内饰车身噪声和振动建模规范

Q/SZJ191001-2017内饰车身噪声和振动建模规范NoiseandVibrationTrimmedBodyModelling20XX20XX-XX-XX实施20XX-XX-XX发布XXXX汽车工程技术有限公司发布Q/SZXX-X-2017内饰车身噪声和振动建模规范范围本标准规定了术语和定义、内饰车身噪声和振动模型的建模方法。本标准适用于CAE部门的内饰车身噪声和振动建模。规范性引用文件无。术语和定义无。摘要AbstractNVH系统建模按车辆的承载能力分为两类：结构部件：这些都是与白车身连接到一起的部件（BIW）。例如包括中通道，IP横梁和门内板。非结构部件（附件）：这些部件都是提供很少或没有承载能力的结构。例如包括电线，外饰。由于我们建模能力的不断扩大，内饰车身建模的精细程度是一个发展趋势，详细说明了小承载能力的部件，这些先进的建模技术将对个别部件进行详细讨论。非结构部件大部分对整车的刚度没有影响。只有它们的质量、惯量矩和/或阻尼特性在车辆系统建模中被模拟。一般来说，非结构性组件建模有两种方法:•简化建模:这个组可以进一步细分为组件模型:集中质量:包括尺寸较小的部件，通过刚性单元连接到车身（BIW）一个或多个部分。例如包括电池、刹车助力器和加速踏板通过分布质量进行模拟:这些部件通常较大，并且通过一个特定的区域进行传递。例如白车身面板上的油漆。•详细建模:这些部件通常对局部刚度和质量贡献量较大。例如地板上的地毯和隔音板的建模，能额外增加刚度和阻尼。建立完整的模型取决于以下：•项目可交付成果/时间•资源（分析人员处理模拟细节的情况）•数据/信息的可用性(设计可能不成熟，无法提供详细的数据)•分析目标(结果保真度)对内饰部件模拟方式的选择决定了相应分析结果的有效性。模型建立的越详细，该模型的有效性就越高，在结构噪声频率范围内，该模型的有效性越高。车辆建模时包括所有的重要质量，使模型质量与实际车辆质量相匹配是非常重要的。车辆模型的质量不仅要准确地反映实际的车辆质量，而且要根据实际情况在整车中正确地分布，同时也要考虑到大型部件的惯量值。NVHsystemmodelingmakesafunctionaldivisionofthecomponentsofavehicleintotwocategoriesbasedontheirload-carryingcapability:·structuralcomponents:Theseareloadcarryingmemberscommonlyassociatedwiththebody-in-white(BIW).Examplesincludelongitudinalrails,IPbeams,anddoorinnerpanels.·non-structuralcomponents(or“trim”components):Thesearecomponentsthatprovidelittleornoloadcarryingcapabilitytothefullvehiclestructure.Examplesincludetheelectricalwiring,andexteriorstylingtrim.Asourcapabilityinmodelingexpands,thereisagrowingtrendtomodeltrimcomponentsindetailtoaccountfortheminorloadcarryingcapability.Theseadvancedmodelingtechniqueswillbediscussedindetailonanindividualcomponentbasis.Thisprocedureisconcernedprimarilywiththemodelingofthenon-structuralcomponents.Themodelingofthemostcommonnon-structuralcomponentsacrossallvehicleplatformsisdescribedhere.Mosttrimcomponentsprovidenosignificantstiffnesscontributiontotheoverallvehicle.Onlytheirmass,momentsofinertia,and/ordampingcharacteristicsaresimulatedinvehiclesystemmodeling.Ingeneral,non-structuralcomponentscanbeidealized/modeledintotwomaingroups:• Simplerepresentation:Thisgroupcanbefurthersub-dividedintocomponentsmodeledas:Concentratedmass:ThisincludespartsthatareusuallysmallinsizeandattachedtotheBIWatoneorseveralpoints.Examplesincludethebattery,brakebooster,andacceleratorpedalDistributedmass:Thesecomponentsareusuallylargeinsizeandspreadthroughaspecificarea.ExamplesincludethepaintontheBIWpanels.• Detailedrepresentation:Thesecomponentsareusuallydeemedsignificantintheircontributiontolocalstiffnessandmass.Anexampleismodelingthecarpetanddeadeneronthefloorpanelstoaccountforadditionalstiffnessanddamping.Selectingtheappropriaterepresentationforatrimcomponentwilldependon:• Programdeliverables/timing• Resources(HPCandanalysttoprocessthedetailinthemodel)• Availabilityofdata/information(designmaybetooimmaturefordetaileddata)• Analysisobjectives(fidelityofresultsrequired)Theparticularselectionofarepresentationfortrimcomponentswillqualifythevalidityofthecorrespondinganalysisresults.Thehigherthedetailcontentofthemodel,themorepotentialtopushthevalidityofthemodeltohigherfrequenciesinthestructurebornenoisefrequencyrange.Itisimportanttoincludeallsignificantmassesinthevehiclemodelsothatthemodelmasscorrectlymatchestherealvehiclemass.Themassofthevehiclemodelshouldaccuratelyreflecttherealvehiclemassnotonlyinoverallweight,butalsointheproperdistributionthroughoutthevehicleandalsowiththeappropriateinertiavaluesforlargecomponents.