Q/SZJ191001-2017整車路面噪聲與振動分析規(guī)范SpecificationofVehicleRoadNoiseandVibrationAnalysis20XX20XX-12-31實施20XX-11-27發(fā)布XXXX汽車工程技術(shù)有限公司發(fā)布Q/SZXX-X-2017整車路面噪聲與振動分析規(guī)范范圍本標準規(guī)定了整車路噪分析的方法。本標準適用于CAE部門整車路噪分析。規(guī)范性引用文件無。術(shù)語和定義無。摘要Abstract當汽車在路面上行駛時，會經(jīng)歷寬頻段的振動激勵。最終振動激勵傳遞到方向盤和座椅觸摸到振動、傳遞到乘員耳朵聽到聲音、傳遞到后視鏡看到搖晃。任何噪聲或振動問題都有激勵源和傳遞路徑。噪聲分為結(jié)構(gòu)噪聲和空氣噪聲。當振動源激勵了輪胎、懸架和車身，在傳遞到車廂內(nèi)聲腔，這種噪聲稱為結(jié)構(gòu)噪聲。激勵源之一是路面不平順。不平順可以用汽車經(jīng)過的輪胎軌跡輪廓來描述，即功率譜密度PSD函數(shù)。整車路面響應(yīng)分析是隨機振動分析，具有線性、穩(wěn)態(tài)和頻域特征。在穩(wěn)態(tài)隨機過程中，隨機變量（如：均值和變化量）統(tǒng)計值不隨時間變化。線性穩(wěn)態(tài)分析類似于整車路面模擬。一旦有可用的整車分析模型，路面響應(yīng)分析的結(jié)果可以用來評估結(jié)構(gòu)或子系統(tǒng)改變和接附點剛度變化對觸覺、視覺、聽覺或動態(tài)應(yīng)力的影響。路面分析中包括兩種分析（NASTRAN中）：第一種是單位加載；第二種是PSD加載。結(jié)構(gòu)噪聲分析屬于第二種。在NASTRAN使用模態(tài)頻率分析模塊（SOL111）。Asavehicletravelsonaroad,itexperiencesabroadspectrumofvibrations.Thefinalmanifestationsofthesevibrationstypicallyoccurinthesteeringcolumnandseatastactilevibration,atthedriver’sandpassengers’earsasnoise,andattherear-viewmirrorasvisualvibration.Anynoiseorvibrationproblemhasanexcitationsourceandatransmissionpath.Dependingonthepathsthevibrationalenergytakesbeforereachingtheear,thenoiseisclassifiedasstructural-borneorair-borne.Whenthesourceexcitesthetires,thesuspensions,andthebodystructure,whichinturnexcitestheaircavityinthevehicle,thenoiseisstructural-borne.Onesourceofexcitationisfromroadroughness.Roughnessisdescribedbytheelevationprofilealongthetiretracksoverwhichthevehiclepasses.ThePowerSpectralDensity–PSDfunctionismostlyusedtorepresentroadroughness.Vehicleroadresponsearesimulatedwithrandomvibrationanalysis.Theanalysisislinear,stationary,andinthefrequencydomain.Inastationaryrandomprocess,thestatisticsoftherandomvariables(e.g.themeanandvariance)donotchangewithtime.Linearstationaryanalysisisausefulapproximationforvehicleroadsimulations.Onceavalidatedvehiclemodelisavailable,theresultsofroadresponseanalysesareusedtoevaluatetheeffectsofstructuralorsubsystemchangesorinterfacemountstiffnesstuningonthetactile,visual,aural,anddynamicstressresponse.Twoproceduresareusedforroadsimulationanalysis.Forthefirstprocedure,onlyadummyloadcaseisneededintheNASTRANfile.Forthesecondprocedure,alltheroadinputPSDinformationandresponseoutputsmustbesuppliedintheNASTRANfile.Theroadstructuralbornenoisesimulationprocedurealsobelongstothesecondprocedure.Inbothprocedures,modalfrequencysolution(SOL111)withCMStechniquesisperformedinNASTRAN.流程圖無。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):Nastran后處理(Postprocessors):Hypergraph建模和分析過程Modeling/AnalysisProcedure路面輪廓RoadProfiles一旦路面類型和車速設(shè)定好，就可以得到適當?shù)腘ASTRAN格式表格數(shù)據(jù)。這些是由測量的位移輪廓數(shù)據(jù)生成的。必須確保分析用的數(shù)據(jù)與測試對應(yīng)。按照車速轉(zhuǎn)換功率譜密度路面輪廓功率譜密度是與車速相關(guān)的函數(shù)。一般都有45英里/小時的功率譜密度數(shù)據(jù)，而分析車速可能是20英里/小時到60英里/小時。其轉(zhuǎn)換公式如下：S(f)=(1/r)*S0*(f/r)其中，r=V/V0，S(f)是轉(zhuǎn)換后功率譜密度、S0是轉(zhuǎn)換前功率譜密度、V是轉(zhuǎn)換后車速、V0是轉(zhuǎn)換前車速、f是頻率。