PATRAN中如何修补模型间隙PPT课件

WORKSHOP8SURFACEMESHINGFORNONCONGRUENTSURFACES,Workshop8SurfaceMeshForNoncongruentSurfaces,ObjectivesImportgeometricsurfacesfromaMSC.Patranneutralfile.Observethemanygapsbetweenadjacentsurfaceedges.Meshthesurfaceswithtriaelements,thenconnectelementswherethereareinternalfreeelementedges.Createageometricsurfacefromthetriamesh.Meshthenewsurface.,Workshop8SurfaceMeshForNoncongruentSurfaces,ProblemDescriptionTocreateafiniteelementmodelforseveralgeometriccomponents(forthiscasemultiplesurfaces;seebelow)itisnecessarytoconnectadjacentelements(e.g.Equivalence)atgeometricinterfaces.Whentherearegaps(largerthanthetolerance(*),ordifferenceofvertices(*)atinterfacesitismoredifficulttoconnecttheelements.Onewaytodealwiththisistocreateatriangular(tria)elementmeshforeachofthegeometricentities,“sew”(equivalence)theregionswheretherearenoelements,thencreateasinglegeometricsurfacefromallthetriaelements.Finally,deletethetriaelementmesh,andcreatea2-Dmesh(e.g.Quad4)bymeshingthesinglesurfaceobtainedfromthetriaelementmesh.,*,*,Workshop8SurfaceMeshForNoncongruentSurfaces,SuggestedExerciseStepsCreateaDatabase.ImportaMSC.Patranneutralfilewithsurfaces.Showthedistancebetweentwopoints.Create2-Dmesh.Closegapsbetweenadjacenttriaelements.Lookatelementfreeedgeboundaries.Deleteoriginalgeometryandcreatenewsurface.Meshnewsurface.,Workshop8SurfaceMeshForNoncongruentSurfaces,Step1.CreateaDatabase,Createanewdatabasenamedshell.File/New.Entershellasthefilename.ClickOK.SelectDefaultundertolerance.SelectMSC.NastranasAnalysisCode.SelectStructuralasAnalysisType.ClickOK.,a,b,d,c,f,e,g,Step2.ImportaMSC.PatranNeutralFileWithSurfaces,Importtheneutralfilecalledshell_prt.out.1.File/Import.SelectNeutralasSource.Locatethefilenamednon_cong_surfs.out.ClickApply.ClickYes.ClickYes.,a,b,c,d,e,f,Thisiswhattheimportedsurfacesshouldlooklike.Lookatthegaps,Step2.ImportanMSC.PatranNeutralFileWithSurfaces(Cont.),Step3.ShowtheDistanceBetweentwoPoints,Determinethedistancebetweentwoadjacentpoints.ThiswillhelpinthedeterminationofthevalueoftheglobaledgelengthforsubsequentPavermeshing.Geometry:Show/Point/Distance.SelectPoint231underFirstPointList.SelectPoint370underSecondPointList.ClickApply.,a,c,b,d,Step4.Create2-DMesh,Create2-DmeshusingPaverforsetofsurfaces.Elements:Create/Mesh/Surface.SelectTria,Paver,andTria3.UncheckAutomaticCalculation.Enter2.0asGlobalEdgeLength.SelectallsurfacesforSurfaceList.ClickApply.,a,b,c,d,e,f,Step5.CloseGapsBetweenAdjacentTriaElements,Closethegapsinthemodelby“sewing”themeshtogether.The“Sew”commandissimilartoEquivalence.Elements:Modify/Mesh/Sew.Enter6.0asTargetElementEdgeLength.ClickonTriaElementListandselectallelements.ClickApply.,a,b,c,d,ShowwheretheelementfreeedgesareElements:Verify/Element/BoundariesSelectFreeEdgesasDisplayType.ClickApply.,Step6.LookatElementFreeEdgeBoundaries,a,b,c,Step7.DeleteOriginalGeometryandCreateNewSurface,Deletetheoriginalgeometryforvisualclarity,andcreateasurfacefromtheexisting2-Dtriameshwithagap/hole.Geometry:Delete/Surface.ClickonSurfaceListandselectallsurfaces.ClickApply.Geometry:Create/Surface/Mesh.CheckDeleteOriginalElements.ClickonElementsListandselectallelements.ChooseNoneforInnerLoopOptions.ChooseFastforSurfaceCreationMethods.ClickApply.,a,b,c,d,e,f,g,h,i,Thisiswhatthenewsurfaceshouldlooklike.,Step7.DeleteOriginalGeometryandCreateNewSurface(Cont.),Step8.MeshNewSurface,MeshthesurfacejustcreatedusingQuad4elements.Elements:Create/Mesh/Surface.SelectQuad,Pav