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GiD User Manual

1. ET LEE 5 1 Introduction In order to carry out this example start by opening the project ToMesh4 gid This project contains a geometry that will be meshed using four different methods each one resulting in a different density of elements in certain zones 5 1 1 Reading the initial project Inthe Files menu select Read Select the project ToMesh4 gid and click Open The geometry appears on the screen It is a set of surfaces Select Render gt Flat from the mouse menu Select Rotate Trackball from the mouse menu This tool is also available within the GiD Toolbox Make several changes in the perspective so as to get a good idea of the geometry of the object Finally return to the normal visualization selecting Render Normal This mode is more user friendly 80 User Manual Figure 1 Contents of the project ToMesh gid The mouse menu appears when the right mouse button is clicked 5 2 Element size assignment methods GiD automatically corrects element sizes according to the shape of the entity to be meshed and its surrounding entities This default option may be deactivated and reactivated by going to the Mesh menu selecting Preferences and then Automatic correct sizes Sometimes however this type of correction is not sufficient and it is necessary to indicate where on the mesh greater accuracy is needed In these cases GiD offers vario
2. Reflection Object axes Label Define reflection Center Plane XY Original Image to clipi Show numbering of the entities Plane XZ for preprocess as well far Plane YZ s Quit postprocess lsometnc Activates or deactivates the layers Redraws geometry of the project which form the Project and changes entities from one laver to another Closes GID New On Off Touse Send 8 Window Copies the drawingimage shown an the screen to the clipboard F F F F 1 5 Command line The Command Line option allows the user to directly enter all executable GiD commands without accessing the commands through drop down menus Enter commands Layer nueva is OFF Layer nueva is ON i Command These commands should be written following the order which GiD would use to define them according to the Right buttons menus A side comment in reference to the Command Line GiD does not distinguish between the use of capital and small letters In addition in cases where ambiguities do not exist commands need not be written in entire words but can be written with the primary characters of each word 19 2 INITIATION TO GiD With this example the user is introduced to the basic tools for the creation of geometric entities and mesh generation Ip D ZI 2 1 First steps we will present a simple example that will Before presenting all the possibilities that GiD offers introduce and familiarize the user w
3. Figure 2 Collapsing the model Importing an IGES file 129 Info window IGES Global section parameters sending System 8100op20 1Gs File name 981000p20 1G5 system ID MATRA DATAVISION EUCLIDS Preprocessor Version IGES E32 1B00 Froduct ID 91000p20 1G5 Model Scale 1 Unit flag Millimeters Date And Time Exchange 07 6 1999 17 19 0 Minimum Resolution 0 025 Appraximate Maximum Coordinate 2500 specication wersion 5 1 Date And Time Modification 07 5 1333 17 19 0 Collapse geometry Time 6 seconds created 2463 points 2026 lines 4 surfaces 0 volumes ImportTolerance 0 059475 Figure 3 Importing process information After the importing process the IGES file that GiD has imported appears on the screen ET m ly d Br mcm sra I mi Figure 4 File base igs imported by GiD NOTE One of the operations in the importing process is collapsing the model Figure 3 We say that two entities collapse when the distance between them being less than the Import Tolerance they become one The Import Tolerance value may be modified by going to the Utilities menu opening Preferences and bringing up the Exchange card By default the Automatic import tolerance value is selected With this option selected GiD computes an appropriate value for the Import Tolerance based on the size of the geometry Collapsing the model may also be done manually This option is found in Geometry gt Edit
4. Sd puto calculate DOUEDUIE T void input J 4 Char filename T024 E ileerr 10241 seul r024 ELLE ip Terr Int aUx je eGrror 0 void J mpline EFITLE strcpy filename projname strcat tulenaeme dat fp fopen filename r for Xre0c 62 4 qumplarxue troy fscanf fp d d amp Nelem amp Nnod x double malloc Nnodt 1 sizeof double if x NULL y double malloc Nnod 1 sizeof double if y NULL N int malloc Nelem 1 3 sizeof int if N NULL imat int malloc Nelemtl1 sizeof int if N NULL if error 4d strcpy fileerr projname oStrocagbt iniloggr orpt ferr fopen fileerr w forinti Terr ERROR Not enough memory Eh PEILOT N errs TITY TO Calculate Weel less elements 7 TClose Perr gt EXELL for 109 162 34 J mpline SEE sau2 1024 error l1 error 1 User Manual error 1 error 1 The main program reading the coordinates for inod 1 inod lt Nnod inod fsScanf fp sd elf cli amp aux ex inod amp y rinod for IsO ue69 LL qJqumplrne Ips reading connectivities for ielem 1 ielem lt Nelem ielemtt bscanf tp ed aux Ior 250 5 HF scant fp gd amp N L Crelem l oT 9 fscanf fp d amp imat ielem if imat ielem 0 strcpy fileerr projname StYrCat raibeerry Tierry ferr fopen file
5. 3 2 6 Rotating and copying the auxiliary lines 1 Use the Copy window located in Utilities gt Copy see Figure 9 2 Repeat the rotating and copying process from section 2 5 for the two auxiliary lines Select the option Lines from the Entities type menuand enter an angle of 36 degrees 3 Select the lines to copy and rotate Do this by clicking Select in the Copy window 4 Press ESC to indicate that the process of selecting lines is finished thus executing the task see Figure 7 40 User Manual Figure 7 Result of copying and rotating the line 5 Rotate the line segment that goes from the origin to point 40 0 by 33 degrees and copy it see Figure 8 a ul Pos e i A AES LV Ma A m Eu gum a m n rs A n Fr Figure 8 Result of the rotations and copies Rotating and copying the auxiliary lines 41 Entities type Lines 7 Transtormatian Rotation 7 Angle 36 Degrees First point Murn x yv 0 0 e z i iw Two dimensions second point Murn x 10 0 y D D 2 Duplicate entities in extrude No iw Maintain layers Multiple copies 1 Select Cancel Figure 9 The copy window NOTE In the Copy and Move windows the option Pick may be used to select existing points with the mouse 3 2 Intersecting lines Choose the option Geometry gt Edit gt Intersection gt Line line Select the upper circle resulting from the 36 degree rotation executed in section
6. 3 Select Mesh gt Generate Mesh When the mesh has been generated a window appears with information about the mesh Figure 29 The result is a non conformal mesh composed of far fewer elements than the meshes generated in the previous section about 5000 elements instead of the 20 000 needed to generate the conformal mesh Dialog window Num of Triangle elements 4238 Mum of nodes 4042 Figure 29 A window containing information about the generated mesh 4 Visualize the result using Mesh gt View mesh boundary Figure 30 The mesh visualized using Mesh gt View mesh boundary 8 3 4 Optimizing a non conformal mesh NOTE By using Chordal Error the geometry may be discretized with great precision The chordal error is the distance between the elements generated by the meshing program and the profile of the real object Entering a sufficiently small chordal error results in small elements in zones where there is 144 User Manual greater curvature Accordingly the approximation of the mesh may be improved in zones with greater curvature by using the option Chordal Error Chordal Error generates an increased number of elements in zones where there is curvature One way of obtaining accurate meshes with few elements is using structured elements in zones where there is curvature The option Allow automatic structur
7. 5 From the Do extrude menu select the Surfaces option 6 Click Select to select the lines that define the cross section of the second pipe Press ESC to Creating the other pipe section 73 conclude the selection Figure 25 A rendering of the two intersecting pipes 4 4 3 Creating the lines of intersection 1 Choose Geometry gt Edit gt Intersection gt Surface surface 2 Select the outer surfaces of each pipe thus forming the intersection of the two surfaces selected 3 Repeat the process to obtain the four lines of intersection ii LE AT iL e eA AC was 7 7 KU C Pa f i fh En N 8 h h 8 h 3 h 3 h i h Figure 26 Creating lines of intersection between the surfaces 4 4 4 Deleting surfaces and lines 1 Choose Geometry gt Delete gt Surfaces and select the small surfaces inside the first pipe Press ESC to conclude the process of selection 2 Choose Geometry gt Delete gt Lines Select the lines defining the end of the second pipe foreground that are still inside the first pipe background The result is shown in Figure 27 74 User Manual eZ SS E ore NE SAVES A Figure 27 Final configuration after deleting surfaces and lines 4 4 5 Closing the volume 1 The model now has three outlets The two farthest from the origin of coordinates must be closed The third will be connected to the rest of the piece when the T
8. coordinates gt x v I conectivities N densities rna conditions node condition value weal CREATES the err file This file is created only if an error occurs nut of memo project name err element with na materia CALCULATION of the CENTER of MASSESS project name log project name pnzi res CREATES the log file t contains the exact coordinates of the center of masses CREATES the res file t contains the distance of each element relative to the center of masses of the object cmas2d c solver structure 158 User Manual NOTE The cmas2d c code is explained in the appendix 9 2 6 Creating the Execution File for the Problem Type Create the cmas2d win bat file This file connects the data file s dat to the calculating module the cmas2d exe program When the GiD Calculate option is selected it executes the bat file for the problem type selected When GiD executes the bat file it transfers three parameters in the following way parameter 3 bat parameter 2 parameter 1 parameter 1 project name parameter 2 project directory parameter 3 Problem type location directory Ja NOTE The win bat fiile as used in Windows is explained below the shell script for UNIX systems is also included with the documentation of this tutorial rem OutputFile 2 1 log A comment line such as rem OutputFile file name log means that the contents of the file
9. 3 Enter an angle of 36 degrees Make sure that the center is point 0 0 0 and that you are working in two dimensions 4 Inthe Multiple Copies box enter 9 This way 9 copies will be made thus obtaining the 10 teeth that form the profile of the model 9 copies and the original 5 Click Select and select the profile Press the ESC key or click Finish in the Copy window in order to conclude the operation The result is shown in Figure 15 Figure 15 The part resulting from this process 44 User Manual 3 2 12 Creating a surface 1 Create a NURBS surface To do this select the option Geometry gt Create gt NURBS Surface gt By Contour This option can also be found in the GiD Toolbox 2 Select the lines that define the profile of the part and press ESC to create the surface 3 Press ESC again to exit the function The result is shown in Figure 16 CA Figure 16 Creating a surface starting from the contour Wl NOTE To create a surface there must be a set of lines that define a closed contour 3 3 Creating a hole in the part In the previous sections we drew the profile of the part and we created the surface In this section we will make a hole an octagon with a radius of 10 units in the surface of the part First we will draw the octagon Select from the menu Geometry gt Create gt Object gt Polygon to create a regular polygon Enter 8 as the number of sides of the polygon Enter 0 0 0 as the center of
10. 8 3 1 Global collapse of the model 1 The option Mesh gt View mesh boundary shows the boundary of all the surfaces of the conformal elements 2 After generating the mesh select Mesh gt View mesh boundary This will result in the image pictured in Figure 15 Figure 15 Visualization of the mesh generation using the option Mesh gt View mesh boundary 3 Visualization of the boundaries shows that in the interior of the piece some surfaces are isolated 4 To generate a conformal mesh first execute a global collapse of the model 5 The GiD collapse depends upon the Import tolerance Two entities are collapsed converted into one when they are separated by a distance less than the Import tolerance parameter To test this enter a new value for the Import tolerance parameter 6 Go to Utilities open Preferences and bring up the Exchange card Enter 0 15 for the Import tolerance value Click Accept Global collapse of the model 137 Preferences W Automatic collapse after import Automatic import tolerance value Importtolerance 0 15 Collapse Ignoring layers i i Each layer separately Figure 16 The Preferences window 7 Select Geometry gt Edit gt Collapse gt Model 8 Select Mesh gt Generate 9 When the GiD finishes the meshing process an error message appears As the window shows there are errors meshing surface number 124 10 Go to Geometry gt Delete gt Surfaces and delete surface 124 11
11. Insert GiD geometry Ctrl x Ctri n Ctrl o Ctrl s Ctrl x Ctri s Ctrl q Cirl4 Ciri d Export files GES CMF ACIS Eihinoceros GD mesh Text date report ASC project QN layers Calculason file sing Template bas only mesh Open the last post files Window to setup some print properties animaze Cirl x Ctri c User Manual 1 2 2 View In the view menu also available from the mouse menu there are all the visualization commands These commands change the way to display the information in the graphical window but they do not change any definition of the geometry or any other data A In om Out Offers variaus rotation Dynamic options Previous ad Offers various Next Trackball zoom options b Screen axes P Frame share for viewing of Object axes Center Plane XY Original Plane x2 Plane Z Isometric Permits translation of the image from one point ta Redraws geometry of aiid another two points or the project i Ean dynamically dynamic i E Redraw Two point To change to a perspective Render P d Dynamic projection Perspective clipping planes id Shaw numbering af the entities for prepracess as well for pastpracesss Draw bv colars the surface curvature Advanced options Set the near and far Offers various illumination options far Normals the image oS La EE Permits to use shadows and Bet yiew stereos
12. One at a time select the rest of the points except the last one Use Join Ctrl a each time in order to ensure that the line passes through the point 11 Before selecting the last point choose Last Point in the Contextual menu Then finish the NURBS line The result is shown in Figure 40 12 Send the new profile See Figure 41 to the profile layer and eliminate the auxiliary lines 58 User Manual Figure 41 Optimizing the design 13 Repeat the process explained in sections 2 11 and 2 12 to create the wheel surface use the rotation tool to create the entire profile and using Geometry gt Create gt NURBS Surface gt By contour select it to create a NURBS surface 14 Repeat the processes explained in section 3 except section 3 1 and sections 4 1 and 4 2 to create the prismatic volume 3 6 2 Modifying the profile of the hole 1 Move the lines of the octagon placed in the profile surface to the profile layer with the Send To button 2 Click Off the prism layer Hiding it simplifies the space on the screen 3 Choose Geometry gt Create gt Object gt Circle 4 Enter 10 5 0 as the center point Enter a normal to the XY plane Positive Z and a radius of 1 5 5 From the Toolbox use the Delete gt Surfaces tool to delete the surface of the circle so that only the line is left This way the Geometry gt Edit gt Intersection gt Multiple Lines option may be used to intersect the circle circumference Selec
13. if imat ielem 0 strcpy fileerr projname StICHEUPIIOGrPQp U I Eques ferr fopen fileerr w EIpr DOTOorerr EBRBOERIIBIements wich no materrslirt 3 fclose ferr exit 1 j j The connectivities are read and the N variable is saved This variable is a Nelem x 3 size table with two fields The nodes assumed triangles of 3 nodes forming the element are saved in the first field The element identifiers are saved in the second one All the elements are checked ensuring that they have been assigned a material If the identifier of the material is 0 meaning that no material has been assigned to the element an err file is created containing information about the error and the program is aborted for qure msos2 sry ump lame IE Esconfirtp cscs 9d 990455 Sauz SN Jz Roq me imx37 gs yumplane AIP reading density of each material for i l i lt Nmat itt bscamr ip sod ALi Caux ALENO sexding eonditcons for 1905 1x 4 144 gumpline fp Tocant rO sd Nendys FOr rs 2568 Hg cpampd mne Ip Lor acids aonde NOnDdgs ecnda4 lt 1 The main program 167 Iscanf fp Tsd SLr amp nodolrendl amp wvalircundal jumpline fp j fclose fp j Reading the remaining information in the dat file The total number of materials is read and stored in the Nmat variable The density of each material are read and stored in the rho table The material id
14. 8 31 11 31 11 11 and 15 11 Press ESC to indicate that the process of creating lines is finished Figure 8 Profile of one of the disks around the pipe 4 From the Copy window choose Lines and Translation A translation defined by points 0 11 and 15 11 will be made In the Multiple copies option enter 8 the number of copies to be added to the original Select the lines that have just been drawn TAI NS Figure 9 The profile of the disks using Multiple copies 5 Choose Line located in Geometry gt Create gt Straight line Select the last point on the profile at 66 User Manual the right part of the profile using the option Join Ctrl a which is in the Contextual menu in the mouse menu Now choose the option No join Ctrl a Enter point 200 11 Press ESC to finish the process of creating lines 6 Again choose the Line option and enter points 0 9 and 200 9 Press ESC to conclude the process of creating lines Figure 10 g mnagcm 7 T T Figure 11 Copy of the vertical line segment starting at the origin of coordinates Figure 10 Creating the lines of the profile 7 From the Copy window choose Lines and Translation As the first and second points of the translation enter the points indicated in Figure 11 Click Select and select the vertical line segment starting at the origin of coordinates Press ESC 8 Choose Geometry gt Edit gt Intersection gt Multiple lines Select
15. Function 1 Geometric Grow factor 2 i p Boundary layer mesh in separated Layer Chordal error Maximum chordal error in model relative s 0 0 absolute 0 00e 000 Minimum element size 0 00e 000 Sphere mesher Algorithm Optimization Radius Max iterations 500 Others amoaathina Normal ad Mesh until end No mesh frozen layers L Avoid elements with all its nodes in boundary L Allow quadrilateral dominant meshes Parallel meshing number of threads to usa 1 E Mesh always by default a ET is Figure 31 The Preferences window 3 Select Mesh gt Unstructured gt Sizes by Chordal error and set the values as shown in Figure 32 146 User Manual Assign sizes by chordal error Chordal Error 0 05 Maximum meshing size 15 Minimum meshing size 0 1 UK Cancel V Figure 32 Defining unstructured size by chordal error 4 Select Mesh gt Generate Mesh 5 A window comes up in which to enter the maximum element size Leave the default value unaltered and click OK 6 Once the process of generating the mesh is finished a window appears with information about the N generated mesh Click OK to visualize the mesh I Q e W t aAA PL c SCE STAAL Be ie ov Ova M Ta ES M S v A p p qu cad RI vay Se NER SZ ee Ln CONI y SG WAAR ZAN NOD iere NN AIEEE BRM ul NS
16. Get meshing parameters from model Automatically GiD generates a mesh for the line The finite element mesh is presented on the screen in a green color The mesh is formed by ten linear elements of two nodes To see the numbering of the nodes and mesh elements select from the Mouse Menu LabelAll and the numbering for the 10 elements and 11 nodes will be shown as below 1 Once the mesh has been generated the project should be saved To save the example select from the Top Menu FilesSave The program automatically saves the file if it already has a name If it is the first time the file has been saved the user is asked to assign a name For this an Auxiliary Window will appear which permits the user to browse the computer disk drive and select the location in which to save the file Once the desired directory has been selected the name for the actual project can be entered in the space titled File Name Save Project Directory ProblemType_ Tutorial fl Ef I Preview Bill cmas d gic Bil example cmaszd gid El Kk Save options File name Save Files of type GID project gid Cancel Wl NOTE Next the manner in which GiD saves the information of a project will be explained GiD creates Creation and meshing of a line 23 a directory with a name chosen by the user and whose file extension is gid GiD creates a set of files in this directory where all the information generated in the pre
17. PACA a Tete i zu T ne wi garant ics t Ly re sar S Vr r1 e IM A J Y ea a P k i Figure 32 The mesh with a concentration of elements on the surfaces of the elbow 7 A greater concentration of elements has been achieved on the selected surfaces 78 User Manual 19 5 ASSIGNING ELEMENT SIZES ASSIGNING SIZES TO THE ELEMENTS OF A MESH The objective of this example is to mesh a mechanical piece using the various options in GiD for assigning sizes to elements and the different surface meshers available In this example a mesh is generated for each of the following methods for assigning sizes using different surface meshers Assigning sizes around points Assigning sizes around lines Assigning sizes on surfaces Assigning sizes with Chordal Error C SS Ss fe PSO ye eS S SSE No ae eet N SV AN VN LS X A y Q f N R WIN d 2 XD y j A M x M SEN aS NN Ni SS E WES SAX S dx M A Av S Sa N NN DA C NV AK N d A i EZ E7 TAN 2 7 LF 7 LF ZS m NZ ES E5 UE TA SCS S R N KRE Navy M A icm QA ETE OZ 2S vom EE SE 2 EZL WW eee aa NK EZ
18. Redraws image Creates a line of type NURBS Creates polyline apart from other lines AN Rotates the image X D ONY Creates a NURBS surface defined by LA Displaces image from one pointto border line another both chosen by the user Cretaes a volume hAl Creates a straight line Creates an arc Delete entities Permits listing of Project entities Toggle zeometry mesh view Saves to disc all information related to the project Prints the Changes the current configuration Creates a Reads a previously project for Opens the ne created GID postprocess copy Opens the project project window preferences phase window Opens the Goes to the List of common layers window previous view views Saving the Select the layerin use Quits GID drawingimage Goes to the next View shown on the screen in one of AN the following Formate Opens the help window T A1 ta A 82 a BES TIFF Z m 3 E Toolbars Geometry and View operations postprocess Enlarges image area which user indicates by drawing a mouse window Reduce image area which user indicate by drawing a mouse window Places image in center of screen Redraws image Rotates the image Displaces image from one point to another both chosen by the user With this option the user can change the vector of the light direction interactively How volumes
19. With option Join a point already created can be selected on the screen The command No Join is used to create a new point that has the coordinates of the point that is selected on the screen We can see that the cursor changes form for the Join and No Join commands o Cursor during use of Join command us Cursor during use of No Join command Now choose on the screen the first point and then the second which define the line Finally press Escape to indicate that the creation of the line is completed NOTE It is important to note that the Contextual submenu in the Mouse Menu will always offer the options of the command that is currently being used In this case the corresponding submenu for line creation has the following options Once the geometry has been created we can proceed to the line meshing In this example this operation will be presented in the simplest and most automatic way that GID permits To do this from the Top Menu select Mesh gt Generate mesh And an Auxiliary Window appears in which the size of the elements should be defined by the user Wl NOTE The size of an element with two nodes is the length of the element For surfaces or volumes the size is the mean length of the edge of the element In this example the size of the element is defined in concordance with the length of the line chosen for this case as size 1 22 User Manual Mesh generation Enter size of elements to be generated L
