Q/SZJ191001-2017內(nèi)飾車身噪聲傳遞函數(shù)分析規(guī)范SpecificationOfNoiseTransferFunctionAnalysisAnalysisForTrimmedBody20XX20XX-09-30實(shí)施20XX-08-28發(fā)布XXXX汽車工程技術(shù)有限公司發(fā)布Q/SZXX-X-2017內(nèi)飾車身噪聲傳遞分析規(guī)范范圍本標(biāo)準(zhǔn)規(guī)定了術(shù)語(yǔ)和定義、內(nèi)飾車身噪聲傳遞分析方法及結(jié)果處理方法。本標(biāo)準(zhǔn)適用于CAE部門的內(nèi)飾車身噪聲傳遞分析。規(guī)范性引用文件無(wú)。術(shù)語(yǔ)和定義無(wú)。摘要Abstract噪聲傳遞函數(shù)分析主要考察聲傳遞特性，是對(duì)車身與底盤之間的主要連接區(qū)域進(jìn)行聲學(xué)傳遞函數(shù)分析，以便找出噪聲傳遞路徑及對(duì)NVH特性影響較大的關(guān)鍵零部件。對(duì)車身與動(dòng)力系統(tǒng)及底盤系統(tǒng)接附點(diǎn)施加單位載荷，分析計(jì)算乘員耳側(cè)的噪聲響應(yīng)。本規(guī)范旨在描述噪聲傳遞函數(shù)的分析方法、要求和評(píng)價(jià)標(biāo)準(zhǔn)。NTFanalysisismainlyfocusedonacoustictransmissioncharacteristics,andtakesacoustictransferfunctionanalysistoidentifynoisetransferpathsandkeypartsofalargerinfluenceontheNVHcharacteristics.Imposetheunitloadontheattachmentpointsbetweenthebodyandpowertrain,chassissystem,thengetthenoiseresponsebesidesthedrivers’earandpassengers’ear.Thisspecificationspecifiesthemethods,requirementsandEvaluationstandardfortheanalysisofthenoisetransferfunction.

流程圖ProcessFlowDiagram收集詳細(xì)模型收集詳細(xì)模型(TrimmedBody)CollectDetailedModels(TrimmedBody)設(shè)置邊界條件和載荷SettheboundaryConstraintsandLoads提交計(jì)算NastranSOL111RunNastranSOL111結(jié)果后處理（HyperGraph）Resultsprocessing（HyperGraph）輸出X向位移（聲壓）OutputXDisplacements(Soundpressure)結(jié)束End優(yōu)化Optimization結(jié)果是否滿足要求？IstheresultOK？YesNo評(píng)價(jià)標(biāo)準(zhǔn)Evaluationstandard圖1流程圖Fig1ProcessFlowDiagram工具描述ToolDescription仿真分析過(guò)程中需要用到的如下軟件:Thefollowingsoftwarefacilitatestheanalyticalsimulationprocess:前處理(Preprocessors):Hypermesh求解器(AnalysisCode):MSC.Nastran后處理(Postprocessors):Hyperview建模和分析過(guò)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(zhǎng)度(Length) 毫米(mm)時(shí)間(Time) 秒(Second)內(nèi)容Contents噪聲傳遞函數(shù)分析主要考察結(jié)構(gòu)在外激勵(lì)作用下乘員艙駕駛員處的噪聲響應(yīng)水平，外激勵(lì)頻域?yàn)?Hz-200Hz。NTFanalysisdetectsthenoiseresponseatthedriver’sseatinthepassengercompartment,onwhichapplytheexternalunitloadvariedwiththefrequencyinthe20Hz-200Hzdomain.噪聲傳遞函數(shù)分析模型分為結(jié)構(gòu)有限元模型和聲學(xué)空腔有限元模型，兩種模型耦合在一起。其中結(jié)構(gòu)有限元模型是帶內(nèi)飾的TrimmedBody模型（以下簡(jiǎn)稱TB模型），TB模型按照是否帶副車架又分為不帶副車架的TB模型和帶副車架的TB模型兩種。ThemodelusedintheanalysisofnoisetransferfunctionincludeFEMmodelandfiniteelementmodelofacousticcavitymodels,andthesetwoarecoupledtogether.StructurefiniteelementmodelsistheTrimmed-Bodymodelswithinteriorbody(hereinafterreferredtoasTBmodel).theTBmodelcanbedividedintotwokinds,onewithasub-frameandtheotherwithoutasub-frame.副車架與車身的連接是軟連接通過(guò)襯套連接的，使用不帶副車架的TB模型進(jìn)行NTF分析。圖2是不帶副車架的NTF分析有限元模型。