導彈拋物沖擊侵蝕分析

Workshop6

ObliqueProjectileImpact

(witherosion)ANSYSExplicitDynamicsWorkshopGoalandProcedureGoal:Performobliqueimpact/penetrationanalysis(witherosion)Procedure:CreateanExplicitDynamics(ANSYS)AnalysisSystemProjectSelecttheunitssystemanddefinethematerialsImportandmeshthearmorgeometryDefineanalysissettings(includingerosion),initialconditions,boundaryconditionsandbodyinteractionsInitiatethesolution(AUTODYN-STR)andreviewtheresultsStep1–CreatetheProjectSchematicStartANSYSWorkbenchandfollowthesequencedstepsusingtheabbreviationsshownbelow:DC=DoubleClickwithLeftMouseButtonSC=SingleClickwithLeftMouseButtonRMB=RightMouseButtonSelectionD&D=DragandDrop=HoldLeftMouseButtondownonitemwhiledraggingittonewlocationandthenreleaseit(i.e.,CopyorMove)DC1.CreateanANSYSExplicitDynamicsAnalysisSystemProjectStep2–SpecifytheProjectUnits2.aSelectMKSfortheProjectUnitsfromtheUnitsListprovided2.bRequestthatNativeApplicationsinWorkbenchhavetheirvaluesbeDisplayedintheProjectUnits2.cCheckthoseunitsystemstoSuppressfromappearingintheUnitsListNote:EngineeringDataisnativeinWorkbench,butMechanicalisNOTatthistime(butwillbeinthefuture).Step3–DefineEngineeringDataMaterial3.aEdittheEngineeringDatacelltoaddamaterialtothedefaultlibrary.3.bSelectexplicitmaterialstoloadinanexistingmaterialmodel.3.cScrolldownandaddCARTBRASS,LEAD,RUBBER1andSTEEL4340DCThebooksymbolconfirmsithasbeenaddedStep3–DefineEngineeringDataMaterial3.dCheckthematerialshavebeenaddedtoengineeringdata3.cWewillusethesematerialsastheyarewithoutmodification

SCStep3–DefineEngineeringDataMaterial...3.gReturntotheProjectSchematic3.hSavetheProjectbyselectingthe“SaveAs

...”iconandBrowsetothedirectoryindicatedbyyourinstructor.Usethename“Oblique_penetration”fortheProjectname.Note:SavingtheProjectsavesalloftheimportantfiles.TheProjectmayalsobeArchived,inwhichallofthesupportingfilesarecompressedandsavedinonefile.Step4–ImportandModifytheGeometryRMBSC4.aImportthegeometrybytheprocedureshown.DoNOTDoubleClickonthe“Geometry”cell...4.bBrowsetotheDesignModeler11.0SP1geometryfilenamed:“oblique_penetration.agdb”Step5–EdittheModelinMechanical5.aEditthemodelinWorkbenchMechanical.SinceEditisthedefaultaction,double-clickingontheModelcellisalsoacceptablehere.RMBSC5.bSelecttheMKSUnitssystemRecallthatMechanicalisnotnativeinWorkbench,sotheUnitsheremaynotmatchtheProjectUnitsNote:Althoughtheunitsystemusedfordataentryandpost-processingistheMKSsystem,theactualunitsystemusedbytheAUTODYNsolveristhemm-mg-mssystem,becauseitprovideshigheraccuracy.ThiswillbeshownlaterwhentheAnalysisSettingsarediscussed.Step5–EdittheModelinMechanical...5.cDefinethematerialsforeachpartinturn(multiplepartscanbeselectedbyholdingthectrlkey):plate1andplate2 -steel4340rubberspacer1→rubberspacer4-rubbersteelwasher1→steelwasher8 -steel4340bolt1→bolt4 -steel4340bulletcase -cartbrassbulletcore -leadStep5–EdittheModelinMechanical...5.d Materialassignmentscanthenbe checked: -SelectGeometry -UnderDisplayStyleselectmaterial -Thescreenplotwillthencolorthe modelbymaterialStep5–EdittheModelinMechanical...5.eDeletetheBondedContact

RegionsRMB5.fReviewtheexistingBodyInteractionspecificationsStep5–EdittheModelinMechanical...5.fReviewtheautomaticallycreatedsymmetryplane5.gSavetheProjectStep6–MeshModel6.aSelecttheMeshbranch6.bSpecifytheMeshDetails:PhysicsPreference=ExplicitElementSize=0.006meters6.cApplyaPatchIndependentTetrahedronsmethodtothetwopartswhichmakeupthebullet(viaRMB

Mesh>Insert>Method)6.dSettheelementsizeto0.005metersStep6–MeshModel6.eApplyabodysizingtothetwoplates(viaRMB

Mesh>Insert>Sizing)6.fSelectthetwoplatesandclickApplyonthegeometryline6.gUndertypeselectSphereofInfluence - selectZXplaneasthespherecentre - setsphereradiusto0.04meters - settheelementsizeto0.003meters6.h Generatethemesh(viaRMBontheMeshbranch>generatemesh)Step7–DefinetheAnalysisSettings7.aSpecifytheAnalysisSettings:EndTime=0.00015seconds

7.bNotetheSolveUnits=mm,mg,msThemm,mg,msunitsystemisthemostaccurateinmostsimulations,soitistheonlyonecurrentlyavailableforsolution.Althoughmoresolverunitsystemswillbeavailableinthefuture,anyunitsysteminthedrop-downlistmaybeusedtoenterdataand/ordisplaytheresults.SCStep7–DefinetheAnalysisSettings...7.cKeeptheremainingdefaultsNote:Therearemultiplewaystocontroltheerosionofanelement.Inthiscase,theelementwillonlyerodewhenthegeometricstrainreaches150%.7.dEnsureretaininertiaoferodedmaterialissettoYES7.dUsethedefaultnumberofdatasetstosaveduringthesolution.Step8–ApplyInitialConditiontobullet8.aapplyinitialvelocitytobullet:SelectInitialConditionsintheOutlinetreeSelectthebodyfilterSelectthetwobulletbodies(whileholdingctrl)RMBonselectedbodies

Insert>velocityEnteravelocityof800m/sSelectthedirectionboxClickononeofthelongedgesofthebulletIftheredarrowpointsthewrongway,clickthearrowicontoreverseitApplytheselectionStep9–InsertResultItemstoPost-process9.aInsertaTotalDeformationplotrequestundertheSolutionbranch9.bInsertanEquivalent(von-Mises)Stressplotunderthesolutionbranch9.cSavetheprojectontheprojectpageRMBRMBSCSCStep10–RuntheAUTODYNSimulation10.aSelectSolverOutputunderSolutionInformationandSolvethesimulation.TheSolverOutputshowstherunstatistics,includingtheestimatedclocktimetocompletion.Anyerrorsorwarningsarealsonoted.Terminationdueto“wrapuptimereached”isexpectedhere.SCStep11–ReviewtheResults11.aSelectTotalDeformationa