20. nodes in the lines and points that mesher skips Now our approximation is significantly improved see Figure 11 Figure 11 Mesh using the RJump mesher and assigning sizes by chordal error Force to mesh some entity 87 5 3 2 Force to mesh some entity If there is a line or a point that the RJump mesher would usually skip but that you wish to be meshed you can specify the entity so that it is not skipped As an example we will force Rjump to mesh line number 43 in order to concentrate elements around point number 29 as it was done in chapter 2 2 1 Select Mesh gt Mesh criteria gt No skip gt lines and select line number 43 Press ESC 2 Select Mesh gt Draw gt Skip entities Rjump to display the entities that will and will not be skipped in different colors As is shown in Figure 12 line 43 will now not be skipped the rest of the lines are unaffected and RJump will either skip or mesh them according to its criteria Figure 12 Entities that will be skipped and not skipped using the RJump mesher 3 Select Mesh gt Unstructured gt Assign size on points A window appears in which to enter the element size around the points to be chosen Enter 0 1 and click Assign 4 Select the point indicated in Figure 4 point number 29 Press ESC to indicate that the selection of points is finished 5 Select Mesh gt Generate Mesh 6 A window opens asking if the previous mesh should be eliminated Click Ok Another window
21. 1e3 in the Weight box Click Assign and select the upper corner point Press ESC when this step is finished Choose Mesh Generate A window appears in which to enter the element size for the mesh to be generated click OK Choose the Calculate option from the Calculate menu thus executing the calculating module Choose the Files Postprocess option Visualize the new results Visualization of the distance from the mass center to each element for an object of heterogeneous material subject to point weight Now the condition is external point weight As anticipated the new center of mass is displaced toward the point under weight 9 4 Aditional information NOTE In this example a code for the program will be developed in C Nevertheless any programming language may be used The code of the program that calculates the center of mass cmas2d c is as follows The cmas2d c file 164 User Manual rine bude lt stdio h gt include lt stdlib h gt include xmalloe n include lt math h gt define MAXMAT 1000 define MAXCND 1000 char projname 1024 ine ipy Gelemsy nod End double x y ine SN Cet int nodc MAXCND double rho MAXMAT wval MAXCND int Nelem Nnod Nmat Nond double x CG y CG VOL input vord void calculate void Void output void Declaration of variables and constants used in the program VOLO marin ant argc char argv 4 strcpy projname argv 1 Inp
22. 3D surfaces The volume calculations are stored in the v variable The geometric center of the element is calculated coinciding with the center of gravity and the coordinates are stored in the x Cgi and y Cgi variables The numerator sums are calculated When the loop is finished the following sums are stored in the x num and y num variables Finally the result of dividing the x num and y num variables by the den variable is stored in the x CG and y CG variables VOLO COUPLE 4 char filename 1024 FICE USED EDIOg double v The output function creates two files post res and log The results to be visualized in GiD Post process are stored in the post res file It is this file that stores the data which enables GiD to represent the distance of each point from the corresponding center of mass The numerical value of the center of mass is saved in the log file The accuracy of this value is directly proportional to the element size JU wr prendg zboqoddurormetion ake Ty strcpy filename projname strcat filename log folog fopen filename w fprineEe i plog CMAS2D routine tO calculate the mass Genter 553 Pprrnttobploo pre 7ecu we OPOoJnusmej Iprintt rplog mass centers Lr br y SCG Cos fclose fplog Creating the log file the log extension is added to the project name and a file is created that will contain the numerical value of the position of the center of mass which in turn
23. 4 oF O N Figure 4 Render Normal Generating a mesh on a volume using points Figure 4 Render Flat Generating a mesh on a volume using points Instead of pressing the ESC key the center mouse button or the mouse wheel can also be used 6 2 3 Generating the mesh using points Select Mesh gt Element type gt Only points Select volume number one and press ESC Select Mesh gt Generate mesh A window comes up asking whether the previous mesh should be eliminated Click Ok Another window appears in which to enter the maximum element size Leave the default value unaltered and click OK The result is a mesh as illustrated in Figure 5 A U N 95 Generating the mesh using points SNA Figure 5 Generating a mesh on a volume using points 5 Now volume number one is meshed using only the generated nodes 6 2 4 Generating the mesh using quadrilaterals 1 Select Mesh gt Element type gt Quadrilateral Select surfaces number 24 and 12 2 Select Mesh gt Generate mesh 3 A window comes up asking whether the previous mesh should be eliminated Click Ok 4 Another window appears in which the maximum element size can be entered Leave the default value unaltered and click OK The result will be the mesh illustrated in Figure 6 M ANE SA WS Figure 6 An unstructured mesh generated using quadrilaterals 5 The surface
24. AIE 8 1 Importing on GiD GiD is designed to import a variety of file formats Among them are standard formats such as IGES DXF or VDA which are generated by most CAD programs GiD can also import meshes generated by other programs e g in NASTRAN or STL formats 128 Files View Geometry Utilities Data Mesh Calculate Help eS New CtxCtr n os L 0 Z v IN d ayer W Open Ctrl o S Recent projects Q Save Ctrl s Save as Ctrl x Ctrl s Lo mapot Export DXF Ctrl d P lid lt Postprocess pod Recent post files d VDA a3 Printto file gt Bhinoceros Page image setup Shapefile P Print XYZ points KML Quit Ctrl q _ lt _ NASTRAN mesh lt T i STL mesh d VRML mesh Hj eK 3DStudio mesh m A CGNS mesh al GID mesh Surface mesh e xs Ply mesh e zr VTK Voxels YZ nodes 9 AK Batch file Ctrl b af Insert GID geometry ER User Manual The file importing process is not always error free Sometimes the original file has incompatibilities with the format required by GiD These incompatibilities must be overcome manually This example deals with various solutions to the difficulties that may arise during the importing process 8 1 1 Importing an IGES file 1 Select Files gt lmport gt IGES 2 Select the IGES formatted file base igs and click Open Processing IGES Figure 1 Reading the file
25. Also the visualization of all types of results can be performed It can be adapted to a specific analysis module by the creation of a problem type Typical problems that can be successfully tackled with GiD include most situations in solid and structural mechanics fluid dynamics electromagnetics heat transfer geomechanics etc using finite element finite volume boundary element finite difference or point based meshless numerical procedures 1 1 User interface Upon opening GiD the following window appears on the screen 2 User Manual i Gib Project L Files View Geometry Utilities Data Mesh Calculate Help OB oC BIS eS S 4 Gil Geometry I 4 Data ta Meshing a Files Go Si Top Menu View 9 iE Util P a Postprocess ae I Quit 2 escape 19 Toolbars A f2 Bw lt e E al A Right buttons P 2o gp E SN i TA e xy te Command line e am Save changes to this project y n x 19 43 Accepted new Graphical preferences E y 9 114 Hb Pa P Command gi f To change the configuration of toolbars and menus use the toolbars option located in Utilities gt Tools gt Toolbars 1 2 Top menu The Top Menu offers various types of commands It is important to note that these options will differ depending on the whether the user is performing a preprocessing or postprocessing analysis and that the options needed in each case differ as well Two possible configurations of the
26. Figure 17 Result of the rotation 4 3 4 Rotating the main pipe 1 From the Copy window select Surfaces and Rotation Enter an angle of 60 degrees Since the rotation may be done in 2D choose the Two Dimensions option The center of the rotation is the intersection of the axes namely point 200 0 Ensure the Do Extrude menu is set to No 2 Click Select and select all the surfaces except those defining the elbow of the pipe Press ESC when the selection is finished 70 User Manual 4 3 5 Creating the end of the pipe 1 From the Copy window select Surfaces and Rotation Enter an angle of 180 degrees Since the rotation may be done in 2D choose the option Two Dimensions The center of rotation is the upper right point of the pipe elbow Make sure the Do Extrude menu is set to No 2 Click Select and select the surfaces that join the two pipe sections 3 In the Move window select Surfaces and Translation The points defining the translation vector are circled in Figure 19 d NC s SN A Figure 19 The circled points define the translation vector 4 Click Select and select the surfaces to be moved Press ESC The result should be as is shown in Figure 20 Creating the end of the pipe 71 Es uH WT Lao Wi in II jl fi i le T i i i i I Figure 20 The final position of the translated elbow 5 Choose Geometry gt Create gt NU
27. Lines in order to select the lines to be translated Select only the lines that form the profile Figure 14 To conclude the selection process press the ESC key or click Finish in the Layers window Figure 14 Lines to be selected Deleting the aux layer 43 3 2 10 Deleting the aux layer 1 Click Off the profile layer 2 Choose Geometry gt Delete gt All Types or use the GiD Toolbox 3 Select all the lines and surfaces that appear on the screen The click and drag technique may be used to make the selection 4 Press ESC to conclude the selection of elements to delete 5 Select the aux layer in the Layers window and click Delete 6 Select the profile layer Wl NOTE When a layer is clicked Off GiD reminds you of this From this moment on whatever is drawn does not appear on the screen since it is in the hidden layer Wl NOTE To cancel the deletion of elements after they have been selected open the mouse menu go to Contextual and choose Clear Selection Wl NOTE Elements forming part of higher level entities may not be deleted For example a point that defines a line may not be deleted Wl NOTE A layer containing information may not be deleted First the contents must be deleted 3 2 11 Rotating and obtaining the final profile 1 Make sure that the activated layer is the profile layer Use the option Layer To use 2 In the Copy window select the line rotation Rotation Lines
28. RQ SBE SM DEA NOSSA NN N 2S NZ LAN SN SWAT MNR SAS SX N CERES NK A IA 4 SKS N oN LO D ITAL Hie x O A N KE ne i F i END W SPS TY EK aN A 7 SEAN TRS 25 p 7 SO DRIN LY A NN DIRE TN EL cu d VEDI LEDER eee S Sp e APO LS AT ERS E d 3 GLEE BAA SERVO SOK RRL LIP LY jd a VEL ETT LAD IRAYA AIST AS A A E a EVV x Ze HPD ra TT l MO MU E VAS PUI SOR MEI Se lt A KEK PEE SS AER EE SEDER TORRES KH AAACN AK NY WS C7 f gt A Q gt RN SN e N y IRK A EN SED WORE C RE PRR T iQ c M D C2 gt 5 Oo O 3 N D a Oo l Q i 2 h O 3 D 3 D V r ep tructured elements are present on the curved surfaces 147 9 DEFINING A PROBLEM TYPE This tutorial takes you through the steps involved in defining a problem type using GiD A problem type is a set of files configured by a solver developer so that the program can prepare data to be analyzed A simple example has been chosen which takes us through all the associated configuration files while using few lines of code Particular emphasis is given to the calculation of the centers of mass for two dimensional surfaces a simple formulation both conceptually and numerically The tutorial is composed of the following steps Starting the oroblemtype Creating the materials definition file Creating the general configurations file Creating the conditions definition f
29. Structured Semistructured Chooses default mesh Cartesian criteria meshing of Boundary layer determined entities or criteria not of others Deletes assigned information for y Generate mesh Erase mesh Edit mesh mesh generation Draw in different colors the different mesh View mesh boundary information Create boundary mes Mesh quality Generates the me l Mesh optonsirom mode Cancel previousl generated mesh Open the window with the last meshing error message Shows boundaries of meshing Shows quality of process mesh elements generated Create boundaries of meshing Process Defines a structured mesh No Lines I Surfaces Volumes gt Defines asemi structured Volumes Set Defines a cartesian mesh e Points _ N Lines lt I Surfaces T Volumes Assign element type to entities Default Linear T Triangle Quadrilateral Circle Tetrahedra Hexahedra Prism sphere Only points Edit and permits changes tothe mesh Move node Split elements d Smooth elements Collapse Delete b Mesh 9 1 2 7 Calculate This command calculates the problem according to the type of problem defined This option requires a previously activated interface between GiD and the corresponding calculation program Start calculation process Calculate Calculate Calculate remote Shows details af the Sends the mesh creaated by SID
30. VLA V a AV VLVLLVLVLELULULTLULULU A AA VEA EHLUHA EE YY AW VEVUULULVLTLULULTA VLULVLULULUCULULVUDA A A ty AVVO VY ORDRE AVVO V LVLVUCVLVUTA VI VI y AVVO VAYAMA VU VL VLA VI Y AVAVLVLALVLVLVLVLVLVLVLV VIV LV LV VLVLV UM V y WVLVVVVVIVVyVvy ul y AVWVWyWyVMWvVWyWwvVWyWyWvyMWy ViVay yay yv av iV ly ly V V v y v v V V VY V 34 GiD only allows the generation of structured meshes of 6 sided volumes NOTE With this example the user has been introduced to the basic tools for the creation of geometric entities and mesh generation 35 3 IMPLEMENTING A MECHANICAL PART 2D TOOLS BASIC 3D TOOLS AND MESHING IMPLEMENTING A MECHANICAL PART The objective of this case study is implementing a mechanical part in order to study it through meshing analysis The development of the model consists of the following steps Creating a profile of the part Generating a volume defined by the profile Generating the mesh for the part At the end of this case study you should be able to handle the 2D tools available in GiD as well as the options for generating meshes and visualizing the prototype 3 1 Working by layers 3 1 1 Defining the layers A geometric representation is composed of four types of entities namely points lines surfaces and volumes A layer is a grouping of entities Defining layers in computer aided design allows us to work collectively with all the entities in one layer The creation of a pro
31. circles Generating a volume mesh using points Generating a mesh using quadrilaterals Generating a structured mesh on surfaces and volumes Generating a semi structured volume mesh Generating a mesh using quadratic elements 6 1 Introduction In order to carry out this example start from the project ToMesh3 gid This project contains a geometry that will be meshed using different types of elements 6 1 1 Reading the initial project 1 In the Files menu select Read Select the project ToMesh3 gid and click Open 2 The geometry appears on the screen It is a set of surfaces and three volumes Select Render gt Flat from the mouse menu or from the View menu In Figure 1 shows the geometrical model loaded 3 Select Rotate Trackball from the mouse menu This option is also available in the GiD Toolbox Make several changes in the perspective so as to get a good idea of the geometry involved 92 User Manual Figure 1 Contents of the project ToMesh3 gid Finally return to the normal visualization Render gt Normal This mode is more user friendly The mouse menu appears when the right mouse button is clicked 6 2 Types Of Meshes Using GiD the mesh may be generated in different ways depending on the needs of each project The two basic types of meshes are the structured mesh and the unstructured mesh For volumes only there is one additional type the semi structured mesh For all these types of
32. click OK This results in a high concentration of elements in curved areas Now our approximation is significantly improved see Figure 9 Assignment with Maximum Chordal Error 85 Figure 9 Mesh using sizes assignment by chordal error Here there is a greater concentration of elements in the curved zones 5 3 Rjump mesher The RJump mesher is a surface mesher that meshes patches of surfaces in 3D space and is able to skip the inner lines of these patches when meshing By default the RJump mesher skips the contact lines between surfaces that are tangent enough and points between lines that are tangent enough By selecting Mesh gt Draw gt Skip entities Rjump the entities that RJump is going to skip and the ones that it is not going to skip are displayed in different colors In this chapter we will see the properties of this mesher 5 3 1 RJump default options 1 Select Mesh gt Reset mesh data to reset all mesh sizes introduced previously 2 A window appears advising that all the mesh information is going to be erased Press OK 3 Go to Utilities and open Preferences Click Meshing In the window that appears you can choose between the three surface meshers available in GiD RFast RSurf and RJump Select RJump mesher Click Accept 4 Select Mesh gt Generate Mesh 5 A window opens asking if the previous mesh should be eliminated Click Yes 6 Another window appears in which you can enter a maximum element size Leav
33. clicking on the play icon We will record a video during the animation 6 Once the animation is finished check the Save option You can choose from several video formats 7 Select AVI mjpeg to include this animation in a MS PowertPoint an apropiate codec is needed like the one supplied with Combined Community Codec Pack CCCP 8 Please select a folder where the video will be saved clicking on the folder icon or writing the path 9 Please click on the play button and the recording will begin This step could take a little bit long Wait until the red circle turns to green 10 Close the Animate window Now we will visualize another result but before we will clear all the results 11 Select View results gt No resultsthrough the menu bar or using the icon Rs Result surface 113 7 3 3 Result surface Another result visualization of interest is this one Pressure Pa 0 55866 0 41617 0 27 368 0 13118 0 011301 0 15379 0 29628 0 43877 0 58126 0 72375 Step 200 Result Surface of Pressure Pa factor 5 To get this visualization follow these steps 1 Switch off all the sets except S interior cil 6 2 Select View results gt Result surface gt Pressure A surface will be drawn which results from moving the nodes along its smoothed normal according to the results value for this node 3 Enter 5 as factor in the command line 4 Select Options gt Result surface gt Show elevations gt None 5 Se
34. ee KE x ZX gt E P KIT gt AD LN pt S d ZY gt ZA 2 GiD also allows the user to concentrate elements in structured meshes This can be done by selecting Mesh gt Structured gt Lines gt Concentrate elements First we must select the lines that need to be assigned an element concentration weight The value of 28 User Manual this weight can be either positive or negative depending on whether the user wants to concentrate elements at the beginning or end of the lines Next a vector appears which defines the start and end of the line and which helps the user assign the weight correctly Select the top line and assign a weight of 0 5 to the end of the line start yeight End vweight 00 A fs start veight End Weight u5 ESO From these operations we obtain the following mesh We can see that in the figure above the elements are concentrated in the left zone of the square WEXIXDEDEDE K X UA X I XXX XXX AAA X 2eSOS SSeS Jesse CS X AN DERRY X PO X gt lt XS eS eS eS XS eS PA I A Xp XX 2 A ei gt j 2 4 Creation and meshing of a volume We will now present a study of entities of volume To illustrate this a cube and a volume mesh will be generated Creation and meshing of a volume 29 Without leaving the project save the work done up to now by choosing Files gt Save and return to
35. enter the maximum element size Leave the default value unaltered and click OK The result is the mesh shown in Figure 13 Figure 13 Semi structured volume mesh of prisms and hexahedra NOTE As can be seen by selecting different element types for different geometrical entities several kinds of meshes can be generated Remember always to take care over the compatibility between element types in shared geometrical entities 102 User Manual 6 2 8 Concentrating elements and assigning sizes Select MeshStructuredLinesConcentrate elements Select some structured lines for example line 43 Press ESC A window comes up in which to enter two values for the concentration of elements Positive values concentrate the elements and negative values spread them Enter 1 as Start Weight and 0 5 as End Weight Press OK Select Mesh gt Generate mesh A window opens asking whether the previous mesh should be eliminated Click OK Another window appears in which to enter the maximum element size Leave the default value unaltered The result is the mesh shown in Figure 14 Figure 14 Concentration of elements on lines 3 and 23 lt is also possible to assign sizes to geometrical entities so that mesh elements can be concentrated in certain zones In the following steps some examples are given 7 Select Mesh gt Unstructured gt Assign sizes on points 8 A window appears in which to enter the size to be assigned to points Enter 0
36. gt Collapse gt Model 130 User Manual Preferences 4sieshing Exchange Fonts Format gt Import Automatic collapse after import Automatic import tolerance value Importtolerance 05984745 Collapse amp Ignoring layers C Each layer separately v IGES Curve on surface from 3D IGES Create all in layer to use Export IGES B Rep output style Figure 5 The Preferences window 8 2 Correcting errors in the imported geometry The great diversity of versions formats and programs frequently results in differences errors between the original and the imported geometry With GiD these differences might give rise to imperfect meshes or prevent meshing altogether In this section we will see how to detect errors in the imported geometry and how to correct them Importing the same file with different versions of GiD might produce slight variations in the results For this tutorial it s necessary load the project imported48 gid which contains the original IGES file translated into GiD format 8 2 1 Meshing by default 1 Select Mesh gt Generate Mesh A window comes up in which to enter the maximum element size for the mesh to be generated Leave the default value provided by GiD unaltered and click OK When the GiD finishes the meshing process an error message appears see Figure 6 This error is due to a defect in the imported geometry As the window shows there have been errors meshing surface numbe
37. important to obtain a precise mesh on the surfaces around the hole and on the surfaces of the teeth Initially we will generate a simple mesh by default Then we will generate a mesh using Chordal Error to obtain a more accurate result 60 User Manual The Chordal Error is the distance between each element generated by the meshing process and the real profile 3 7 1 Generating a mesh for the new design by default 1 Choose the option Mesh gt Generate mesh 2 Awindow appears in which to enter the maximum element size for the mesh to be generated Leave the default value provided by GiD unaltered and click OK Figure 45 A detail of the mesh generated by default 3 7 2 Generating a mesh using Chordal Error 1 Choose Mesh gt Unstructured gt Sizes by Chordal error 2 Provide the values shown in figure 46 Assign sizes by chordal error Chordal Error 0 05 Maximum meshing size 1 5 Minimum meshing size 0 1 OK Cancel M Figure 46 Chordal error window 3 Choose Mesh gt Generate mesh 4 A greatly improved approximation has been achieved in zones containing curves and more specifically along the wheel profile and the profile of the hole see Figure 47 Figure 47 A detail of the mesh generated using Chordal Error 61 4 IMPLEMENTING A COOLING PIPE ADVANCED 2D amp 3D TECHNIQUES AND MESHING IMPLEMENTING A COOLING PIPE This case study shows the modeling of a more complex piece and conc