流程图ProcessFlowDiagram座椅座椅CAD模型seat-in-whiteCADmodel建立简化模型BuildSimpleModel建立详细模型BuildSimpleModel模态计算SubmittoNastranorOptistruct模型配重CheckModelMass模型输出ModelCheckout:图1流程图Fig1ProcessFlowDiagram工具描述ToolDescription仿真分析过程中需要用到的如下软件:Thefollowingsoftwarefacilitatestheanalyticalsimulationprocess:前处理(Preprocessors):Hypermesh求解器(AnalysisCode):MSC.Nastran后处理(Postprocessors):Hyperview建模和分析过程Modeling/AnalysisProcedure单位Units分析中所用单位制如下所示:Theunitsusedintheanalysisareasfollows:力(Force) 牛顿(N)质量(Mass) 吨(Ton)长度(Length) 毫米(mm)时间(Time) 秒(Second)内容ContentsTrimmedbody包含所有重要的质量。Trimmedbody应包含：白车身、发动机罩、行李箱、挡板、地毯、顶盖内饰板、散热器总成、制动助力器、电池、备胎、座椅、阻尼器、安全带、转向管柱、洗涤液瓶、雨刷、ABS控制器的、计算机模块、非结构车身、车门等。任何重要的质量都必须包括在内。每个内饰部分的质量，以及搭建的总质量必须与实际内饰车身质量相匹配。Thetrimmedbodyshouldcontainallofthesignificanttrimmedmasses.Thetrimmedbodyshouldcontain:Bip,Hood,decklid,tailgate,carpet,headliner,radiatorassembly,brakebooster,battery,sparetire,seats,bakeondampers,seatbelts,steeringcolumn,washerbottle,windshieldwipers,ABScontroller,computermodules,nonstructuralbodypanels,doorsandetc.Anysignificantconcentratedordistributedmassesmustbeincluded.Themassofeachtrimpart,aswellasthetotalmassofthetrimbodymustmatchtheactualmassofthetrimmedbody.坐标系CoordinateSystems分析采用整车坐标系,有些弹簧需要建局部坐标系。Analysisusesvehicleglobalcoordinatesystem,Localcoordinatesystemsareneededforsomespringsinthetrimmedbody.建模技巧ModelingTechniques简化的建模技术•3D单元内饰建模建模包括大质量和惯量的部件（＞3kg）。质量和惯量等效为集中质量和转动惯量（conm2）。对于大质量部件（＞3kg），具有显著的惯量特性，建议把这些惯量值附在集中质量单元（conm2）上，这些属性会显著影响系统模型的动态特性。内饰附件用刚性单元（RBE2、RBE3）与白车身进行连接。刚性单元应该按照实际的位置范围进行连接，集中质量附在部件的质心位置，RBE2是刚性单元能增加刚度，RBE3单元本身不提供刚度。对于非常硬的部件（雨刮电机和支架），就要用RBE2单元来模拟相对刚性的附件。然而，大部分的组件建模都采用详细模型，因为它能够精准的反映部件与部件之间的连接关系。此外，当用刚性单元建模时，必须考虑刚性单元自由度。一般建模方法用刚性单元和集中质量。图2简化建模方法Fig2GeneralmodelingtechniqueRBE2刚性单元主点和从点都有6个自由度。一般建模方法用集中质量。图3简化建模方法RBE3Fig3GeneralmodelingtechniqueRBE3主点是6个自由度，从点有1-3自由度。对具有显著的惯性特性的转动刚体模态的部件，使用刚度单元RBE2在质心位置加集中质量点。•2D单元内饰建模（通过多点连接到车身）参考之上描述的3D建模方法。2D单元非结构质量（附与在车身上的区域）质量和附件采用非结构质量单元模拟（NSM,NSM1），在属性Pshell卡片里设置非结构质量单元NSM。2D单元部件的刚度（附加在白车身一个区域内），质量、阻尼和内饰附件模拟都要仿照实际车辆状况来定义板件属性。•1D单元质量为集中质量（conm2），惯量通常被忽略。附件直接与白车身结构安装孔进行连接。为了与实际车辆重量匹配，可以通过集中质量进行配重。