整车FEM建模手册-绝密

PAGEPAGE24用于碰撞被动安全性CAE分析FEM建模手册车身模型建模要求一般要求GeneralRequirements1.Thepartsshallbemodelledusinglinear(3or4noded)shellelements.2.Thepartsshallbemodelledonthemidsurface.Ifthedeliveredgeometryisnotamidsurfacerepresentation,thegeometryshallbemodifiedtorepresentthemidsurface.3.Noelementsareallowedtocrossthe“symmetry”liney=0(nodesshallbepositionedony=0)4.Theshellelementsshallbeconsistentlydefined.5.Thepartsshallbemodelledinthefollowingunitsettings:Lengthinmillimetres(mm)Timeinsecond(s)MassintonneForceinNewton6.EachpartshallhaveoneuniquePID,withthefollowingexceptions:PartsmadeoftailoredblanksshallbedividedintodifferentPIDsaccordingtothedifferentthicknessandmaterialqualitiesoftheparts.ExtrudedpartsshallbedividedintodifferentPIDsaccordingtothedifferentthicknessandmaterialsofextrusion.Thethicknessatdifferentlocationsonacast/mouldedpart7.Thepreferrednamingconventionasbelow:ST3700=1234567_A1A_3.5_B-Pillarmaterialdrawingnodrawingrevthicknesspartname8.AllpartswithidenticalmaterialspropertiesshallrefertothesameMID.9.Onemodelshallbeusedforallcrashsimulation建模要求MeshingGuideline1.Deformationareashallbemeshwithaaveragelength10mm.Deformationareashallbemeshwithaminimumlengthofnotlessthan5mm.Maximumlengthshallnotexceed12mm.注：变形区域：正面碰撞：A柱与B柱中间位置以前的所有零件及其某些零件的前部（车门除外），另外前端吸能部件，包括纵梁前段、翼子板支撑结构等的平均单元长度为8mm；侧面碰撞：前后从A柱至C柱（包括A柱与C柱），横向左半部所有零件及其某些零件的左半部（框内的零件及其某些零件的框内部分）；背面碰撞：C立柱（包括C立柱）以后的所有零件及其某些零件的后部（车门除外）。2.Noneformationareashallbemeshwithaaveragelength15mm.Allpartsshallbemeshwithaminimumlengthofnotlessthan5mm.Maximumlengthshallnotexceed18mm.3.NopenetrationsareallowedintheFEmodel.FEmodeshallbeglobalpenetrationcheck.(partthicknessscaleis0.65.)4.Elementtype:QUAD4andTRIA3(max10%ofthefullmodel)5.ElementCheck:Aspectratio<3.0Skewness<60Warping<15CrashTimeStep*＞8.1e-07InternalAngleMinMaxQUAD40140TRIA30120Jacobian>0.5*CrashtimestepforpartB-pillarsystem,longitudinal,bumpersystemis6.0e-7Thepartshallbecompletelymeshed.Un-meshedareasshallnotexistA“freeedge”checkshallbeperformedtoverifythatthereareno”cracks”inthemesh.A“shellelementnormal”checkshallbeperformedtoverifythatthenormalsareconsistentlydefinedNoduplicategridpointnumbersshallexist.NoduplicateelementnumbersshallexistNoduplicatestructuralelementsshallexist.Aduplicateelementisdefinedasanelementofthesametypeandattachedtothesamegridpointsasanotherelement.Avoidpackingtrianglestogethertothesamegridpoint6.ModellingoffilletIftheradiusofthefilletissmallerthan5mm–norepresentationofthefilletIftheradiusofthefilleris=/>5mm,aminimalofoneelementinfilletismodelled.7.ModellingofflangesSpotweldedflangesshallbemodelledaccordingtothefigurebelow:Trytokeeptheoriginalangleoftheflange.In(a),theflangehasanewangle,whichisnotrecommended.Therecommendedpracticeistomodeltheflangeasin(b).Thisisforassemblyreasons;flangeswithlargeangulardifferencesmayyieldpoorweldingelements8.ModellingofhemflangesHemflangescanberecognizedbythatthepartisfoldingarounditself(seefigurebelow)Hemflangesshouldbemodelasfigurebelow:9.Modellingofholesa)BoltholesForboltholes,6ormorenodesaroundisrequiredaroundtheperimeterofthebolthole.Theouterperimeterofwashers,distancesandnutsintheboltjointshallbeprojectedonthepartandmodelledusingpreferably6ormorenodesaroundtheprojectedperimeter.Incaseswheretheaverageelementlengthissmallcomparedtothesizeofthewasher,itisallowedtousemorethanonerowofelementsbetweentheouterandtheinnerwasherperimeter.Iftheouterperimeterofwashers,distancesandnutsintheboltjointisnotknown,acirclewithcentreinpointCandadiameterof2.0×Dmin(Dmin=minimumdiameterofbolthole)maybeused.Itisallowedtoslightlymodifytheperimeterofeithertheboltholeortheprojectedoneofwashers,distancesandnutsinthebolt,ifthatimprovestheelementqualityaroundthebolthole.Iftheminimumdiameteroftheholeissmallerthantheminimumelementlength(5mm),theholeshallnotbemodelled.b)RivetholesRivetholesshallnotbemodelled10.ModellingofspotweldSpotweldaremodelledasPLINKinpamcrashmodel.PLINKisdefinedbyoneindependentnodedescribingthelocationofthespotweldaswellasthepartswhichisneededtobespotwelded.ThelocationofspotweldtobedefinedinVIPfilePLINKForarcwelding,thepositionofthearcweldingshallberepresentedbyanode.ThisnodetobemodelledwithTIEDCONTACT(TYPE32)–“NodetoElement”12.ModellingforglueModellingofglueisbySOLID(PENTA/HEXA).Thesolidistobemadegridtogridtoitsconnectingparts.13.铰接厚度不同的铸造铰链体用SOLID(PENTA/HEXA)单元模拟，其余用壳单元模拟。较销用spring单元模拟，spring单元只有三个移动自由度方向的刚度，三个转动自由度方向的刚度为零。较销与铰链体之间用rigid单元连接。动力传动系统模型建模要求（1天）GeneralEachpartoftheenginecomponentstobemodelledseparatelyintodifferentPIDsEnginepackagecanbeseparatedintoafewdifferentcategoriesasperbelow:a)ENGINE:EngineblockCylinderHeadCylinderCoverOilpanb)AGGREGATES:GeneratorWaterpumpAirconditioningcompressorOilFilterPulleys,etcc)INJECTIONSYSTEM:ManifoldAirductAirfilterIgnitionsystemd)ENGINEBAYCOMPONENTS:WatertanksBatteryBrakebooster,brakecylinder,brakefluidtankABSFuseboxe)GEARBOXGearboxDriveshaftDifferentialf)EXHAUSTSYSTEM:ExtractorCatalyticconverterPipesSilencersBrackets/Hooksg)ENGINEMOUNTINGh)COOLER:Radiator,AirconditioncoolerFan,CageBracketsetcMeshingGuideline1.EngineMeshingsize15~20mmOnlyoutersurfaceismeshToavoidhourglassissues,theribsaretobemodelledwith2elementrows.发动机本体在分析中作为刚体处理，但必须保证单元质量，为此可以作适当的几何简化处理2.AggregatesMeshingsizeis10mmThesepartsaremostlynotdeformablebuttherecouldbeapossiblerupturetoitsbracketsBracketshavetobemodelledmiddlesurfacewithtruethicknessAggregatescanbemodelwithoutershell.Toavoidhourglassissues,theribsaretobemodelledwith2elementrows.3.InjectionsystemandenginebaycomponentsMeshingsizeis10mmPartstobemodelledwithoutersurface4.GearboxMeshingsizeis15~20mmPartstobemodelledwithoutersurface5.ExhaustsystemMeshingsizeis10mmExhaustmanifold/extractorandcatalyticconverterismodelledwithoutershellPipes,silenceranditsribsandtobemodelwithmiddlesurfaceAllpartsforexhaustsystemtobeconnectedgridtogrid.Thecompartmentinthesilencerhastobemodelledinrib(pleaseseefigurebelow)6.EnginemountingMeshingsizeis10mmEnginemountingtobemodelledwithmiddlesurface橡胶垫采用弹簧单元模拟7.CoolerMeshingsizeis10mmFan,fancage,pipesneedtobemodelledwithshellsHoneycombonthecooler/radiatortobemodelledwithSOLIDelements.Aminimumof3layersofsolidismodelledoverthethicknessofcooler.底盘系统模型建模要求一般要求底盘系统模型包括转向系统转向拉杆转向助力器齿轮结构转向柱转向盘支架悬架系统轮胎羊角摆臂弹簧减振器橡胶垫建模要求1、转向系统转向拉杆用R和BEAM单元模拟转向拉杆套筒采用尺寸为mm壳单元模拟转向助力器与齿轮系统只建壳体，采用尺寸为mm壳单元模拟转向柱采用BEAM单元模拟转向柱套筒采、支架、转向盘用尺寸为mm壳单元模拟、悬架系统悬架系统轮胎采用气袋模型模拟，因此采用尺寸完15MM的壳单元建立封闭体，轮毂采用尺寸为20MM的壳单元作弹性体处理。连接摆摆臂、轮毂、悬架、转向拉杆等的羊角采用RIGID单元作为刚性体处理，在其原点附质量单元，其质量为羊角本身质量加制动系统的质量。板壳件摆臂采用壳单元，实体件摆臂采用SOLID单元。螺旋弹簧和橡胶垫的弹性属性采用BAR单元模拟，螺旋弹簧外形轮廓采用壳单元模拟，周围弹性材料处理。减振器外形轮廓与弹簧托架采用壳单元模拟。座椅模型建模要求MeshingGuidelineSeatpositionTheseatmustbepositionedinthemiddleforbothslidingrailaxis