Oncetheroadandvehiclespeedareselected,theappropriateNASTRANroadprofiletableneedstobeobtained.TheseNASTRANtablesaregeneratedfrommeasureddisplacementprofiles.Theusershouldalsomakesurethattheprofileisforthesamesegmentofroadusedinanytestingorevaluations.PSDConversionforVehicleSpeedTheroadprofilePSDisafunctionofvehiclespeed.SomeoftheoriginalbaselinePSDsarefor45mphvehiclespeed.Thesimulationspeedofthevehicleistypicallyintherangeof20to60MPH(e.g.30,35,40,45,50)ToconvertaroadprofilePSD(S0)atagivenspeed(V0)toacorrespondingprofilePSD(S)atanotherspeed(V),thefollowingformulacanbeused:S(f)=(1/r)*S0*(f/r)Wherer=V/V0,r>0,andf=frequencyinHz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)時間(Time) 秒(Second)內(nèi)容Contents無。坐標系CoordinateSystems無。建模技巧ModelingTechniques無。假設(shè)和限制Assumptions/Limitations無。載荷和邊界條件Loads/BoundaryConditions約束唯一的約束是約束每個輪胎的接地點。也是路面激勵的加載點。Theonlyboundaryconditiononthevehiclemodelisaconstraintoneachofthetirepatchpoints.Thisisdoneinconjunctionwiththeroadprofileloading.載荷第一步是加載單位正弦激勵，可以建立傳遞函數(shù)矩陣；第二步是加載隨機功率譜密度函數(shù)和相關(guān)正弦激勵。Thefirststepistocreateloadcardstoapplysinusoidalloadsatallinputpointswiththeappropriatephaserelationships,etc.Thiscreatesthetransferfunctionmatrix(H).ThesecondstepistocreatecardsfortherandomPSDfunctionandassociatethesewiththesinusoidalloadcases.ThePSDs(S)arealreadysetupwiththeroadtables(TABRNDcardsandRANDPScards).TheusermustverifythatthesubcaseIDsontheRANDPScardsmatchthosetheusercreatedforthesinusoidalloads.結(jié)果Results結(jié)果格式ResultsFormats所有原始數(shù)據(jù)來自NASTRAN分析。對于毫米-噸-牛-秒單位制模型，功率譜密度單位是(mm/s^2)^2/Hz。響應(yīng)的測量點在座椅內(nèi)側(cè)（一般四個安裝點都會測）、方向盤12點和6點處。所有振動輸出響應(yīng)是自動功率譜密度加速度進行分貝處理，參考值為1(meter/sec^2)^2/Hz。輸出值為均方根幅值。不過由于輸入的路面激勵值已經(jīng)是均方根形式，因此就不需要進行轉(zhuǎn)換了。要求輸出峰值，NASTRAN卡片設(shè)置為PARAM,ACOUT,PEAK。AllrawresponsedatacomingfromNASTRANisinmodelunits.Foramm-Mg-N-smodel,thatwouldbeunitsof(mm/s^2)^2/Hz.Theresponsepointscalledoutinthetestprocedurearetherearinboardattachmentofthefrontseat(althoughallfourattachmentpointsareoftenused),steeringcolumn12O’clockand6O’clock.AlloutputresponseforvibrationaretheAUTO-PSDofaccelerationexpressedinDBreferencedto1(meter/sec^2)^2/Hz.TheoutputsareexpressedinRMSAmplitude.TheroadprofiletablesarealreadyinRMSamplitude;therefore,theuserdoesnotneedtoconverttheNASTRANoutput,andthePARAM,ACOUTshouldbeleftatthedefaultofPEAK相關(guān)測試CorrelationTests無。性能要求PerformanceRequirements無。分析要求ANALYSISREQUIREMENTS懸架襯套和懸置襯套參數(shù)有±15%變化內(nèi)可使用。輪胎參數(shù)（模態(tài)坐標下的剛度和阻尼）可使用。靜止輪胎與滾動輪胎的參數(shù)具體如何變化，還不是很清楚。但是從靜止到滾動，輪胎模態(tài)頻率一般會下降10%，甚至有的模態(tài)甚至是25%；而阻尼會翻倍，甚至三倍。減振器的阻尼（和剛度）要包括。內(nèi)飾質(zhì)量點（蓄電池和大燈）可以用±5%變化量。Suspensionbushingandpowertrainmountratevariationof+/-15%shouldbeused.Tireproperties(stiffnessanddampingofthemodalmasssystems)shouldalsobeused.Lessisknownaboutthevariationintirepropertiesbutknowledgeofhowthepropertieschangefromnon-rollingtorollingandthroughoutthespeedrangemaybeofuse.Thereistypicallya10%reductioninmodalfrequencyfromnon-rollingtorolling,withextremesofa25%reductionforsomemodes.Thedampingoftendoublesfromnon-rollingwithsomemodesincreasingbyafactorofthree.Shockdamping(andpossiblystiffness)mayalsobeincluded.Massoftrimmassitems(i.e.battery,headlamp,etc.)canbeusedprobablywitharangeof+/-5%.參考文件DOCUMENTATION無。聯(lián)系人CONTACTS無。