38. is meshed with quadrilaterals forming an unstructured mesh surface 12 seems structured but if you zoom in you will see that it is not 96 User Manual 6 2 5 Generating a structured mesh surfaces 1 To mesh surfaces with a structured mesh select the option Mesh gt Structured gt Surfaces gt Assignnumber of cells Select all top surfaces 9 24 26 and 12 and press ESC A window appears in which to enter the number of divisions that the lines to be selected will have Enter 4 Press Assign and select one vertical line parallel to the Y axe Press ESC Another window appears in which to enter the number of divisions on the lines Enter 6 Press Assign and select the 4 bottom lines Press ESC Another window appears in which to enter the number of divisions on the lines In this case all the N N o Oo A boundary lines have already been defined Therefore click Close Select Mesh gt Element type Triangle Select surfaces 26 and 12 Co E ANN 9 RRR B XX RAY X AS E uw NS 4 44 E 1 M c CIE x ce gt 3 are ftt RA A MIAN NETS LN BS AE E P Wer uot SUL S i 7 DS i D Figure 7 Structured mesh of quadrilateral and triangular elements on surfaces IO 9 Select MeshGenerate mesh 10 A window comes up asking whether the previous mesh sould be eliminated Click Ok 11 Another window appears in wihich to ente
39. junction is imported 2 Choose Geometry gt Create gt NURBS Surface gt By contour and then select the lines defining the outlet in the foreground of Figure 28 Press ESC see Figure 28 Figure 28 Creating a NURBS surface to close the outlet in the foreground 3 Repeat the process for the other outlet to be closed 4 From the Files menu select Save to save the file Enter a name for the file and click Save 4 5 Importing the T Junction to the main file The two parts of the model have been drawn Now they must be joined so that the final volume may be created and a mesh of the volume may be generated 4 5 1 Importing a GiD file 1 Choose Open from the Files menu Select the file where the first part created in section 3 was saved Click Open 2 Choose Files Import Insert GiD geometry from the menu Select the file where the second part created in section 4 was saved Click Open 3 The T junction appears Bear in mind that the lines which define the end of the first pipe background of the T junction and which have been imported were already present in the first file Importing a GiD file 75 Notice that the lines overlap This overlapping will be remedied by collapsing the lines i Ro mmm a Uu E EI Figure 29 Importing the T junction file to the main file Some points are duplicated and must be collapsed 4 Choose the option Geometry gt Edit gt Collapse gt Lines Select the overlapp
40. lines 3 5 1 Generating the mesh by default 1 Choose Mesh Generate Mesh 2 A window comes up in which to enter the maximum element size of the mesh to be generated Figure 28 Leave the default value given by GiD unaltered and click OK Generating the mesh by default 51 Mesh generation Enter size of elements to be generated 3 A window appears showing how the meshing is progressing Once the process is finished another window opens with information about the mesh that has been generated Figure 29 Click OK to visualize the resulting mesh Figure 30 Dialog window Mum of Tetrahedra elerents 31 70 Mum af nadesz1148 Figure 30 The mesh generated with default settings 4 Use the Mesh View mesh boundary option to see only the contour of the volumes meshed without the interiors Figure 31 This visualization mode may be combined with the various rendering methods 52 User Manual TEXT m Le M A A gt on e HEN ae RI SA i LANI ANE Cam cro E i Mus i M Th Ri nn M Bd UN ME mL SE esp v SN vei ASSI SUR een CRORE NL E NECS g Ire A Tac EEE ek RRN Eao n EKN 7 oe Ue ce I P re 4 iz F Lr Hi ORE e Ta i Ls zi P S iem E n s t7 LA m di ed Mn me ut A a a TA aS A Vi y K ia ras a E Xd t X v NM TAS t fi grae gt it 2 FE M e th m X Fe 3 rz x P
41. mesh a variety of elements may be used linear ones triangles quadrilaterals circles tetrahedra hexahedra prisms spheres or points In this tutorial you will become familiarized with the mesh generating combinations available in GiD A structured mesh is one in which each node is connected to a constant number of elements A semi structured volume mesh is one in which you can distinguish a fixed structure in one direction i e there is a fixed number of divisions However within each division the mesh need not be structured This kind of mesh is only practical for topologically prismatic volumes 6 2 1 Generating the mesh by default 1 Select Mesh gt Generate mesh 2 A window comes up in which to enter the maximum element size for the mesh to be generated Leave the default value unaltered and click OK 3 A meshing process window comes up Then another window appears with information about the mesh generated Click OK to visualize the mesh 4 The result is the mesh in Figure 2 There are various surfaces and volumes By default mesh generation in GiD obtains unstructured meshes of triangles on surfaces and tetrahedra on volumes 5 Select Render gt Flat to see the mesh in render mode As is shown in Figure 3 volume meshes are Generating the mesh by default 93 represented a little bit differentlyfrom surface meshes although in both cases triangles are shown If the triangles you see are the boundary of a volume me
42. on Our model is composed by 11 layers Now we will change all the layers to boundaries style 2 Select all the layers 3 Select Boundaries in the Style option at the bottom of the window You can also do it clicking on par in the St column or the same icon in the main window 4 By selecting one set and right clicking on one corresponding style icon at the St column the style for the selected mesh is changed Bear in mind that a boundary visualization of the surface of a Changing mesh styles 109 sphere nothing will be visualized as a sohere surface has no borders 5 Play a little with the options of these windows but to continue the tutorial let a Boundaries style selected for all meshes 6 Click on Close button Contextual d Zoom d Rotate d Fan d i Redraw Renger d Label d f Image to clipboard sl Quit Mouse menu Clicking the right mouse button on the main graphical window opens an on screen menu with some visualization options To select one of them use the left or right mouse button to quit left click anywhere outside the menu The first option in this menu is called Contextual You can select from different options relevant to the function currently being used Zoom Rotate Pan and Redraw are the same options as in preprocess mode Label node element or result shows a label with the current node number element number or current visualizaed result s value for the selected nodes or gauss poin
43. parallel to the Y axis into 8 segments Enter 8 and click OK 6 Select an edge of volume 1 or 2 parallel to the Y axis and press ESC Again the line division window comes up Since we have already finished the assignments click Close 98 User Manual Figure 9 Structured volume mesh of hexahedra an tetrahedra 7 For structured volumes GiD generates hexahedron meshes by default but tetrahedron structured meshes can also be assigned Select Mesh gt Element type gt Tetrahedra and then select volume number 2 Select Mesh gt Generate mesh 8 A window appears asking whether the previous mesh should be eliminated Click Yes 9 Another window comes up in which to enter the maximum element size Leave the default value unaltered and click OK The result is the mesh shown in Figure 10 10 GiD can obtain volume structured meshes made of hexahedra tetrahedra or prisms As can be seen in Figures 9 and 10 there are two kinds of tetrahedron structured mesh the one shown in Figure 9 is obtained when the option Utilities gt Preferences gt Meshing gt Symmetrical structured tetrahedra is set If this option is not set the mesh presented in Figure 10 is produced with fewer nodes than if using the previous option also it is not topologically symmetrical Generating structured meshes volumes 99 Figure 10 Structured volume mesh of tetrahedra with the option Symmetrical structured tetrahedra not set 6 2 7 Generating semi str
44. point element on the line closest to the coordinates entered 2 Enter the coordinates of the point that will divide the line In this example the coordinates are 40 0 On dividing the line a new point entity has been created 3 Select the line that is to be divided by clicking on it 4 Press ESC to indicate that the process of dividing the line is finished Figure 3 Division of the straight line near point coordinates 40 O 3 2 3 Creating a 3 8 radius circle around point 40 0 1 Choose the option Geometry gt Create gt Object gt Circle 2 The center of the circle 40 0 is a point that already exists To select it go to Contextual gt Join Ctrl a in the mouse menu right click The pointer will become a square which means that you may click an existing point 3 The Enter Normal window appears Set the normal as Positive Z and press OK 4 Enter the radius of the circle The radius is 3 8 Two circumferences are visualized the inner circumference represents the surface of the circle Press ESC to indicate that the process of creating the circle is finished unt Figure 4 Creating a circle around a point 40 O In GiD the decimals are entered with a point not a comma 38 User Manual 3 2 4 Rotating the circle 3 degrees around a point 1 Use the Move window which is located in Utilities gt Move 2 Within the Move menu and from among the Transformation possibilities select Ro
45. surfaces and cuts should be drawn 1 4 Mouse menu 17 IW Ooo we WS x Switch volume sets on or off d Switch surface sets on or off Switch cuts sets on or off FN j Do cuts 2 points 3 points succession axis Set m ximum value Set minimum value Set logaritmic view Set multiplier factor n iN ZW S e Set adder factor Reset contour limit values Contour fill Permits listing of project entities The Mouse Menu is the auxiliary menu which appears by clicking on the right mouse button while the cursor is over the GiD screen The Mouse Menu permits the user to quickly access various image placement and viewing commands to facilitate easy management and definition of the project Furthermore the Mouse Menu contains the Contextual menu which permits the user to access to all options available in previously performed commands The option Contextual is only available after the user has performed a command from the Top Menu 18 I User can access options available in A In P Qut Dynamic Previous Next each distinct command once they have been executed Frame Offers various zoom options far viewing of piece User Manual Iwo point JL Dynamic Offers varinus iluminati an options for the image Zoom z Elat Offers various rotation options Rotate Smooth Pan d Trackball Redraw Change light dir Screen axes Render e
46. the geometry last created by choosing Geometry gt View geometry In order to create a volume from the existing geometry firstly we must create a point that will define the height of the cube This will be point 5 with coordinates 0 0 10 Superimposed on point 1 To view the new point we must rotate the figure by selecting from the Mouse Menu RotateTrackball This option is also available in the toolbar 9 Rotate the figure until the following position is achieved Next we will create the upper face of the cube by copying from point 1 to point 5 the surface created previously To do this select the copy command Utilities gt Copy In the Copy window we define the translation vector with the first and second points in this case 0 0 0 and 0 0 10 Option Do extrude surfaces must be selected this option allows us to create the lateral surfaces of the cube 30 User Manual Entities type Surfaces 7 Transformation Translation 7 First paint um x 0 0 v OO e z lI second point Num x OO v 0 0 a z 0 Duplicate entities Do extrude Surfaces Create contacts Maintain layers Multiple capies 1 Select Cancel NOTE If we look at the Copy Window we can see an option called Duplicate entities By activating this option when the entities are copied in this case from point 1 to point 5 GiD would create a new point point 6 with the same coordinates as point 5 If the user does not choose op
47. the ESC key the center mouse button or the mouse wheel can also be used Assignment around lines 83 5 2 3 Assignment around lines 1 Select Mesh gt Unstructured gt Assign size on lines In the window that appears enter the size of the elements around the lines that will be chosen Enter 0 5 and click OK 2 Select the lines defining the base of the prism i e lines 1 2 3 4 and 40 To see entity numbers select Label from the mouse menu or from the View menu If you wish geometrical entity labels to be displayed the view mode has to be set to Geometry using View gt Mode gt Geometry this option may also be found in the GiD Toolbox and the render mode must be set to Normal Press ESC 3 Select Mesh gt Generate Mesh 4 A window opens asking if the previous mesh should be eliminated Click Yes 5 Another window appears in which you may enter a maximum element size Leave the default value unaltered and click OK This results in a high concentration of elements around the chosen lines given that the selected element size 0 5 is much smaller than that of the rest of the elements in the model see Figure 7 Figure 7 Mesh with a concentration of elements around lines 5 2 4 Assignment on surfaces 1 Select Mesh gt Unstructured gt Assign size on surfaces In the window that appears enter the size of the elements to be assigned on the surfaces that will be chosen Enter 0 5 and click OK 2 Select the triangular su
48. the last two lines created and the vertical line segment coming down from the tangential center see Figure 12 Press ESC OOE N S Figure 12 Selecting the lines to intersect 9 Choose Geometry gt Delete gt All Types This tool may also be found in the GiD Toolbox Select the lines and points beyond the vertical that passes through the tangential center Press ESC They will be deleted and the result should look like that shown in Figure 13 Creating the profile 67 Figure 13 Profile of the pipe and the auxiliary lines 4 3 2 Creating the volume by revolution 1 Rotation of the profile will be carried out in two rotations of 180 degrees each This way the figure will be defined by a greater number of points 2 From the Copy window select Lines and Rotation Enter an angle of 180 degrees and from the Do extrude menu select Surfaces The axis of rotation is that defined by the line that goes from point 0 0 to point 200 0 Enter these two points as the First Point and Second Point Be sure to enter 1 in Multiple Copies 3 Click Select For an improved view when selecting the profile click Off the aux layer Press ESC when the selection is finished The result should be that illustrated in Figure 14 Figure 14 Result of the first step in the rotation 180 degrees 4 Repeat the process this time entering an angle of 180 degrees 5 To return to the side view elevation choose Rotate gt Plane XY 68 Us
49. to p calculation process a remote server which calculates View process info Calculate window __ Opens the calc late window Interrrupts the calculation process 1 2 8 Help This menu permits the user to obtain different types of help and information about GiD Interactive help covering all GID options Help on how to configure GID for a particular type of analysis What is newin this version Help GID tutorials Help F1 Customization Help Tutorials What is new Frequently asked FACE questions about GID Use this option ta register GID and useits professional versian Register GiD Register Problem ype Regi ster problem types Visit GID web pati About Go to the oficial website Gives basicinformaton far GID and the versi n being used 10 User Manual 1 2 9 Files GID PostProcess bil Gib Project UNNAMED edge Files View Utilities Do cuts View results Options Window Help This Top Menu of the postprocess phase is the same of that as the preprocess phase and has the same name The user can read and save files save screen images return to preprocess phase options and exit the program Reads mesh and results information from an ASCII file Starts a new postprocess ject projec Open the last post files Files Reads postpracess qe m New Impart files ern Gp a HASTRAN mesh ie multiple FEMAP file Read
50. two textures to eee To delete meshes sets View b To collapse nodes those Add b Volume sets are together in a set Change surface sets Cut sets d 12 User Manual 1 2 11 Do cuts With the option Do cuts the user can make cuts through entities Makes parallel sections defining an axis in the normal direction ta the cuts and the numer af divisians desired alongthis us Divides volumen sets in two parts cutting through tow points and relative to the plane perpendicular ta the Creates a set with the user screen ar by three selection tw Cut Plane gt Divides surface sets in two Makes sectian through a Divide by selection parts cutting through two plane This can be defined by Divide volume sets d points and relative to the plane two points and relative to the Drade surface sets 4 perpendicular to the screen or plane perpendicular ta the Divide lines by three points screen or by three points i Cut Wire Cut Sphere Convert cuts to surface sets Automatically convert cut to set Makes a spherical cut ly The user specifies a plane whichis used to get the lines at ane side of this With this options cuts can be plane converted to surface sets automatically or manually sa they can be saved or cut again Do cuts 13 1 2 12 View results This option permits the user to choose the viewing type in which the results of the postprocess calculation will be presented Results
51. user wants to view everything that has been created to this point the image can be centered on the screen by choosing in the Mouse Menu Zoom gt Frame This option is also available in the toolbar Finish the square by creating point 10 10 0 and the lines that join this point with points 2 and 3 3 0 10 0 1 0 0 2 10 0 0 Now we will create the surface that these four lines define To do this access the create surface command by choosing Geometry gt Create gt NURBS surface gt By contour This option is also available in the toolbar GiD then asks the user to define the 4 lines that describe the contour of the surface Select the lines using the cursor on the screen either by choosing them one by one or selecting them all with a window Next press Escape As can be seen below the new surface is created and appears as a smaller magenta colored square drawn inside the original four lines Once the surface has been created the mesh can be created in the same way as was done for the line From the Top Menu select Mesh gt Generate mesh An Auxiliary Window appears which asks for the maximum size of the element in this example defined Creation and meshing of a surface 25 as 1 POAAKARS ORR ES OAR vA DY gt AERO Va S OOOO We can see that the lines containing elements of two nodes have not been meshed Rather the mesh generated over the surface consists of planes of three nodded triangular elemen
52. 1 9 Select point number 15 and press ESC 10 11 12 13 14 15 16 17 Another window appears in which to enter the size to be assigned to points In this case we donot want to assign sizes to any other points so click Close Select Mesh gt Unstructured gt Assign sizes on lines A window appears in which to enter the size to be assigned to lines Enter 0 5 Select line number 25 and press ESC Another window appears in which to enter the size to be assigned to lines In this case we do not want to assign sizes to any more lines so click Cancel Select Mesh gt Generate mesh A window appears asking whether the previous mesh should be eliminated Click Ok Another window appears in which the maximum element size should be entered Leave the default value unaltered The result is not the desired we just get the previous mesh This is because surrounding surfaces and lines are structured so they do not have enought freedom to achive the Concentrating elements and assigning sizes 103 given sizes 18 SelectMesh gt Unstructured gt Assign entities gt Surfaces 19 Select Surfaces 26 and 12 Press ESC 20 SelectMesh gt Unstructured gt Assign entities gt Lines 21 Select lines 48 26 and 27 Press ESC 22 Select Mesh gt Generate mesh 23 A window appears asking whether the previous mesh should be eliminated Click OK 24 Another window appears in which the maximum element size should be entered Leave the default v
53. 2 5 Select the line resulting from the 33 degree rotation executed in section 2 6 see Figure 10 Press ESC to conclude the intersection of lines c1 A O N Create a line between point 55 0 and the point generated by the intersection To select the points use the option Join Ctrl a in the Contextual menu 6 Choose the option Geometry gt Edit gt Intersection gt Line line in order to make another intersection between the lower circle and the line segment between point 40 0 and point 55 0 see Figure 11 7 Then continue selecting to make an intersection between the upper circle and the farthest segment of the line that was rotated 36 degrees see Figure 12 2 Figure 10 The two lines selected Figure 11 Intersecting lines Figure 12 Intersecting lines 42 User Manual 3 2 8 Creating an arc tangential to two lines 1 Choose Geometry gt Create gt Arc gt Fillet curves 2 Enter a radius of 1 35 inside the command line see footnote 2 3 Now select the two line segments shown in Figure 13 Then press ESC to indicate that the process of creating the arcs is finished _ a Figure 13 The line segments to be selected 3 2 9 Translating the definitive lines to the profile layer 1 Select the profile layer in the Layers window The auxiliary lines will be eliminated and the profile layer will contain only the definitive lines 2 In the Sent To menu of the Layers window choose
54. 2E View results Main Mesh Reference mesh View Contour Fill M step Analysis RANSOL 105 5 a Pressure Fa Velocity m s 2 Vorticity 1 s Apply Close 7 3 1 Iso surfaces Menu View results gt lso Surfaces With this result visualization a surface or line is drawn passing through all the points which have the same result s value inside a volume mesh or surface mesh To create isosurfaces there are several options 1 Select View results gt lso Surfaces gt Automatic Width gt Velocity m s gt V throught the menu bar or clicking on SN After choosing the result you are asked for a width This width is used to create as many isosurfaces as are needed between the Minimum and Maximum defined values these are included 2 Select the default value 3 Select View gt Render gt Smooth in order to get a better view Several configuration options can be set via the Options menu Iso surfaces 111 Menu Options gt Iso surfaces In order to see the inner zones we will set the transpacency on the iso surfaces 4 SelectOptions gt lso surfaces gt Transparency gt Transparent 5 Move the model to see the inner zones 6 SelectOptions gt lso surfaces gt Transparency gt Opaque 1 3137 1 0509 0 78819 0 52546 0 26273 z A step 103 Iso Surfaces of Velocity m s V Other interesting options are Options gt lso surfaces gt convert to cutwhich consolidates the isosurface as me
55. Chordal Error 4 6 2 Generating the mesh by assignment of sizes on surfaces 5 ASSIGNING ELEMENT SIZES 5 1 Introduction 5 1 1 Reading the initial project 44 44 45 46 46 47 49 50 50 53 55 56 56 58 59 59 60 60 61 61 61 62 62 63 65 65 67 68 69 70 71 71 72 13 73 74 74 74 75 76 76 7 19 19 19 iV User Manual 5 2 Element size assignment methods 80 5 2 1 Assignment using default options 80 5 2 2 Assignment around points 81 5 2 3 Assignment around lines 83 5 2 4 Assignment on surfaces 83 5 2 5 Assignment with Maximum Chordal Error 84 5 3 Rj ump mesher 85 5 3 1 RJump default options 85 5 3 2 Force to mesh some entity 87 6 METHODS FOR GENERATION THE MESH 91 6 1 Introduction 91 6 1 1 Reading the initial project 91 6 2 Types Of Meshes 92 6 2 1 Generating the mesh by default 92 6 2 2 Generating the mesh using circles and spheres 94 6 2 3 Generating the mesh using points 94 6 2 4 Generating the mesh using quadrilaterals 95 6 2 5 Generating a structured mesh surfaces 96 6 2 6 Generating structured meshes volumes 97 6 2 7 Generating semi structured meshes volumes 99 6 2 8 Concentrating elements and assigning sizes 102 6 2 9 Generating the mesh using quadratic elements 103 7 POSTPROCESSING 107 7 1 Loading the model 107 7 2 Changing mesh styles 108 7 3 Viewing the results 110 7 3 1 Iso surfaces 110 7 3 2 Animate 111 7 3 3 Result surface 113 7 3 4 Contour fill cuts and limits 114 7 3 5 Combine
56. GiD User Manual he personal pre and postprocessor Table of Contents Chapters Pag 1 PRESENTATION OF GiD 1 1 1 User interface 1 1 2 Top menu 2 1 2 1 Files Pre 2 1 2 2 View 4 1 2 3 Geometry 5 1 2 4 Utilities Pre 6 1 2 5 Data 7 1 2 6 Mesh 8 1 2 7 Calculate 9 1 2 8 Help 9 1 2 9 Files 10 1 2 10 Utilities 11 1 2 11 Do cuts 12 1 2 12 View results 13 1 2 13 Options 14 1 2 14 Postprocess windows 15 1 3 Toolbars 16 1 4 Mouse menu 17 1 5 Command line 18 2 INITIATION TO GiD 19 2 1 First steps 19 2 2 Creation and meshing of a line 19 2 3 Creation and meshing of a surface 23 2 4 Creation and meshing of a volume 28 3 IMPLEMENTING A MECHANICAL PART 35 3 1 Working by layers 35 3 1 1 Defining the layers 35 3 1 2 Creating two new layers 36 3 2 Creating a profile 36 3 2 1 Creating a size 55 auxiliary line 36 3 2 2 Dividing the auxiliary line near point coordinates 40 0 37 3 2 3 Creating a 3 8 radius circle around point 40 0 37 3 2 4 Rotating the circle 3 degrees around a point 38 3 2 5 Rotating the circle 36 degrees around a point and copying tt 38 3 2 6 Rotating and copying the auxiliary lines 39 3 2 7 Intersecting lines 41 3 2 8 Creating an arc tangential to two lines 42 3 2 9 Translating the definitive lines to the profile layer 42 3 2 10 Deleting the aux layer 43 3 2 11 Rotating and obtaining the final profile 43 Table of Contents 3 2 12 Creating a surface 3 3 Creating a hole in the part 3 3 1 Creating a hole i
