Q/SZJ191001-2017NVH輪胎建模建模規(guī)范ModelingSpecificationOfTireandWheelForNVH20XX20XX-XX-XX實(shí)施20XX-XX-XX發(fā)布XXXX汽車工程技術(shù)有限公司發(fā)布Q/SZXX-X-2017NVH輪胎建模規(guī)范范圍本標(biāo)準(zhǔn)規(guī)定了NVH輪胎建模方法。本標(biāo)準(zhǔn)適用于CAE部門輪胎NVH模型建模。規(guī)范性引用文件下列文件對(duì)于本文件的應(yīng)用是必不可少的。凡是注日期的引用文件，僅注日期的版本適用于本文件。凡是不注日期的引用文件，其最新版本（包括所有的修改單）適用于本文件。有限元網(wǎng)格建模規(guī)范CAE整車模型命名規(guī)范術(shù)語和定義無。摘要Abstract輪胎供應(yīng)商已經(jīng)使用復(fù)雜的有限元分析模型來模擬輪胎行為，但他們通過需要的模型自由度數(shù)目過于龐大，并不適用于整車噪聲與振動(dòng)分析。對(duì)于整車分析，需要相對(duì)簡單的建模方法，即模態(tài)輪胎模型。該模型可用于抓取輪胎/懸架的跳躍、踏步模態(tài)，轉(zhuǎn)向系統(tǒng)模態(tài)和側(cè)向模態(tài)等。輪胎結(jié)構(gòu)比較復(fù)雜，見下圖所示。因此輪胎的機(jī)械性能具有高度的非線性和非彈性，影響因素有尺寸、構(gòu)成、預(yù)載荷、氣壓、頻率、溫度、靜止或滾動(dòng)、靜態(tài)或動(dòng)態(tài)。Sophisticatedfiniteelementmodelshavebeenusedbytiremanufacturerstosimulatetirebehavior.Theyusuallyrequirelargenumbersofdegreesoffreedomandspeciallytailoredsolutiontechniqueswhicharenotsuitableforfullvehiclenoiseandvibrationanalysis.Forfullvehiclenoiseandvibrationanalysisarelativelysimplemodelingmethodiscurrentlyused:themodaltiremodel.Itisprimarilyusedtocapturetire/suspensionhop,tramp,steerandlateralmodes.Thetiresusedinmodernautomobileshavecomplicatedconstruction,asshowninfigurebelow.Therefore,themechanicalpropertiesofthetirearehighlynonlinear,inelasticanddependonmanyfactorssuchastiresize,construction,pre-load,airpressure,frequency,temperature,motionstatusofrollingornon-rolling,staticordynamic.圖1輪胎結(jié)構(gòu)模態(tài)輪胎模型通過縮減非線性輪胎有限元模型到模態(tài)空間后獲得，此模型可由輪胎供應(yīng)商提供。模態(tài)輪胎適用于整車噪聲和振動(dòng)分析，最高頻率至150Hz。值得注意的是：要建立模態(tài)輪胎模型，一般需要花費(fèi)供應(yīng)商數(shù)周或數(shù)月的時(shí)間。Amodaltiremodelisobtainedbyreducingadetailednon-lineartireFEMmodeltomodalspaceandisprovidedbytiremanufactures.Amodaltiremodelisappropriateforvehiclesystemnoiseandvibrationanalysisupto150Hz.Itshouldbenotedthat,whenplanningtobuildasystemmodel,ittypicallytakesfromseveralweekstoseveralmonthsforthesuppliertorespondtothesystemanalyst’srequestforamodaltiremodel.流程圖建模建模InitiateModeling已有模型？ModelExists?聯(lián)系供應(yīng)商Contactmodaltiremodelliaisontodetermineifmodelalreadyexists完成并發(fā)布需求給供應(yīng)商Completeandsubmitrequestformtoliaison等待模型完成Waitformodelcompletion使用模型UseModel否NO圖2流程圖工具描述ToolDescription仿真分析過程中需要用到的如下軟件:Thefollowingsoftwarefacilitatestheanalyticalsimulationprocess:前處理(Preprocessors):Hypermesh求解器(AnalysisCode):Abaqus/Nastran后處理(Postprocessors):HyperView建模和分析過程Modeling/AnalysisProcedure單位Units分析中所用單位制如下所示:Theunitsusedintheanalysisareasfollows:力(Force) 牛頓(N)質(zhì)量(Mass) 噸(Ton)長度(Length) 毫米(mm)時(shí)間(Time) 秒(Second)內(nèi)容Contents簡化后的輪胎模型包括：模態(tài)質(zhì)量、剛度、阻尼和幾何表示的輪胎輪廓和連接點(diǎn)（轉(zhuǎn)向節(jié)主軸安裝孔心、接地點(diǎn)）Thecontentsofthesimplifiedtireandwheelmodelshouldincludealumped-parameterrepresentationofthetireandwheel,includingmodalmass,stiffnessanddampingandgeometricrepresentationoftirecarcassandinterfacepoints,includingthewheelspindleandtirepatchorroad-interfacepoints..