例子EXAMPLESSingleRoadandSpeedSOL111CEND$METHOD=1FREQUENCY=20$$STUD_DAMAGEDCONCRETEMPG(2000)RANDOM=85198$RCROSS(PHASE,NOPRINT,PUNCH,PSDF)=1000$SUBCASE1$INPUTSATRIGHTSIDETIRESFOR20MPHDLOAD=10SUBCASE2$INPUTSATLEFTSIDETIRESFOR20MPHDLOAD=15$BEGINBULK$$EIGENVALUEEXTRACTIONEIGRL1-1.250.021.0EIGRL11-1.300.021.0$FREQUENCYFREQ1,20,20.,1.0,180INCLUDE<model.bdf>$$EXCITATIONATTIREPATCHGRIDS:LHS$DLOAD101.01.0100121.0100131.0100141.0100151.0100161.0100171.0100181.0100191.010020$RLOAD1100121012110141120DISPRLOAD1100131012210142120DISPRLOAD1100141012310143120DISPRLOAD1100151012410144120DISPRLOAD1100161012510145120DISPRLOAD1100171012610146120DISPRLOAD1100181012710147120DISPRLOAD1100191012810148120DISPRLOAD1100201012910149120DISPSPCD10121546080131.SPCD10122546080231.SPCD10123546080331.SPCD10124546080431.SPCD10125546080531.SPCD10126546080631.SPCD10127546080731.SPCD10128546080831.SPCD10129546080931.$DELAY1014154608013.000000DELAY1014254608023.000676DELAY1014354608033.001351DELAY1014454608043.002027DELAY1014554608053.002702DELAY1014654608063.003378DELAY1014754608073.004053DELAY1014854608083.004729DELAY1014954608093.005404$$$$EXCITATIONATTIREPATCHGRIDS:LHS$DLOAD151.01.0150121.0150131.0150141.0150151.0150161.0150171.0150181.0150191.015020$RLOAD1150121512115141120DISPRLOAD1150131512215142120DISPRLOAD1150141512315143120DISPRLOAD1150151512415144120DISPRLOAD1150161512515145120DISPRLOAD1150171512615146120DISPRLOAD1150181512715147120DISPRLOAD1150191512815148120DISPRLOAD1150201512915149120DISPSPCD15121546090131.SPCD15122546090231.SPCD15123546090331.SPCD15124546090431.SPCD15125546090531.SPCD15126546090631.SPCD15127546090731.SPCD15128546090831.SPCD15129546090931.$DELAY1514154609013.000000DELAY1514254609023.000676DELAY1514354609033.001351DELAY1514454609043.002027DELAY1514554609053.002702DELAY1514654609063.003378DELAY1514754609073.004053DELAY1514854609083.004729DELAY1514954609093.005404$$TABLED1,120,,10.0,1.0,1000.0,1.0,ENDT$$$ROADPROFILE$$*********************************************************************$*$*NASTRANBASEDRIDEMETRICROADPROFILEDATA$*$*********************************************************************$$NOTE:DELAYcardmustmatchveh.speedforroadprofileselected.$Speedusedare20/25/35/45/55/60/65mph.$$RANDOMrrryy:rrr=RideMetricRoadNumber,yy=YearofMeasurement$=====================================================================$RANDOM85198$851(37.5mph)N&VRoadStudDamagedConcreteMPG1998$Processedfrom20mphdata$********************************************************************$Thedatainthetablesbelowisformillimetermodels.$********************************************************************$N&VRoadStudDamagedConcreteat20mphRANDPS85198111.00.0851981RANDPS85198221.00.0851982RANDPS85198121.00.0851983RANDPS85198120.0-1.0851984$TABRND1851981+0.4690.26E+000.9370.12E+011.4060.23E+011.8750.19E+01…+,ENDT$OutputrequestfortheAuto-PSDforsoundpressurelevelat$driversearposition(grid8500700)RCROSS,1000,DISP,8500700,1,DISP,8500700,1$ENDDATAMultipleRoadsand/orSpeedsSOL111CEND$METHOD=1FREQUENCY=20$RCROSS(PHASE,NOPRINT,PUNCH,PSDF)=1000$SUBCASE110$INPUTSATRIGHTSIDETIRESFOR20MPHDLOAD=10SUBCASE120$INPUTSATLEFTSIDETIRESFOR20MPHDLOAD=15$SUBCASE210$INPUTSATRIGHTSIDETIRESFOR35MPHDL