver Type Number of DOF Memory Speed Multi Notes needs CPU only for trusses ZSSR uc Cholesky Solver up to 30 00 and beams in Z88Aurora V2 a very stable and reliable solver for very large structures useful with Z88R t c direct Solver with up to 150 000 i several CPUs parao Fill In with 32 Bit PCs very high very high yes and very much memory ZSSR t c conjugated no limits tested sicee or gradients solver with more than 12 an absolute adinm Bis with pre Mio DOF ona minimum 8 conditioning normal PC 4 3 2 SOME NOTES ON STRESS CALCULATION The results are presented in the file Z8803 TXT The stress calculation is controlled via the file Z88MAN TXT see chapter 3 It defines among other th
129. ment for view 0 1 to 2 0 display RESOLUTION Size of Aurora input window Possible sizes see option menu Backface Culling Culling of not CULLING viewed surfaces to achieve a faster display SPIDER_START Work flow support SPIDER ao po 7 with support CPU_NUM Number of computing kernels used Ito in the calculation 8 no culling 7 with culling INTORD TYP 1 24 Integration order in compilation se number of Gaussian INTOS_ TYP 1 24 Integration order for stress display ier number of Gaussian Shows toolbar values relate to re 0 hidden spective icon see user manual 1 shown Shows additional toolbar values O hidden TOOLBAR 2 relate to respective icon see user 1 shown manual Shows additional toolbar values TOOLBAR 3 relate to respective icon see user manual TOOLBAR 4 Shows additional toolbar values 0 hidden relate to respective icon see user 1 shown manual TOOLBAR 1 0 hidden 1 shown INTOS_ TYP_1 24 defines the number of Gaussian points which are used for the stress cal culation 0 Calculation of stress in the corner nodes comparison stress calculation is not possible For isoparametric elements Nr 1 7 8 10 11 12 19 20 21 and 23 1 2 30r4 re NxN Calculation of stress in the Gaussian points comparison stress calculation is possible A good value is 3 3x3 gaussian points For type and type 20 2 2x2 gaussian points may suffice for type 19 4 4x4 gauss
130. menu File gt Import gt DXF files In the selection menu you can choose which of the following files are supposed to be created e a file of general structure data ZSSI1 TXT or e a complete Z88 data record with ZSSI1 TXT ZS812 TXT ZSS8I3 TXT and ZS8I5 TXT if applicable e aZssll TXT from a super structure which you can mesh manually in Aurora e a Z8sI1 TXT from a super structure which is meshed with the information deposited in the DXF file for this purpose the mapped mesher Z88N is launched directly after wards The same functionalities are available when you access the Z88 import via the toolbar Then define material data element parameters and integration orders in Z88Aurora V2 Z88X IN DETAIL Proceed in the following steps and reserve the following layers Z88GEN Layer for general information 1st input group in the mesh generator input file Z88NI TXT and general structure data file Z88STRUCTURE TXT Z88KNR Layer including the node numbers Z88EIO Layer including the element information like element type and in the case of mesh generator input file Z88NI TXT control information for the mesh generator Z88NET Layer containing the mesh which was drawn or outlined in defined order A further layer Z88PKT is produced by Z88X if you convert from Z88 to CAD It shows all nodes with a point marker in order to better recognize the nodes For the reverse step from CAD to Z88 it is completely insignificant Ist step Design your
131. n local x direction for overview reasons nodes 9 20 from typ 10 are f not shown local z direction Figure 5 Definition of local x y and z direction using the example of different element types 37 LOG brscoxa Theorie Manual 3 2 6 SOLVER CONTROL FILE ZS8SCONTROL TXT The solver control file Z88CONTROL TXT is divided into three parts the GLOBAL the solver parts and the STRESS part The next figure shows a typical Z88CONTROL TXT DYNAMIC START a a ee Ea ea A eT TN RN et TE SO eT eT ee TR eT EME OO ee eT TE ee OE RO eR ar ate Tg ee aE GLOBAL i E E E E GLOBAL START SIMCASE TI ICORE 4 GLOBAL END apes EA EE E E E EE E E E ee ke E EE LINEAR SOLVER E E E EE E E E S a a ee Sid hi A E E E EE LMSOLVER START ICFLAG 4 MAXIT 10000 EPS 1 00E 006 ALPHA 1 00E 004 OMEGA 120 LMSOLVER END e E EE ee E E E E E E E E E A E a ie Sa NONLINEAR SOLVER E EE E E E E a ee E E ee ee a ee ee NLSOLVER START ICFLAG 4 MAXIT 20000 EPS 1 00E 008 ALPHA 1 00E 004 OMEGA 1 20E 000 NLFLAG 1 NLAERH 25 MAXNLIT 1000 EXIT 1 TOL 1 00E 007 AUTOGAUSS 0 OUTPUTFLAG 1 OUT CAUCHY l OUT _INT90FFS 1 PARSP 0 BGLAENG 1 00E 000 NLSOLVER END Wie a Se a E E e E a a e E E E a E E a E a E VIBRATION SOLVER ESSOLVER START ICFLAG 5 MAXIT 20000 EPS 1 00E 008 EIGDIFF 1 00E 006 EIGNUM 15 EIGSTEP 50 ESSOLVER END Ea a ea mae EE a AE ea a a a a E EE E a E E a ee EE E THERMAL SOLVER TMSOLVER START ICFLAG 4 MAXIT 10000 EPS 1
132. n of a FE structure with 8 FE Plane Stress Ele ments no 7 from a super structure with 2 Plane Stress Elements No 7 looks the same with axisymmetric elements no 8 Specials The mesh generator checks which nodes are already known at the production of new FE nodes For this check it needs a trap radius a computer cannot meet a floating point number exactly This trap radius is provided for all 3 axes per default 0 01 Modify the trap radiuses when processing very small or very large numerical values 117 LIB on Theorie Manual ERS OSA a Oe LEMON Me a ie aa a wee PS ES S E 1 O e amp Ene TA Koinzidenz 1 Superelement 1 2 3 4 5 6 7 8 Koinzidenz 2 Superelement 4 3 9 10 7 11 12 13 Figure 45 Transformation of super elements into finite elements Attention mesh generator Z88N The generator can generate input files easily which blast all limits of the FE solver Generate therefore at first rougher FE structures check the results then refine if necessary A good starting point Produce approx 5 10 times more finite ele ments than super elements Note mesh generator Z88N If the coordinate flag KFLAGSS is set in the mesh generator input files Z88NI TXT 1 e input values are polar or cylindrical coordinates then the mesh generator output files Z88I1 TXT normally have Cartesian coordinates and KFLAG is set to 0 If you set the coordinate flag output KFLAG to 1 however then the coordinates are polar or cylindrical in the output
133. n the Gauss points INTOS not 0 Results Displacements in X and Y Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations For KDFLAG 1 the radial stresses SIGRR the tangential stresses SIGTT and the accompanying shear stresses SIGRT are computed additionally makes only sense if a rotational symmetric structure is available For easier orientation the respective radiuses and angles of the nodes points are printed Optional von Mises or principal or Tresca stresses Nodal forces in X and Y for each element and each node 132 66 Aurora 86 Theory Manual 58 TORUS NO 8 WITH 8 NODES D This is a curvilinear Serendipity torus element with quadratic shape functions The transformation is isoparamet ric The integration is carried out numerically in both axes according to Gauss Legendre Thus the integration order can be selected in Z88ENVIRO DYN The order 3 is mostly sufficient This element calculates both dis placements and stresses very exactly The integration order can be chosen again for the stress calculation The stresses are calculated in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly You may combine this element with elements no 15 Torus elements No 8 can be generated by the mesh generator Z88N from the super elements torus elements No 8 or No 12 Thus Torus No 8 is well suited as super element Input
134. n to create pure ASCII texts which means without concealed control characters Every word processor program includes such an option The solver input files are 3 1 COMPARISON OF Z6 amp 8 FILE FORMATS The file formats of Z88 versions Z88Aurora V2 Z88V14 0 and Z88Aurora V1 are very simi lar but especially in Z88Aurora V2 the input is distributed to more and different input files compared to older versions so that the GUI can be used more efficiently and expansion can be taken into account The same file structure is used in Z88 V14 OS Adequate converters for older formats are available Table 3 data formats of the four ZS8 versions ZSSAurora V2 Z88V14 OS Z88V13 0A and ZS8Aurora V1 a Z88V14 OS Z88Aurora V2 Z88Aurora VI Z88 V13 0A Z8811 TXT Z88STRUCTURE TXT Z8811 TXT Z8811 TXT Material definitions ZSSMAT TXT ZSSSETSACTIVE TXT ZSSMAT TXT ZSS11 TXT TXT TXT TXT Z88ELP TXT Z88SETSACTIVE TXT Z88ELP TXT Z88I1 TXT Integration orders for dis ZSSINT TXT ZSSENVIRO DYN ZSSMAT TXT ZSSI1 TXT placement calc Integration orders for stress ZSSINT TXT ZSSENVIRO DYN ZSSMANAGE TXT Z8813 TXT calc Z88MAN TXT Z88CONTROL TXT Z88I4 TXT Z8812 TXT ZS8SETSACTIVE TXT Z8812 TXT Z8815 TXT Z88SETSACTIVE TXT Z8815 TXT ZS88MAT TXT Z88SETSACTIVE TXT Z88I1 TXT Z88I1 TXT Z88STRUCTURE TXT Z88I1 TXT Z88MAN TXT Not applicable Z88I1 TXT Z88MAN TXT Not applicable Z88I1 TXT Surface load Flag IQFLAG Not applicable Not applicable Z88MANAGE TXT Z8811 TXT