Onthesituationtheconnectionbetweenthesub-frameandthebodyissoft,useTBmodelwithoutasub-frametodoNTFanalysis.Thefiniteelementmodelwithoutasub-frameusedinNTFanalysisisshowinfigure2.圖2不帶副車架的NTF有限元模型Fig2ThefiniteelementmodelwithoutsubframeinNTF車架與車身連接是硬連接通過(guò)螺栓連接的，使用帶副車架的TB模型進(jìn)行VTF分析。圖3是帶副車架的VTF分析有限元模型。Whenthesubframeandbodyisconnectedbythehardbolts,VTFanalysisusesaTBmodelwithsub-frame.Figure3showsafiniteelementmodelwithsub-frameinVTFanalysis.圖3帶前后副車架的NTF有限元模型Fig3Thefiniteelementmodelwithfrontandrearsub-framesinNTF坐標(biāo)系CoordinateSystems分析采用整車坐標(biāo)系,有些彈簧需要建局部坐標(biāo)系。Analysisusesvehicleglobalcoordinatesystem,Localcoordinatesystemsareneededforsomespringsinthetrimmedbody.建模技巧ModelingTechniques請(qǐng)參閱TrimmedBodyRefertotheTrimmedBodymodelingguidelines.接附點(diǎn)的襯套直接用螺栓與車身側(cè)連接時(shí)，需要建立一維CBEAM或CBAR單元螺栓模型，如擺臂接附點(diǎn)，見圖4所示。加載點(diǎn)在CBEAM或CBAR單元的中點(diǎn)。Onthesituationthebushismodeledasaboltconnectedtothebody,a1DCBEAMelementorCBARelementcanbeusedtomodelthebolt.Forinstance,anattachmentpointattheswingarmisshowedinFigure4.TheloadingpointisatthemiddlelocationofCBEAMorCBAR.圖4襯套直接用螺栓與車身側(cè)連接的建模示意圖Fig4Bushingasabolt接附點(diǎn)的襯套以支架總成形式與車身側(cè)連接時(shí)，需要將固定襯套橡膠的鋼圈用RBE2單元連接，鋼圈中心點(diǎn)為RBE2主節(jié)點(diǎn)，鋼圈上節(jié)點(diǎn)為RBE2從節(jié)點(diǎn)，RBE2單元耦合全部6個(gè)自由度。加載點(diǎn)在RBE2主節(jié)點(diǎn)，如發(fā)動(dòng)左懸置接附點(diǎn)見圖5所示。Onthecircumstancethemountingpointbushispresentedbyabracketassemblyconnectedtothebodyside,aRBE2elementshouldbeusedtomodeltherimsonthefixedbushingrubber.Theindependentnodeisthecenterofrim,andtheindependentnodesconnectthewholerim.TheRBE2coupledall6degreesoffreedoms.TheloadisimposedontheindependentnodeofRBE2.Forinstance,theleftenginemountpointisasshowninFig5.圖5發(fā)動(dòng)機(jī)左懸置接附點(diǎn)建模示意圖Fig5Theleftenginemountmodeling如圖6所示，為前、后減振彈簧安裝支座處接附點(diǎn)建模方式，其加載點(diǎn)為前后減振彈簧支座中心點(diǎn)。ThemodelingmethodoffrontandreardampingspringinstallationsupportsisshowedinFigure6.Theloadingpointisthecenterpointofsprings.圖6前、后減振彈簧接附點(diǎn)建模示意圖Fig6frontandreardampingSpringsmodeling車身側(cè)排氣系統(tǒng)接附點(diǎn)的建模方式為，將被動(dòng)側(cè)掛鉤與掛鉤隔振器相連的區(qū)域的節(jié)點(diǎn)用RBE2單元與從節(jié)點(diǎn)連接，主節(jié)點(diǎn)自動(dòng)生成，RBE2單元耦合全部6個(gè)自由度。加載點(diǎn)在RBE2單元的主節(jié)點(diǎn)。圖7是車身側(cè)排氣系統(tǒng)接附點(diǎn)的建模示意圖。Bodysideexhaustsystemmodelingmethod：TheRBE2isusedtomodelthemountingpoint,withitsdependentnodesconnectingthenodesontheregionwhichrelatedthepassivelinktothelinkisolator,whileitsindependentnodeisautomaticallygenerated.TheRBE2couplesall6degreesoffreedom.Itsindependentnodeistheloadingpoint.Figure7showsthebody-sideexhaustsystemmodeling.