坐標(biāo)系CoordinateSystems模型使用局部坐標(biāo)系。每個(gè)不同位置的輪胎對(duì)應(yīng)一個(gè)局部坐標(biāo)系。局部坐標(biāo)系的原點(diǎn)在未變形輪胎的幾何圓心處。局部坐標(biāo)系建立步驟如下：X軸是整車坐標(biāo)系的前后方向，指向從前到后；Y軸是整車的側(cè)向，指向從左到右；Z軸是整車垂向，指向從底到上。Themodelsshouldbesuppliedinlocalcoordinates.Onecoordinatesystemdefinitionshouldbeusedforeachtiremodel.Thecoordinatesystemoriginshouldresideatthegeometriccenteroftheun-deformedtire.Thecoordinatesystemshouldbedefinedasfollows:X-axisshouldcorrespondtovehiclefore/aft,withdirectionfromfronttorear,Y-axisshouldcorrespondtovehiclelateral,withdirectionfromlefttoright,andZ-axisshouldcorrespondtovehiclevertical,withdirectionfrombottomtotop.建模技巧ModelingTechniques模態(tài)輪胎模型來源于詳細(xì)的非線性有限元模型，包括輪胎和車輪。設(shè)置好合適的預(yù)載、胎壓和其他條件后，從詳細(xì)有限元模型中提取超過200Hz的模態(tài)分析結(jié)果。在通過Craig-Bampton或其它方法進(jìn)行模態(tài)縮減，即將詳細(xì)有限元模型規(guī)模龐大的物理節(jié)點(diǎn)自由度縮減到有限數(shù)目的模態(tài)自由度，在NASTRAN中通過SPOINT單元來實(shí)現(xiàn)。每一對(duì)SPOINT單元對(duì)應(yīng)一階模態(tài)。在NASTRAN中，模態(tài)輪胎模型包括以下單元：CMASS3、CELAS3和CDAMP3，一起組成彈簧-質(zhì)量-阻尼系統(tǒng)來代表每一階模態(tài)，在同MPC來連接SPOINT到保留的物理節(jié)點(diǎn)。模態(tài)質(zhì)量CMASS3和模態(tài)剛度CELAS3由動(dòng)態(tài)縮減過程直接得到。而模態(tài)阻尼CDAMP3由模態(tài)試驗(yàn)得到。對(duì)于整車分析，只有兩套物理節(jié)點(diǎn)需要保留在模態(tài)輪胎模型中：連接車輪的轉(zhuǎn)向節(jié)主軸點(diǎn)；輪胎接地點(diǎn)。其中接地點(diǎn)數(shù)目一般為9或更多。接地點(diǎn)數(shù)目由輪胎加上預(yù)載后與地面接觸的長度決定。接地點(diǎn)數(shù)目的增加要對(duì)稱增加，每次增加2個(gè)。接地點(diǎn)與輔助SPOINT單元相連。同時(shí)接地點(diǎn)也對(duì)稱分布與輪胎中心線兩側(cè)，其中一個(gè)點(diǎn)直接位于轉(zhuǎn)向節(jié)主軸點(diǎn)下方。如果在一個(gè)接地點(diǎn)加載垂向載荷，在轉(zhuǎn)向節(jié)主軸點(diǎn)上，不僅會(huì)出現(xiàn)垂向力，也會(huì)出現(xiàn)前后方向力，這是由于接地點(diǎn)耦合了輪胎的垂向模態(tài)和前后向模態(tài)。為了顯示需要，使用NASTRANPLOTEL單元來代表輪胎輪廓。在建立轉(zhuǎn)向節(jié)主軸點(diǎn)與模態(tài)自由度之間的MPC方程時(shí)，必須保證轉(zhuǎn)向節(jié)主軸點(diǎn)是獨(dú)立的，便于與整車相連。Themodaltiremodelisderivedfromthedetailednon-linearfiniteelementmodel,includingboththetireandthewheel.Byapplyingappropriatepre-load,tirepressureandotherconditions,normalmodesofadetailedfiniteelementmodelareextractedtogreaterthan200Hz.ByusingtheCraig-Bamptonmethodorothersimilarmethods,thesenormalmodesareusedtoreduceallphysicalgridsofthedetailedmodelintoalimitednumberofmodaldegreesoffreedom,modeledbyNASTRAINSPOINTs,toformamodaltiremodel.EachpairofSPOINTscorrespondstoonenormalmode.InNASTRAN,amodaltiremodelconsistsofthefollowingelements:CMASS3,CELAS3andCDAMP3spring-mass-dampersystemstorepresenteachmode,andMPCsconnectingtheSPOINTstoeachphysicalgridbeingkept.ThemodalmassCMASS3andmodalstiffnessCELAS3valuesarethedirectresultofthedynamicreductionprocess.However,themodaldampingvaluesCDAMP3areobtainedfromanexperimentalmodaltest.Forvehiclesystemanalysispurposes,onlytwosetsofthephysicalgridsneedtobekeptinthemodaltiremodel:thewheelspindlepointandthetiretogroundcontactpointsreferredaspatchpoints.Therearenormally9ormorepatchpoints.Thenumberofpatchpointsisdependentuponthelongitudinaldimensionofthecontactpatchafterthetirepreloadisapplied.Thenumberofpatchpointscanonlyincreaseinincrementsoftwosincetheyaresymmetricallylocatedaboutthetirecenterline.ThepatchpointsareconnectedtoauxiliarySPOINTs.Also,thepatchpointsarephysicallylocatedonthetirecenterlineandequallydistributedfore-aftwithonepointdirectlyunderthespindlepointatthegroundsurface.Ifaverticalinputisappliedtoonepatchpointatatime,thiscreatesnotonlyaverticalbutalsoafore-aftforcetoaconstrainedspindle,becauseofthecouplingofpatchpointstobothverticalandfore-afttiremodes.Forvisualizationpurpose,NASTRANPLOTELelementsareusedtorepresentthecarcassofatire.InformingtheNASTRANMPCequationbetweenthespindlepointandthemodaldegrees-of-freedom,thespindlepointmustbeanindependentpointintheequation,tofacilitateinterfacingofthespindlepointwiththefullvehiclesystemmodel.圖3模態(tài)輪胎模型要提供四個(gè)模態(tài)輪胎。如果同一輪胎分別用于左右兩個(gè)輪胎，必須小心生成輸出文件。由輪胎結(jié)構(gòu)決定，當(dāng)生成對(duì)稱的輪胎時(shí)，要使用鏡像（Reflect）命令，而不是旋轉(zhuǎn)（Rotate）命令。隨時(shí)注意保證正確的物理特征，如接地點(diǎn)數(shù)和朝向。每個(gè)輪胎對(duì)應(yīng)至少9個(gè)接地點(diǎn)，要釋放垂向自由度（即NASTRAN中的節(jié)點(diǎn)3自由度），并要在MPC方程中體現(xiàn)。在NASTRAN中，質(zhì)量要?dú)w一化，以用于模態(tài)質(zhì)量、模態(tài)剛度和模態(tài)阻尼進(jìn)行物理意義的縮放。模態(tài)輪胎最高頻率要超過200Hz。轉(zhuǎn)向節(jié)主軸點(diǎn)關(guān)聯(lián)的MPC方程要包含所有輪胎模態(tài)，不要分為如下兩部分（繞X旋轉(zhuǎn)、繞Y旋轉(zhuǎn)、繞Z旋轉(zhuǎn)）（X向、Y向、Z向）。Fourmodelsshouldbeprovided–oneforeachtire.Ifasingletireismodeledforuseasboththerightandlefttires,caremustbetakenwhengeneratingtheoutputfile.Dependingonthetireconstructiondetails,itmaybenecessarytoreflectthemodelusingthevehiclecenterplaneratherthanusingrotationaboutaverticalaxis.Inanycase,correctphysicalbehavioraswellascorrectpatchpointnumberingandorientationmustbeprovided.Eachtireshouldhaveatleast9patchpointsunlessotherwiserequested.Verticaldegreesoffreedomshouldbemodeledatthepatchpoints.Thatis,degreeoffreedom3shouldbeincludedinthepatchMPCrelations.NASTRANMASSnormalizationshouldbeusedsothatthemodalmass,stiffnessanddampingarescaledinaphysicallymeaningfulmanner.Tiremodelsshouldbeprovidedatvehiclespeedsof0,30,60,80km/hourunlessotherspeedsarerequested.Theresonantfrequencyofthehighesttiremodeincludedinthemodalmodelshouldexceed200Hz.SpindleMPCequationsshouldbecoupledwithalltiremodes,notbedividedintotwosets(fore/aft,rotation,steer)(lateral,vertical,camber).假設(shè)和限制Assumptions/Limitations假設(shè)Assumptions這種建模方法假定所有組件的行為都是線性的。不模擬非線性行為。Thismethodofmodelingassumesallcomponentsbehaveinalinearfashion.Nonlinearbehaviorisnotsimulated.限制Limitations模態(tài)輪胎不包括輪胎內(nèi)聲腔的作用，因此無聲腔的模態(tài)輪胎只用于150Hz以下分析，有聲腔的模態(tài)輪胎可用于250Hz及以上分析。Oftenthemodaltiremodeldescribeddoesnotincludetheeffectsofthetireacousticcavity.Theusefulfrequencyrangewithoutanacousticcavityislimitedtoabout150Hz.Theusefulfrequencyrangewithanacousticcavitymodelcanextendto250Hzormore.