135. ne stress elements shells axisymmetric elements and plates therefore it is up to you to feed Z88G the right in formation The reason for this is that Pro ENGINEER only recognises the FE type shell or volume Here too you must enter the appropriate data 1 e what you have already designed in Pro ENGINEER Before running the conversion choose the right type of elements The generation of volumes is easy but the generation of plane stress elements plates and to rus elements axisymmetric elements is tricky First build a volume with small thickness in Pro E Set reference points especially for axis symmetric elements Launch Pro MECHANICA and idealize the volume into shells Model gt Idealizations gt Shells gt Midsurfaces This eliminates the depth When working with axisymmetric elements keep in mind that you are working in cylinder coordinates Your coordinate system coincidates with the axis of rotation and the volume lies on the corresponding radiuses see figure Please keep in mind These FEA output data formats especially the NASTRAN format are modified almost on a daily basis Thus consult our homepage www z88 org for updates Anyway Z88G looks quite harmless but properly operated is Z88G a mighty tool which al lows you to file very large FEA structures to Z88 Datei Editieren Ansicht Einf gen Analyse Info Applikationen Tools Fenster Hilfe 4 ce 5 O4r ame 0 fe E 8 Q a i gE E Erfol
136. nge is done automatically if there are extremely small structures if it is deactivated 0 there is no change OUTPUTFLAG controls the solution output output only for the total load at the end of the algorithm Q output after each partial load 1 or output after every iteration 2 OUT CAUCHY controls the stress calculation 1 stress is calculated or 0 no stress calcu lation 4 LIB on Theorie Manual OUT_INT9OFFS activates the provision of a special storage field that is required e g for stress calculation if stress calculation is active this flag must be active too l active Q inactive PARSP organizes the storage management if the falg is active 1 additional storage is pro vided to save the sparse pinter IP and IEZ to accelerate the calculation if it is inactive 0 an iterative recalculation is carried out BGLAENG determines the arc length for the method by Riks STRESS KDFLAG Long 0 standard stress calculation 1 additional calculation of the radial and tangential stresses for the element no 3 7 11 14 ISFLAG Choice of the reduced stress hypothesis Long 0 no calculation of the reduced stresses 1 von Mises stresses 2 principal or Rankine stresses 3 Tresca stresses Example 1 A structure featuring plane stress elements no 7 may calculate in addition radial and tangential stresses thus KDFLAG I The reduced stresses calculation may use the v Mises criterion ISFLAG I Thus
137. ning the solver If the memory is exhausted during the calculation the solver will inevitably quit with an error message This solver works at very high speed for medium struc tures 100 000 1 000 000 DOF because it is multi processor compliant but needs more memory than the iteration solver by several orders of magnitude Therefore this solver is only really useful on machines with very much memory and 64 bit pointers and integers We rec ommend the 64 bit version of Z88Aurora a 64 bit Windows operating system and a minimum of 4 GByte 8 or 16 GByte are even better of memory for this solver When using a 32 bit Operating system and 4 GByte of memory you are limited to structures with 150 000 DOF The actual solver core used is PARDISO by O Schenk University of Basel Switzerland Define the number of CPUs in Z88MAN TXT The values preceding have no significance they must be there however Please take care that in the Windows settings System Properties gt Advanced gt Environment Variable you do not have this kind of variable NUM_THREADS OMP_SET_NUM_THREADS This might clash with the settings in Z88CONTROL TXT 103 Yoho Theorie Manual Input files for both modes e Z88il TXT general structure data o Z8812 TXT boundary conditions o Z88I5 TXT surface and pressure loads e Z88MAT TXT material defini and one or more material files in TXT format e Z88ELP TXT element parameters e Z88INT TXT integration orders e Z88MAN TXT so
138. node numbering Tetrahedron No 16 cannot be generated by the mapped mesh generator Z88N Caution The automeshers of CAD systems very often produce very bad nodal numbering resulting in an useless large amount of memory needs of Z88R s Cholesky solver Thus you may renumber especially the nodes or use one of the sparse matrix solvers 1 e SICCG SORCG Pardiso Input Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt 3 degrees of freedom for each node gt Element type is 16 gt 10 nodes per element Z88ELP TXT gt Cross section parameter QPARA is 0 or any other value has no influence Z88INT TXT 143 Yih Theorie Manual gt Integration order INTORD for displacement calculation 4 is usually good Allowed are 1 for 1 Gauss point 4 for 4 Gauss points and 5 for 5 Gauss points gt Integration order INTOS for stress calculation 0 Calculation of stresses in the corner nodes 1 4 5 Calculation of stresses in the Gauss points Z88MAT TXT gt Define materials ref chapter 3 1 4 and 3 1 5 ZT88MAN TXT gt Radial Tangential stress flag KDFLAG has no meaning gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the Gauss points INTOS not 0 2 principal or Rankine stresses in the Gauss points INTOS not 0 3 Tresca stresses in the Gauss points INTOS not 0 Z8815 TXT This file is only used see 3 1 3 if in addition to nodal forces press
139. nts konstruktionslehre EG isscoxa Theorie Manual License Software Products Z88 Aurora Software as delivered Software Licensor Chair for Engineering Design and CAD LCAD This is a legal agreement between you the end user and Chair for Engineering Design and CAD Universitaetsstr 30 95447 Bayreuth Germany By installing by downloading or by agreeing to the integrated conditions of this End User License Agreement you are agreeing to be bound by the terms of this agreement If you do not agree to the terms of this agreement promptly return the Software and the accompanying items including written materials and binders or other containers to the place you obtained them for a full refund 1 Grant of license This LCAD license agreement license permits you to use a copy of the Software acquired with this license on any computer in multiple number of installations The Software is in use on a computer when it is loaded into the temporary memory or installed into the permanent memory e g hard disk CD ROM or other storage device of that computer PA Copyright The Software is owned by LCAD and is protected by copyright laws international treaty provisions and other national laws Therefore you must treat the Software like any other copyrighted material e g a book There is no right to use trademarks pictures documentation e g without naming LCAD 3 Other restrictions You may not rent or lease the S
140. numbers and the element numbers of the FE structure Definition e Local x axis points in direction of local nodes 1 and 2 e Local y axis points in direction of local nodes 1 and 4 e Local z axis points in direction of local nodes and 5 Super structures in space are subdivided first in z then in y and finally in x direction 1 e the FE element numbers start along the z direction To plane and axially symmetric structures applies analogously The numbering starts along the y axis or for axially symmetric elements along the z axis cylinder coordinates Along the local axes a subdivision can be conducted as follows e equidistant e increasing geometrically from node 1 to 4 or 5 mesh becomes rougher e decreasing geometrically from node 1 to 4 or 5 mesh becomes finer It is obvious that for lines or areas which are shared by two super elements the super ele ments must be subdivided exactly the same The mesh generator does not check this and then generates useless or totally meaningless FE meshes Example wrong local y right local y equal division different Figure 44 Subdivision of the super elements Since the local axes x y and z are defined by the location of the local nodes 1 4 and 5 it is possible to generate almost arbitrary numberings for nodes and elements of the FE structure by corresponding construction of the coincidence list in the mesh generator input file Z88NI TXT See figure 44 for an example for the generatio
141. o 20 Export this mesh as a DXF file and use Z88X to produce a mesh genera tor input file Z88NI TXT Run the mapped mesher Z88N and generate a finite elements mesh with plates No 19 Then you may supply the boundary conditions 149 8B on Theorie Manual 5 Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt set plate flag IPFLAG to I or 2 if you want to reduce the shear influence gt 3 degrees of freedom for each node w O 0 gt Element type is 19 gt 16 nodes per element Z88ELP TXT gt Cross section parameter QPARA is the element thickness Z88INT TXT gt Integration order INTORD for displacement calculation 4 is usually good gt Integration order INTOS for stress calculation 0 Calculation of stresses in the corner nodes 1 2 3 4 Calculation of stresses in the Gauss points Z88MAT TXT gt Define materials ref chapter 3 1 4 and 3 1 5 Z88MAN TXT gt set plate flag IPFLAG to I gt Radial Tangential stress flag KDFLAG has no meaning gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the Gauss points INTOS not 0 2 principal or Rankine stresses in the Gauss points INTOS not 0 3 Tresca stresses in the Gauss points INTOS not 0 Z8815 TXT This file is only used see 3 1 3 if in addition to nodal forces pressure loads are applied onto element no 19 otherwise enter a O into the first line gt Element number with
