Patran for Advanced Users Exercise_14_MPCs

PATRAN302ExerciseWorkbook-Release8.014-1LESSON14UsingListsandMulti-PointConstraintsObjectives:■UseListstoisolateandgroupnodesofinterest.■DefineMPC’stoconvertsolidtranslationsintoshellrotations.■Createacyclicsymmetricboundaryconstraintalongthe0degreeand30degreefaces.14-2PATRAN302ExerciseWorkbook-Release8.0LESSON14UsingListsandMulti-PointConstraintsPATRAN302ExerciseWorkbook-Release8.014-3ModelDescription:InthisexerciseyouwillcreateMPC’stoattachtheshellelementsinyourmodeltothesolids.Shellandsolidelementsareincompatible.Solidelementsprovidestiffnessinonlythethreedisplacementdirectionsforeachnode,whileplateelementsinP3/FEAprovidestiffnesstothreedisplacementdirectionsandtworotations(in-planerotationisundefined).ToconnectthetwodissimilarelementstogetherrequiresMPCelementstoaccountfortherotationaldegreesoffreedomdefinedbytheshellelement.TheMPCequationsyouwillusewillcreaterelationshipsbetweenthenodesontheshellelements,andthoseontheupperandloweredgesofthesolids.YouwilluseListstogroupthesenodes.TheMPCequationsyouwillneedtouseandthejustificationforeachareasfollows:Firstthetranslationaldegreesoffreedomarelinearlyinterpolatedtoobtainthetranslationatthemid-planeofthesolid.Thetranslationsoftheplateedgeisthensetequaltothatvalue.FIGURE1.(EQ1)ZRθshells0.4topbottomUrshell0.5UrtopUrbottom+()=14-4PATRAN302ExerciseWorkbook-Release8.0(EQ2)(EQ3)ToaccountfortherotationsoftheshellweapplytheKirchhoff-Loveassumptionwhichstatesthatplanesnormaltotheneutralplaneremainplanarduringdeformation.Figure1isaschematicofadeformationattheinterface,showingapositiverotation.Forsmallvaluesofθ,sinθ=θ,thus:(EQ4)(EQ5)(EQ6)SuggestedExerciseSteps:■Make3lists:onefornodesattachedtotheedgeoftheshellelementsatthesurfacetosolidinterface,onefornodesontheupperedgeofthesolidelementsatthatsameinterface,andoneforthenodesontheloweredgeofthesolidelements.■CreateoneMPCtotietogetherthetranslationaldegreesoffreedomalongtheshelltosolidinterface.Themotionofthenodesontheshellisdependentonthemotionofthenodesonthesolid.■CreateadditionalMPC’stoassignrotationtotheplateelementsbycouplingsolidtranslations.■Defineacyclicsymmetryboundaryconstraintsalongthe0oand30ofacesofthemodel.Theseconstraintsareappliedusingthecylindricalcoordinatesystem.Uθshell0.5UθtopUθbottom+()=Uzshell0.5UztopUzbottom+()=Urotrshell0=Urotθshell10.4-------UztopUzbottom–()=Urotzshell10.4-------U–θtopUθbottom+()=LESSON14UsingListsandMulti-PointConstraintsPATRAN302ExerciseWorkbook-Release8.014-5Files:Allthefilesusedinthisexercisearelistedbelow.Eachlistingincludesthefile,whereitoriginated,itsformat(text/binary)andsummaryinformationastohowitrelatestothisexercise.FileSupplied/CreatedDescriptionmpc.dbCreatedinex2ThisisaPATRANdatabase(binary)createdinExercise2.ThegeometryforthemodelwascreatedinExercise2.ThemeshforthemodelwasgeneratedinExercise6.Finally,multi-pointconstraintswillbecreatedinExercise7.ExerciseProcedure:1.Opendatabasempc.db.2.Createalistofnodesalongtheedgeoftheshellelementsatthesolidtosurfaceinterface.ClickonToolsintheControlPanel,selectList/Create...fromthepull-downmenuandthenselectthefollowing:Thenodesalongtheedgeoftheshellareataradiusof6.2unitsandanaxiallocationof2units.Togroupthenodesthatsharethesecoordinates,changetheRefer.CoordinateFrametothecylindricalcoordinateframeinyourmodelandsearchontheabovelistedcoordinatevalues.Tools/List/Create...Model:Object:Method:AttributeCoordValueRefer.CoordinateFrameCoord1■R■ZR6.2CreatingListsforinterfacenodesFEMNodeAttributeCreatingListsforBottomNodes14-6PATRAN302ExerciseWorkbook-Release8.03.Createalisttoreferencenodesonthebottomofthesolid.YounowhavetwolistsbutweneedtousethreetodefinetheMPC’s.Tocreatethethirdlist,weneedalist‘c’.4.Createalisttoreferencenodesonthetopofthesolid.ClickonTools/ListintheControlPanelandselectBoolean...fromthepull-downmenu.Youwillmakealistcthatduplicatesthecurrentcontentsoflistb.Youwilluselistcwhenyouneedtoreferencenodesonthebottomofthesolids.Youwillcreateanewlistbreferencingthenodesonthetopedgeofthesolidforyourthirdlist.Youwilluselistbwhenyouneedtoreferencenodesonthetopofthesolids.Inordertomovethecontentsofthecurrentlistbintolistc,ontheBooleanListform,clickontheiconforB-A.Atthispoint,‘listc‘contentsand‘listb‘contentsshouldbeidentical:thenodesonthebottomofthesolids.OntheListBform,clickClear.Z2TargetList◆“A”ApplyTargetList◆“B”R6.0Z2.0ApplyTools/List/Boolean...ClearCreatingListsforBottomNodesCreatingListsforTopNodesABB-ALESSON14UsingListsandMulti-PointConstraintsPATRAN302ExerciseWorkbook-Release8.014-7OntheCreateListform,enterthefollowingtocreatelistb:Younowhave3lists:list‘a’referencesthenodesatthesolid/shelledgeoftheshellelements,listbreferencesthenodesatthetopedgeofthesolidsalongtheinterface,andlist‘c’,thenodesalongthebottomedgeofthesolids.5.CreateaMPCtotietogetherthetranslationaldegreesoffreedomalongtheshelltosolidinterface.ThefirstMPCyouwillcreatewilltietogetherthetranslationaldegreesoffreedomalongtheshelltosolidinterfaceasshowninEquation1throughEquation3onpage-4.Thedependentnodeswillbethoseinlista,whichareassociatedwiththequadelements.Clicko