57. Now it s necesary regenerate the surface Go to Geometry gt Create gt NURBS surface 12 Select the lines of old surface 124 and press ESC 13 Select Mesh gt Generate 14 Visualize the results with Mesh gt View mesh boundary Some of the contiguous surfaces in the interior of the model have now being joined However there are still some surfaces that prevent the mesh from being completely conformal These surfaces must be modified manually M UO o UM ML By VEND aaan i a T E UU M Figure 17 The mesh after the collapse 138 User Manual 8 3 2 Correcting surfaces and creating a conformal mesh 1 With the option View gt Zoom In magnify the zone illustrated in Figure 18 L J T M Figure 18 Zone in the mesh to zoom in Select View gt Mode gt Geometry to visualize the geometry of the piece aos ti Brea j i a 2 Jj j i PL Fi i fi i i i i r i for fr Gd y IT A FS LU JA aul F Ma 4 i Figure 19 An image like that shown in Figure 19 appears There is a rectangular surface that does not fit within the boundaries of a rounded corner surface a hole in this case We will suppose that the problematic surface is planar This way it can be erased and recreated in order to fit the rounded corner boundary Select Geometry gt Delete gt Surfaces Select the problematic surface and press ESC Select Geometry gt Delete gt Lines
58. RBS Surface gt By contour and select the four lines that define the opening of the pipe Figure 21 Press ESC 6 From the Files menu choose Save in order to save the file Enter a name for the file and click Save Figure 21 Opening at the end of the pipe 4 4 Creating the T junction Now an intersection composed of two pipe sections will be created in a separate file and the surfaces will be trimmed Then this file will be imported to the original model to create the entire piece 4 4 1 Creating one of the pipe sections 1 Choose Files gt New thus starting work in a new file 2 Choose Geometry gt Create gt Point and enter points 0 9 and 0 11 Press ESC to conclude the creation of points 3 From the Copy window select Points and Rotation Enter an angle of 180 degrees and from the Do extrude menu select Lines The axis of rotation is the x axis Enter two points defining the axis one in First Point and the other in Second Point for example 0 0 0 and 100 0 0 Figure 22 4 Click Select and select the two points just created 5 Repeat the process this time entering an angle of 180 degrees thus creating the profile of the pipe section with a second rotation of 180 degrees The rotation could have been carried out in only one 12 User Manual rotation of 360 degrees However in the present example each circumference must be defined between two points Figure 23 A Z Figure 23 The combined r
59. Select the lines forming the problematic surface and press ESC Use the option Geometry gt Delete gt Points to erase the points that do not belong to any surface With Geometry gt Create gt NURBS surface gt By contour create a new surface The result is shown in Figure 20 Correcting surfaces and creating a conformal mesh 139 Figure 20 Visualize the mesh again using Mesh gt View mesh boundary and magnify the zone indicated in Figure 21 T D 7 A LA M icm ee j UL f Tee Figure 21 140 User Manual Select View gt Mode gt Geometry In this example the situation involves a contour of four lines that does not correspond to any real surface of the piece These lines were too far apart to be collapsed Figure 22 Figure 22 Select Geometry gt Create gt NURBS surface gt By contour Select the lines Press ESC Magnify the zone indicated in Figure 23 eee j i Er c zn c f ana n pee ee Figure 23 There are two surfaces that overlap each other at one end Figure 24 SS Figure 24 The magnified zone with two overlapping surfaces In this case the best solution for correcting the boundary is to trim the overlap Select Correcting surfaces and creating a conformal mesh 141 Geometry gt Create gt NURBS Surface gt Trimmed Select the surface to be trimmed Then select the new boundary Figure 25 Figure 25 The surface to be trimmed
60. TA In GiD the information in the cmas2d prb file is managed in the problem data window which is located in Data Problem Data Problem Data Unit System SI Tithe Default_title The GiD Problem Data window for configuring of the general conditions of the cmas2d module PROBLEM DATA QUESTION Unit_System CB SI CGS User VALUE SI QUESTIONS Title VALUE Default_title END GENERAL DATA 9 2 3 Creating the Conditions File Create the cmas2d cnd file which specifies the boundary and or load conditions of the problem type in question In the present case this file is where the concentrated weights on specific points of the geometry are indicated Enter the boundary conditions using the following format CONDITION Name of the condition CONDTYPE Type of entity which the condition is to be applied to This includes the parameters over points over lines over surfaces over volumes or over layers In this example the condition is applied over points CONDMESHTYPE Type of entity of the mesh where the condition is to be applied The possible parameters are over nodes over body elements or over face elements In this example the condition is applied on nodes QUESTION Name of the parameter of the condition VALUE Default value of the parameter 152 User Manual END CONDITION In GiD the information in the cmas2d cnd file is managed in the conditions window which is found in Data Condi
61. The graph size is readapted We will change several style options of a graph 5 Select the second grahp of the list Line_Graf_in_up 2 6 Select Line in the Style option 7 Set to red the Color option You can do it writing ffO000 or selecting the red clicking on the right color window 8 Set to 4 0 the Line width 9 Click on Apply button 10 Click on Close button We can export the graph information in order to open it later with GiD 11 Select Files gt Export gt Graph gt All You are asked for the location where to save the grf file 12 Choose the location Now you can import the selecting Files gt Import gt Graph 13 Select Options gt Graphs gt Clear graphsin order to delete all the graphs 124 User Manual cas nis MNNNMNNENEEENNEKNR 5 Create General Options Coordinates Type Graph Management Options 7 4 Creating images Style Color Color as contour fill 4 0 Line width _ Pattern Pattern factor 1 5 0 Point size Nama Line Graf in u p fe Apply Close Menu Files gt Page and capture settings Finally we will take some snapshots of our model You can save images in several formats The properties of the image resolution size etc can be assigned in Page and capture settings option Check the Auto crop A U N Click on Close button Select Files gt Page and c
62. Top Menu are presented below iil cio Project UNNAMED MMNENENNENI Files View Geometry Utilities Data Mesh Calculate Help And in the postprocessing phase bil Gib Project UNNAMED edgebased levelse Files View Utilities Do cuts View results Options Window Help These two options will be presented in more detail later Next each drop down menu in the Top Menu will be described in detail 1 2 1 Files Pre Two main types of functions can be controlled in this menu 1 the handling of files i e create read save etc of GiD projects and 2 the importing and exporting of files Files Pre Creates a new project Reads a previously created GID raject Saves to disc all infarmatian related to the project Saves information with name chosen by the user Changes the configuration for postprocess phase Saves the drawing Postprocess image show on the Recent post files screen in one of the p Print to file following formats Page image setup Prnt Quit PS EPS Screen FS EFSVectorial BMP GIF JPEG PNG TGA TIFF Closes GID Send the image to the printer Open the last models IGES DF Farasalid ACIS VDA Rhinoceros Shapetile are points EML NASTRAN mesh STL mesh YRML mesh 3DStudio mesh COGNS mesh GID mesh Surface mesh Fly mesh VTK Vowels ae nodes Batch file
63. V VIXI TK J A NN pe D m SS SESS Se p ad Moa Hh RIS REA ALS Saas di Figure 3 Meshing by default Zone where elements are smaller because of the surface shape 5 2 2 Assignment around points 1 Select Mesh gt Unstructured gt Assign size on points A window appears in which to enter the element size around the points to be chosen Enter 0 1 and click OK 2 Select the point indicated in Figure 4 Press ESC to indicate that the selection of points is finished 3 Select Mesh gt Generate Mesh 4 A window opens asking whether the previous mesh should be eliminated Click Ok 5 GiD then asks you to enter the maximum element size Leave the default value unaltered and click OK 82 User Manual X SAMA NNSA ES V TE ssi A Wes CRRA SISO Wo gt Vas eae eae HEROD ERERER SSeS WE CUO REESE Sh mne EAE CURSUM My Wee eS Ones CM WIE A ld ut AUN WEERSKCA Figure 4 Geometry of the model The point around Figure 5 The mesh with a concentration of which the mesh will be concentrated elements around the point 6 A concentration of elements appears around the chosen point given the selected size 0 1 of these elements see Figure 5 7 Go to Utilities and open Preferences Click Meshing In the window that appears there is the option Unstruc
64. a mers tay NEM he a or DR A Vi xiu CHE U y iin mm acu ims V n Hh M i i GAO Hn ur x ALS Wei aum PR P Cie ACE X O x E an ED is AP i T EA pod A kra en XS E a A a i NL 75 Los EX v3 m Y M m i Y 1 me as i i a rag A x Ri XL H EY n a E 3 um Va af E LEE on Fi AN EE NS L et ey a ee fo JL bm H aa REM pee ww eek abe i Plt Tm L Figure 31 Mesh visualized with the Mesh gt View mesh boundary option 5 Visualize the mesh generated with the various rendering options in the Render menu located in the mouse menu Generating the mesh by default 53 Figure 32 Mesh visualized with MeshView mesh boundary combined with RenderFlat 6 Choose View gt Mode gt Geometry to return to the normal visualization NOTE To visualize the geometry of the model use View gt Mode gt Geometry To visualize the mesh use View gt Mode gt Mesh 3 5 2 Generating the mesh with assignment of size around points 1 Enter view rotate angle 90 90 ESC in the command line This way we will have a side view i Wi Figure 33 Side view of the part 2 Choose Mesh gt Unstructured gt Assign sizes on points A window appears in which to enter the element size around the point to be selected Enter 0 7 54 User Manual 3 Select only the points on the wheel profile Fi
65. alue unaltered The result is the mesh shown in Figure 15 Figure 15 Unstructured size assigned in a point and a line 10 Start Weight and End Weight refer to the start point and end point of the line oriented as it is drawn when you select it 6 2 9 Generating the mesh using quadratic elements Select Zoom In from the mouse menu this option may also be found in the GiD Toolbox or in the View menu Enlarge one area of the mesh e g the zone near point number 3 1 Select Label gt All in gt Points The result is shown in Figure 16 104 User Manual Lf Fal Figure 16 Each number identifies a node There is a node for each element vertex 2 The node identifiers created by generating the mesh appear on the screen There is one identifier for each vertex of each element 3 Select Utilities gt Preferences gt Meshing gt Quadratic type gt Quadratic Wl NOTE By default GiD meshes with first degree linear elements To find out which mode GiD is working in goes to Utilities gt Preferences gt Meshing gt Quadratic type 4 Select Mesh gt Generate mesh 5 A window opens asking whether the previous mesh should be eliminated Click OK 6 Another window appears in which the maximum element size should be entered Leave the default value unaltered and click OK 7 Once the mesh has been generated select Label gt All in gt Points The result is shown in Figure 17 Now there are not only nodes at the vertices but als
66. and the new boundary Select Geometry gt Delete gt Surfaces Select the original surface Figure 26 Press ESC Figure 26 The original surface to be deleted Use Geometry gt Delete gt Lines and Geometry gt Delete gt Points to select the lines and points that belong to the surface that has been trimmed and which no longer belong to any surface Figure 27 142 User Manual Figure 27 Lines and point that no longer belong to any surface Select Mesh gt Generate Mesh Then visualize the result using the option Mesh gt View mesh boundary T a RA j T Tea m Figure 28 The mesh visualized with the option MeshView mesh boundary A conformal mesh has been achieved In this case all the visible lines may be selected since the program will only eliminate those which do not have entities covering them that is those which belong to the problematic vertices 8 3 3 Creating a non conformal mesh NOTE Non conformal meshes may be used with some calculating modules i e stamping a plate Using non conformal meshes significantly reduces the number of elements in the mesh This cuts down on computation time 1 Select View gt Mode gt Geometry Creating a non conformal mesh 143 2 Select Geometry gt Edit gt Uncollapse gt Surfaces Select all the surfaces in the model Press ESC A sufficient number of lines is created so that no surface of the object shares lines with any contiguous Surface
67. anges made relative to the previous design This example begins with a file named optimizacion gid 3 6 1 Modifying the profile 1 First download the Preprocess Tutorial 1 from our web www gidhome com Inside Support Tutorials Choose Open from the Files menu and open the file optimizacion gid 2 The file contents appear on the screen In order to work more comfortably select Zoom In thus magnifying the image This option is located both in the GiD Toolbox and in the mouse menu under Zoom i Figure 39 Contens of optimizacion gid 3 Make sure that the aux layer is activated Modifying the profile 5 4 Choose Geometry gt Edit gt Divide gt Lines gt Num Divisions This option divides a line into a specified number of segments A window comes up in which to enter the number of partitions Enter 8 Select the line segment from the upper part of a tooth Figure 39 and press ESC Using the option Geometry Create Point and create a point with the coordinates 40 8 5 Choose Geometry gt Create gt NURBS line to create a NURBS curve The NURBS line to be created will pass through the two first points which have been created on dividing the line at point 40 8 5 CO N Ol and by the two last points of the divided line Figure 40 Optimizing the design 9 Select the first point through which the curve will pass To do this use Join Ctrl a located in Contextual in the mouse menu 10
68. appears in which you can enter a maximum element size Leave the default value unaltered and click OK This results in a mesh like the one obtained before in Figure 10 but with high concentration of elements around point number 29 Note that there are nodes on line number 43 because we have forced RJump not to skip this line see Figure 13 88 User Manual a E te Fi p J res X KT bet i res ai i eez SS ae RL dios Tm j Tas Nec ae 1 5 Jl nne ccr j ee i erence TEN re I Ka PETER EE 3 it T T ea ea oe ee en AN Memes S Rec rs eoe IY Naess I coc n i LLEI a pIE m mm M e e a o ET THLRN F i Wi eso ae Ira aU IIIS a i iC mast er ET alee Le Figure 13 Mesh using the RJump mesher assigning sizes by chordal error and forcing an entity to be meshed In this last example we have forced the mesher not to skip an entity but it may be interesting in some models to allow the mesher only to skip a few entities meshing almost all or them In this case a different surface mesher can be selected in the Preferences window One option is the RSurf mesher which meshes everything except the entities that you ask it to skip using the Mesh gt Mesh criteria gt Skip command Here because RJump is not selected no entity will be skipped automatically according to tangency with neighboring entities The next example shows how to work with this mesher 8 Select Mesh gt Reset mesh data to reset all mesh sizes introduced pr
69. apture settings image option in order to cut the image in the model limits Click on Set Page button Menu Files gt Print to file AA Landscape 29 x 210 mm Resolution Screen dpi V Auto crop image White background on images White background on animations E Transparent background on images Transparent background on animations set Page Close Creating images 125 This option asks you for a file name and saves an image in the required format with the defined properties in Page and capture settings 1 Select Files gt Print to file gt PNG throught the menu bar or clicking on ad and then MT 2 Choose the location where you want to save the image 3 Choose a name for the file 4 Click on Save button 126 User Manual 127 8 IMPORTING FILES IMPORTING FILES The objective of this case study is to see how GiD imports files created with other programs The imported geometry may contain imperfections that must be corrected before generating the mesh For this study an IGES formatted geometry representing a stamping die is imported These steps are followed Importing an IGES formatted file to GiD Correcting errors in the imported geometry and generating the mesh Generating a conformal mesh and a non conformal mesh Pice provided by courtesy of PSA DEGAD MAC
70. are not viewed Selects for which step of analysis results will be viewed Same as contour fill but with defined anges No Results Shows location and value of a No Graphs selected maximum and minimum numerical result Graphs are not viewed Chooses whichresults to view in colored iso areas Default Analysis Step Chooses which result to view in Contour Fil 7 ontour r1 i Ue E X eee 4 Selects which vector result to mac ntaur ri view Contour Lines i M A ae age Creates iso areas of the results ralssd irmus ET shoeing with colored strips the place p ay where each subdivisian finished Iso Surfaces d Shows outline of a particle bv vectoc JE Jl Stream Lines d Exact ield as lines tangent to the result Graphs rim rapi Automatic Automatic Width vectors Result Surface eformation Line Diagram F Graphs Integrate Clear Pointevolution Graph style lines will be Point graph drawn over the line Border graph elements only active videi when line elements are usedin the mesh Permits calculate the integral Scalar of scalar or vectorial result Vector Draws a scalarresult following the element i shows mesh deformation normal according to a displacement filed 14 User Manual 1 2 13 Options Options permit the user to make choices related to the presentation of results for example color changes number of result subdivisions etc Change t
71. ates Window Then from the Top Menu select GeometryCreatePoint In the coordinate window opened previously the following indicated steps should be used Coordinates window C system Cartesian a Local axes Global a x 0 00000 1 Introduce y 0 00000 oo ERN 2 Create point 1 by d 1 OMM clicking on the button Lo Create new point Ask Change Apply or by pressing Enter on the kevboard Lise tab Shittab and Return Apply Close And create point 2 in the same way introducing its coordinates in the Coordinates Window The last step in the creation of the points as well as any other command is to press Escape either via the Escape button on the keyboard or by pressing the central mouse button Select Close to close the Coordinates Window Now we will create the line that joins the two points Choose from the Top Menu Geometry gt Create gt Straight line Option in the Toolbar shown below can also be used as Next the origin point of the line must be defined In the Mouse Menu opened by clicking the right mouse button select Contextual gt Join C a Creation and meshing of a line 21 Contextual Base Join Ctrl a Zoom k Faint In Line Rotate b Faint In Surface Fan P Tangent In Line i Redraw Normal In Surface Render Arc Center Label b 5 Line Parameter eye E Lotions Image to clipboard Undo m Close H Quit Number Escape NOTE
72. change this color to transparent 6 Select Options gt Contour gt Min Options gt Out Min Color gt Transparent Contour fill cuts and limits 117 Pressure Pa 0 55696 0 49507 0 43319 0 37131 0 30942 0 24754 0 18565 0 12377 0 061884 z A step 103 Contour Fill of Pressure Pa 7 3 5 Combined results An interesting postprocess options is to combine several result visualizations like this one Pressure Pa 0 55696 0 49507 0 43319 0 37131 0 30942 0 24754 0 18565 0 12377 0 061884 Y step 103 Contour Fill of Pressure Pa To get this view follow these steps 1 Clear all results visualizations with View Results gt No results or the icon Rs 2 Select Window gt Several results Then following window appears 118 User Manual Several Results Results views t onebyone one over another Current list of results Delete Delete all Id 18 leo Surfaces RANSOL 103 0 Pressure Pa Pressure Pa 1 0 Pressure Pa Pressure Pali RAN SOL 1103 000000 ld 23 Contour Fill RAN SOL 103 0 Pressure Pa Pressure Pa 0 0 3 In this window select one over another With this option GiD is told to visualize one result over another 4 Select View Results gt Default Analysis Step gt Ransol gt 103 5 Select View Results gt lso surfaces gt Exact gt Pressure through the menu bar or clicking on the D In the following questions How many isosurfaces Enter 1 E
73. color graph size amp detail Set contour fill color Set initial step Change line width b Set max length Change line pattem set max points Change pattemfactor Elevations are lines that connect the Set initial rotation Change point size nodes and the zauss points of the line Show arrows Change title graph t element and the graph style Invert graph sense Jelete graph b oe _ Shewelevations None ille J Nod Defines options for Reset axis values e dup result surfaces X exis Whole line Y exis L s Filled line Clear graphs Contour filled Options Results View Taig F Autometic Limits AA O Delormation enimalion View results Main Mesh Fuerence mesh View Contour Fill Sup Analysis SE e a MC DISTANCE usa stop values as sc C Delay between steps 200 C Usestep values at seconde 1 I E 000270 r Seve THF nn E Xen rends homobar ho abia s Ioui Table wall be applsed to curren result Marna 16 User Manual 1 3 Toolbars Option Utilities gt Tools gt Toolbars opens a window where it s possible to configure the toolbars position or switch them on and off Geometry and View operations preprocess Standard toolbar Enlarges image area which user indicates by drawing a mouse idi Bc Reduce image area which user indicate by drawing a mouse window Placesimage in center of screen
74. copic vision smooth Recent view files Change light di Background image Reflection Image to clipboard Multiple windows Define reflection Opens afile image as a Mode background Draws the surfaces normal Fit screen sans line tangents Real size Default This option Draw by colors the amount of ermits to Copy the image to the P have several clipboard views of the same project Switch the visualization mode to geometry mesh or postprocess parents of an entity Options ta manage the position of the current view save read and acces tn recent views View 1 2 3 Geometry Geometry permits the user to create delete edit and model geometry Creates drawing entities e Point 5 Straightline i NURBS line Changes from the mesh viewing ta Parametric line the geometry x J Polyline RAC T NURBS surface Parametric surface View geomet Contact surface Surface mesh Create Geometry from mesh Delete lines __ i Delete b Edit b volume Contact Foints Lines Object Surfaces volumes Edits and permits All types changes to entities Move point Divide Join Lines operations d Swap arc Polyline d Suresh Edit NURBS Convertto NURBS Simplify NURBS d Hole NURBS surface Hole volume Collapse b Uncollapse Intersection d Surface boolean op User Manual 1 2 4 Utilities Pre In the Utilities menu GiD allows the user to define preferences or perform operations on both