142. of stresses in the corner nodes quite good Computing effort medium Size of element stiffness matrix 24 x 24 y 4 12 66 Aurora 56 Theory Manual AXISYMMETRIC PROBLEMS Torus No 6 D Linear function Quality of displacements average Quality of stresses in the corner nodes inaccurate Computing effort Low Size of element stiffness matrix 6 x 6 Z Y 2 R X Torus No 8 D Quadratic Isoparametric Serendipity element Quality of displacements very good Quality of stresses in the Gauss points very good Quality of stresses in the corner nodes good Computing effort High Size of element stiffness matrix 16 x 16 Torus No 12 Uz Cubic Isoparametric Serendipity element Quality of displacements excellent Quality of stresses in the Gauss points excellent Quality of stresses in the corner nodes good Computing effort Very high Size of element stiffness matrix 24 x 24 13 IB oe Theorie Manual Torus No 15 Dz Quadratic Isoparametric Serendipity element Quality of displacements very good Quality of stresses in the Gauss points very good Quality of stresses in the corner nodes good Computing effort High Size of element stiffness matrix 12 x 12 Cam No 5 ail Linear function for torsion and tensile stress cubic function for bending stress Quality of displacements exact Hooke s law Quality of stresses exact Hooke s law Computing
143. oftware but you may transfer your rights under this LCAD license agreement on a permanent basis provided you transfer all copies of the Software and all written materials and the recipient agrees to the terms of this agreement You may not reverse engineer decompile or disassemble the Software Any transfer must include the most recent update and all prior versions The Software is for calculation Finite Element Structures there is no warranty for accuracy of the given results 4 Warranties LCAD gives no warrants the Software will perform substantially in accordance with the accompanying documentation Any implied warranties on the Software are not given 5 No liability for consequential damages In no event shall LCAD be liable for any other damages whatsoever including without limitation damages for loss of busi ness profits business interruption loss of business information or other pecuniary loss personal damage arising out of the use of or inability to use this Software product even 1f LCAD has been advised of the possibility of such damages 7 Governing Law This Agreement shall be governed exclusively by and be construed in accordance with the laws of Germany without giving effect to conflict of laws 66 Aurora 56 Theory Manual TABLE OF CONTENTS WELCOMES TO Z88AURORA cosseccccssecccssseccessiseceseicestsiscesiiiesttiessitieestticestittsesititeessteeces 3 1 THE FINITE ELEMENTS PROGRAM Z88AURORA a 8 1 1 GENERA
144. ogram is only as good as the applied graphic kernel Thus if the CAD display contains mistakes these mistakes are export ed along with the data and might impede the processing These mistakes are partially caused by the kernel itself partially by the export of cluttered models e In the CAD system apply a modelling tolerance as high as possible geomet rical tolerance e g lt 0 01 if you have the possibility to repeatedly specify a tolerance during export select a higher one than the modelling tolerance e g 0 01 e Make sure that you use AP203 or AP214 during export e Should problems arise during the import consider simplifying your model be fore exporting it Often small fillets or chamfers are the cause for very small edges and surfaces which impede the processing If they are not mandatory for the FE simulation they can be eliminated and therefore not exported Which CAD systems can cooperate with the Step converter Any CAD systems which can export 1 e write STEP files However we cannot guarantee any success Which elements are supported by the converter Z88Aurora first generates an STL file from the imported STEP files for visualization This can be transferred into structures from elements No 16 or No 17 linear or quadratic Tetra hedrons by means of the existing meshers Which functions does the converter offer ZS8Geocon gt Conversion gt from step or stp to visualised super structure ZSSI1 txt Ho
145. on status is determined Characteristics of the mesh of the mesher number of elements size of elements size of load material name or beam properties cross section moment of inertia etc are saved in this file 1 value number of lines 1 input group identifier NODES ELEMENTS MESH 2 keyword e g CONSTRAINTS MATERIAL FREE_MESH MAPPED_MESH ELEMENTGEO 3 value 1 SET active or 2 SET inactive 4 consecutive number 5 x value Property depending on application x 1 name of set Example 4 MESH FREE MESH 1 1 1 14 17 1 000000E 001 mesh rulel ELEMENTS MATERIAL 1 2 3 1 steel NODES CONSTRAINT 1 3 1 11 123 1 0 000000E 000 fixed NODES CONSTRAINT 1 4 2 11 123456 2 5 000000E 000 pressure 3 2 4 MATERIAL DATA TXT Aurora features a material database with 50 standard materials These materials cannot be edited but you may create and edit copies or create a new material For more information refer to the user manual Example AURORA_V2_ MATERIAL COMMON START ID 1 NAME 1 Maschinenbau Stahl NAME 2 Engineering steel DESCRIPTION R295 NUMBER 1 0050 ANNOTATION N mm t COMMON END LINEAR START YOUNG MODULUS 210000 00 POTSSON RATIO eo DENSITY 1 80n 009 LINEAR END THERMAL START THERMAL CONDUCTIVITY 0 054 THERMAL EXPANSION 1 11E 005 THERMAL END 33 LIB on Theorie Manual 3 2 5 MESH GENERATOR INPUT FILE ZS8NI TXT The layout of Z88NI TXT is very simi
146. onditions The user can enter the temperature either in Kelvin K or in Celsius C This makes no difference for the calculation results The heat flux density is a surface related load 1 e she defines the heat flux per surface unit W mm The heat flux unit W as a nodal load can be applied either uniformly distributed or distributed Uniformly distributed means here that the same entered value is assigned to every node Distributed applies the loads according to FE rules If one wants to carry out a thermo mechanical simulation one must define only new sets with additional mechanical boundary conditions e g of a constraint Then the Solver automatically recognises that the user would like to carry out such a simulation As a calcula tion core can be selected between three equations solvers PARDISO directly and multi core running SICCG and SORCG iterative figure 40 The Cholesky Solver cannot be chosen here 110 ony Choose solver Failure theory Theory Manual ran PARDISO No equivalent stress GEH von Mises Rankine Tresca Solver parameter sIccG F Solver parameters SICCG Number of iterations too0c Residuum 1 000000E 006 Alpha 1 000000E 004 Help ox X Cancel sorce T Solver parameters SORCG Number of iterations L000 Residuum 1 000000E 006 Omega 1 200000E 000 Help 2 OK X Cancel Figure 40 Choose the
147. oordinates while on input of 1 polar or cylindrical coordinates are expected The latter are then converted into Cartesian coordinates and thereupon stored in this form in Z8800 TXT Caution The axisymmetric elements No 6 8 12 and 15 positively expect cylindrical coordinates set KFLAG to 0 here 2 input group Starting with line 2 containing coordinates of nodes one line per node node numbers strictly ascending 1 number node number Long 2 number Number of the degrees of freedom for this node Long 3 number X coordinate or if KFLAG is 1 R coordinate Double 4 number Y coordinate or if KFLAG is 1 PHI coordinate Double 5 number Z coordinate or if KFLAG is 1 Z coordinate Double The Z coordinate can be dropped at 2 dimensional structures Enter angles PHI in radian Example 1 The node no 156 has 2 degrees of freedom and the coordinates X 45 3 and Y 89 7 gt Thus 156 2 45 3 89 7 Example 2 The node no 68 is supposed to have 6 degrees of freedom a Beam No 2 is at tached and cylindrical coordinates R 100 PHI 0 7854 corresponds to 45 Z 56 87 gt Thus 68 6 100 0 7854 56 87 3 input group Starting after last node containing coincidence 1 e the allocation of the element type and the corresponding nodes of every element Enter two lines for every finite element The element numbers like the node numbers must be entered strictly ascending 1 line Ist number Element numbe