SimplifiedModelingTechnique•3D“Block”TrimComponentsTheseincludetrimcomponentsofsignificantmass(>3kg)andinertia.Massandinertiaismodeledasconcentratedmassandinertia(CONM2).Forlargecomponents(>3kg)thathavesignificantinertiaproperties,itisrecommendedthattheseinertiavaluesbeincludedintheCONM2element,asthesepropertiesmaysignificantlyaffectthebehaviorofthesystemmodel.AttachmenttotheBIWismodeledwithrigidelements(RBE2orRBE3).Therigidelementsshouldattachtothevehiclestructureinthesamelocationsasthecomponentattachmentswhosemassisbeingmodeled.BewarethatRBE2elementsaddinfinitestiffnessandRBE3elementsaddzerostiffness.Forverystiffcomponents(suchasthewindshieldwipermotorandbrackets),anRBE2elementspidershouldbeusedtomodelthisrelativelyrigidattachment.However,mostcomponentsthataremodeledarelessrigidlyattached.Therefore,anRBE3spidershouldbeusedinthesecasesbecauseitprovidesamoreaccuraterepresentationofthecomponentanditsattachmenttothevehiclestructure.Also,whenmodelingwithrigidelements,considerationmustbegiventowhatdegreesoffreedom(DOF’s)areused.GeneralmodelingtechniqueusedforRBE2/CONM2representation:RBE2：DependentGrids(DOF1-6)RBE2：IndpendentGrids(DOF1-6)GeneralmodelingtechniqueusedforRBE3/CONM2representation:RBE3：DependentGrids(DOF1-6)RBE3：IndpendentGrids(DOF1-3)VisualizationofrotationalrigidbodymodesoftrimcomponentswithsignificantinertiamayrequireavisualizationRBE2attachedtotheCG/CONM2point.•2D“Sheet”TrimComponents(AttachedtotheBIWatafewpoints)See3D“Block”TrimComponents(above)•2D“Sheet”TrimComponents(AttachedtotheBIWoveranarea)Massandattachmentismodeledasnon-structuralmass(NSM,NSM1orfield9onPSHELLcard)onthestructuralelementsthatthecomponentisattachedto.Formassbookkeepingpurposes,therecommendationistouseNSMLorNSML1asmultipletrimcomponentssmearedontoonePSHELLcardremovesaccountabilityofmass.•2D“Sheet”TrimComponentswithstiffness(AttachedtotheBIWoveranarea)Stiffness,Mass,DampingandattachmentismodeledusingduplicateelementsontheexistingstructuralBIWmodelwithreferencetotheirownindividualpropertycard(PSHELL).•1D“Line”TrimComponentsMassismodeledasconcentratedmass(CONM2)andinertiaisusuallyneglected.AttachmentisdirecttoexistingpointsontheBIWstructure.VisualizationofthetrimcomponentcanbeexecutedwithPLOTELsconnectingtheconcentratedmasses(CONM2s)forthepurposesofmassaccountability.详细的建模方法参照下面列出的内饰部件电池建模：简化模型，模型讲解：这部分采用刚性单元把集中质量及惯量附加到质心位置上，与电池托盘进行连接来模拟电池结构。集中质量单元与电池托盘的连接结构如下：单元类型：RBE2主点：集中质量（conm2）加载在主点上，自由度1-6从点：电池与托盘的接触面积大概选15个网格范围，此接触面积不是真正的接触面积，而是电池与电池支架连接产生的预应力接触面积，通常取电池托盘面积的40%，不要过度限制电池托盘的面积。从点自由度：1-6详细建模：无图4电池简化模型RBE3Fig4BatterySimpleModelBatteryModelingSimpleModel,ModelingNotes:ThiscomponentismodeledusingoneCONM2elementlocatedatitsCGandanRBEelementtoattachittothebatterytraystructure.InertiaisREQUIRED.TheattachmentfromtheCONM2tothebatterytraystructureshouldbeasfollows:ElementType: RBE2IndependentGrid: CONM2GRIDIndependentDOF: 1-6DependentGrids: Minimumnumberis15MappedtocontactareaofBatteryontray.ThiscontactareaisNOTthe“touching”contactarea,butthesignificantpre-stressedcontactareaduetobatterytiedown.Traditionallythisareaisabout40%oftotalbatterytrayarea.Donotoverconstrainthebatterytray.DependentDOF: 1-6详细建模：无DetailedModel：NotAvailable扬声器建模：简化模型，模型讲解：这部分建模把集中质量点和惯量附加在质心上，通常刚性单元连接范围在门内板上。