圖7車身側(cè)排氣系統(tǒng)接附點(diǎn)建模示意圖Fig7Thebody-sideexhaustsystemmodeling假設(shè)和限制Assumptions/Limitations無(wú)。載荷和邊界條件Loads/BoundaryConditions約束：自由模態(tài)。Noconstraints.包括底盤懸架系統(tǒng)與車身相連的接附點(diǎn)、發(fā)動(dòng)機(jī)與車身相連的接附點(diǎn)、副車架與車身相連的接附點(diǎn)、排氣與車身相連的接附點(diǎn)。不同車型間可能因?yàn)榈妆P懸架系統(tǒng)、發(fā)動(dòng)機(jī)安裝方式、副車架連接和排氣系統(tǒng)的不同，而存在差異。圖8為接附點(diǎn)位置示意圖，其中副車架、前懸、后擺臂、后減振器、后彈簧安裝點(diǎn)、排氣吊掛安裝點(diǎn)。Includeschassissystemandvehiclebodyattachmentpoints,engineandbodyattachmentpoints,sub-frameandbodyattachmentpoints,exhaustandbodyattachmentpoints.Betweendifferentmodelsbecausethechassissuspensionsystems,engineinstallation,connectedtotheframeandexhaustsystemsofdifferent,therearedifferences.Figure8-mountpoints,subframe,frontsuspension,rearswingarm,rearshockabsorbers,rearspringmountingpoint,exhaustsuspensionattachmentpoints.圖8接附點(diǎn)位置示意圖Fig8mountpoints加載：在接附點(diǎn)處分別沿XYZ三個(gè)方向，加載1N隨頻率（2Hz~200Hz）變化的動(dòng)載荷。ApplyunitloadsattheattachmentpointsinX,YandZdirectionsontheseparatesubcases.andfrequencyfrom2Hzto200Hz;加載方向和接附點(diǎn)的受力方向一致。接附點(diǎn)受力方向如果與整車坐標(biāo)不一致，需要根據(jù)受力方向建立局部坐標(biāo)，如擺臂接附點(diǎn)。圖9是局部坐標(biāo)、整車坐標(biāo)示意圖。Applytheloadintheattachmentpointsforceddirection.Iftheloadingdirectionisinconsistentwiththeglobalcoordinatesystem,thelocalcoordinatesystemisneeded.anattachmentpointattheswingarmisshowedinFigure8.Figure8showsthelocalandglobalcoordinatesystems.圖9局部坐標(biāo)、整車坐標(biāo)示意圖Fig9Thelocalcoordinatesystemandtheglobalcoordinatesystem載荷大?。?jiǎn)挝惠d荷1N。Load:unitload1N模態(tài)阻尼：1-20Hz是0.1，20－400Hz是0.04；Modaldamping:1-20Hzwas0.1,20-400Hzwas0.04;載荷激勵(lì)頻率范圍：2Hz－200Hz；Loadexcitationfrequencyrange:20Hz－200Hz；結(jié)構(gòu)模態(tài)頻率范圍：0Hz－400Hz；Structuralmodalfrequencyrange:0Hz－400Hz聲腔模態(tài)頻率范圍：0Hz－600Hz；Acousticmodefrequencyrange:0Hz－600Hz；求解采用NASTRAN模態(tài)頻率響應(yīng)SOL111。Solve111聲固耦合用NASTRAN語(yǔ)句ACMODL來(lái)控制。表1是NTF分析中ACMODL卡片參數(shù)，參數(shù)具體含義參考NASTRAN手冊(cè)。Acoustic-structuralcoupletakestheNASTRANstatementsACMODLtobecontrolled.Table1showstheACMODLcardparametersusedintheNTFanalysis,andthespecificmeaningofparametersreferstotheNASTRANmanual.表1NTF分析中ACMODL卡片參數(shù)ACMODLDIFFGRIDS1.BW0.50.750.5NOREL具體的參數(shù)設(shè)置詳見13例子Specificparametersettingsisshowninchapter13EXAMPLES.結(jié)果Results輸出駕駛員外耳、副駕駛員以及后排乘員內(nèi)外耳聲壓（即位移）Outputtheearpressure(displacement)insideandoutsideofthedriver,co-pilotandcrewintheback.圖10輸出點(diǎn)位置示意圖Fig10outputpointslocation輸出XYZ三個(gè)方向響應(yīng)曲線，曲線是輸出點(diǎn)的聲壓級(jí)響應(yīng)曲線。輸出曲線X軸表示頻率，單位為Hz，Y軸為響應(yīng)的聲壓級(jí)，單位為dB。輸出結(jié)果的響應(yīng)頻率是20Hz－200Hz。圖11是右前擺臂后點(diǎn)NTF響應(yīng)曲線示意圖。