148. oparametric Serendipity Plane Stress Element with 12 nodes Ele ment type 11 used as super element into finite elements of type 7 1 e isoparametric Seren dipity Plane Stress Elements with 8 nodes Element type 7 Subdivide in local x direction three times equidistantly and subdivide in local y direction 5 times ascending geometrically The super element is supposed to have the number 31 Write e g into the middle of the ele ment with the TEXT function SE 31 11 7 3 E 5 L eor E for equidistant is equivalent For super elements 3 dimensional Hexahedrons No 10 and Shells No 21 SE Element number Super element type Type of the finite elements to be produced by meshing Subdivision in local x direction Type of subdivision in local x direction Subdivision in local y direction 68 66 Aurora 56 Theory Manual Type of subdivision in local y direction Subdivision in local z direction Type of subdivision in local z direction Write into one line separate each item by at least one blank Example Subdivide an Isoparametric Serendipity Hexahedron with 20 nodes Element type 10 as super element into finite elements of the type Isoparametric Hexahedrons with 8 nodes Element type 1 Subdivide equidistantly three times in local x direction 5 times ascending geometrically in local y direction and subdivide equidistantly 4 times in local z direction The super element is supposed to have the number 19 Write e g into the middle of the elem
149. ora V2 was tested on WINDOWS 7 32 and 64 Bit WINDOWS Vista 32 and 64 bit and WINDOWS XP 32 Ubuntu 9 04 10 4 11 04 and openSuSE 12 1 LINUX and Mac OS X Snow Leopard amp Lion Yolh Theorie Manual 1 2 SUMMARY OF THE Z88 ELEMENT LIBRARY 2D PROBLEMS PLANE STRESS PLATES BEAMS TRUSSES Plane Stress Triangle Element No 3 EP Shape functions quadratic but linear Quality of displacements very good Quality of stresses in the centre of gravity good Computing effort average Size of element stiffness matrix 12 x 12 3 Plane Stress isoparametric Element No 7 EP Quadratic isoparametric Serendipity element Quality of displacements very good Quality of stresses in the Gauss points very well Quality of stresses in the corner nodes good Computing effort High Size of element stiffness matrix 16 x 16 a3 d 1 xX 2 Truss No 9 F Linear function Quality of displacements exact Hooke s law Quality of stresses exact Hooke s law Computing effort Minimal Size of element stiffness matrix 4 x 4 Y 2 10 66 Aurora 56 Theory Manual Plane Stress Isoparametric Element No 11 P Cubic isoparametric Serendipity element Quality of displacements excellent Quality of stresses in the Gauss points excellent Quality of stresses in the corner nodes good Computing effort Very high Size of element stiffness matrix 24 x 24 23 Beam No 13 T Linear function for tensile stres
150. ordinates R 100 PHI 0 7854 corresponds to 45 Z 56 87 gt Thus 68 6 100 0 7854 56 87 3 input group Starting after last node containing coincidence 1 e the allocation of the element type and the corresponding nodes of every element Enter two lines for every finite element The element numbers like the node numbers must be entered strictly ascending 1 line Ist number Element number Long 2nd number Element type 1 to 24 Long 2 line Depending on element type Ist number 1 node number for coincidence Long 2nd number 2 node number for coincidence Long 20 number 20 node number for coincidence Long Write all numbers into a line separate at least by one blank respectively All numbers here of type Long Example An Isoparametric Serendipity Plane Stress Element No 7 has element number 23 The coincidence has the global nodes 14 8 17 20 38 51 55 34 locally these are the nodes 1 2 3 4 5 6 7 8 gt Thus resulting in two lines 23 7 14 amp 17 20 38 51 55 34 30 66 Aurora 86 Theory Manual 3 2 2 GROUP DATA Z88MARKS TXT amp ZSSSETS TXT New in Z88Aurora V2 is the possibility to create node and element groups with Z88MARKS TXT and Z88SETS TXT and afterwards apply e g material properties or boundary conditions with the file SETSAKTIVE TXT Z88MARKS TXT contains nodes and elements which have been selected in the user interface as a group You can select surfaces edges l
151. ou For further information regarding the application and options of post processing please con sult the Z88Aurora User Manual 125 LIB on Theorie Manual 5 DESCRIPTION OF THE FINITE ELEMENTS 5 1 HEXAHEDRON NO 1 WITH 8 NODES The hexahedron element calculates deflections and stresses in space using linear shape functions It is a trans formed element therefore it may be wedge shaped or may have another oblique angled form The transfor mation is isoparametric The integration is carried out numerically in all three axes according to Gauss Legendre Thus the integration order can be selected in Z88ENVIRO DYN The order 2 is mostly sufficient Hexahedron No 1 is also well usable as a thick plate element if the plate s thickness is not too small against the other dimen sions Hexahedrons No 1 can be generated by the mesh generator Z88N from super elements Hexahedrons No 10 and Hexahedrons No 1 Input CAD see chapter 4 1 4 Upper plane 1 2 3 4 1 quit LINE function Lower plane 5 6 7 8 5 quit LINE function 1 5 quit LINE function 2 6 quit LINE function 3 7 quit LINE function 4 8 quit LINE function Z88STRUCTURE TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt 3 degrees of freedom for each node gt Element type is 1 gt amp nodes per element Z88ENVIRO DYN gt Integration order INTORD for displacement calculation 2 is usually good gt Integration order INTOS for
152. per elements Plane Stress Elements No 11 Thus the Plane Stress Element No 11 is well suited as super element However Plane Stress Elements No 11 cannot be generated by the mesh generator Z88N from super elements Plane Stress Elements No 11 Input CAD see chapter 4 1 4 5 6 2 7 8 3 9 10 4 11 12 1 Z88STRUCTURE TXT gt KFLAG for Cartesian 0 or polar coordinates 1 gt 2 degrees of freedom for each node gt Element type is 11 gt 12 nodes per element Element parameters f Section Ht Thickness enter here the thickness of the elements Z88ENVIRO DYN gt Integration order INTORD for displacement calculation 3 is usually good gt Integration order INTOS for stress calculation 0 Calculation of stresses in the corner nodes 1 2 3 4 Calculation of stresses in the Gauss points Z88CONTROL TXT gt Radial Tangential stress flag KDFLAG 0 Calculation of SIGXX SIGY Y and TAUXY gt Radial Tangential stress flag KDFLAG 1 Additional calculation of SIGRR SIGTT and TAURT gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the Gauss points INTOS not 0 2 principal or Rankine stresses in the Gauss points INTOS not 0 3 Tresca stresses in the Gauss points INTOS not 0 Results Displacements in X and Y Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations For KDFLAG 1 the radial stress
153. r Long 2nd number Element type 1 to 24 Long 2 line Depending on element type Ist number 1 node number for coincidence Long 2nd number 2 node number for coincidence Long 20 number 20 node number for coincidence Long 54 66 Aurora 86 Theory Manual Write all numbers into a line separate at least by one blank respectively All numbers here of the type Long Example An Isoparametric Serendipity Plane Stress Element No 7 has element number 23 The coincidence has the global nodes 14 8 17 20 38 51 55 34 locally these are the nodes 1 2 3 4 5 6 7 8 gt Thus resulting in two lines 23 7 14 8 17 20 38 51 55 34 BOUNDARY CONDITIONS FILE Z88I2 TXT In the file Z88I2 TXT the boundary conditions displacements and forces affecting the model are entered Surface loads are put into the file Z88I5 TXT Mind the following formats Long 4 bytes or 8 bytes integer number Double 8 bytes floating point number alternatively with or without point 1 input group Number of boundary conditions loads Ist number Number of boundary conditions loads Long nd 2 input group The boundary conditions and loads are defined For every boundary condition and for every load one line respectively Ist number node number with boundary condition load or constraint Long 2nd number Respective degree of freedom 1 2 3 4 5 6 Long 3rd number Condition flag 1 force Long or 2 displacement Lon
154. r can be imported without thermal boundary conditions In the material data base must be added for the thermo analysis the thermal conductivity and for the thermo mechanical simulation in further addition the thermal expansion Figure 38 shows exemplarily a material just available in the material data base with which these are already predefined Q Edit General Name Engineering steel Description E295 Number 1 0050 Annotation N mm t Material properties Linear Thermal Heat conductivity 5 400000E 002 Heat expansion 1 110000E 005 X Cancel Figure 38 material definitions for thermo mechanical calculations In the real boundary condition menu there is an addition figure 39 for the thermal boundary conditions as temperature heat flux and heat flux density which 4 are marked After defin ing the appropriate sets the boundary conditions may be assigned and information of the di rection is not necessary because the thermal boundary conditions feature only one degree of freedom in the space 109 Yoho Theorie Manual View iz 7 Settings thermo_Setl thermo_Set2 Set3 v Directions Rotations C X direction C X Axis C Y direction C Y Axis C Z direction C Z Axis Type Displacements C Pressure Force uniformly distributed Surface load Projected surface load Line load Projected line load Value e Figure 39 thermal boundary c