设计部门提供惯量：单元类型：RBE3从点：集中质量（conm2）加载在从点上主点：车门内板螺栓或者螺钉孔主点自由度：1-3SpeakersModelingSimpleModel,ModelingNotes:ThiscomponentismodeledusingoneCONM2elementlocatedatitsCGandanRBEelementtoattachittothedoorinnerstructure.InertiaisRECOMMENDED.TheattachmentfromtheCONM2tothebatterytraystructureshouldbeasfollows:ElementType: RBE3DependentGrid: CONM2GRIDDependentDOF: 1-6IndependentGrids: Mappedtobolt/screwlocationsondoor.IndependentDOF: 1-3图5扬声器简化模型Fig5SpeakersSimpleModel扬声器详细建模，模型讲解：该部件可分为部件结构和部件质量。扬声器的支架模型采用壳单元建模，与车门内板通过刚性单元或者梁单元来模拟螺栓连接。扬声器的惯量加在集中质量点或RBE3从点上，方法同简化模型。DetailedModel,ModelingNotes:Thiscomponentcanbesub-dividedintocomponentstructureandcomponentmass.Speaker“housing”ismodeledwithadetailedCQUADRmeshandconnectedtothedoorinnerswithRBE2orCBEAMelementstorepresentthebolts/screws.SpeakerinternalsaremodeledwithaCONM2/RBE3asinthe“simplemodel”图6扬声器详细模型Fig6SpeakersDetailedModel散热器总成建模：简化建模，模型讲解：用蜘蛛状多点刚性单元（rbe2）与安装点进行连接，集中质量点加载在刚性单元（rbe2）的主点上，刚性单元（rbe2）的从点通过零长度的弹簧单元与车身侧安装点进行连接，刚性单元（rbe2）有6个自由度。由于散热器可以用硬座或使用橡胶垫或衬套与车身进行连接，弹簧用于模拟散热器的安装刚度，通常情况下，这些橡胶垫的刚度可以通过测试或者由供应商提供。散热器模拟要有充足的冷却液，当冷却密度不可用时，可使用常规值1.04e-9吨/立方毫米。当弹簧刚度无法提供，用RBE3代替RBE2和弹簧单元，这种方法往往降低了散热器本身的刚度，应谨慎使用这种方法。散热器安全刚度（弹簧刚度值）KX=50N/mmKY=50N/mmkz=70N/mmRadiatorAssemblyModellingSimpleModel,ModelingNotes:Onespider-shapedRBE2rigidelementshouldbeusedtoconnecttheCONM2elementtothemountinglocationsoftheFESM.TheCONM2elementshouldbeplacedattheindependentgridoftheRBE2andthedependentgridsoftheRBE2elementshouldbeconnectedtotheFESMmountingpointsthroughzero-lengthCBUSHspringelements.AllsixDOFsoftheRBE2elementshouldbeused.Sincetheradiatorcanbeeitherattachedtothebodybyahardmountorbyusingrubberpadsorbushings,theCBUSHelementsusedtomodeltheradiatormountstiffnesswillvaryintheirspringratevalues.Typicallythestiffnessoftheserubberpadscaneitherbemeasuredorobtainedfromthemanufacturer.Theradiatorissimulatedbyassumingthatthereisafullcapacityofcoolant.Whenthecoolantdensityisnotavailable,anominalvalueof1.04e-9tonnes/mm3maybeused.Thoughlessdesirable,whentherubbermountstiffnessisnotavailableRBE3elementswithoutCBUSHspringelementsmaybeusedinsteadofRBE2/CELASelementsasstatedabove.Thismethodtendstounderestimatethestiffnesscontributionofradiatortothebodyandshouldbeusedwithcaution.Nominalratesfortheradiatormountsare:Kx=50N/mmKy=50N/mmKz=70N/mm图7推荐的简化建模方法Fig7recommendedmodelingpractice图8刚度值无法提供时使用的建模方法Fig8ModeltobeUsedifMountTatesareUnavailable散热器详细建模，模型讲解：一个完全详细的散热器模型通常由供应商提供。工程师必须对供应商交付的模型进行质量和模态相关检查。散热器的侧面安装点应采用刚性单元rbe2连接，并与弹簧单元连接，弹簧单元代表了散热器的安装刚度和阻尼。散热器详细建模，模型讲解：一个完全详细的散热器模型通常由供应商提供。工程师必须对供应商交付的模型进行质量和模态相关检查。散热器的侧面安装点应采用刚性单元rbe2连接，并与弹簧单元连接，弹簧单元代表了散热器的安装刚度和阻尼。RadiatorAssemblyDetailedModel,ModelingNotes:AfullydetailedradiatormodelismostoftenSUPPLIERderived.Theanalystmustperformamassandmodalcorrelationcheckonasupplierdeliveredmodel.MountpointsonradiatorsideshouldbemodeledwithRBE2,andconnectedtotheFESMwithzerolengthCBUSHelementsrepresentingmountstiffness&damping.图9散热器详细模型Fig9RadiatorAssemblyDetailedModel备用轮胎建模简化模型，模型讲解：一个备用轮胎，应该用一个刚性单元把集中质量和惯量附加在质心位置来模拟，通过多点蜘蛛型刚性单元rbe2进行连接，主点为轮胎中心点，从点为轮胎底部与地板接触的周边，集中质量点和惯量都加在刚性单元主点上。应至少使用16个接触点，并沿一周接触面均匀分布。