載荷和邊界條件Loads/BoundaryConditions無。結(jié)果Results無。性能要求PerformanceRequirements輪胎無約束模態(tài)分析：在約束接地點(diǎn)的所有自由度后，進(jìn)行輪胎模態(tài)分析。分析結(jié)果與供應(yīng)商提供的數(shù)據(jù)進(jìn)行對(duì)比。Tire(Unconstrained)NormalModesAnalysis.NASTRANnormalmodesanalysisshouldbeperformedbyconstrainingthetirepatchgridsinalldegreesoffreedom.TheMPCsshouldbereferencedinthecasecontrolsection.Thenaturalfrequenciesandmodeshapesobtainedshouldbecheckedagainstthoseprovidedbysupplier.Anexampleisshownasbelow:圖4輪胎模態(tài)頻率圖輪胎靜態(tài)平衡檢查：約束所有接地點(diǎn)自由度（SPC1~6）；轉(zhuǎn)向節(jié)不約束；在轉(zhuǎn)向節(jié)上加載1000N垂向力；讀取接地點(diǎn)上反力。通過接地點(diǎn)反力與加載力相差不超過5%（如950N）。Tire(Constrained):StaticLoadEquilibriumCheck.Tocheckthestaticequilibriumintegrityofatiremodel,thefollowingprocedureisrecommended:Tirepatchpointsareconstrained(SPC1-6);Spindleisunconstrained;1000Nisappliedverticallydownwardsatthespindlepoint;Reactionforcesarerecoveredatthepatchpoints.Thesummationofreactionforcesatthepatchmustbewithin5%oftheappliedload,i.e.950N.分析要求ANALYSISREQUIREMENTS使用NASTRAN進(jìn)行模型檢查和驗(yàn)證NASTRANshouldbeusedformodelcheckoutandverification.參考文件DOCUMENTATION無。聯(lián)系人CONTACTS無。例子EXAMPLES$************************************************************************$===========RightFrontTireModalModel==========$************************************************************************$ ModalTireModelforNASTRAN$$ TireSize: 215/65R15$$ TireConstruction: 35167AB$ WheelSize: 15x6J$ WheelType: Aluminum$ WheelOffset(mm): 15.4mm $ WheelCGOffset(mm): 0.54mm$ WheelMass(Kg): 9.5Kg$ WheelInertiaIxx(Kg-m**2):0.152Kg-m**2$ WheelInertiaIyy(Kg-m**2):0.241Kg-m**2$ WheelInertiaIzz(Kg-m**2):0.152Kg-m**2$ $ VehicleSpeed(KPH): 0.0KPH$$ TireInflationPressure(psi)30.0psi$ TireLoad(N): 4658.0N$ TireCamber(Degrees): 0.0Degrees$$ TireDeflection(mm): 22.8mm$ ModelTimeUnits: seconds(s)$ ModelLengthUnits: millimeters(mm)$ ModelMassUnits: Megagrams(Mg)$$ ModelForceUnits: Newtons(N)$ Normalization: MAX$ Highest-FrequencyMode(Hz):231.815Hz$ NumberofTirePatchPoints:9$ TirePatchPointActiveDOF:1,2,3,4$$*************************************************************************$ ValidationandCorrelation$$ Describevalidationandcorrelationofthemodelandthemethod$usedtoobtainarollingtiremodelinthislocation.)$$*************************************************************************$************************************************************************$$ ModeShapeDescriptionsandFrequencies$$Mode#FrequencyIDDescription$$14.426Y01stLateralMode$28.025X01stFore/AftMode$320.234Z01stVerticalMode$423.200W01stSteeringMode$534.534U01stBendingMode$658.739V01stTorsionalMode$765.999Y12ndLateralMode$884.127W12ndSteeringMode$984.970U12ndBendingMode$1096.773Z12ndVerticalMode$1196.460X12ndFore/AftMode$12103.195W23rdSteeringMode$13105.702Z23rdVerticalMode$1484.135V12ndTorsionalMode$15118.407X23rdFore/AftMode$16129.423U23rdBendingMode$17128.286Z34thVerticalMode$18146.706W34thSteeringMode$19142.326X34thFore/AftMode$20155.946Z45thVerticalMode$21157.044U34thBendingMode$22173.531W45thSteeringMode$23172.691X45thFore/AftMode$24189.368Z56thVerticalMode$25183.534U45thBendingMode$26192.141W56thSteeringMode$27207.130X56thFore/AftMode$28210.397U56thBendingMode$29225.098W67thSteeringMode$30231.815U67thBendingMode$$$*************************************************************************$********************************************************************$$LocalCoordinateSystem$$ PointA:GeometricCenteroftheTire$ PointB:Z-Axis,TowardsthetopofthevehiclefromPointA$ PointC:X-Axis,TowardstherearofthevehiclefromPointA$CORD2R 9500000A1A2A3B1B2B3C1C2C3$$ SpindlePoint$GRID950000095000000.00.00.0$$ TireInternalModalDOF(CouplingSpindletoModalDOF)$SPOINT9501001THRU9501999$$ TireInternalModalDOF(CouplingTirePatchPointstoModalDOF)$SPOINT9502001THRU9502999$$ ModalMassCMASS3950100195010019502001PMASS9501001.007365CMASS3950100295010029501002PMASS9501002.007310$...$$ ModalStiffness$CELAS39502001950200195010019502001PELAS950200121.16CELAS39502002950200295010029501002PELAS95020029.15$...$$ ModalDamping$CDAMP39503001950300195010019502001PDAMP9503001.0316CDAMP39503002950300295010029502002PDAMP9503002.0207$...$$*********************************************************************$$ MPCRelations-SpindletoModalDOF$$ SpindleFore/AftDeflection(X)MPC195020021-.58449095020010.00622195000000-1.095020030-.000352$...$$ SpindleLateralDeflection(Y)MPC195020022-.00662895020010-.62235395000000-1.095020030-.083250$...$$ SpindleVerticalDeflection(Z)MPC195020023-.00226795020010-.13077095000000-1.095020030.990243$...$$ SpindleCamberRotation(U)MPC195020024.00001695020010.00124795000000-1.095020030-.000006$...$$ SpindleAxisRotation(V)MPC195020025-.00119295020010.00001495000000-1.095020030-.000002$...$$ SpindleSteerRotation(W)MPC195020026-.00011495020010.00000195000000-1.095020030.000009$...$$ MPCRelations-PatchPointstoModalDOF$MPC195010010-1.095000011-.0155++95000021-.010095000031.0007++95000041.003595000051.0074++95000061.013995000071.0142++95000012-.099395000022-.2153++95000032-.255895000042-.2673++95000052-.256295000062-.2147++95000072-.097695000013-.0151++95000023-.011895000033-.0061++95000043-.005595000053-.0112+95000063-.028595000073-.0405$...$**********************************************************************$ PatchGRIDs$GRID9500001950000070.0740.84-322.710123456GRID9500002950000046.3440.83-322.710123456GRID9500003950000023.0940.89-322.710123456GRID95000049500000.0041.00-322.710123456GRID95000059500000-23.0941.11-322.710123456GRID95000069500000-46.3441.17-32