155. rd For Windows you may load Perl from www perl org You may install either Strawberry Perl or ActiveState Perl This is a one click installation without any problems and does no harm to your system Then launch the file checker in a Windows command prompt or an UNIX terminal as follows perl z88vry pl english aurora This will check the Z88 files Z88I1 TXT Z88I2 TXT and Z88I5 TXT Although Z88VRY recognizes many conceivable faulty possibilities and is internally quite tricky situations like with compilers may occur where faults are not detected or seem to be recognized on other passages Z88VRY stops when detecting the first error because otherwise resulting sequence errors are usually generated from this Therefore a recognized error must be fixed right now An error free input file recognized from Z88VRY can nevertheless lead to subtle faults at the later program run However the probability is low to some extent This statement refers to formal errors Z88VRY neither recognizes inconsistent structures nor wrong or too few boundary conditions EE Kingabentfordern e c puffer gt perl z88vry pl english aurora ata ate ata w by Prof FRANK RIEG C Germany 2012 V15 Z88VRY PL a Perl written Z88 file checker Start Z88VRY PL Aurora mode 1 gt Check of input data no boundary conditions 2 gt Check of input data boundary conditions included 3 gt Check of mapped mesher file z88ni txt 9 gt Quit Z88VRY
156. rder INTORD for displacement calculation 3 7 and 13 are possible 7 is usually good gt Integration order INTOS for stress calculation 0 Calculation of the stresses in the corner nodes 3 7 13 Calculation of the stresses in the Gauss points 161 Yoho Theorie Manual Z88MAT TXT gt Define materials ref chapter 3 1 4 and 3 1 5 Z88MAN TXT gt Set shell flag IHFLAG to I or to 2 or 3 in case of thin shells and to 4 in case of very thin shells gt Radial Tangential stress flag KDFLAG has no influence gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the Gauss points INTOS not 0 2 principal or Rankine stresses in the Gauss points INTOS not 0 3 Tresca stresses in the Gauss points INTOS not 0 Z8815 TXT This file is only used see 3 1 3 if in addition to nodal forces surface and pressure loads are applied onto element no 24 otherwise enter a O into the first line gt Element number gt Pressure positive if pointing towards the surface gt 3 corner nodes and 3 mid nodes of the loaded surface Mathematically positive in top view iy Results Displacements in X Y and Z and global Rotations around X and Y axis 0x u Oy Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations The stresses SIGXX SIGYY and TAUXY as well as optionally von Mises or principal or Tresca stresses are outpu
157. refiner for tetrahedrons e The Shell thickener for flat shells amp Super elements Access of the meshers in the pre processor menu via the icon B super cements S Menu Preprocessor y y Ara montc g i j 4 ay fy Iy j Meshing Z88N mesh gt Tetrahedrons amp super elements generator Set Administration F Picking Element parameters E Sectior Thickness Material UIE Database Constraints Define Figure 43 Menu pre processor with start icon Super Elements of the mesh generator ZSSN 4 7 1 ZS8N FOR 2D AND 3D ELEMENTS A mesh generation is only usefull and permitted for continuum elements An overview of the possible finite element structures can be found in Table 7 Table 7 Possible super structures in ZSSAurora 116 66 Aurora 86 Theory Manual Mixed structures e g containing Plane Stress Elements No 7 and Trusses No 9 cannot be processed Mode of operation of the mesh generator For generating FE meshes proceed as follows The continuum is described by so called super elements short SE which practically corresponds to a quite rough FE structure The super structure is then subdivided This is done super element wise starting with SE 1 SE 2 up to the last SE SE 1 produces the finite elements short FE 1 to J SE 2 the FE j 1 to k SE 3 the FE k 1 to m and so on Within the SE the direction of the local coordinates de termines the nodal
158. rom existing files can be edited and altered directly on the 788 Aurora user interface The following table offers an overview of the input and output files Table 2 Input and output of ZSSAurora Name Purpose C ar p r ig DN Z88 DYN Z88 FCD ZS88EN VIRO DYN ZS8MAN TXT TXT TXT ZS8MARKS TXT ZS8SETS TXT ZS8SETSACTIVE TXT Z88STRUCTURE TXT Output files Z8800 TXT Z88O1 TXT Z88O02 TXT Z8803 TXT Z8804 TXT Z8805 TXT Z8808 TXT Z88TOO TXT Z88TO1 TXT Z88TO2 TXT Z88TO3 TXT Z88TO4 TXT Z88TOO TXT Z88TOO TXT Z88NLO2 TXT Z88NLO3 TXT ZS8NLOH TXT Z88AURORA LOG ZS88TRAIL TXT mport files G COS NAS INP ASY DXF STP T SIL ZS8NI TXT memory and language header file fonts colors dimensions header file setting variables Aurora header file Aurora material data for data base in Aurora user interface node and element marks node and element sets for applying boundary conditions and materials currently used sets of project structure data similar to Z88I1 TXT in Z88 V14 rocessed structure data rocessed constraints computed displacements computed stresses computed nodal forces or internal use in Z88Aurora o m or internal use in Z88Aurora computed temperature computed heat flow computed thermal expansions computed thermal forces computed displacements computed forces thermo mechanical computed stresses thermo mechanical computed displacements nonlinear calculation
159. s cubic function for bending stress Quality of displacements exact Hooke s law Quality of stresses exact Hooke s law Computing effort Low Size of element stiffness matrix 8 x 8 Y U Y algebraic X U4 1 2 X Plane Stress Isoparametric Element No 14 EP Quadratic Isoparametric Serendipity element Quality of displacements very good Quality of stresses in the Gauss points very good Quality of stresses in the corner nodes good Computing effort medium Size of element stiffness matrix 12 x 12 Y 11 LIB on Theorie Manual Isoparametric Plate Element No 18 Hy Quadratic Isoparametric Serendipity element following Reissner Mindlin s theory Quality of displacements very good Quality of stresses in the Gauss points good Quality of stresses in the corner nodes acceptable Computing effort medium Size of element stiffness matrix 18 x 18 Isoparametric Plate Element No 19 Hy Cubic Isoparametric Lagrange element following Reissner Mindlin s theory Quality of displacements very good Quality of stresses in the Gauss points very good Quality of stresses in the corner nodes good Computing effort High Size of element stiffness matrix 48 x 48 16 Isoparametric Plate Element No 20 Hy Quadratic Isoparametric Serendipity element following Reissner Muindlin s theory Quality of displacements very good Quality of stresses in the Gauss points good Quality
160. s carried out numerically in all axes according to Gauss Legendre All nodes have to be on a common surface which may be placed arbitrarily in a space which is very useful for the data exchange with 3D CAD systems The integration order can be selected in Z88INT TXT The order 7 i e 7 Gauss Points is mostly sufficient This element calculates both displacements and stresses quite good The integration order can be chosen again for the stress calculation The stresses are calculated in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly For this element the shell flag IHFLAG should be set to 1 in Z88MAN TXT In case of thin shells set IHFLAG to 2 or 3 In case of very thin shells set it to 4 The first three degrees of freedom are the global displacements in X Y and Z The degrees of freedom 4 and 5 are the global torsions on the respective node thus quite useless degree of freedom 6 is a pseudo DOF without practical significance Only the global displacements in X Y and Z are practically useful and of interest for mechanical engineers Input CAD 4 2 5 3 6 1 see chapter 4 1 7 Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt 6 degrees of freedom for each node but only DOF 1 3 are of interest gt Element type is 24 gt 6 nodes per element Z88ELP TXT gt Cross section parameter QPARA is the element thickness Z88INT TXT gt Integration o
161. s os o OY y hexahedron No 10 quadra x o o s J OM CYT a tetrahedron A tetrahedron No 16 quadratic V J 7 YT CT tetrahedron No 17 finer VO YM YT a l k plane stress me plane stress No 3 quadratic so fos oos oos f y o plane stress No 7 quadratic V YM oo s o y r o plane stress No 11 eubie s fos os J s y plane stress No 14 quadrani 7 f YT s o e r o torus Hi torus No 6 flinear Oos s s s J 7 torusNo 8 Jawara YT MT y r tousNo 12_feudic os ooe forusNo 15__ quadratic oY OY o o o j a 8 plate plateNo 18 quadratic f 7 YT TT plateNo 19 oui fo OT CT plate No 20 quadratic oY OY TC Shell w shell No 21 fauadraie s fo os os o s 7 quadratic o s fos o os o o e 7 quadratic o s OY OT e o e y 7 shell No 24 quadratic f s o 7 o o e o e f y truss and beam structures with special case cam ye trussNo 4 fea o oo o a trussNo 9 exact oo e o e f F beamNo 2 exact fo os oos oo o e f o beam No 13 feat oo oe oos ooe oe f camnos fa oo e oo o e o e f a SISISIS SISISIS ESTN S SISISISIS 25 LIB on Theorie Manual 3 THE INPUT AND OUTPUT OF Z88AURORA V2 Generally the input and output files in Z88Aurora unlike in Z88 V14 OS are created while operating the user interface Of course it is possible to load existing Z88 V14 files directly and to migrate Z88Aurora V1 input files by use of our external migration tools to Z88Aurora Ad ditionally all boundary conditions f