刚性单元与地板之间用3个平动自由度弹簧单元进行连接，所有轮胎接触点都可以使用相同的弹簧刚度。应该通过模型的模态和频率响应与硬件测试关联起来确定的一个值。备胎接触模拟弹簧刚度值为0.8N/mm/mm。如果备用轮胎的支撑结构导致备用轮胎的共振频率（局部模态），那么支承结构应该被建模为结构构件。这样的一个例子，轮胎在汽车的尾部，轮胎的托架通常是管状结构，附在汽车后地板和后挡板之间，管状结构应用梁单元来模拟，表示轮胎本身的结构刚度。当弹簧刚度无法提供，又没有相关的测试数据来参考，可用RBE3代替刚性单元RBE2和弹簧单元，这种方法往往降低了轮胎本身的刚度，应谨慎使用这种方法。SpareTireModellingSimpleModel,ModelingNotes:AsparetireshouldbemodeledusingoneCONM2elementlocatedatitsCGtorepresentitsmassandinertia.Onespider-shapedRBE2rigidelementshouldbeusedtoconnecttheCONM2elementtothefloortiretubatthecenterboltlocationandseveraltire-to-floorcontactlocations.InertiaisREQUIRED.Aminimumof16contactpointsshouldbeusedandevenlydistributedalongthecontactpatch.CBUSHelementswiththreetranslationalstiffnessesshouldbeusedbetweentheRBE2andthefloor.AlltirecontactpatchpointCBUSHelementsmayusethesamestiffnessrates.TheCBUSHstiffnessesshouldbedeterminedbycorrelatingnormalmodesandFRFsofthemodelwiththoseofhardwaretests.NominalvaluesforCBUSH/Contactforsparewheel=0.8N/mm/mmIfthesupportingstructureforthesparetiregeneratesresonantfrequenciesofthesparetire(localmodes),thenthesupportingstructureshouldbemodeledasastructuralmember.Anexampleofthiswouldbethetirecarrierthatsupportsthetireattherearofthevehicle.Thetirecarrieristypicallyatubularstructurethatattachestotherearpillarandtheendgate.ThetubularstructureshouldbemodeledwithCBEAMelementstorepresentthestructuralstiffnessofthecarrier.Thoughlessdesirable,whenthereisnohardwaretestavailableforcorrelationandnohistoricaldataavailableforreference,RBE3elementswithoutCBUSHelementsmaybeusedinsteadofRBE2/CBUSHmethodstatedabove.Thismethodunderestimatesthestiffnesscontributionofsparetiretothebodyandshouldbeusedwithcaution.图10备用轮胎简化模型Fig10SpareTireSimpleModel详细模型，模型讲解：应该由供应商提供详细的轮胎模型。详细的模型应符合以下参数：轮胎：采用四边形和三角形建模轮毂：采用四面体或者六面体建模轮胎的性能参数应通过测试提供，在没有硬件测试的条件下，轮胎的常规性能参数如下：弹性模型：24兆帕泊松比：0.11密度=1.08e-09吨/立方毫米一圈单独RBE2单元采用点对点与备胎托架的接触面进行连接。另一个RBE2从外缘内表面与中心螺栓孔进行连接。最后,检查模型质量是否与实际质量一致。DetailedModel,ModelingNotes:Ifpossibleoravailable,acquirethecompletetire/wheelmodelfromSUPPLIER.Thedetailmeshshouldconformtothefollowingguidelines:Tire:CQUADRandorCTRIARRim:CTETRA10andorCHEX20Thepropertiesofthetirearetunedtohardwaretests.Intheabsenceofhardwaretests,nominalpropertiesofthetireare:E=24MPa=0.11=1.08E-09Tonnes/mm3or(Mg/mm3)AringofindividualRBE2sordirectnode-to-nodecontactwiththesparewheeltubrepresentsthecontact-attachmentconditiontothesparewheeltub.AnRBE2fromtheriminnersurfacetocenterboltattachmenttosparewheeltubrepresentsthesecuringbolt.Finally,thesparewheel/tiremodelshouldbecheckedtohaverepresentativemasswithrespecttohardware.图11备用轮胎详细模型Fig11SpareTireDetailedModel座椅建模简化模型，模型讲解：座椅模型把集中质量点和惯量附加在质心位置来模拟。集中质量单元通过RBE3与地板安装孔进行连接，集中质量点附在RBE3的从点上，RBE3的主点有6个自由度。警告：该模型不考虑座椅的运动关系，不能代表座椅的本体模态。它能提高车辆结构的连接刚度。SeatModellingSimpleModel,ModelingNotes:TheseatismodeledusingoneCONM2elementlocatedatitsCGtorepresentitsmassandinertia.RBE3elementsareusedtoconnecttheCONM2elementtothefloorattachmentlocations.TheCONM2elementshouldbeplacedatthedependentgridoftheRBE3elements.InertiaisREQUIRED.AllsixDOF’softheRBE3elementshouldbeused.WARNING:Thismodeldoesnotconsidertheseatflexibilityandcannotrepresentseatlocalmodes.Itdoesnotincludethestiffeningeffectontherestofvehiclestructure.