75. d results 117 7 3 6 Stereo mode 3D 118 7 3 7 Show Min Max 119 7 3 8 Stream lines 120 7 3 9 Graphs 122 7 4 Creating images 124 8 IMPORTING FILES 127 8 1 Importing on GiD 127 8 1 1 Importing an IGES file 128 8 2 Correcting errors in the imported geometry 130 8 2 1 Meshing by default 130 8 2 2 Correcting surfaces 132 8 3 The conformal mesh and the non conformal mesh 135 8 3 1 Global collapse of the model 136 8 3 2 Correcting surfaces and creating a conformal mesh 138 Table of Contents 8 3 3 Creating a non conformal mesh 8 3 4 Optimizing a non conformal mesh 9 DEFINING A PROBLEM TYPE 9 1 Introduction 9 1 1 Interaction of GiD with the calculating module 9 2 Implementation 9 2 1 Creating the Materials File 9 2 2 Creating the General File 9 2 3 Creating the Conditions File 9 2 4 Creating the Data Format File Template file 9 2 5 Creating the Execution file of the Calculating Module 9 2 6 Creating the Execution File for the Problem Type 9 3 Using the problemtype with an example 9 3 1 Executing the calculation with a concentrated weight 9 4 Aditional information 9 4 1 The main program 142 143 147 147 148 149 149 150 151 152 157 158 159 162 163 164 vi User Manual 1 PRESENTATION OF GiD This chapter will introduce the user to the user interface and graphic environment of GiD GiD is a general purpose pre postprocessor for computer analysis All the data geometry and mesh generation can be performed inside
76. e Options menu Menu Options gt Stream lines The options can be also managed through the Size amp detail window 10 Select Options gt Stream lines gt Size amp detail 11 Check the Dynamic update option 12 Select Options gt Contour gt Color Scale gt Standard 13 Select Stream contour filled The stream lines will be drawn with the colors used in the velocity contour fill 14 Set 5 for the Arrows Size option 15 Set 10 for the Arrows Frequency option 16 Check the Show Arrows option 17 Close the window 18 Select Options gt Stream lines gt Delete 19 Select all the stream lines with the mouse 20 Click the middle mouse button or press the Esc key in order to finish the operation 21 You may play with the diferent stream types points ribbons or 4 sided prisms If the ribbons type is selected you may adjust the initial swirl to rotate the ribbon 122 User Manual NOTE A way to achive the best results is to first create a cut of the volume mesh throught the region of interest and then use these nodal information as support to create stream lines and its options along line in a quad etc 7 3 9 Graphs Menu View results gt Graphs From this menu several graphs types can be created we will try some of them Graphs are supported for results defined over nodes The Point evolution graph displays a graph of the evolution of the selected result along all the steps of the default analysis for the
77. e lines that form the displaced octagon and press ESC to conclude the selection Again press ESC to exit the function of creating the surfaces Figure 24 The surface created on the translated octagon 5 In the Copy window choose Translation and Surfaces Make a translation of 110 units Enter two points that define a vector for this translation for example 0 0 0 and 0 O 110 6 Tocreate the volume defined by the translation select Do Extrude Volumes in the Copy window 7 Click Select and select the surface of the octagon Press ESC The result is shown in Figure 25 Figure 25 Creation of the volume of the prism 8 Choose the option Render gt Flat from the mouse menu to visualize a more realistic version of the model Then return to the normal visualization using Render gt Normal Creating the volume of the prism 49 Figure 26 Visualization of the prism with the option RenderFlat Wl NOTE The Color option in the Layers window lets you define the color and the opacity of the selected layer This color is then used in the rendering of elements in that layer 3 4 3 Creating the volume of the wheel 1 Visualize the profile layer and activate it The volume of the wheel will be created in this layer Deactivate the prism layer in order to make the selection of the entities easier 2 In the Copy window choose Translation and Surfaces A translation of 10 units will be made To do this enter two poin
78. e the default value unaltered and click OK This results in a mesh where contact lines between surfaces that are tangent enough do not have nodes contact points between lines tangent enough are also skipped when meshing see Figure 10 86 User Manual F T T Er M ente Fur m 1 niae ws FH or 2 i F zs m 38 TL ol TU 4 E n air 7 J m Ki mU Pium 7 ip he h Toa ees Lc tht a EE Hea toe as Nr HH ee y T i a Raye acs bis RT 4 ET n DER s ut Eras E a 1 T ua SRM k m T al T 18S LS d i I L m E T EW om i or E TELA ts P Tu b ea ES ie AL ELE rs Figure 10 Mesh using the RJump mesher Note that the smaller elements shown in Figure 3 do not appear in this mesh because of the properties this mesher Using the RJump mesher it is possible to assign sizes to different entities As an example select Mesh gt Unstructured gt Size by chordal error 7 GiD asks for the minimum element size Enter 0 1 8 GiD asks for the maximum element size Enter 10 9 Enter the chordal error This error is the maximum distance between the element generated and the real object Enter 0 05 and press OK 10 Again select Mesh gt Generate Mesh 11 A window opens asking if the previous mesh should be eliminated Click Ok 12 Another window appears in which you can enter a maximum element size Leave the default value unaltered and click OK This results in a high concentration of elements in curved areas without the
79. ed located in Preferences may be combined with the option of limiting the chordal error thus achieving an accurate mesh with fewer elements It only makes sense to use Allow automatic structured when working with a non conformal mesh NOTE The option Allow automatic structured generates highly distorted elements that might with some calculating modules lead to erroneous results In the case of stamping a plate we recommend using Allow automatic structured with the calculating modules 1 Open Utilities gt Preferences 2 On the Meshing card activate the option Allow automatic structured and enter the value of 0 9 in the box labeled Unstructured size transitions Click Accept The option Unstructured size transitions defines the size gradient of the elements the value ranging from O0 to 1 The greater the value the faster the variation of the element sizes in space and so there will befewer elements in the mesh Optimizing a non conformal mesh 145 General Graphical Meshing Exchange Fonts Format Grid Quadratic type Normal Quadratic Quadratic9 Unstructured mesher curface ia RFast RSurf Rump Volume Advancing front Delaunay Isosurface Automatic correct sizes O Mane Normal Hard Unstructured size transitions Regular transition near boundary Structured mesh Allow automatic structured Symmetrical structured triangles tetrahedra Boundary Layer Mesh stretching function
80. elems all the command to include all element types of the mesh when making the loop ElemsNum returns the identifier of the present element ElemsConec returns the nodes of an element in a counterclockwise order ElemsMat returns the number of the assigned material of the present element Begin Materials N Materials nmats This gives the total number of materials in the project nmats returns the total number of materials Mat Density loop materials format 41 13 5e set var PROP1 real Operation MatProp Density real MatNum PROPI end This provides a rundown of all the materials in the project and a list of the identifiers and densities for each one MatProp density real returns the value of the property density of the material in a real format Creating the Data Format File Template file 155 Operation expression returns the result of an arithmetic expression This operation must be expressed in C Set var PROP1 real Operation MatProp Density real assigns the value returned by MatProp which is the value of the density of the material to the variable PROP1 a real variable PROP1 returns the value of the variable PROP1 MatNum returns the identifier of the present material Poin condrrons Set Cond Point Weight nodes xset var NFIX int CondNumEntities int Concentrate Weights NFIX This provides the number of entities with a particular condition Set Cond Po
81. ely x double malloc Nnodt 1 sizeof double if x NULL error 1 y double malloc Nnod 1 sizeof double if y NULL error 1 N int malloc Nelem 1 3 sizeof int if N NULL error 1 imat int malloc Nelem l sizeof int if N NULL error 1 if error strcpy fileerr projname otrocati fileerr exr s ferr fopen fileerr w Iprintr rterr Taran ERRORS NOt enough memory Eare 3 LEPIHULTUOPOGPP rey EO Calculate with bess elenenbs S fclose ferr exit 1 j por ques 2265 dob q mplrnue CEDE Space is reserved for storing the coordinates of the nodes pointers x y the connectivities pointer N and the materials corresponding to each element pointer imat In case of error insufficient memory a file is created with the extension err This file contains information about the error and the program is aborted The next six lines are jumped over reading the coordinates for inod 1 inod lt Nnod inod 166 User Manual PScent rp sede elt galf 6aux amp x 12n0d 6ylanod fOr a 0y 25568 ace qumpdrgne Ipi The coordinates of the nodes are read and stored in the x and y variables The node identifier indexes the tables of coordinates PE reading Connec ctivities 77 for ielem 1 ielem Nelem ielemttyi Iscanf ip sd deux Pori e0 p lt 37 7 bscant ip 9d amp NI r elem L 3930 3 fscanf fp d amp imat ielem
82. entifier indexes the densities The total number of conditions is read and stored in the Ncnd variable The nodes associated with a condition are read and stored in the nodc table indexed by the condition identifier The value of the condition is stored in wval another table indexed by the condition identifier void calculate double svyauxl ogux2 4ux2j int ndl 254 nS nC mat double x CGis y CG1 double x_num 0 y_num 0 den 0 This is the function that calculates the center of mass Declaration of the local variables used in calculate for ielem 1 ielem lt Nelem ielemt nl N 0 ielem 1 3 n2 N 1 ielem 1 3 n3 N 2 ielem 1 3 CaleulaLting the volume volume 18 the area for surfaces y vettabsermr 9 pm2 xrn2 pmlepmESl T wmEU sLmb p vrmsl eemelewgmip ecrns wwo2 1 725 x CGi x nl x n2 x n3 3 y_CGi y n1 y n2 y n3 3 mat imat ielem x numt rho mat v x CGi y numt rho Mat vy CGI dent rho mat v j puntual weights 168 User Manual for icnd 1 icnd Ncnd icnd t f inod nodc icnd x mumt wvaltzxecnal xdxnocdls v numse wval licnd y nod dent wval icnd x CG x num den y CG y num den The identifiers of the nodes of the present element are saved in n1 n2 n3 This loop makes a rundown of all the elements in the mesh The volume is calculated for each element Here the volume is the area provided we are dealing with
83. ents appears around a node and that the element size is as uniform as possible To generate this type of mesh choose Mesh gt Structured gt Surfaces Using this command the user should first select the 4 sided NURBS surface that will be defined by the mesh Then the number of subdivisions for the surface limit lines should be entered Pairs of lines define the partitions in the following way 1 Select 10 divisions for the horizontal lines Wl 2 Select 10 more divisions for the vertical lines NOTE GiD only generates structured meshes for surfaces of the type 4 sided surface or NURBS surface When this has been done the mesh is generated in the same way as the unstructured mesh by Creation and meshing of a surface choosing Mesh gt Generate mesh Assign a general element size of 1 though in this case it is not necessary We can see here that the default element type used by GiD to create a structured mesh is a square element of four nodes rather than a three nodded triangular element To obtain triangular elements the user can specifically define this type of element by choosing Mesh gt Element type gt Triangle and selecting the surface to mesh as a triangular element Regenerate the mesh and the following figure is obtained PEIX S E 5 es PPPS E CSS 2S SX XKKKKK xp oe gt P PS P XX X PURUS LDLC COI S SOROR LL LLLP LSLS LELLI PVPPPPP
84. er Manual 6 Choose Render gt Flat from the mouse menu to visualize a more realistic version of the model Return to the normal visualization with Render gt Normal This option is more comfortable to work with Figure 15 The pipe with disks created by rotating the profile 14 NOTE To select the profile once the first rotation has been performed first select all the lines and then delete those that do not form the profile Use the option Rotate Trackball from the mouse menu to rotate the model and make the process of selection easier 4 3 3 Creating the union of the main pipes 1 Choose the Zoom In option from the mouse menu Magnify the right end of the model 2 Make sure the aux layer is visible 3 From the Copy window select Lines and Rotation Enter an angle of 120 degrees and from the Do extrude menu select Surfaces Since the rotation may be done in 2D choose the option Two Dimensions The center of the rotation is the tangential center Creating the union of the main pipes hi LATI 69 f a M a Y 3 ae A nim Bo P m Ps MAX I IT PLENIS aise Ey 1 EU EFE x jj if iFa PES Wl Al yo j n i der qul PP UE LT reek LT E A Y 7d SH y a Figure 16 The magnified right end of the model and the lines to be selected 4 Click Select and select the four lines that define the right end of the pipe see Figure 16 Press ESC when the selection is finished
85. err w IprqswEroterr U9tgSBORT Elements wlth mo wMarer Ladki ea 79x fclose ferr ext Cl j fOr LUA aoe qub quiptirne Crp y ESCani Ipp oS 169 70 Seuls SS Nia h FOr ques Ior dep ume pe ION reading density of each material for i 1 1i lt Nmat itt scant ip sd SltU Saux XrmHopil fs Pegging condritrions FOr i907 4 ai junpline Ep Iscanflirpy Td eNend for r cDo aaO xL Jumplrne tp for icnd 1 icnd lt Ncnd icnd 4 ESGant ip sd slL amp nuodc iendly amp wvalrondgol s jumpline fp fclose fp 171 172 User Manual void calculate double v ine ily Wi Moy ine mat double x_CGi y_CGi double x_num 0 y_num 0 den 0 for ielem 1 ielem lt Nelem ielemt nl N 0 ielem 1 3 n2 N Iir T relem 1 3 n3 N 2t rielem 1 3 Calculating the volume volume is the area for surfaces vesrabsd sep sem Z aris sep e sea eben does sese DA hs x CGi x nl x n2 x n3 3 y_CGi y nl l y n2 y n3 3 mat imat ielem x numt rho mat v x CGi Vv XmTe Dro mat wy Cer dent t rho mat v j puntual weights tor rendel icnd sNend cxend 1i inod nodc icnd x numb wve sen 3 Toc FS y2num wvalrend l y znod l dent wval icnd j x CG x num den y CG y num den vord Output s char filename 1024 FILLE US CPDIOg double v PR Wien Bog Bqrormqcioon X
86. esult of the first rotation and Figure 22 The result of the first180 degree rotation the second rotation of 180 degrees thus obtaining the profile of the pipe section 6 From the Copy window choose Lines and Translation In First Point and Second Point enter the points defining the translation vector Since the pipe section must measure 40 length units the vector is defined by points 0 0 0 and 40 O 0 7 From the Do extrude menu choose the Surfaces option 8 Click Select to select the lines that define the cross section of the pipe Press ESC to conclude the selection process Figure 24 Creating a pipe by extruding circumferences 4 4 2 Creating the other pipe section 1 Choose Geometry gt Create gt Point and enter points 20 9 and 20 11 Press ESC to conclude the creation of points 2 From the Copy window select Points and Rotation Enter an angle of 180 degrees and from the Do extrude menu select Lines Since the rotation can be done on the xy plane choose Two Dimensions The center of rotation is the coordinates 20 0 0 3 Click Select and select the two points just created Repeat the process this time entering an angle of 180 degrees 4 From the Copy window select Lines and Translation In First Point and Second Point enter the points defining the translation vector Since this pipe section must also measure 40 length units the vector is defined by points 0 0 0 and 0 O 40
87. eviously 9 A window opens advising that all the mesh information is going to be erased Press OK 10 Go to Utilities and open Preferences Click Meshing In the window that appears you can choose between the three surface meshers available in GiD RFast RSurf and RJump Select the RSurf mesher Click Accept 11 Select Mesh gt Mesh criteria gt Skip gt lines and select lines 48 and 53 Press ESC 12 Select Mesh Generate Mesh 13 A window opens asking if the previous mesh should be eliminated Click Yes 14 Another window appears in which you can enter a maximum element size Leave the default value unaltered and click OK The result is a mesh similar to the first example obtained in chapter 2 see Figure 2 but the smaller elements highlighted in Figure 3 do not appear because lines 48 and 53 which were meshed before are now skipped when meshing see Figure 14 89 Force to mesh some entity Figure 14 Mesh using the RSurf mesher with some lines skipped 90 User Manual 91 6 METHODS FOR GENERATION THE MESH The objective of this example is to mesh a model using the various options available in GiD for controlling the element type in structured semi structured and unstructured meshes It also presents how to concentrate elements and control the distribution of mesh sizes The six methods covered are Generating a mesh using tetrahedral Generating a volume mesh using spheres Generate a mesh using
88. file of the mechanical part in our case study will be carried out with the help of auxiliary lines Two layers will be defined in order to prevent these lines from appearing in the final drawing The lines that define the profile will be assigned to one of the layers called the profile layer while the auxiliary lines will be assigned to the other layer called the aux layer When the design of the part has been completed the entities in the aux layer will be erased 36 User Manual 3 1 2 Creating two new layers 1 Open the layer management window This is found in Utilities gt Layers 2 Create two new layers called aux and profile Enter the name of each layer in the Layers window Figure 1 and click New 3 Choose aux as the activated layer To do this click on aux to highlight it and then click on the Layer To Use button Next to this button the name of the activated layer will appear aux in the present case From now on all the entities created will belong to this layer Figure 1 The Layers window 3 2 Creating a profile In our case the profile consists of various teeth Begin by drawing one of these teeth which will be copied later to obtain the entire profile 3 2 1 Creating a size 55 auxiliary line 1 Choose the Line option by going to Geometry gt Create gt Straight line or by going to the GiD Toolbox 2 Enter the coordinates of the beginning and end points of the auxiliary
89. following format MATERIAL Name of the material without spaces 150 User Manual QUESTION Property of the material For this example we are interested in the density of the material VALUE Value of the property HELP A help text optional field END MATERIAL In GiD the information in cmas2d mat file is managed in the materials window located in Data Materials Materials S Ol asin a Density 1 01 Assign Draw Unassign Exchange The GiD Materials window for assigning materials MATERIAL Air QUESTION Density VALUE 1 01 HELP material density END MATERIAL MATERIAL Steel QUESTION Density VALUE 7850 HELP material density END MATERIAL MATERIAL Aluminium QUESTION Density VALUE 2650 HELP material density END MATERIAL 9 2 2 Creating the General File Create the cmas2d prb file This file contains general information for the calculating module such as the units system for the problem or the type of resolution algorithm chosen Enter the parameters of the general conditions in cmas2d prb using the following format PROBLEM DATA Creating the General File 151 QUESTION Name of the parameter If the name is followed by the CB instruction the parameter is displayed as a combo box The options in the menu must then be entered between parentheses and separated by commas For example Unit_System CB SI CGS User VALUE The default value of the parameter END GENERAL DA
90. format 965i9614 5e9614 5e NodesNum NodesCoord 1 real NodesCoord 2 real end nodes Connectivities Element Node 1 Node 2 Node 3 Material loop elems format 101 101 101 1 0196101 ElemsNum ElemsConec ElemsMat end elems Begin Materials N Materials nmats Mat Density loop materials format 964i9613 5e set var PROP 1 real Operation MatProp Density real MatNum PROP 1 Point conditions User Manual Size Database Creating the Data Format File Template file Set Cond Point Weight nodes set var NFIX int CondNumEntities int Concentrated Weights NFIX Potentials Prescrits Node Tipus Valor Etiqueta Set Cond Point Weight nodes loop nodes OnlylnCond NodesNum cond 1 9 2 5 Creating the Execution file of the Calculating Module 157 Create the file cmas2d c This file contains the code for the execution program of the calculating module This execution program reads the problem data provided by GiD calculates the coordinates of the center of mass of the object and the distance between each element and this point These results are saved in a text file with the extension post res Compile and link the cmas2d c file in order to obtain the executable cmas2d exe file The calculating module cmas2d exe reads and generates the files described below void input main void calculate void output L project name dat READS the dat file
91. g from blue minimum through yellow and green to red maximum 1 Select Options gt Contour gt Color Scale gt Inverse Standard You can also set your own scale 2 Select Options gt Contour gt Color scale gt User defined In this window you can change the number of diferent colors used in the scale If you need more Contour fill cuts and limits accuracy you can increase this number or decrease it for a higher contrast 3 Change the number of colors to 10 4 Click on Apply button 5 Click on Close button Pressure Pa 0 55696 I 0 27759 0 13791 0 0017787 0 14146 0 28115 0 42083 0 56052 0 7002 z 0 83988 A step 103 y Contour Fill of Pressure Pa Cuts In order to view the inner zone we will do several cuts along the model Pressure Pa 0 55696 0 41727 0 27759 0 13791 0 0017787 0 14146 0 28115 0 42083 0 56052 0 7002 re 0 83988 step 103 Contour Fill of Pressure Pa Menu Do cuts In order to make it easier first we will change the plane visualization 1 Please select View gt Rotate gt Plane XY Original through the menu bar Rotate Plane XY Original throught the contextual menu or clicking on ao or ui Now you have a top view of the model 116 User Manual 2 Select Do cuts gt Cut plane gt Succession through the menu bar or clicking on P d and thenie a With the succession option you specify an axis that will be used to create cut planes orthogonal to t
92. gure 34 One way of doing this is to select the entire part and then deselect the points that form the prism hole Press ESC to conclude the selection process Figure 34 The selected points of the wheel profile 4 Choose Mesh Generate mesh 5 A window opens asking if the previous mesh should be eliminated Figure 35 Click Yes Another window appears in which the maximum element size should be entered Leave the default value unaltered Dialog window The old mesh will be erased Continue Figure 35 6 Athird window shows the meshing process Once it has finished click OK to visualize the resulting mesh Figure 36 Figure 36 Mesh with assignment of sizes around the points on the wheel profile 7 A greater concentration of elements has been achieved around the points selected 8 Choose View gt Mode gt Geometry to return to the normal visualization Generating the mesh with assignment of size around points 55 Another option equivalent to view rotate angle 90 90 is RotatePlane XY located in the mousemenu 3 5 3 Generating the mesh with assignment of size around lines 1 Open the Preferences window which is found in Utilities and select the Meshing card In this window there is an option called Unstructured Size Transitions which defines the size gradient of the elements A high gradient number means a greater concentration of elements on the wheel profile To do this select a gradient size of 0 8 C
93. h Mesh gt Generate Mesh 9 A window comes up in which to enter the maximum element size for the mesh to be generated Leave the default value provided by GiD and click OK The mesh generating process may be carried out with no further errors found 135 17556 5491 T 2 ej i T C ET C Z i Figure 13 Window with information about the meshing process Mum of Triangle elements Mum of nodes Correcting surfaces NN hes pees DRAA LAN RRR TIN ERE an I FASES EA ERE v E LA NNAS FINNA SR AS ESO A e IRAN 7 IE RIRO Figure 14 vie a Moe ON fO DEE DS ADE ivive ery NL s A OS 5 UNDC c3 m A Woo BOA KU SC MISES 10 The imported piece is now meshed Figure 14 A mesh of the imported geometry after correcting some errors we were able to mesh the imported geometry thus This option is also found in the GiD Toolbox In the previous section sides To achieve this condition contiguous surfaces of the piece must share lines and points of the obtaining a non conformal mesh A conformal mesh is one in which the elements share nodes and 8 3 The conformal mesh and the non conformal mesh 136 User Manual mesh Most calculating modules require conformal meshes however some modules accept non conformal meshes A non conformal mesh normally requires less computation time since it generates fewer elemenis