162. s section parameter QPARA is the element thickness Z88INT TXT gt Integration order INTORD for displacement calculation 7 is usually good Possible is 3 for 3 Gauss points 7 for 7 Gauss points and 13 for 13 Gauss points For easy combination with plane stress elements No 7 function ISOD8S8 of Z88 uses internally these values integration order I or 2 3 Gauss points integration order 4 7 Gauss points Example ZSSINT TXT uses an entry of 2 for INTORD Thus plane stress elements No 7 use 2x2 4 Gauss points and plane stress elements No 14 use 3 Gauss points for integration gt Integration order INTOS for stress calculation 0 Calculation of stresses in the corner nodes 1 7 13 Calculation of stresses in the Gauss points 139 8B on Theorie Manual Z88MAT TXT gt Define materials ref chapter 3 1 4 and 3 1 5 ZT88MAN TXT gt Radial Tangential stress flag KDFLAG 0 Calculation of SIGXX SIGYY and TAUXY gt Radial Tangential stress flag KDFLAG 1 Additional calculation of SIGRR SIGTT and TAURT gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the Gauss points INTOS not 0 2 principal or Rankine stresses in the Gauss points INTOS not 0 3 Tresca stresses in the Gauss points INTOS not 0 Z8815 TXT This file is only used see 3 1 3 if in addition to nodal forces edge loads are applied onto el ement no 14 otherwise enter a O into the first line
163. se any symmetric profile in contrast to other FEA programs which incorporate a variety of different special beam and profile subroutines without matching all symmetric profiles as necessary The element matches exactly Ber noulli s bend theory and Hooke s law It uses no approximate solution compared to the continuum elements Y algebraic sign Input CAD see chapter 4 1 4 Line from node I to node 2 Z88STRUCTURE TXT gt KFLAG for Cartesian 0 or polar coordinates 1 gt 3 degrees of freedom in a node gt Element type is 13 gt 2 nodes per element Element parameters aL Section m4 Thickness enter here the parameters for the elements gt Cross sectional area QPARA gt insert 0 for second moment of inertia I bending around y y axis gt insert 0 for max distance ey from neutral axis y y gt Second moment of inertia l bending around z z axis gt Max distance e from neutral axis z z gt insert 0 for second moment of area torsion Ir gt insert 0 for second modulus torsion Wr Z88ENVIRO DYN gt Integration order INTORD for displacement calculation any order has no influence gt Integration order INTOS for stress calculation any order has no influence Z88CONTROL TXT gt Radial Tangential stress flag KDFLAG has no meaning gt Reduced stress flag ISFLAG has no meaning Results Displacements in X and Y and rotations around Z Stresses SIGXX TAUXX Normal stress shear stress SIGZZ1 SI
164. seeeecee 33 3 2 4 MATERIAL DATA TXT cesecccsssscccsssscccsesecesssecestiecesitbecesitiecesiteecesttceessteeees 33 3 2 5 MESH GENERATOR INPUT FILE Z88NLTXT n 34 3 2 6 SOLVER CONTROL FILE Z88CONTROL TXT an 38 3 2 7 SOLVER CONTROL FILE Z88CONTROL TXT n 43 3 2 8 DEFINITION FILE Z88ENVIRO DYN cecsccccssscccsssscccssisecessseceesssecessteceesseeeee 45 3 2 9 OUTPUT FILES Z88O2 TXT n 49 A THE Z88 MODULES a 50 Al CAD amp FE INTERFACES cocccccssccccsssecccsstecccssssecesttessiscestiiecettieesitecesticecetteesstee 50 A 1 1 IMPORTING Z88 FILES an 52 4 1 2 MANUALLY CREATING OF Z88 FILES au 53 4 1 2 THE STEP CONVERTER Z88GEOCON au 63 4 1 3 THE STL CONVERTER Z88GEOCON au 64 4 1 4 THE DXF CONVERTER Z88X an 65 ZBSX IN DETAIL ceccscccccsssscccsesecccssssecsseseseseseeseteeesiseesit esses eseiteeestsecesse 67 EXAMPLE 1 FOR Z88X FINITE ELEMENTS STRUCTURE ceceocccccccceccsececceseeesee 75 EXAMPLE 2 FOR Z88X SUPER ELEMENTS STRUCTURE r 84 5 Yoho Theorie Manual 42 THENASTRAN amp COSMOS CONVERTER ZBO 9 4 1 6 THE ANSYS CONVERTER Z88ASY secccsssssccccssessccsesseteeeeseeeeseceseteesseesse 94 4 1 7 THE ABAQUS CONVERTER Z88A INP n 95 4 2 PICKING amp THE SET MANAGEMENT n 97 A 2 1 SURFACE LOADS cecccsssscccccsssessecccssessscecesseseeeesesti eesti bebestbi se eesetteceeesse 98 A y THE LINEAR SOLVER Z88R ooscccsssssssccccssessececeeseeeeeseesteebeebibebbetteebeseeteesee 100 4 3 1 WHICH SOLVER TO TAKED E 104 432 SOME NOTES ON STRESS
165. sses SIGRR the tangential stresses SIGTT and the accompany ing shear stresses SIGRT are computed additionally makes only sense if a rotational symmetric structure is available For easier orientation the respective radiuses and angles of the centre of gravity are printed Optional von Mises stresses in the center of gravity Nodal forces in X and Y for each element and each node 128 66 Aurora 86 Theory Manual 5 4 TRUSS NO 4 IN SPACE XY The truss element No 4 can take any location in space It is part of the simplest elements in Z88 and is calculated extremely fast The truss elements match Hooke s law exactly Hint Trusses No 4 are very suitable for model ling spring supports or oblique angled supports Z gt X Input CAD see chapter 4 1 4 Line from node I to node 2 Z88STRUCTURE TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt 3 degrees of freedom for each node gt Element type is 4 gt 2 nodes per element Element parameters L Section Bd Thickness enter here the cross section area for the elements Z88ENVIRO DYN gt Integration order INTORD for displacement calculation any order has no influence gt Integration order INTOS for stress calculation any order has no influence Z88CONTROL TXT gt Radial Tangential stress flag KDFLAG has no meaning gt Reduced stress flag ISFLAG has no meaning Results Displacements in X Y and Z Stresses Normal stresses Nodal forces in X
166. st lt gt Quadrant EJ Apparent intersection X V Intersection E Parallel V Extension command A tracking vector appears when you move the cursor 0 To track from an Osnap point pause over the point while in a To stop tracking pause over the point again Options ok Cancel Help T1 Pahi Aurora Theorie Manual 78 ye 66 Aurora ma 032D Drafting amp Annotation b6_3 dwg Type a keyword or phrase Insert Annotate Parametnc View Manage Output Express Tools Theory Manual Ekla 8 GOA E Ee szala A bi Oo ra k G amp Ah Unsaved Layer State ine ove N amp 55 C 7 9 of W zsexner Modify v Layers v Properties Utilities Clipboard Current layer ZB8KNR j amp EY amp 6 Filters SF All All Used Layers lt F Definitions wf Z88KNR J 4i PL Model Layout Command Command layer Command Henge ae Palos RAs Ae ok i Tesi Ges ekinini 4th step Define the Layer Z88EIO and make it the active layer Write the element infor mation with the TEXT function anywhere of course it looks nicer with the element info s placed in middle of the respective finite element or super element The order of the work sequence is up to you You can describe element 1 first step to the attaching element 17 and then proceed with element 8 However your element choice and description must make sense for
167. stem The working directory must not be confused with the project directory which is selected or defined independently by the user when starting the program Purpose and structure of the definition file Z88 DYN At the start of the program Z88Aurora requests a certain amount of memory which can be controlled via the file Z88 DYN Apart from this Z88 DYN defines the language for Z88Aurora and any accessed Z88 modules For the allocation of memory the file features different parameters which define the maximum possible size of structures to be computed MAXK for example determines the maximum number of nodes for the finite element calcu 43 Yoho Theorie Manual lation If it becomes apparent during the use of Z88Aurora that the memory does not suffice you will get a respective error message see figure 7 Figure 7 Memory overflow because of too many nodes After that the dialog box Options opens where the respective parameter can be increased under the tab Memory see figure 8 The memory parameters always have an offset of about five for safety and stability reasons Thus for the calculation of a model with 1000 nodes the memory parameter MAXK should be set to 1005 After closing the dialog box Z88Aurora is quitted In the background the definition file was changed according to the adjustments When running Z88Aurora the next time these changes are taken into account There will be no data loss The memory parameters can
168. stress calculation 0 Calculation of stresses in the corner nodes 1 2 3 4 Calculation of stresses in the Gauss points Z88CONTROL TXT gt Radial Tangential stress flag KDFLAG has no influence gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the Gauss points INTOS not 0 2 principal or Rankine stresses in the Gauss points INTOS not 0 3 Tresca stresses in the Gauss points INTOS not 0 Results Displacements in X Y and Z Stresses SIGXX SIGYY SIGZZ TAUXY TAUYZ TAUZX respectively for corner nodes or Gauss points Optional von Mises or principal or Tresca stresses Nodal forces in X Y and Z for each element and each node 135 LIB on Theorie Manual 5 11 PLANE STRESS ELEMENT NO 11 WITH 12 NODES E This is a curvilinear Serendipity plane stress element with cubic shape functions The transformation is isoparametric The integration is carried out numerically in both axes according to Gauss Legendre Thus the integration order can be selected in Z88ENVIRO DYN The order 3 is mostly the best choice This element calculates both displacements and stresses with outstanding precision The integration order can be chosen again for the stress calculation The stresses are calculated in the corner nodes good for an overview or calculated in the Gauss points substan tially more exactly Plane Stress Elements No 7 can be generated by the mesh generator Z88N from su