图12座椅简化模型Fig12SeatSimpleModel详细模型，模型讲解：座椅轨道与地板有各种不同的连接方式。通常座椅有限元模型由座椅供应商建立。座椅模型要适用于噪声和振动分析的系统模型。详细的座椅模型实例图13：图13座椅详细模Fig13SeatDetailedModel座椅总成一般可分为两部分:座椅骨架(SIW)和座椅附件。座椅骨架（SIW）采用壳，梁单元，和弹簧单元进行详细建模。座椅用集中质量单元或非结构质量单元建模。一个集中质量单元通过RBE3分布一个区域内，有多少RBE3和集中质量相连接取决于座椅类型，在图12中显示了一个相对详细的座椅内饰质量的例子。分析人员应该验证座椅模型是否设计合理，质量和惯量，质心，以及是否与一些适当的测试数据相吻合。DetailedModel,ModelingNotes:Therearevarioustypesofseatstructuresandseattrack-to-floorconnections.Thedetailedseatmodelsinfiniteelementsarenormallybuiltbyseatsuppliers.BothSMTandSystemmodelsfornoiseandvibrationanalysesapplythereceivedseatmodels.SomeoftheexamplesofthedetailedseatmodelsareshowninFigures12.Componentsoftheseatassemblycanbegenerallydividedintotwogroups:seat-in-white(SIW)andseattrim.ASIWismodeledindetailusingshell,beam,andspringelementsasstated.SeattrimismodeledusingeitherCONM2ornon-structuralmassasstatedinthisdocument.ThelumpedmassofaCONM2isdistributedoveranareabyRBE3spider.HowmanyRBE3spidersandwheretoconnectthemdependsontheseattypeandtherelativesignificanceofthelumpedmass.ArelativedetailedexampleofmodelingtheseattrimmedmassisshowninFigure12.Thesystemanalystshouldverifythattheseatmodelrepresentstherightdesignlevel,themass/momentofinertia,centerofmass,andifithasbeencorrelatedtosomeappropriatetestdata.车门建模简化模型，模型讲解：在车门质心位置附加一个集中质量单元（CONM2）和惯量。刚性单元(RBE2)用于连接铰链和锁扣位置。集中质量单元附在刚性单元的主点上，刚性单元有6个自由度。刚性单元与侧围连接采用零位移的弹簧单元模拟连接刚度。弹簧刚度由试验测试得出。工程师可以使用以下典型的锁紧刚度值：KX=6.7x102牛/毫米，KY=9.0×104牛/毫米，kz=6.7x102牛/毫米。工程师可以使用下面的典型的上铰链刚度值：KX=1.0×104牛/毫米，KY=5.0×104牛/毫米，kz=5.0×104牛/毫米。工程师可以使用以下典型的下铰链刚度值：KX=5.0×104牛/毫米，KY=5.0×104牛/毫米，kz=5.0×104牛/毫米。刚性的车门模型易于创建，只需要少量的计算机资源即可运行。警告：该模型不考虑车门的运动关系，不能代表车门的本体模态。它能增强车辆结构的连接刚度。DoorModellingSimpleModel,ModelingNotes:ThedoorassemblyismodeledusingoneCONM2elementlocatedatitsCGtorepresentitsmassandinertia.RBE2elementsareusedtoconnecttheCONM2elementtothedoorhingeandlatchlocations.TheCONM2elementshouldbeplacedattheindependentgridoftheRBE2elements.AllsixDOFsoftheRBE2elementshouldbeused.TheRBE2elementsareattachedtothedoorframeusingCBUSHforthehingeandzero-lengthCBUSHelementstorepresenttheattachmentstiffnessthatthedoormayaddtothebodystructure.InertiaisREQUIRED.ThespringratesoftheCBUSHelementsaredeterminedbycorrelatingwithtestdata.Theanalystmayusethefollowingtypicallatchstiffnessvaluesasastartingpoint:Kx=6.7x102N/mm,Ky=9.0x104N/mm,Kz=6.7x102N/mm.Theanalystmayusethefollowingtypicaltophingestiffnessvalues:Kx=1.0x104N/mm,Ky=5.0x104N/mm,Kz=5.0x104N/mm.Theanalystmayusethefollowingtypicalbottomhingestiffnessvalues:Kx=5.0x104N/mm,Ky=5.0x104N/mm,Kz=5.0x104N/mm.Therigiddoormodeliseasytocreateandneedslittlecomputerresourcetorun.WARNING:Thisrepresentationdoesnotconsiderthedoorflexibilityanddoesnotrepresentdoorlocalmodes.Itmayhaveanover-stiffeningeffectonthebody.