94. he name Change color assigned to af the volumen surface and cut vnlumes surfaces Selects box which shows the value sets and cut sets lvi show Volumesets gt Opaque Surface sets ag Show Title Cut sets x Draw User Limits Border Number of Colors Width Intervals Change Title Permits Allows Set Limits Outside change user to Define Limits ug Automatic Comments cal ars label select the i Reset Limit Values T Reset All s divisions number of Mex Options b of the colors in Min Options Border Angle nv olor Scale Massive Body Sues me in Sais type Transparent size of the Bright color pague idi interval s c Color window Opaq Foint options volumes alee Scale result Line options surfaces and Covering mesh cuts should Create delaunaymeshes User can choose how to view the vectors Display Style Selects 3 Interior All vectors Transparency viewing Number of Colors Color Mode options af iso nge Color Mode Change color Change Nam Offset Convert to cuts Change Color mono xg Drew always Contour Detail d w Showisolines Vectors size ee Iso Surfaces LI Eilter factor Stream Line b Defines options for Result Surface i options Kind of i j viewing graphics Line Diagrams label calor and delete Coordinates type p opten Model view n l Outline on model Shange color Grids Color Mode d Current style Delete Change style graph v Label Change
95. he object under study and generates a mesh of elements each one of which is assigned a material and some conditions This preprocessing information in GiD mesh materials and conditions enables the calculating module to generate results For the present example the calculating module will find the distance of each element relative to the center of mass of the object Finally the results generated by the calculating module will be read and visualized in GiD Post process Preprocess Postprocess B SOLVER INPUT OUTPUT FILE FILE Diagram of the workflow GiD must adapt these data to deal with them Materials boundary and or load conditions and general problem data must be defined GiD configuration is accomplished through text formatted files The following files are required prb configuration of the general parameter not associated to entities mat configuration of materials and their properties cnd configuration of the conditions imposed on the calculation bas template file the file for configuring the format of the interchange file that mediates between GiD data and the calculating module The file for interchanging the data exported by GiD has the extension dat This file stores the geometric and physical data of the problem bat the file that can be executed called from GiD This file initiates the calculating module The calculating module in this example cmas2d exe solves the equations in the proble
96. his axis The number of planes is also asked for 3 Please specify the line through the X axis in the middle of the model and ask for 7 cuts You should obtain 7 parallel planes to Y axis 4 Now change the display style Utillities gt View style in order to see only the cuts You can see that several layers had appeared a prefix like CCutSetX indicating which mesh or set has been cut These names can always be changed through the Window View Style Select all the layers except the cuts and change their style to Boundaries You can rotate the model in order to see the contour fill result on the cut planes 5 In the same window select all the CCutSetX and click on Delete button in order to delete all the cuts 6 Select Options gt Contour gt Reset all in order to set all the defaults options Define limits You can set the limit values for the contour fill In our case we only want to see the positive values In order to do this we will set the minimum value to O 1 Select Options gt Contour gt Define Limits through the menu bar or clicking on a 9 Choosing the first option the Contour Limits window appears With this window you can set the minimum maximum value that Contour Fill should use Check the Min checkbox Change the value to 0 Click on the Apply button Click on the Close button oF O Tnm Outliers will be drawn in the colour defined in the Out Min Colour option In order to view it better we will
97. ie w The main program 173 strcpy filename projname strcat rfIrlename log folog fopen filename w EDEINEE ip log OMASZD routine bo cabeulLate the mass center 7 torinutr rploo pro jectu lt 7s pro jname gt Iprrntr rplog mass center Lf alf T x CG yo60G s fclose fplog T WwPIUIg SJpoStobes 57 strcpy filename projname strcat filename post res fp fopen filename w LDPISHEPULD Gib Pose ROSUulIUtS ETIS Leg 927 fprintf fp Result MC DISTANCE LOAD ANALYSIS 1 Scalar OnNodes fprintf fp ComponentNames MC DISTANCE fprantt rtp values j for ilnod 1 inod lt Nnod inod distance or each node to the center of masses V SOrL0 x CE xanod x2 CG x a nod ytty CG y Larod S y CG y inod I POPLINE ip oO Lr ood yy ftorincr fp End values 7 fclose fp Free x 3 free y free N free imat j void jumpline FILE filep char buffer 1024 Igets burrer 1024 T11 p 5
98. ile Creating the data format file Creating the calculating program file and the execution files Executing the calculating module and visualizing the results using GiD By the end of the example you should be able to create a calculating module that will interpret the mesh generated in GiD Preprocess The module will calculate values for each element of the mesh and store the values in a file in such a way as they can be read by GiD Post process 9 1 Introduction Our aim is to solve a problem that involves calculating the center of gravity center of mass of a 2D object To do this we need to develop a calculating module that can interact with GiD The problem calculate the center of mass The center of mass Xcm Ycm of a two dimensional body is defined as p xL xXx Il x p F A vt I v Mai 77 Jn p X m p xX y um where p x y is the density of the material at point x y and S is the surface of the body mi are concentrated masses applied on the point x y To solve the problem numerically the integrals will be transformed into sums d H m dn T H ve Y an TD i eim inl cir ial Au 7 Ye Ho m cim i H E elim lai eim 148 User Manual Each of the N elements is treated as concentrated weight whose mass is defined as the product of the surface density and the area of the element 9 1 1 Interaction of GiD with the calculating module GiD Preprocess makes a discretization of t
99. indicated will be shown if the user clicks Output View in Calculate Calculate window In this example the log file is shown This file contains the coordinates of the center of mass Process window Froject Starttime UID Priority Output view Terminate Start remote Remote The Process window rem ErrorFile 2 31 err A comment line such as rem ErrorFile file name err means that the indicated file will contain the errors if any If the err file is present at the end of the execution a window comes up showing the error The absence of the err file indicates that the calculation is considered satisfactory GiD automatically deletes the err files before initiating a calculation to avoid confusion del 2 1 1log del 24 1 post res This deletes results files from any previous calculations to avoid confusion Creating the Execution File for the Problem Type 159 3 cmas2d exe 2 1 This executing the cmas2d exe and provide the dat as input file file 9 3 Using the problemtype with an example In order to understand the way the calculating module works simple problems with limited practical use have been chosen Although these problems do not exemplify the full potential of the GiD program the user may intuit their answers and therefore compare the predicted results with those obtained in the simulations Create a surface for example from the menu Geometry gt Create gt Object gt Polygon Create a po
100. ing lines and press ESC 4 5 2 Creating the final volume 1 Choose Geometry gt Create gt Volume gt By contour and select all the surfaces that define the volume Press ESC to conclude the selection process 2 Choose Render gt Smooth to visualize a more realistic version of the model Figure 30 A rendering of the finished piece of equipment 76 User Manual 4 6 Generating the mesh Now that the model is finished it is ready to be meshed The mesh will be generated using Chordal Error in order to achieve greater accuracy in the discretization of the geometry The chordal error is the distance between the element generated by the meshing process and the real profile of the model By selecting a sufficiently small chordal error the elements will be smaller in the zones with greater curvature 4 6 1 Generating the mesh using Chordal Error Choose the option Mesh gt Unstructured gt Sizes by Chordal error Enter 1 for the minimum element size Enter 15 for the maximum element size Enter 0 2 for the chordal error Choose Mesh gt Generate mesh O 0O A OO N A window opens in which to enter the maximum element size of the mesh to be generated Leave the default value provided by GiD unaltered and click OK 7 When the meshing process is finished a window appears with information about the mesh that has been generated Click OK to visualize the mesh 8 Choose Mesh gt View Mesh Boundary to see only the con
101. int Num x 10 0 y 10 0 e z 10 0 Duplicate entities Do extrude No rc iw Maintain layers Figure 3 Creating the axes Multiple copies 1 Select Cancel Figure 4 The Copy window This option can also be found in the GiD Toolbox s Pressing the ESC key is equivalent to pressing the center mouse button 4 2 2 Creating the tangential center 1 Choose the menu option Geometry gt Create gt Straight line On the mouse menu choose Contextual and use Join Ctrl a to select points 0 0 and 0 25 Press ESC 2 In the Copy window choose Rotation from the Transformation menu and Lines from the EntitiesType menu Enter an angle of 120 degrees and the coordinates 0 25 0 in First point also check the Two dimensions option Finally select last line created 3 In the Copy window choose Translation from the Transformation menu and Lines from the EntitiesType menu The translation vector for the translation to be made is the line just created As the first point of the translation select the point farthest from this line segment For the second point select the other point of the line Figure 5 To select an existing point you must change the No Join Join option located in the contextual submenu from 3rd mouse s button menu or use the shortcut Control a notice that the cursor change from a cross to a box 64 User Manual Second point Figure 5 The line segment selected is the translation Figure 6 Resu
102. int Weight nodes this command enables you to select the condition to work with from that moment on For the present example select the condition Point Weight CondNumEntities int returns the number of entities with a certain condition Set var NFIX int CondNumEntities int assigns the value returned by the command CondNumEntities to the NFIX variable an int variable NFIX returns the value of the NFIX variable Potentials Prescrits Node Tipus Valor Etiqueta loop nodes OnlyInCond NodesNum cond 1 end This provides a rundown of all the nodes with the condition Point Weight with a list of their identifiers and the first weight field of the condition in each case loop nodes OnlyInCond executes a loop that will provide a rundown of only the nodes with this condition cond 1 returns the number 1 field of a condition previously selected with the set cond command The field of the condition may also be selected using the name of the condition for example cond weight cmas2d bas 156 General Data File YoYo YoYo Yo YoYo Yo YoYo Vo Vo SV Vo Vo Vo Vo Problem Yo Yo YoYo Yo YoYo Yo YoYo Vo Vo So YoYo YAY Vo Vo Vo Vo Vo Vo Vo Vo Vo Vo Vo VoVo Vo Vo Number of Elements amp Nodes nelem npoin YoYo YoYo Yo YoYo Yo YoYo Vo Vo Vo Vo Vo Vo Vo Vo Vo Mesh Yo Yo YoYo Yo YoYo Yo YoYo Vo Vo Vo Vo Yo YoYo Vo Vo Vo Vo Vo Vo Vo Vo Vo Vo Vo Vo Vo Vo Coordinates Node X Y set elems all loop nodes
103. is stored in the x CG and The main program 169 y y_CG variables of the program Creating the post res file The output data results are stored in this file The format of the post res file is explaned in the GiD help see section Posprocess data files gt Postprocess results format JT writing postres strcpy filename projname strcat filename post res fp fopen filename w fprintr fp Gib Post Results File 1 0 1 fprintf fp Result MC DISTANCE LOAD ANALYSIS 1 Scalar OnNodes fprintf fp ComponentNames MC DISTANCE Iprintr rp values 5 for inod 1 inod sNnod inod t distance or each node to the center of masses vesdgrut oecGG x Ia2nod x CG x inod v ycCo yvILrmnod i yv CGo yvirnodl s POPPI EDs oO oli Trod y j Iprintrf rp Eng values y fclose fp In this example only a scalar result with a single time step is written in the res file This is the full source code of this program include lt stdio h gt include lt stdlib h gt include lt malloc h gt txnmobrude lt math h gt define MAXMAT 1000 define MAXCND 1000 char projname 1024 ine iy elem inod senos double 43 y IAC SSND Aimat int nodc MAXCND double rho MAXMAT wval MAXCND int Nelem Nnod Nmat Nend 170 double x_CG y_CG VOL AnpuULVOrdi void Calculete vod void output void void main nt ergo char arov l 4 strcpy projname argv 1
104. ith the GiD program The example will develop a finite element problem in one of its principal phases the preprocess and will include the consequent data and parameter description of the problem This example introduces creation manipulation and meshing of the geometrical entities used in GiD First we will create a line and the mesh corresponding to the line Next we will save the project and it will be described in the GiD data baseform Starting from this line we will create a square surface which will be meshed to obtain a surface mesh Finally we will use this surface to create a cubic volume from which a volume mesh can then be generated 2 2 Creation and meshing of a line We will begin the example creating a line by defining its origin and end points points 1 and 2 in the following figure whose coordinates are 0 0 0 and 10 0 0 respectively It is important to note that in creating and working with geometric entities GiD follows the following hierarchical order point line surface and volume 20 User Manual fF r 2 m To begin working with the program open GiD and a new GiD project is created automatically From this new database we will first generate points 1 and 2 Next we will create points 1 and 2 To do this we will use an Auxiliary Window that will allow us to simply describe the points by entering coordinates It is accessed by the following sequence Utilities gt Tools gt Coordin
105. lect Options gt Result surface gt Show elevations gt Contour fill With this last option the surface is colored according to the pressure value Play with the other options as you will 114 User Manual 7 3 4 Contour fill cuts and limits Contour fill 0 83988 z A step 103 Y Contour Fill of Pressure Pa Menu View results gt Contour Fill 1 Please select View results gt Contour Fill gt Pressure Pa through the menu bar or clicking on e or using the Window View results window This option allows the visualization of coloured zones in which a scalar variable or a component of a vector varies between two defined values GiD can use as many colours as permitted by the graphical capabilities of the computer The number of colours can be set through Options gt Contour gt Number of colours A menu of the variables to be represented will be shown and the one that is chosen will be displayed using the default analysis and step selected In the model the pressure has been calculated We can visualize the result for each step in a contour fill You can choose the step that you want to view through the View results window or clicking on EE F aj 2 Select the step 103 Several configuration options can be set via the Options menu Menu Options gt Contour You can change the color scale in orther to get a more comfortable view You can select several predefined color scales The default scale is standard startin
106. lick Accept 2 Choose Mesh gt Reset mesh data to delete the previously assigned sizes 3 Choose Mesh gt Unstructured gt Assign sizes on lines A window appears in which to enter the element size around the lines to be selected Enter size 0 7 Select only the lines of the wheel profile Figure 37 in the same way as in previous section Figure 37 Selected lines of the wheel profile 4 Choose Mesh gt Generate mesh A window appears asking if the previous mesh should be eliminated Click Ok 5 Another window opens in which the maximum element size should be entered Leave the default value unaltered 6 A greater concentration of elements has been achieved around the selected lines In contrast to the case in previous section this mesh is more accurate since lines define the profile much better than points do Figure 38 96 User Manual Figure 38 Mesh with assignment of sizes around lines 3 6 Optimizing the design of the part The part we have designed can be optimized thus achieving a more efficient product Given that the part will rotate clockwise reshaping the upper part of the teeth could reduce the weight of the part as well as increase its resistance We could also modify the profile of the hole in order to increase resistance in zones under axle pressure To carry out these optimizations we will use new tools such as NURBS lines The final steps in this process will be generating a mesh and visualizing the ch
107. line For our example the coordinates are 0 0 and 55 0 respectively Besides creating a straight line this operation implies creating the end points of the line 3 Press ESC to indicate that the process of creating the line is finished 4 If the entire line does not appear on the screen use the Zoom Frame option which is located in the GiD Toolbox and in Zoom in the mouse menu Figure 2 Creating a straight line Creating a size 55 auxiliary line 37 NOTE The Undo option located in Utilities gt Undo enables you to undo the most recent operations When this option is selected a window appears in which all the operations to be undone can be selected The GiD Toolbox is a window containing the icons for the most frequently executed operations For information on a particular tool click on the corresponding icon with the right mouse button The coordinates of a point may be entered on the command line either with a space or a comma between them If the Z coordinate is not entered it is considered O by default After entering the numbers press Return Another option for entering a point is using the Coordinates Window found in Utilities gt Tools gt Coordinates Window Pressing the ESC key is equivalent to pressing the center mouse button 3 2 2 Dividing the auxiliary line near point coordinates 40 0 1 Choose Geometry gt Edit gt Divide gt Lines gt NearPoint This option will divide the line at the
108. lt of the translation with copy vector 4 Click Select to select the line segment that forms an angle of 60 degrees with the horizontal Press ESC to indicate that the selection has been made 5 Choose Geometry gt Edit gt Intersection gt Line line 6 Select the two inner lines 7 Click Yes to confirm that there is an intersection and that therefore the shortest distance between the two entities is 0 The intersection between the two entities lines creates a point This point will be the tangential center 8 Press ESC to indicate that the process of intersection between lines is finished Figure 7 The auxiliary lines with tangencia center Wl NOTE The Undo option allows you to undo the operations most recently carried out If an error is made go to Utilities Undo a window appears where you can select all the options to be eliminated Creating a component part 65 4 3 Creating a component part In this section the entire model except the T junction will be created The model to be created is composed of two pipes forming a 60 degree angle To start with the first pipe will be created This pipe will then be rotated to create the second pipe 4 3 1 Creating the profile 1 Select the ok layer and click on Layer To use From now on all entities created will belong to the ok layer 2 Choose the Line option located in Geometry gt Create gt Straight line 3 Enter the following points 0 11 8 11
109. ludes with a detailed explanation of the corresponding meshing process The piece is a cooling pipe composed of two sections forming a 60 degree angle The modeling process consists of four steps Modeling the main pipes Modeling the elbow between the two main pipes using a different file Importing the elbow to the main file Generating the mesh for the resulting piece At the end of this case study you should be able to use the CAD tools available in GiD as well as the options for generating meshes and visualizing the result 4 1 Working by layers Various auxiliary lines will be needed in order to draw the part Since these auxiliary lines must not appear in the final drawing they will be in a different layer from the one used for the finished model 4 1 1 Creating two new layers 1 Open the layer management window which is found in the Utilities gt Layers menu 2 Create two new layers called aux and ok Enter the name for each layer in the Layers window Figure 1 and click New 3 Choose aux as the activated layer To do this click on aux to highlight it and then click on the Layer To Use button The name of the activated layer will appear next to the button aux in this case From now on all the entities created will belong to this layer 62 User Manual Figure 1 The Layers window 4 2 Creating the auxiliary lines The auxiliary lines used in this project are those that make it possible
110. lygon with 5 sides centered in the 0 0 0 and located in the XY plane normal 0 0 1 and whit radius 1 0 Surface used for this example Load the problemtype menu Data Problem type cmas2d Choose Data Materials The materials window is opened From the Materials menu in this window choose the option Air 160 User Manual Materials window Click Assign Surfaces and select the surface Press ESC when this step is finished Choose the Mesh Generate option A window appears in which to enter the maximum element size for the mesh to be generated Accept the default value and click OK The mesh shown will be obtained AMAVAV AVATA OERAKKV The mesh of the object Now the calculation may be initiated but first the model must be saved Files gt Save use example cmas2d as name for the model Choose the Calculate option from the Calculate menu to start the calculation module Wait until a box appears indicating the calculation has finished Using the problemtype with an example 161 Process info Process jeje started at Wed Apr FN 07 12 22 00 has finished Process information box Choose the option Files Postprocess From the Windows menu choose the View results option A window appears from which to visualize the results By default when changing to postprocesses mode no results is visualized From the View combo box in the View Results window choose the Contour Fill option A set of a
111. m and saves the results in the results file This module may be programmed in the language of your choice C in used in this example Interaction of GiD with the calculating module 149 GiD Post process reads the following files generated by the calculating module project_name post res results file Each element of the mesh corresponds to a value project_name post msh file containing the post process mesh If this file does not exist GiD uses the preprocess mesh also for postprocess ma Preprocess GiD OG project_name dai ry 37 F Results file Postprocess mesh file DO propect namepast res project nama past resh Postprocess GiD Diagram depicting the files system 9 2 Implementation Creating the Subdirectory for the Problem Type Create the subdirectory cmas2d gid This subdirectory has a gid extension and will contain all the configuration files and calculating module files prb mat cnd bas bat exe ba NOTE If you want the problem type to appear in the GiD Data Problem type menu create the subdirectory within problemtypes located in the GiD folder for instance C GiD Problemtypes cmas2d gid 9 2 1 Creating the Materials File Create the materials file cmas2d mat This file stores the physical properties of the material under study for the problem type In this case defining the density will be enough Enter the materials in the cmas2d mat file using the