169. t Nodal forces first for each element then for each node 162
170. ted line load Value Figure 30 Possibilities of the boundary conditions in the boundary condition menu Force uniformly distributed applies always the same force to the nodes while Surface load and Line load distributes the load according to FEA rules For the elements with linear shape function e g Hexahedrons No 1 and Torus No 6 edge loads and surface loads are distributed to the elements simply and straight forward onto the respective nodes However for elements with higher shape functions i e square Plane Stress No 3 No 7 To rus No 8 Hexahedron No 10 etc or cubic Plane Stress No 11 and Torus No 12 edge and surface loads have to be put onto the elements according to certain rules which are not always physically obvious but mathematically absolutely correct Amazingly some load components can have negative values Though these facts are not obvious nevertheless they lead to cor rect results which is not the case for intuitive distribution of loads to the respective nodes An example may clarify the facts 98 66 Aurora voi Theory Manual wrong distribution of load 142 86 142 86 142 86 142 86 142 86 142 86 142 86 element 1 element 2 element 3 right distibution of load 595 59 222 22 111 11 222 22 111 11 222 22 55 55 element 1 element 2 element 3 Figure 31 the distribution of loads An FE structure consists of three plane stress elements No 7 with the load of 1 000 N distrib uted on the upp
171. the suitable INPENVIRO Z88 in the BIN directory of Z88Aurora ABAQUS scripts cannot be processed For the import of an ABAQUS file proceed as follows Importing and meshing the component in ABAQUS The ABAQUS converter only processes components which you can arbitrarily import into ABAQUS CAE and fit into an Assembly It is up to you whether you select Mesh on Part or Mesh on Instance Allocate either Hex or Tet as meshing properties see figure 27 and gener ate a mesh which meets your requirements Mesh Controls xX Element Shape Technique Asis Medial axis C Free a Minimize the mesh transition fp structured L Advancing Front te Sweep a Bottom up i Multiple OK Algorithm Use mapped meshing where appropriate Redefine Sweep Path Defaults Cancel Figure 27 Allocation of the appropriate element type in ABAQUS 6 8 4 Note Extended settings of the mesh control and element selection are not adopted since there are no corresponding equivalents in Z88Aurora Thus in case you have chosen hybrid formu lation or an element for acoustic analysis this will be transformed into a pure Z88 type when being imported into Z88 Remarks Z88AINP processes all loads of a step which are given in the ABAQUS file Should you have defined several simulation steps in your CAE model note that you should provide a new model by copying in which all steps are deleted except the desired simulation
172. thus you may use it as your standard solver In Z88 Aurora the solver types are selected via the solver menu Z Linear mechanical e 35 Choose solver Failure theory pak PARDISO No equivalent stress GEH von Mises Rankine Tresca Solver parameter sIccG sorce F Solver parameters F Solver parameters SICCG SORCG Number of iterations t0000 Residuum 1 000000E 006 Number of iterations 00n Residuum 1 000000E 006 Alpha 1 000000E 004 Help Omega 1 200000E 000 Help ome Figure 1 Solver menu 20 66 Aurora voi Theory Manual 2 2 2 THE VIBRATION SOLVER Z88EI This eigen solver for natural frequency uses a numeric method that is especially approved in FEA and was introduced already in 1950 by Cornelius Lanczos Although no one could have thought about numeric model analysis then the algorithm features many advantages for FE programing The basic idea to reduce the matrix to a tridiagonal matrix non zero elements only in the main diagonal and the first diagonal below and above by iteration is very effec tive regarding memory management Additionally it is guaranteed mathematically that the eigenvalues of this tridiagonal matrix are approximately equal to the eigenvalues of the origi nal matrix Each iteration of the solver can be divided into two stages Initially an additional row or column of the tridiagonal matrix is calculated basi
173. ting towards the edge gt 3 corner nodes of the loaded surface Mathematically positive in plain view The local nodes to 3 may differ from the local nodes 1 to 3 used for the coincidence Results 1 Displacements in X Y and Z Stresses SIGXX SIGYY SIGZZ TAUXY TAUYZ TAUZX respectively for corner nodes or Gauss points Optional von Mises or principal or Tresca stresses Nodal forces in X Y and Z for each element and each node 146 66 Aurora 86 Theory Manual 5 18 PLATE NO 18 WITH 6 NODES amp 8 This is a curvilinear Serendipity Reissner Mindlin plate element with quadratic shape func tions The transformation is isoparametric The integration is carried out numerically in both axes according to Gauss Legendre Consequently the integration order can be selected in Z88INT TXT The order 3 3 points is mostly sufficient reduced integration This ele ment calculates both displacements and stresses quite good The integration order can be cho sen again for the stress calculation The stresses are calculated in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly For this element you need to set the plate flag IPFLAG to 1 Attention In contrary to the usual rules of the classic mechanics Z88 defines 0 the rotation around the X axis and 0 the rotation around the Y axis This element type is implemented for use with automeshers Thus a mesh generation with ZSSN is
174. tion The local x y and z axes are defined as follows e Local x axis points in direction of local nodes 1 and 2 e Local y axis points in direction of local nodes 1 and 4 e Local z axis points in direction of local nodes and 5 See following sketch below Example Subdivide an Isoparametric Serendipity Plane Stress Element with 12 nodes Ele ment No 11 into finite elements of type Isoparametric Serendipity Plane Stress Element with 8 nodes Element No 7 Subdivide in local x direction three times equidistantly and subdi vide 5 times increasing geometrically in local y direction The super element is supposed to have the number 31 Thus resulting in two lines 36 66 Aurora voi Theory Manual 31 ll 7 3 E 5 L eor E for equidistant are equivalent amp 5 input group optionally after the end of input group 4 Input group 6 is required 1f NIFLAG was set to 1 1 e the trap radius is supposed to be modi fied 1 line Ist number Trap radius in global X direction EPSX Double 2 number Trap radius in global Y direction EPSY Double 3rd number Trap radius in global Z direction EPSZ Double Skip the Z detail for 2 dimensionalen structures Example The trap radiuses shall be set to 0 0000003 for X Y and Z respectively gt Thus 0 0000003 0 0000003 0 0000003 This is effective only if NIFLAG was set to I in the first input group Types 7 8 Types 11 12 local y direction local y direction local x directio
175. to generate a complete FE structure or a super structure which can be meshed further by means of the integrated mapped mesher Z88N The finite elements of the source program are properly transformed into the corresponding type in Z88Aurora and material data can be adopted As expected the pure geometry interfaces only contain the function to import a 3 dimensional image without any FE information Table 5 Model data which can be transferred from FE structure data ZS ae 140S DXF ABAOUS ANSYS COSMOS NASTRAN AutoCAD gt Z 2 rA E ca RSA tions 7 s Surface and pres y sure loads via MITOO Please note The import of AutoCAD DXF files only imports geometry data or FE mesh data with optionally boundary conditions The material data elements parameters and integration 5I LIB on Theorie Manual orders can be defined easily in Z88Aurora afterwards Only then data consistency in Z88Aurora V2 projects can be guaranteed NASTRAN ANSYS ABAQUS and COSMOS files can be imported with boundary conditions The material properties cannot be transferred intentionally they are added in Z88Aurora An overview over material data that can be imported can be found in table 5 information about the possible element types can be found in table 1 in chapter 2 4 1 1 IMPORTING ZS88 FILES What is the basic idea and which are the features Downward compatibility is one of the basic prerequisites for the effective application o