图14车门简化模型FigDoorSimpleModel详细模型，模型讲解：车门总成可分为两组：白门和门内饰。白门(DIW)使用壳单元（shell）进行详细的建模，内饰部门采用集中质量（conm2）和非结构质量建模。门锁使用弹簧单元（CBUSH）来模拟，可以对弹簧刚度进行调整，使分析模态结果与试验结果保持一致，前提是测试数据准确。弹簧刚度的常规值可参考上面的“简化模型”部分。侧围与车门之前的密封条可以采用弹簧单元（cbush）建模。正常的密封条总的刚度值是3000牛/毫米，即每根弹簧的刚度是由车门弹簧总刚度除以总数量。密封条刚度直接影响车辆的刚度，并需要提供相关的测试数据。密封条需要建立矢量。应采用以下局部坐标系：局部X=指向密封线方向局部y=同全局Y向局部Z=垂直与局部坐标系X和Y向刚性模型和柔性模型这两种建模方式，柔性建模是最准确的一种。这对声学分析尤为重要。然而，柔性建模往往会产生大量的自由度，需要较长的时间来建模，并需要更多的计算机资源。DetailedModel,ModelingNotes:Allcomponentsofthedoorassemblyaredividedintotwogroups:Door-in-white(DIW)andDoortrim.EachDIWpartismodeledindetailusingshellelementsasindocument.EachtrimpartismodeledusingeitherCONM2ornon-structuralmassasstatedinthisdocument.ThedoorlatchismodeledusingCBUSHelements.ThespringratesoftheCBUSHelementsshouldbetunedproperlytoaddtherightstiffnesstotherestofvehiclestructuresothattheresultsofadoorandbodystructuremodalanalysismatchthemodaltestresultsunderthesameconditions,ifsuchtestinformationisavailable.Fornominalvaluessee“simplemodel”sectionabove.Theweatherstrips/sealsbetweenbodystructureanddoormaybemodeledusingCBUSHelements.Atypicalvalueoftotalnormalstiffnessis3,000N/mm;i.e.thestiffnessforeachspringelementisthetotalstiffnessdividedbythetotalnumberofspringelementsusedforeachdoor.Thiswillchangefromvehicletovehicleandneedstobecorrelatedtotestdata.Localcoordinatesystemswillbeneededfortheweatherstrips.Thefollowingcoordinatesystemshouldbeemployed:LocalX’ =OrientedwithdirectionofseallineLocalY’ =OrientedwithGlobalYLocalZ’=OrientedperpendicularwithbothlocalX’andlocalY’Theflexibledoormodelisthemostaccurateoneofthetwomodelingmethodsstatedhere.Itprovidesgoodrepresentationofbothrigiddoormodesandflexibledoormodes.Thisisespeciallyimportantforacousticanalysis.However,ittendstogeneratealargenumberofDOF’s,takesalongertimetomodel,andneedsmorecomputerresourcestorun.图15车门详细模型Fig15DoorDetailedModel前罩建模简化模型，模型讲解：前盖应仿照车门模型中所描述的相同的步骤进行建模。除了铰链和锁扣，通常在前罩的左前角和右前角有两个垂直的凸起橡胶缓冲块，可能还会有两个侧向的橡胶缓冲块来缓冲侧向的运动。当前罩要建立详细模型或刚性模型时，这些橡胶块应该在局部坐标系内建立零长度的弹簧单元模拟。可以对缓冲块的弹簧刚度进行调整，使分析模态结果与试验结果保持一致。工程师可以使用以下典型的铰链刚度值：KX=5.0×104牛/毫米，KY=1.0×104牛/毫米，kz=5.0×104牛/毫米。工程师可以使用以下典型的锁扣刚度值：KX=1.0×104牛/毫米，KY=1.0×104牛/毫米，kz=1.0×104牛/毫米。工程师可以使用以下典型橡胶缓冲器的刚度值：KX=5.0x100牛/毫米，KY=5.0x100牛/毫米，kz=5.0x101牛/毫米。HoodModellingSimpleModel,ModelingNotes:Thehood/shouldbemodeledfollowingthesameprocedureforthedoorsasstatedinthedoormodel.Inadditiontothehingesandlatch,thereareusuallytwoverticalrubberbumpsbetweenthehoodandtheFESMatthefrontleftcornerandfrontrightcorner.Theremaybetwomorelateralrubberbumpstostabilizethelateralmotionofthehood.Whenthehoodismodeledasdetailedorrigidhood,thesebumpsshouldbemodeledusingzero-lengthCBUSHelementsandanappropriatelocalcoordinatesystem.ThestiffnessratesoftheCBUSHelementsshouldbetunedsothatthenormalmodesandFRF’softhehoodandFESMcorrelatewiththoseofhardwaretest.Theanalystmayusethefollowingtypicalhingestiffnessvalues:Kx=5.0x104N/mm,Ky=1.0x104N/mm,Kz=5.0x104N/mm.Theanalystmayusethefollowingtypicallatchstiffnessvaluesasastartingpoint:Kx=1.0x104N/mm,Ky=1.0x104N/mm,Kz=1.0x104N/mm.Theanalystmayusethefollowingtypicalrubberbumpstopstiffnessvalues:Kx=5.0x100N/mm,Ky=5.0x100N/mm,Kz=5.0x101N/mm.