112. n the surface of the mechanical part 3 4 Creating volumes from surfaces 3 4 1 Creating the prism layer and translating the octagon to this layer 3 4 2 Creating the volume of the prism 3 4 3 Creating the volume of the wheel 3 5 Generating the mesh 3 5 1 Generating the mesh by default 3 5 2 Generating the mesh with assignment of size around points 3 5 3 Generating the mesh with assignment of size around lines 3 6 Optimizing the design of the part 3 6 1 Modifying the profile 3 6 2 Modifying the profile of the hole 3 6 3 Creating the volume of the new design 3 7 Generating the mesh for the new design 3 7 1 Generating a mesh for the new design by default 3 7 2 Generating a mesh using Chordal Error 4 IMPLEMENTING A COOLING PIPE 4 1 Working by layers 4 1 1 Creating two new layers 4 2 Creating the auxiliary lines 4 2 1 Creating the axes 4 2 2 Creating the tangential center 4 3 Creating a component part 4 3 1 Creating the profile 4 3 2 Creating the volume by revolution 4 3 3 Creating the union of the main pipes 4 3 4 Rotating the main pipe 4 3 5 Creating the end of the pipe 4 4 Creating the T junction 4 4 1 Creating one of the pipe sections 4 4 2 Creating the other pipe section 4 4 3 Creating the lines of intersection 4 4 4 Deleting surfaces and lines 4 4 5 Closing the volume 4 5 Importing the T Junction to the main file 4 5 1 Importing a GID file 4 5 2 Creating the final volume 4 6 Generating the mesh 4 6 1 Generating the mesh using
113. name of the new layer and click New 2 Select the prism layer and click Layer To use to choose it as the activated layer 3 Choose Lines in the Sent To menu in the Layers window Select the lines that define the octagon Press ESC to conclude the selection Creating the prism layer and translating the octagon to this layer 47 Ce Figure 21 The lines that form the octagon 4 Select the profile layer and click Off to deactivate it 3 4 2 Creating the volume of the prism 1 First copy the octagon a distance of 50 units relative to the surface of the wheel which is where the base of the prism will be located In the Copy window choose Translation and Lines Since we want to translate 50 units enter two points that define the vector of this translation for example 0 0 0 and 0 0 50 Make sure that the Multiple Copies value is 1 since the last time the window was used its value was 9 2 Choose Select and select the lines of the octagon Press ESC to conclude the selection dis Figure 22 Selection of the lines that form the octagon 3 Since the Z axis is parallel to the user s line of vision the perspective must be changed to visualize the result To do this use the Rotate Trackball tool which is located in the GiD Toolbox and in the mouse menu 48 User Manual Figure 23 Copying the octagon and changing the perspective 4 Choose Geometry gt Create gt NURBS surface gt By contour Select th
114. nd surface 149 Figure 8 An enlargement of the zone arounnd surface 149 2 Several line segments are superimposed over each other thus creating an incorrect surface boundary Select Geometry gt Edit gt Divide gt Lines gt Nearpoint and then select point 21 to select it go to Contextual in the mouse menu then select the option Join C a Point 21 is the point at which to make the cut Correcting surfaces 133 3 Then select line 3005 Press ESC After the cut is made the result will be as illustrated in Figure 10 Figure 9 The zone after cutting line 3005 at point 21 4 Now that the lines are precisely connected a local collapse may be executed Select Geometry gt Edit gt Collapse gt Lines Then select the lines that appear on the screen Figure 10 The situation after collapsing the lines 5 After the collapse the surface boundary is correct and the surface may be drawn with the new boundary The labels are no longer needed so click Label gt Off in the contextual menu 6 Select Geometry gt Create gt NURBS gt surfaceTrimmed Select surface 149 Then select the lines defining the recently repaired boundary Press ESC 134 User Manual Figure 11 Surface 123 with its new boundary 7 Select Geometry gt Delete gt Surfaces Select surface 149 and press ESC Ps a Jl d f Pd 7 a a E Figure 12 The surface to be eliminated 8 To begin the second example in this section mesh the geometry again wit
115. nter the 1 value Enter 0 CO N O Select View Results gt Contour Fill gt Pressure 9 Set the minimum value to 0 10 Select Options gt Contour gt Min options gt Out min color gt Transparent 11 Select Options gt Contour gt Color scale gt Terrain Map 7 3 6 Stereo mode 3D Advanced viewing settings ggg m mmm l Perspective cd stereo mode Anaglyph colors 0 050 Eo eye distance C switch eyes eye distance made scaled with the model left color mask W red green blue alpha right calor mask C red W green V blue W alpha Use shadow O black O 020 shadow color ambient ll shadow bias V finer silhouette FramebufferObject quality very high 4 Dynamic update Menu View gt Advanced options If you have an anaglyphic glasses you can try this option The model can be set as an anaglyphic image in order to provide a stereoscopic 3D effect when viewed with 2 color glasses each lens a Stereo mode 3D 119 chromatically opposite color usually red and cyan Anaglyphic images are made up of two color layers superimposed Since the glasses act as red and cyan filters we should be careful with the model s colors To avoid problmes we will change the contour fill color scale 1 Select Options gt Contour gt Color Scale gt 3D Anaglyphs 2 SelectView gt Advanced options 3 Check the Use stereo option 4 Check the Dynamic update option in order t
116. o at the midpoints of the edges of the elements Generating the mesh using quadratic elements 105 2475 3211 CIE ae 3125 r i 3 4l Bor 194 yi z p a 33 28959 53l 038 E 3188 3037 32b 3053 Figure 17 Each number identifies a node There is a node at each element vertex and at the midpoint of each edge 8 Select Utilities gt Preferences gt Meshing gt Quadratic type gt Quadratic9 9 Select Mesh gt Generate mesh 10 A window opens asking whether the previous mesh should be eliminated Click OK 11 Another window appears in which the maximum element size should be entered Leave the default value unaltered 12 Select Label gt All in gt Points see Figure 18 13 Notice that the four sided elements quadrilaterals also have a node in the center in addition to the nodes at the vertices and midpoints of the edges Similarly hexahedra alsohave a node at their center point 3935 4647 1298 4405 4187 1297 Abb 1804 1549 Figure 18 Each number identifies a node There is a node at each vertex at the midpoint of each edge and in the center of quadrilaterals and hexahedra 106 User Manual 107 7 POSTPROCESSING The objective of this tutorial is to do a postprocess analysis of an already calculated fluid simulations no preprocess option is used Not only the model is already meshed and the constraints are assigned but also the results have been calculated For more information about the prepr
117. o change the options without the need to click the Apply button Set the eye distance to the value where you can see the 3D effect Unheck the Use stereo option Close the window Select View results gt No Results Oo ON OA Change the view style to boundaries for all the layers like in Changing style chapter Pressure Pa 0 55696 _ 0 49507 0 43319 0 37131 0 30942 0 24754 0 18565 0 12377 0 061884 b y step 103 Contour Fill of Pressure Pa 7 3 7 Show Min Max Menu View results gt Show Min Max With this option you can see the minimum and maximum value of the chosen result in the chosen analysis step In our case we will choose the Vy component of velocity result for the first analysis step 1 Select View results gt Default Analysis Step gt RANSOL gt 91 5 throught the menu bar or clicking on TT EE 2 Select View results gt Show Min Max gt Velocity m s gt Vy throught the menu bar or clicking on The label shows the node number and the value of the result I2 3 Select View results gt No Results 120 User Manual z A step 91 5 Show Min Max of Velocity m s Vy 7 3 8 Stream lines A Menu View results gt Stream Lines With this option you can display a stream line or in fluid dynamics a particle tracing in a vector field 1 Select View results gt Stream Lines Velocity m s throught the menu bar or clicking on Se After this the program asks you fo
118. ocess part of GiD please check the preprocess tutorials In this tutorial the model Cylinder bin has been used The problem type used to do this simulations is Tdyn particularly the Ransol model Tdyn is a fluid dynamic CFD simulation environment based on the stabilized Finite Element Method Steps followed in this tutorial Loading the model e Changing mesh styles Visualization of results e Creating images A 7 1 Loading the model Loading the model There are two ways to load the results simulation information into GiD e f the model has been calculated inside GiD and so the results are inside a GiD project then just loading the GiD project and the changing to postprocess mode is enough This can be achieved clicking on this icon or selecting the Files gt Postprocess menu entry lf only a mesh and results file s is present then GiD should be started and switched to postprocess 108 User Manual ui before loading the file s In this tutorial only Cylinder bin is present with the postprocess information so the steps to follow are 1 Start GiD 2 Switch to postprocess mode e or Files gt Postprocess 3 Open the model with Files 2Open Ctrl o or clicking on 7 2 Changing mesh styles Through the Select amp Display style window several options can be specified for volumes surfaces and cuts Among these options volumes surfaces and cuts can be switched on and off their colour proper
119. ow opens asking whether the previous mesh should be eliminated Click OK 12 Another window appears in which to enter the maximum element size Leave the default value unaltered and click OK The result is the mesh shown in Figure 12 Figure 12 Semi structured volume mesh of hexahedra Generating semi structured meshes volumes 101 In case of volume number 3 there is only one direction in which it can possibly be structured i e in the direction of the prism If the volume is prismatic in more than one direction there are two ways to choose between them selecting one top surface Mesh gt SemiStructured gt Set gt Master surface or the direction of the structure Mesh gt SemiStructured gt Set gt Structured direction The following example explains this procedure 13 Select the option Mesh SemiStructured Volumes 14 A window opens in which to enter the number of divisions in the structured direction prismatic Enter 6 15 Select volume 1 and press ESC 16 Another window appears click Close 17 Select Mesh gt SemiStructured gt Set gt Structured direction 18 Select one line parallel to theX axis of volume number 1 for example line number 11 and press ESC 19 Select Mesh gt Unstructured gt Assign EntitiesSurfaces 20 Select surfaces 1 and 6 and press ESC 21 Select Mesh gt Generate mesh 22 A window opens asking whether the previous mesh should be eliminated Click OK 23 Another window appears in which to
120. r 149 Meshing by default 131 MeshErrors Curmaces wrong suraces Mum Description 143 Couldn t mesh at this location signal Close Figure 6 Dialog window warning of an error found when meshing surface 149 In this part of the tutorial we focuson repairing surface number 149 To locate surface 149 select the line 149 couldn t map this point in the dialog box and press the Signal button the same effect is obtained by double clicking over the message with the left mouse button NOTE If user clicks the right button over a message in the Mesh Errors window three options are displayed Signal problematic point More help or List The first option is the same as the Signal button while the List option presents a list of the problematic geometrical entities to make selection easier when performing some common procedures like sending the entities to a separate layer erasing the entities etc The More help option gives advice about to correct the geometrical model so the mesh can be generated NOTE 7he Mesh Errors window can be recovered while dealing with the model by selecting the Show errors option in the Mesh menu 132 User Manual Figure 7 Signaling surface 149 NOTE The identifiers of the entities vary each time the instruction Mesh gt Generate Mesh is executed 8 2 2 Correcting surfaces 1 With the View gt Zoom In option on the mouse menu magnify the zone arou
121. r a point from which to start plotting the stream line This point can be given in several ways We will select the nodes using the Along line option 2 Open the mouse menu and select Contextual gt Along line With this option you can define a segment along which several start points will be chosen The number of points will also be asked for including the ends of the segment In the case of just one start point this will be the center of the segment Stream lines 121 We want to create several stream lines along the model doing 2 lines 3 Write the initial point in the command line 10 15 3 4 Write the final point in the command line 10 15 3 5 You are asked for the number of points along the line Choose 5 The first line with 5 stream lines is created 6 Write the initial point in the command line 10 15 7 7 Write the final point in the command line 10 15 7 8 You are asked for the number of points along the line Choose 3 The second line with 3 stream lines is created 9 Click the middle mouse button or press the Esc key in order to finish the operation t Quick Mice lw Dynamic update stream Size Type af stream Initial swirl 0 0 M Show Arrows 1 0 points 0 0 Color Ap p hy Arrows Size 4sided prisms 5 EET Close Arrows Frequency 10 10 ET t ribbons Original C Monochrome Stream contour tilled Result contour filled Several configuration options can be set via th
122. r the maximum element size Leave the default value unaltered an click Ok The result is the mesh shown in Figure 8 12 As seen in Figures 7 and 8 GID can obtain surface structured meshes made of quadrilaterals or triangles There are tow kinds of structured mesh that use triangles the one shown in Figure 7 is obtained when the Utilities gt Preferences gt Meshing gt Symmetrical structured gt triangles option i set If this option is not set the mesh presented in Figure 8 is produced with fewer nodes than if using the previous option Generating a structured mesh surfaces 97 i Pat Ta T RP PY Loa S2 XE CTI oc EA EN m ilie LX VRA l YS Figure 8 Structured mesh of quadrilateral and triangular elements on surfaces with the option Symmetrical structured triangles not set When selecting a line GID automatically selects all lines parallel to it 6 2 6 Generating structured meshes volumes 1 To mesh volumes with a structured mesh select the option Mesh Structured Volumes 2 Select volumes 1 and 2 and press ESC 3 A window appears in which to enter the number of divisions that the lines to be selected will have Enter 6 4 Select lines of both volumes parallel to the X and Z axes GiD automatically selects all the lines in each volume parallel to these in order to create the structured mesh Press ESC 5 Another window appears in which to enter the number of divisions on the lines Divide the lines
123. rface resulting from the section of one of the vertexes of the prism surface number 1 Press ESC 3 Select Mesh gt Generate Mesh 4 A window opens asking if the previous mesh should be eliminated Click Yes 5 Another window appears in which you can enter the maximum element size Leave the default value unaltered and click OK This results in a high concentration of elements on the chosen surface due to the value selected 0 5 see Figure 8 84 User Manual E c ee E Ses EN e e tr ow Nuus wok S eg 1 na E a zT uu s ES BUE ee 5 zT A t OM s gr E Tet a J d s Ee LA Pn UT Pan UA Ne kx EM FOX XL 8 E MR F je L is Tu i Ld LI NS ae V We i XC x iV WB 4 m Hc j t cT ce NS oU NS Is Ps qs or MN SE URR OE Figure 8 Mesh with a concentration of elements on a surface 5 2 5 Assignment with Maximum Chordal Error Select Mesh gt Unstructured gt Sizes by chordal error GID asks for the minimum meshing size Enter 0 1 GiD asks for the maximum meshing size Enter 10 A U N Enter the chordal error This error is the maximum distance between the element generated and the real object geometry Enter 0 05 and press OK 5 Select Mesh gt Generate Mesh 6 A window opens asking if the previous mesh should be eliminated Click Yes 7 Another window appears in which you can enter a maximum element size Leave the default value unaltered and
124. s the postprocss files M ro E Menge TECPLOT ASCII file with multiples meshes Recent post file 3D Studio file STYE asc points Import ort s A Save the current Exp Graph image in the Preprocess selected format Recent projects b Print to file b Post information i Page and capture settings Print P Printinz apti ans TX z Quit Cover mesh Visible surfaces to STL Send the image to the printer Closes GID Open the last models Changes userinterface to the prepracess phase Files 11 1 2 10 Utilities In the postprocess phase the Utilities command permits the user to obtain information about entities Opens a window to handle the visualization style and the sets Lists Project entities and Chooses the preferred options for project X Preferences Indicates on the screen the amp View style location of entities Severals tool like macros B calculator Lools Nodes erg oy Copy Elements Status Opens the postprocess copy window i List Id Signal d With this aptian its possible to add Gives information about useful Distance textual information to the model such general data of the project Dimension 4 TF as distances angles or coordinates Create d Identifies any node af the Delete mesh being viewed Edit Showbox showingits label number and spatial coordinates Calcualtes distance To jnin several sets into ane To add between
125. selected nodes 1 Select View results gt Graphs gt Point evolution gt Velocity m s gt V 2 Write 20 0 4 in the command line in order to specify the point The Line graph displays a graph defined by the line conectig two selected nodes of surfaces or volumes or any arbitrary points on any projectable surface and in any position 3 Select View results gt Graphs gt Line graph gt Velocity m s gt V 4 Write 30 4 in the command line in order to specify the initial point 5 Write 50 0 4 in the command line in order to specify the final point Once the graphs are created are showed in the main window several graphs can be showed at the same time You can swap this view with the model view 6 Select View results gt No Graphs throught the menu bar or clicking on o You can also select the Model view option in order to get a view of the model while you are working with the graph 7 Select Options gt Graph gt Model view gt Show 8 Choose Yes By default the model view s size it s a 50 of graph s size 9 Select Options gt Graph gt Model view gt Size 10 Choose 75 Graphs 123 IVI IVI VI IVI RANSOLDistanceDistanceDistance You can also create the graphs and change their options using the graph window Select Window View graphs Select the Graph management tab Select the first graph of the list Point 20 0 4 evolution Click the Delete button A U N
126. sent example is saved All the files have the same name of the directory to which they belong but with different extensions These files should have the name that GiD designates and should not be changed manually Each time the user selects option save the database will be rewritten with the new information or changes made to the project always maintaining the same name To exit GiD simply choose FilesQuit To access the example ejemplo gid simply open GiD and select from the Top Menu FilesOpen An Auxiliary Window will appear which allows the user to access and open the directory iniciacion gid 2 3 Creation and meshing of a surface We will now continue with the creation and meshing of a surface First we will create a second line between points 1 and 3 3 0 10 0 1 0 0 0 2 10 0 0 We will now generate the second line We will now use again the Coordinates Window to enter the points Utilities gt ToolsCoordinates gt Window Select the line creation tool in the toolbar Enter point 0 10 0 in the Coordinates Window and click Apply C System Cartesian E Local axes Global Y x 0 0000 0 0000 Create new point Ask Change Use tab Shifttab and Return Apply Close 24 User Manual With option Join Contextual mouse menu click over point 1 A line should be created between 0 10 0 and 0 0 0 Press Escape With this a right angle of the square has been defined If the
127. sh they are shown with black edges that are thicker than surface meshes triangles If the triangles form a boundary volume mesh and at the same time a triangle surface mesh this can be obtained if surfaces are selected with the option Mesh gt Mesh criteria gt MeshSurfaces the wider edges are colored with the color of the surface layer Examples of these different kinds of render are shown in Figure 3 SENI ae 7 VA M Figure 2 Generating the mesh by default Figure 3 Different render styles a surface mesh b volume mesh c surface mesh and volume mesh together surface layer is red and volume layer is blue 94 User Manual 6 2 2 Generating the mesh using circles and spheres 1 Select Mesh gt Element type gt Sphere Select volume number one and press ESC To see entity numbers select Label from the mouse menu or from the View menu If you wish the geometrical entity labels to be displayed the view mode needs to be changed to Geometry using View gt Mode gt Geometry this option may also be found in the GiD Toolbox Select RenderNormal to see the labels Select Mesh gt Element type gt Circle Select surface number 24 and press ESC Select Mesh gt Generate mesh A window comes up asking whether the previous mesh should be eliminated Click Ok Another window appears in which to enter the maximum element size Leave the default value unaltered and click OK The result is a mesh as illustrated in Figure
128. sh which can be exported to a file Options gt lso surfaces gt result contour fill allows to draw the contour fill of any result over the isosurface Select this option and then do a contour fill of any result Options gt Ilso surfaces gt draw iso lines this options allows the user to switch isolines of surafaces on or off 7 3 2 Animate Menu Window gt Animate This window allows the user to animate the current visualized results If only one step is present then the Static analysis animation profile button is enabled so that a custom animation profile can be step to animate that one step 112 User Manual i Results View mE static iw Automatic Limits analysis Detormation animation profile Endless ji From step 3 ta step amp cet duration by f Total Time 5 5 use step values as scaled delays t Delay between steps 200 ms t Use step values as seconds Step number step value 931 5 Ww Save MPEG Default Resize If one result has several steps you can visualize them in an animation In this case we will use the iso surfaces result 1 Select View gt Render gt Normal 2 Select Window gt Animate to open the animation window Please notice that we have from step 1 to 13 We will do the animation only of some of these steps 3 Check the From step option and set 3 to step 8 4 Select the Delay between steps option and set it to 800 ms The animation should take 4 seconds 5 Try it
129. st be entered In this example the value is 1 Progress in me 5j as eec el Meshing surface number D LLC CC C C EC EZZ Num of Tetrahedra elements 9694 Num af nodes 14976 Wleshed h surfaces af h Meshing volume number Meshed volumes of 1 Humber af nodes efile Humber of elements HUG Stop Creation and meshing of a volume 33 Ne V UE The mesh generated above is composed of tetrahedral elements of four nodes but GiD also permits the use of hexahedral eight nodded structured elements We wil generate a structured mesh of the volume of the cube This is done by selecting Mesh Structured Volumes Now select the volume to mesh and enter the number of partitions in its edges which will be created Then create again the mesh Enter value window Dialog window 2 Enter number of cells to assign to lt lines Mum of Hexahedra elements 1000 Mum of nadesz1331 User Manual A _A_A_A_A_A_A_A_A_A_ AL ALALALALALALAL AL AL A AVAVAVAVAVAVAVAVAWAV AY AVWWVIVVVVIVevayuvAsxMy AVOID LAURI A AVLALVLALVLAL VLA VLA VLVLVLW VUA VLA VUA M V AY TE A A AVVO A AVI VEVLOLULVLVLVLVLVLVLULVLTLVLULVLVLVLVUV A y AV VLVLVLULULVLTLULULTLULULULU A VA DEDERAT DLE REDE AV VLVLULULULULULULULULULULULULULULULULULUL VA V y TIMOR MUTARE TUNE LUNA LULA AV VLULULULVLVLVLULULTLULVLDLU ULT V ULULIA VLA V nurum PLLLELCDLAEDAELCA LED UST A ULVLULULULELULULTLULULVLULULULDLULULUL VL