176. ture to Z88Aurora super structure Figure 23 Accessing the DXF converter Z88X and import options in ZSSAurora Which elements are supported by the converter All element types from 1 to 24 Which functions does the converter offer D F structure to 88Aurora structure DXF structure and constraints to 788Aurora DAF super structure to 68Aurora super structure DXF super structure nach Z88Aurora structure How to proceed In the CAD system 1 Design your component Order and layers as you like 2 Define the FEA structure or the super structure by lines and points Any order and layers therefore unproblematic and fast 3 Number the nodes with the TEXT function on the layer Z88KNR Any order therefore unproblematic and fast 4 Write the element information with the TEXT function on the layer Z88EIO Any order therefore unproblematic and fast 5 Outline each element with the LINE function on the layer Z88NET The only section with 66 66 Aurora 86 Theory Manual firm work rules and orders because of the topological information 6 Write general information material information and control information for the stress pro cessor Z88D on the Layer Z88GEN 7 Define the boundary conditions on the layer Z88RBD 8 Define the surface and pressure loads af needed on the layer Z88FLA 9 Export or store your 3 D model or 2 D drawing under the name Z88X DXF In Z88Aurora Launch the CAD converter Z88X Select in the
177. uitive distribution of loads to the respective nodes An example may clarify the facts see figure 16 wrong distribution of load 142 86 142 86 142 86 142 86 142 86 142 86 142 86 element 1 element 2 element 3 right distibution of load 99 95 222 22 111 11 222 22 111 11 222 22 55 55 element 1 element 2 element 3 Figure 16 Load distribution on the nodes A FE structure consists of three plane stress elements No 7 with the load of 1 000 N distribut ed on the upper edge in Y direction see figure 16 Incorrect 1 OOON 7 142 86 N per node Not correct for elements with square shape function Correct 2 x 1 6 2 x 1 6 1 6 3 x 2 3 18 6 3 corresponds to 1 000 N 1 6 points 1 000 18x1 55 55 2 6 points 1 000 18x2 111 11 2 3 points 1 000 18x4 222 22 Control 255 55 2x111 11 3x222 22 1 000 N o k Here s why 56 66 Aurora 56 Theory Manual 1 4 1 4 1 2 1 2 1 4 1 4 1 4 1 4 1 4 ms Figure 17 Elements with linear shape functions e g Hexahedron No 1 4 12 1 3 1 12 1 6 1 6 1 12 2 3 1 3 1 3 1 3 t 1 3 1 12 1 12 1 3 1 3 1 12 1 3 1 12 12 Figure 18 Elements with quadratic shape functions e g plane stress element No 3 and 7 Torus No 8 Hexahedron No 10 1 8 3 16 3 16 1 8 1 8 3 8 3 8 1 8 o 1 8 3 16 3 16 1 8 Figure 19 Elements with cubic shape functions e g plane stress element No 11 Torus No 12 SURFACE AND PRESSURE LOADS FILE Z88I5 T
178. ure 2 or 3 2 number Number of nodes of the FEA structure 3 number Number of elements 4 number Number of degrees of freedom 5 number Coordinate flag KFLAG 0 or 1 Attention This position was in former Z868 versions reserved for the number of materials NEG and the identifier AURORA_V2 29 LIB on Theorie Manual Explanations KFLAG On input of 0 the coordinates are expected Cartesian coordinates while on input of 1 polar or cylindrical coordinates are expected The latter are then converted into Cartesian coordinates and thereupon stored in this form in Z8800 TXT Caution The axisymmetric elements No 6 8 12 and 15 positively expect cylindrical coordinates set KFLAG to 0 here 2 input group Starting with line 2 containing coordinates of nodes one line per node node numbers strictly ascending 1 number node number Long 2 number Number of the degrees of freedom for this node Long 3 number X coordinate or if KFLAG is 1 R coordinate Double 4 number Y coordinate or if KFLAG is 1 PHI coordinate Double 5 number Z coordinate or if KFLAG is 1 Z coordinate Double The Z coordinate can be dropped at 2 dimensional structures Enter angles PHI in radian Example 1 The node no 156 has 2 degrees of freedom and the coordinates X 45 3 and Y 89 7 gt Thus 156 2 45 3 89 7 Example 2 The node no 68 is supposed to have 6 degrees of freedom a Beam No 2 is at tached and cylindrical co
179. ure loads are applied onto element no 16 otherwise enter a O into the first line gt Element number with pressure load gt Pressure positive if pointing towards the edge gt 3 corner nodes and 3 mid nodes of the loaded surface Mathematically positive in plain view The local nodes 1 to 6 may differ from the local nodes 1 to 6 used for the coincidence Results Displacements in X Y and Z Stresses SIGXX SIGYY SIGZZ TAUXY TAUYZ TAUZX respectively for corner nodes or Gauss points Optional von Mises or principal or Tresca stresses Nodal forces in X Y and Z for each element and each node 144 66 Aurora 86 Theory Manual 5 17 TETRAHEDRON NO 17 WITH 4 NODES amp This is a volume element with linear shape functions The transformation is isoparametric The integration 1s carried out numerically according to Gauss Legendre Thus the integration order can be selected in Z88INT TXT The order 1 is good This element type is implemented for use with automeshers The converter functionality in ZSS8Aurora offers the possibility to import and process files with this element type For further information see chapter 4 1 8 Tetrahedron No 17 also applies well for thick plate elements if the plate s thickness is not too small compared to the other dimensions Basically this element calculates deflections and stresses very badly i e inaccurately One needs very fine meshes to obtain useful results Its one and only r
180. volume shells element no 21 and element no 22 Further details to the application see user s handbook simple shell volume shell Figure 48 Flat shells upper and volume shells lower 120 v 56 Aurora Theory Manual File View Pre processor Solver Post processor Tools Help O O HW i Linear mechanical oo BS ae A Oeeor OIl tk ESFI SFY OEEO PF RNR SEF Taggen aoaa Pisma 30 view B Element geometry Administration a Add E Create mesh m Delete f Remove mesh Close E Mesh info Rules for mesh active Name Ee Figure 49 Shell thickener in ZSSAurora 121 66 Aurora Theorie Manual 4 8 THE POST PROCESSOR Structures illuminated with three light sourced wireframe or hidden line structures can be plotted undeflected deflected or both of them overlaying In the same way a colour range for stresses and X Y and Z deflections can be displayed In case of node and element numbers areas can be specified which is very helpful in case of large structures A plotter or printer output is not explicitly intended Why should it be Simply make a screenshot with Shift Print in the clipboard and edit or print it with the Windows program Paint or a paint program such as for example CorelPaint etc Z88Aurora uses OpenGL Therefore your computer must be able to deal with OpenGL In case of the more recent Windows versions this is activated by default and usually a c
181. w to proceed 1 Construct the 3D geometry to be calculated in your CAD system In the process please keep in mind the above mentioned particularities if possible Export the geom etry as STEP AP203 or AP214 file Please take care to export a volume model not 2D or wireframe model It is recommended to check the original model and the inter change file with an integrated geometry check for defective and very small surfaces 2 In Z88Aurora select File gt Import gt STEP data In the subsequent selection box you can only select STEP files Therefore select the desired file Figure 21 63 Yoho Theorie Manual 3 From your file Z88GEOCON generates an STL which is required for visualisation in Z88Aurora This data type can now be meshed and processed The same functionalities are available when you access the STEP import via the toolbar r f Choose STEP file A Z88AuroraV2 docu de Beispiele Import b14 amp zahnrad stp 24 04 2012 amp Lokaler Datentrager C gt Daten D amp 3 DVD RW Laufwerk E Z8 s Hinzuf gen stp v Sox X Abbrechen Figure 21 Importing STEP files 4 1 3 THE STL CONVERTER ZSSGEOCON What is the basic idea and which are the features Like STEP STL stereo lithography is an established and standardised interchange format which can be generated from many CAD and CAM systems and is often used for Rapid Pro totyping and mould flow simulations In addition t
182. x GS e Pointer vector IP points to the diagonal elements GS 1 e Pointer vector IEZ points to the column index GS x J Example ref Schwarz H R Methode der finiten Elemente Let the lower part of GS be aol T cen foca __ _ jaca acs _ aay Jaco wen foc Joos _ desea fT doses d osoo GS results in the following vector of non zero elements LIB on Theorie Manual SSG D TGS 5 3 _ GSG 5 _ GS6 2 _ fasa GS 66 d o o IEZ will result in UP PePePBE BEB hs 2 4 fe and IP The pointer IEZ holds MAXIEZ elements the vector GS holds MAXGS elements These limits are determines in the test mode of the solver In the second run the actual computation run the solver computes the element stiffness ma trices compiles the total stiffness matrix incorporates the boundary conditions scales the system of equations and solves the huge system of equations by the conjugate gradient algo rithm Preconditioning is done for better convergence You can choose whether to use a SOR step or a so called incomplete Cholesky decomposition for precondition Default is the incomplete Cholesky decomposition shifted incomplete Cholesky decomposition SIC be cause the main parameter the so called shift factor a is easy to handle The SOR precondi tioning needs less memory but the control parameter the relaxation parameter cannot be determined a priori In addition you must enter several param

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