图16前罩简化模型Fig16HoodSimpleModel详细模型，模型讲解：前罩总成可分为两组：白前罩（HIW）和前罩内饰。白前罩(HIW)使用壳单元（shell）进行详细的建模，内饰部件采用集中质量（conm2）和非结构质量建模。前罩锁扣使用弹簧单元（CBUSH）来模拟，可以对弹簧刚度进行调整，使分析模态结果与试验结果保持一致。分析师可以使用以下典型的锁扣刚度值：KX=1.0×104牛/毫米，KY=1.0×104牛/毫米，kz=1.0×104牛/毫米。分析师可以使用以下典型橡胶缓冲器的刚度值：KX=5.0×100牛/毫米，KY=5.0×100牛/毫米，kz=5.0×101牛/毫米。DetailedModel,ModelingNotes:Allcomponentsofthehoodassemblyaredividedintotwogroups:Hood-in-white(HIW)andHoodtrim.EachHIWpartismodeledindetailusingshellelementsasindocument55-00-001.EachtrimpartismodeledusingeitherCONM2ornon-structuralmassasstatedinthisdocument.ThehoodlatchismodeledusingCBUSHelements.ThespringratesoftheCBUSHelementsshouldbetunedtotestdata.Theanalystmayusethefollowingtypicallatchstiffnessvaluesasastartingpoint:Kx=1×104N/mm,Ky=1×104N/mm,Kz=1×104N/mm.Theanalystmayusethefollowingtypicalrubberbumpstopstiffnessvalues:Kx=5.0x100N/mm,Ky=5.0x100N/mm,Kz=5.0x101N/mm.图17前罩详细模型Fig17HoodDetailedModel行李箱盖建模简化模型，模型讲解：行李箱盖应仿照车门模型中所描述的相同的步骤进行建模。除了铰链和锁扣，通常在行李箱盖的左后角和右后角有两个垂直的凸起橡胶缓冲块。当行李箱盖要建立详细模型或刚性模型时，这些橡胶块应该在局部坐标系内建立零长度的弹簧单元模拟。应该通过对模型的模态和频率响应与硬件测试关联起来确定弹簧的刚度值。工程师可以使用以下典型的锁扣刚度值：KX=1.0×104牛/毫米，KY=1.0×104牛/毫米，kz=1.0×104牛/毫米。工程师可以使用以下典型橡胶缓冲器的刚度值：KX=5.0x100牛/毫米，KY=5.0x100牛/毫米，kz=5.0x101牛/毫米。DecklidModellingSimpleModel,ModelingNotes:Thedecklidshouldbemodeledfollowingthesameprocedureforthedoorsasstatedabove.Inadditiontothehingesandlatch,thereareusuallytwoverticalrubberbumpsbetweenthedecklidandtheBIWattherearleftcornerandrearrightcorner.Whenthedecklidismodeledasdetailedorrigidhood,thesebumpsshouldbemodeledusingzero-lengthCBUSHelementsandanappropriatelocalcoordinatesystem.ThestiffnessratesoftheCBUSHelementsshouldbetunedsothatthenormalmodesandFRF’softhedecklidcorrelatewiththoseofhardwaretest.Theanalystmayusethefollowingtypicallatchstiffnessvaluesasastartingpoint:Kx=1.0x104N/mm,Ky=1.0x104N/mm,Kz=1.0x104N/mm.Theanalystmayusethefollowingtypicalrubberbumpstopstiffnessvalues:Kx=5.0x100N/mm,Ky=5.0x100N/mm,Kz=5.0x101N/mm.图18行李箱盖简化模型Fig8decklidSimpleModel详细模型，模型讲解：行李箱盖总成可分为两组：白行李箱盖（DIW）和行李箱盖内饰。白行李箱盖(DIW)使用壳单元（shell）进行详细的建模，内饰部门采用集中质量（conm2）和非结构质量建模。行李箱盖锁扣使用弹簧单元（CBUSH）来模拟，弹簧刚度应按测试数据进行调整。侧围与行李箱盖之间的密封条连接可以参考上面的车门密封条建立方法。正常的密封条总刚度值是3000牛/毫米，即每根弹簧的刚度是由车门弹簧总刚度除以总数量。工程师可以使用以下典型的锁扣刚度值：KX=1.0×104牛/毫米，KY=1.0×104牛/毫米，kz=1.0×104牛/毫米。工程师可以使用以下典型的橡胶缓冲块刚度值：KX=5.0×100牛/毫米，KY=5.0×100牛/毫米，kz=5.0X101牛/毫米。DetailedModel,ModelingNotes:Allcomponentsofthedecklidassemblyaredividedintotwogroups:Decklid-in-white(DIW)andDecklidtrim.EachDIWpartismodeledindetailusingshellelementsasindocument55-00-001.EachtrimpartismodeledusingeitherCONM2ornon-structuralmassasstatedinthisdocument.ThedecklidlatchismodeledusingCBUSHelements.ThespringratesoftheCBUSHelementsshouldbetunedtotestdata.Theweatherstrips/sealsbetweenbodystructureanddecklidshouldbemodeledasinthedoormodelingguildlines(asabove).Atypic