130. t only the circle and the two straight lines that intersect it 6 Choose Copy from the Utilities menu and make seven copies Multiple copies 7 rotating the circle 45 degrees 7 Using the intersection options delete the auxiliary lines leaving only the valid lines thus obtaining the new profile of the hole The result is illustrated in Figure 42 8 Create the hole in the surface of the wheel using Geometry gt Edit gt Hole NURBS Surface the result is shown in Figure 43 Modifying the profile of the hole Figure 42 The new hole profile 3 6 3 Creating the volume of the new design Repeat the same process as in section 4 3 59 f gt d Pert F i T Y n yop temC oe ao F ng Ao M 1 7 UM m 5 a n po EE Em a i E j r kt k hs ki m Y mu o Aa 1 n L NA a bn late i i E a Ww La mn L Fi Figure 43 The surface of the new optimized design 1 In the Copy window choose Translation and Surfaces Enter two points that define a translation of 10 units for example 0 0 10 and 0 0 0 Make sure that the Multiple Copies value is 1 2 Choose Do Extrude Volume in the Copy window 3 Click Select and select the surface of the wheel Press ESC Figure 44 The volume of the optimized design 4 Click On the prism layer 3 7 Generating the mesh for the new design Generating the mesh for the optimized design is more complex In this geometry it is especially
131. tance beteween points With this aptionit s posible to add textual information to the model such as distances angles or coordinates Utilities Pre 7 1 2 5 Data This menu allows access to the definition of all data related to materials boundary conditions etc which will be necessary for the calculations that follow The form of this data will depend on the type of the analysis to be performed Defines type of problema calculation ansys55 d edgebased_levelset Examples b fluent Transform Intemet Retrieve Load Unload Debugger Describes the properties of the problem and other data related to the geometric entities Problem ype Conditions i WDR Divides infarmtatian af Describes materials used iz Problem Data mifi splen hune prablemaintaintervals Local _ 4 New Current Describes generally Delete the prablema data Changes and defines local coordinate axes Define Drew Drew all Delete Delete all User Manual 1 2 6 Mesh Mesh permits the user to generate and edit the mesh as well as to select mesh creation preferences Assigns element sizes to entities for non structured e Assign sizes on points Assign sizes on lines a mas 1 y Assign sizes on surfaces M Assign sizes on volumes Sizes by chordal error Sizes by background mesh Correct sizes Assign entities d Defines a boundary layer 2 dimensioanl Unstructured
132. tation The type of entity to receive the rotation is a surface so from the Entities Type menu choose Surfaces 3 Enter 3 in the Angle box and check the Two dimensions box Provided we define positive rotation in the mathematical sense which is counter clockwise 3 degrees equates to a clockwise rotation of 3 degrees 4 Enter the point 0 0 0 under First Point This is the point that defines the center of rotation 5 Click Select to select the surface that is to rotate which in this case is that of the circle 6 Press ESC or Finish in the Move window to indicate that the selection of surfaces to rotate has been made thus executing the rotation Entities type Surfaces Transformation Rotation Angle 3 Degrees First point Mur x 0 0 v 0 0 e zi 00 W Two dimensions Second point Mur x 10 0 y D D z 00 Duplicate entities Do extrude Create contacts iw Maintain layers Multiple copies Select Cancel Figure 5 The Move window 3 2 5 Rotating the circle 36 degrees around a point and copying it 1 Use the Copy window located in Utilities gt Copy 2 Repeat the rotation process explained in section 2 4 but this time with an angle of 36 degrees see Figure 6 Rotating the circle 36 degrees around a point and copying it 39 Figure 6 Result of the rotations Ja NOTE The Move and Copy operations differ only in that Copy creates new entities while Move displaces entities
133. the geometry and the mesh entities GID is flexible in tis configuration of the screen and accommodates different menus depending on the user s preference Undo commands Toolbars ececuted during the work Save window conf session Move Screen Objects in Utilities Coordinates window Chooses the Undo Bead batch window preferred options f r 9X Preferences Ctr p Comments project i ll 2 Animation controls rs Girl S Leye Animation scnpt Tools Macros Ion win Opens the layers Copy s Ctri c IDEE window Move Calculator Report i Notes i Lisi Moves entities as translation rotation symmetry scale in Id this case without duplicating entities Swap new or existing points Manage the orientation of the entity normal Check the internal coherence of the data base Renumber Signal istance Gives information about usefu Dimension eneral data ot the project PEE Repair model List Project entities and their properties Shows labels and coordinates o Copies all types af entities normals bv performing a translation rotation mirror symmety or entity scaling Renumbers the entity labels in order to avoid gaps in numbering cause by the elimination of entities during the description of geometry andits properties Renumbers the mesh to decrease the analysis interval Create b Delete Edit ShowBox Calculate the dis
134. the polygon Enter or select 0 0 1 Positive Z as the normal of the polygon Enter 10 as the radius of the polygon and press ENTER Press ESC to finish the action 0O A O N We get the result as shown in figure 20 As we only need the boundary we should remove the associated surface Select the option Geometry gt Delete gt Surfaces and then select the surface of the octagon Press ESC to finish Creating a hole in the part 45 Figure 17 Regular 8 sided polygon 3 3 1 Creating a hole in the surface of the mechanical part 1 Choose the option Geometry gt Edit gt Hole NURBS Surface 2 Select the surface in which to make the hole Figure 18 3 Select the lines that define the hole Figure 19 and press ESC Figure 18 The selected surface in which to create the hole Figure 19 The selected lines that define the hole 4 Again press ESC to exit this function 46 User Manual CA Figure 20 The model part with the hole in it 3 4 Creating volumes from surfaces The mechanical part to be constructed is composed of two volumes the volume of the wheel defined by the profile and the volume of the axle which is a prism with an octagonal base that fits into the hole in the wheel Creating this prism will be the first step of this stage It will be created in a new layer that we will name prism 3 4 1 Creating the prism layer and translating the octagon to this layer 1 In the Layers window type the
135. this first part of cmas2d bas file general information on the project is obtained nelem returns the total number of elements of the mesh npoin returns the total number of nodes of the mesh Coordinates Node X Y loop nodes format 51 14 5e 14 5e NodesNum NodesCoord l1 real NodesCoord 2 real end nodes 153 This command provides a rundown of all the nodes of the mesh listing their identifiers and coordinates loop end commands used to indicate the beginning and the end of the loop The command loop receives a parameter loop nodes the loop iterates on nodes loop elems the loop iterates on elements loop materials the loop iterates on assigned materials format the command to define the printing format This command must be followed by a numerical format expressed in C syntax 154 User Manual NodesNum returns the identifier of the present node NodesCoord returns the coordinates of the present node NodesCoord n real returns the x y or z coordinate in terms of the value n n 1 returns the x coordinate n 2 returns the y coordinate n 3 returns the z coordinate Connectivities Element Node 1 Node 2 Node 3 Material set elems all loop elems sTOrmMac TlO LOIS LOTS LOIS LUTS ElemsNum ElemsConec ElemsMat end elems This provides a rundown of all the elements of the mesh and a list of their identifiers the nodes that form them and their assigned material set
136. ties can be changed and their transparency too Other interesting options which can be changed are the style of the set and the width of the edges From this window volumes surfaces or cuts can be deleted or their names can be modified To access this windows select Windows View Style or Utilities 2 View style o click the icon Mesh styles can also be changed clicking on the icon Sell placed in the left icon bar This style affects all sets of the model Select Dispioy She CNEENENRMEAREAEEREEEECC iw Volumes M Surfaces M Cuts alphabetic order b Elements 717 793 tetrahedras 96 000 tetrahedras 1 101 460 tetrahedras 25 556 triangles 1 414 triangles 1 760 triangles 7 436 triangles 6 400 triangles 8 800 triangles 21 584 triangles 21 720 triangles o C Name Y volumes V cil V wake 5 volumes 1 Triangle 5 inlet 3 Triangle 5 outlet 4 Triangle 5 lateral 5 Triangle 5 interior cil 6 Triangle 5 ext cil Triangle S up amp Triangle 5 down 9 Triangle Oo 6 x r 7 Rename LI T Delete Style Body Bound Show conditions None v 3 L3 C3 Cy Cy C3 C3 Cy Cr C3 C3 x CJ CR CR CR CR C3 COR COR 99 08 EB ED EB EB ED EB EI EL E E E 5s M m H m um rj 8 rj Y Y 8 rj r rj u r a gt Render Normal v Preprocess model None v Culling T No v Model render Normal v To back Send to 1 Select Utilities gt View style using the menu bar or clicking
137. tion Duplicate entities point 6 will be merged with point 5 when the entities are copied By labeling the entities we could verify that only one point has been created Finishing the copy command for the surface we obtain the following surfaces Creation and meshing of a volume 31 Now we can generate the volume delimited by these surfaces To create the volume simply select the command Geometry gt Create gt Volume gt By contour This option is also available in the toolbar Select all the surfaces GiD automatically generates the volume of the cube The volume viewed on the screen is represented by a cube with an interior color of sky blue Before proceeding with the mesh generation of the volume we should eliminate the information of the structured mesh created previously for the surface Do this by selecting Mesh gt Reset mesh data and the following dialog box will appear on the screen 32 User Manual Dialog window o Sure you want to reset all meshing information In which the user is asked to confirm the erasure of the mesh information NOTE Another valid option would be to assign a size of 0 to all entities This would eliminate all the previous size information as well as the information for the mesh and the default options would become active Next generate the mesh of the volume by choosing Mesh gt Generate mesh Another Auxiliary Window appears into which the size of the volumetric element mu
138. tions Conditions E PointWeight Mica S Weight UU Entiti Dra Unassig Close The GiD Conditions window for assigning the cmas2d boundary and load conditions CONDITION Point Weight CONDTYPE over points CONDMESHTYPE over nodes QUESTION Weight VALUE 0 0 HELP Concentrated mass END CONDITION 9 2 4 Creating the Data Format File Template file Create the cmas2d bas file This file will define the format of the dat text file created by GiD It will store the geometric and physical data of the problem The dat file will be the input to the calculating module NOTE It is not necessary to have all the information registered in only one bas file Each bas file has a corresponding dat file Write the cmas2d bas file as follows The format of the bas file is based on commands Text not preceded by an asterisk is reproduced exactly the same in the dat file created by GiD A text preceded by an asterisk is interpreted as a command Example bas file dat file Creating the Data Format File Template file EEE 535 Problem Size Problem 5555 Number of Elements amp Number of Nodes Elements amp 5379 4678 Nodes nelem npoouxn The contents of the cmas2d bas file must be the following bas file Title GenData Title 551551551465659595959 Problem Size 1 1551551 551465 55 55 560560500900090 Number of Elements amp Nodes nelem npoin In
139. to determine the center of rotation and the tangential center which will be used later to create the model 4 2 1 Creating the axes Choose the Line option by selecting Geometry gt Create gt Straight line E Enter the coordinate 0 0 in the command line Enter the coordinate 200 0 in the command line Press ESC to indicate that the process of creating the line is finished If the entire line does not appear on the screen use the option Zoom Frame which is located in the GiD Toolbox and in Zoom in the mouse menu 6 Again choose Line Draw a line between points 0 25 and 200 25 The result is shown in Figure 2 or O N Figure 2 7 Goto the Copy window Figure 4 which is found in Utilities 2 Copy 8 Choose Rotation from the Transformation menu and Lines from the Entities Type menu 9 Enter an angle of 60 degrees and click on Two dimensions 10 Enter point 200 0 0 in First Point This is the point that defines the center of rotation 11 Enter 60 degrees with option Two dimensions checked 12 Click Select to select the first line we drawn Creating the axes 63 13 After making the selection press ESC or Finish in the Copy window to indicate that the selection of lines to be rotated is finished The result is shown in Figure 3 Entities type Lines E Transformation Rotation Angle 60 Degrees First point Num x 200 0 y 0 0 e 2 0 0 iw Two dimensions Second po
140. tour of the volumes meshed but not the interiors 9 The visualization may be rendered using the various options in the Render menu located in the mouse menu NOTE By default GiD corrects element size depending on the form of the entity to mesh This correction option may be deactivated or reactivated in the Meshing card in the Preferences window under the option Automatic correct sizes Figure 31 The mesh generated for the piece Generating the mesh by assignment of sizes on surfaces 77 4 6 2 Generating the mesh by assignment of sizes on surfaces 1 Choose Mesh gt Unstructured gt Assign sizes on surfaces A window opens in which to enter the element size for the surfaces to be selected Enter size 1 2 Select the surfaces of the elbow 3 Choose Mesh gt Generate mesh 4 Awindow appears asking whether the previous mesh should be eliminated Click Ok 5 Another window appears in which the maximum element size should be entered Leave the default value provided by GiD unaltered and click OK 6 Choose Mesh gt View Mesh Boundary to see only the contour of the meshed volumes but not the interiors Figure 32 De o A TTA ic i a De D EE a aT a a i ae SE e a EY a a A C in ae ee veru VIP T ME eh ll rat zr ux s Fa Fi A dl ATATA P iM P ms ok ay vera 2 SV evt MU NS PU UV e le od vr APT EY i 00k na vv SV NANI a AY
141. ts M NOTE GiD meshes by default the entity of highest order with which it is working GiD allows the user to concentrate elements in specified geometry zones Next a brief example will be presented in which the elements are concentrated in the top right corner of the square This operation is realized by assigning a smaller element size to the point in this zone than for the rest of the mesh Select the following sequence Mesh gt Unstructured gt Assign sizes on points The following dialog box appears in which the user can define the size Enter value window o Enter size to assign to points 0 0 to unassign We must now regenerate the mesh canceling the mesh generated earlier and we obtain the following 26 Wate p INVI V Vi VA D VV NN NN OY OOS SNO KAKA aT wan NAA Kx AZ WAN Ee ACE N XM VAY AAA MV M Ae N N N N XXK TN BO N N m V V NNI VA N LN NEN V NA YV V N XK WKY p S S SA e SV NN User Manual As can be seen in the figure above the elements are concentrated around the chosen point Various possibilities exist for controlling the evolution of the element size which will be presented later in the manual To generate a surface mesh in which the elements are presented uniformly the user can select the option for a structured mesh This guarantees that the same number of elem
142. ts Menu View gt Render In order to improve the visualization and to get a more realistic view we can change the render mode There are three main options Normal With this visualization mode no illumination is applied to the model and so no 3D perception can be achieved Ideal for 2D models and quick 3D temporal visualization Flat lighting Solid model with flat illumination the triangle faces can be distinguished as no smoothing is done between triangles Smooth lighting Solid model with smooth illumination better quality i e illumination is smoothed between triangles if their angle is bigger than the one specified in Options gt Geometry gt Border angle In the Render menu we can also set more options Change light direction With this option you can change the vector of the light direction interactively 110 User Manual this can also be done by entering the vector components in the command line Reflection with this option an environment or a pattern will be reflected on the surfaces For the moment we will select the Normal render 1 Select View gt Render gt Normal throught the menu bar or in the mouse menu select Contextual gt Render gt Normal 7 3 Viewing the results Several results had been calculated for several time steps You can check these results through the Results menu or opening the View Results window Menu View Results Window gt View Results View Results amp Deformation
143. ts that define a vector for this translation for example 0 0 0 and 0 0 10 3 Choose the option Do Extrude Volumes from the Copy window The volume that is defined by the translation will be created 4 Make sure that the Maintain Layers option is not checked hence the new entities created will be placed in the layer to use otherwise the new entities are copied to the same layers as their originals 5 Click Select and select the surface of the wheel Press ESC 6 Select the two layers and click them On so that they are visible 7 Choose Render gt Flat from the mouse menu to visualize a more realistic version of the model Figure 27 50 User Manual Figure 27 Image of the wheel 3 5 Generating the mesh Now that the part has been drawn and the volumes created the mesh may be generated First we will generate a simple mesh by default Depending on the form of the entity to be meshed GiD performs an automatic correction of the element size This correction option which by default is activated may be modified in the Meshing card of the Preferences window under the option Automatic correct sizes Automatic correction is sometimes not sufficient In such cases it must be indicated where a more precise mesh is needed Thus in this example we will increase the concentration of elements along the profile of the wheel by following two methods 1 assigning element sizes around points and 2 assigning element sizes around
144. tured Size Transitions This option defines the transition gradient of element sizes size gradient whose values are between 0 and 1 The greater the size gradient the greater the change in space To test this enter the value 0 4 and click Accept 8 Again select Mesh gt Generate Mesh OK 9 A window opens asking whether the previous mesh should be eliminated Click Ok 10 GiD then asks you to enter the maximum element size Leave the default value unaltered and click Te is 7 SK EXER EZS CAM ARRIM ABER i SC 5s 7 IZN V Y M IN vi A TN ex VERA in AWA Cae NA h A FAN vAYA VA n N H i 4 a fay L as a eat a 2 a Ss Im A KEY n gt Rh e a RNV Im n IY i A IN PA VY M VW My ER UE ASA VS d AN N x 9 A K x JD LV L IN mea oo acm JS EEEN a a el N eat Ny a Pa DY S R zi eS Figure 6 Mesh with the elements concentrated around a point with a size gradient of 0 8 11 The size gradient 0 4 results in a higher density around the point see Figure 6 12 Now go back and enter 0 6 in Unstructured Size Transitions This will result in a mesh more suitable for our objectives Click Accept Instead of pressing
145. uctured meshes volumes 1 To mesh volumes with a semi structured mesh select the option Mesh gt SemiStructured gt Volumes 2 A window appears in which to enter the number of divisions for the direction in which it is structured the prismatic one Enter 8 3 Select volume 3 and press ESC As volume 3 is prismatic in one direction only i e parallel to Y axis GiD will automatically detect this fact and will select it to be the direction in which the semi structured volume mesh is structured 4 Another window appears in which to enter the number of divisions in the direction of the structure In this case we do not want to select any more volumes so click Close 5 Select Mesh gt Generate mesh 6 A window appears asking whether the previous mesh should be eliminated Click Yes 7 Another window appears in which to enter the maximum element size Leave the default value unaltered and click OK The result is the mesh shown in Figure 11 100 User Manual Figure 11 Semi structured volume mesh of tetrahedra As can be seen volume 3 has been meshed with tetrahedra Semi structured volumes are meshed with prisms by default However in this case it was not possible because of volume 2 which has tetrahedra assigned and shares one surface with volume 3 In the following steps a hexahedron mesh is produced 8 Select Mesh gt Element type gt Hexahedra 9 Select volumes 2 and 3 and press ESC 10 Select Mesh gt Generate mesh 11 A wind
146. us options and methods allowing sizes to be assigned to elements Five examples are shown to illustrate the default method and the four other methods The Preferences option can also be found in the Utilities menu Automatic correct sizes automatically executes the options Assign sizes gt By geometry and Assign sizesCorrect sizes 5 2 1 Assignment using default options 1 Select Mesh gt Generate Mesh 2 window appears showing the maximum element size Leave this default size unaltered and click OK 3 A meshing process window opens Then another window appears with information about the mesh generated Click OK to visualize the mesh see Figure 2 Assignment using default options 81 Figure 2 Meshing by default Note that in the zone highlighted in Figure 3 elements are smaller than in the rest of the model This is because of the shape of the surface placed there When all meshing preferences are set to their default levels as for this example the RFAST surface mesher is used In this way geometrical entities are meshed hierarchically first of all lines are meshed then the surfaces and finally the volumes The line elements size depends on the shape of surfaces as can be seen in this example Later on we will see an example using RJUMP mesher where element sizes are distributed differently EL SOS ees 7 OM AOS Se ny i VE VV i i gt TN W _s di iu ANAS i K
147. ut catculate r OUEDUC I 9 4 1 The main program The main program is called from the cmas2d win bat file and has as parameter the name of the project This name is stored in the variable projname The main program calls the input calculate and output functions The input function reads the dat file generated by GiD The dat file contains information about the mesh The calculate function read and processes the data and generates the results The output function creates the results file VOLO not uy 4 cher cXrlenaemell024 cvileersr l024 saul O24 6 sau 1024 The main program 165 BOINB UID Lerr It aux erfror 0 void jumpline FILE strcpy filename projname otrcatdcrrlenegme dact rpetoperni tilenamegtrtys The first part of the input function links the project name with the dat extension thus obtaining the name of the file that is to be read This file is opened in order to be read The jumpline FILE function is declared This function simply reads a line from the file that it receives as a parameter It is used to jump lines of the text when reading the dat file tor 107 1x07 ur Jump lane CE fscanf fp sd td amp Nelem amp Nnod The first six lines of the dat file are jumped over since these are lines of information for the user see bas file Then the total number of elements and nodes of the project are read and stored in the variables Nelem and Nnod respectiv
148. vailable results only one for this case are displayed View Results amp Deformation EA view Resuts amp Deformatic View results Main Mesh Reference mesh View results Main Mesh Reference mesh e a UI tow conoeru al ep Analysis LOADANALYSIS v h Analysis LOADANALYSIS eja The View Results window Now choose the MC DISTANCE result and click Apply A graphic representation of the calculation is obtained 162 User Manual Visualizing the distance MC DISTANCE from the center of mass of the objectto each element for an object of homogeneous material The results shown on the screen reproduce those we anticipated at the outset of the problem the center of mass of an object made of homogeneous material coincides with its geometric center The log file will provide the exact coordinates of this point 9 3 1 Executing the calculation with a concentrated weight Executing the calculation for an object of heterogeneous material and subject to external point weight Choose the Files preprocess option to go back to preprocess Choose the Data Conditions option A window is opened in which the conditions of the problem should be entered Since the condition to be entered acts over points select over points from the Type menu in the Conditions window Executing the calculation with a concentrated weight 163 Conditions o Faint veight Weight 0 0 The Conditions window Enter the value

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