圖11NTF響應(yīng)曲線示意圖Fig11NTFresponsecurveTheoutputcurveisthesoundpressurelevelresponsecurve.TheXaxisoftheoutputcurverepresentsthefrequency,andtheunitisHz.TheYaxisrepresentssoundpressureresponse,theunitisdB.Theresponsefrequencyrangeoftheoutputis20Hz-200Hz.Figure11istheNTFresponsecurveofarightfrontarm.車內(nèi)結(jié)構(gòu)噪聲是車身噪聲傳遞函數(shù)與激勵(lì)力的乘積，降低車身噪聲傳遞函數(shù)是降低車內(nèi)噪聲的有效方法之一。車身噪聲傳遞函數(shù)用表示，單位是dB,參考聲壓是。………….（1）代表車身結(jié)構(gòu)的振動(dòng)傳遞函數(shù)，代表車身振動(dòng)轉(zhuǎn)化為測(cè)量點(diǎn)處的噪聲能力。把測(cè)量點(diǎn)的空氣壓力轉(zhuǎn)化為聲壓級(jí)………..（2）參考聲壓=參考聲壓為28.28e-12，peak為20.0e-12Bodystructurenoiseistheproductofthenoisetransferfunctionandtheexcitationforce.Reducingvehiclenoisetransferfunctionisoneofthemosteffectivewaystoreduceinteriornoise.BodynoisetransferfunctioncanberepresentedbyP/F,andtheunitisdB，referencesoundpressureis.………….（1）Representsbodystructurevibrationtransferfunction，Representstheperformancethatthebodyvibrationsconvertstothenoiseofthemeasurementpoints.Converttheairpressuretothesound-pressurelevelofthemeasuringpoint.………..（2）referencesoundpressure=referencesoundpressureis28.28e-12，peakis20.0e-12性能要求PerformanceRequirements分析得到的結(jié)果曲線是噪聲傳遞函數(shù)的聲壓級(jí)響應(yīng)曲線，響應(yīng)曲線與目標(biāo)值進(jìn)行比較，如果分析得到的響應(yīng)曲線結(jié)果小于目標(biāo)值，則滿足NTF分析的要求；響應(yīng)結(jié)果曲線如果有高于目標(biāo)值曲線的，則不滿足NTF分析要求。Theresults-curveisthesoundpressure-levelcurveofthenoisetransferfunction.Comparethecurvewiththetargetcurve.TheresultmeetstherequirementsofNTFanalysisifitislessthanthetargetvalue.Itisfailedwhenthecurveishigherthanthetargetvaluecurve.通用目標(biāo)值，排氣掛鉤≤60dB，其它接附點(diǎn)≤55dB。Thegeneraltarget:exhaustlinkedpoint<=60dB,otherpoints<=55dB.針對(duì)不同車型定位不同，目標(biāo)值可根據(jù)具體項(xiàng)目要求進(jìn)行調(diào)整。Thetargetvaluecanbeadjustedaccordingtothespecificprojectrequirements.分析要求ANALYSISREQUIREMENTS參考文件DOCUMENTATION無(wú)。聯(lián)系人CONTACTS無(wú)。例子EXAMPLESSOL111$=======================================================================$CASECONTROLSECTION$AUTOSPC(NOPRINT)=YESECHO=NONEMETHOD(STRUCTURE)=10METHOD(FLUID)=20FREQ=30SDAMPING=40$$$$$$$$$$$$$$NodeSETforOutputaboveAllSubcases.SET99=9001$$DISPLACEMENT(PLOT)=99$$SUBCASE1SUBTITLE=FLTOPMTGXDLOAD=1$SUBCASE2SUBTITLE=FLTOPMTGYDLOAD=2$SUBCASE3SUBTITLE=FLTOPMTGZDLOAD=3$$$=======================================================================BEGINBULK$$PARAMPOST-1PARAMCOUPMASS1$PARAM LFREQ2.0PARAMGFL0.16PARAM ACOUT RMS$PARAM,CHECKOUT,YESACMODLDIFFGRIDS1.BW0.50.750.5NOREL$==============================================================================$RLOAD110011000150DLOAD11.01.01001DAREA10001101011.0DLOAD21.01.01002RLOAD110021000250DAREA10002101