SourcePathContributionWheredoesthesoundcomefrom?Howdoesitgetthere?Whichnoisesourcesareimportant?Whichnoisepathsaremostcritical?Howdonoisepathsinteract?Howdoesthenoisegetfromtheretothedriver?Isthesourcetooloudordoesthepathtransmitthenoisetooeasily?Whatwillmyvehiclesoundlikewiththesecomponents?WhatwillhappentothesoundwhenImakeadesignchange?SourcePathContributionanswersthesequestionsandmoreSoundPressureatthedriverspositionVibrationatthegearshiftetc.BodySourcesEngineTiresetc.Airborne–AcousticsourcethroughAirtoaReceiverStructureBorne–VibrationthroughSolid(viaAir)toaReceiverPaths(SPR)ModelsSSPPRSPSPSourcePathContributionmethodswhichcanbeusedtocreateSPRmodelsSPRModelsquantifytheindividualpathcontributionsfromallofthesourcesbeingimportantforthesoundorvibrationperceivedbyoccupantsinthevehicleFrequencyDomain–StationarySignalsRotational/OrderDomain–Non-Stationaryrun-up/-downTimeDomain–Stationary–Non-Stationary–Transient(StructureBorne)nnvntotFHP1OperatingForcesonPassive/BodysideofMountsnFOperationaltests&LaboratorytestsFrequencyResponseFunctionfromBodytoReceiverOftencalledNoiseTransferFunctionnanFPH/LaboratorytestsPtot1F2FnF…….ContributionatdriverspositionMountStiffnessMethodImpedanceMatrixMethod1F2FnF1a2aia1iamamnmnmnnnxxFXFXFXFXFXFXff........................111122212121111MountStiffnessMethod/ExperimentaldeterminationofdisplacementbymeasuringOperationalaccelerations,bothsidesExperimentaldeterminationofComplexStiffnessbymeasuringForceandDisplacementofmountsCalculatingOperatingForceusingComplexStiffnessandOperationaldisplacementnnxKFOperationaltestsLaboratorytestsdttXtXtXBA)()()(:DynamicForceEstimationDynamicForceinputtobodyF=K•XBodySidePassiveSideLiveSideActiveSideCorrecttransducerselection&mountingiscriticaldttXtXtXBA)()()(–testrigVerticalTestonOneEngineMountLateralTestusingTwoEngineMounts(X,Y,Z)02004006008001k1.2k1.4k[Hz]3005007001k[N/mm]CursorvaluesX:760HzY:975.11N/mmComplexstiffnessformountTransmissionMnt/X(Magnitude)ComplexstiffnessformountTransmissionMnt/Y(Magnitude)ComplexstiffnessformountTransmissionMnt/Z(Magnitude)FrontEngineMount(X,Y,Z)02004006008001k1.2k1.4k[Hz]4006008001k1.2k[N/mm]CursorvaluesX:800HzY:674.15N/mmComplexstiffnessformountFrntEngMnt/X(Magnitude)ComplexstiffnessformountFrntEngMnt/Y(Magnitude)ComplexstiffnessformountFrntEngMnt/Z(Magnitude):MeasureOperatingAccelerationonbothsidesofMounts[Ao]–MeasureActiveandBodySideofMount–Simultaneousmeasurements–DetermineoperatingdispacementfrommeasuredaccelerationsStep2:MeasuredynamicStiffnessofMount–Removeelastomericelementsofthevehicle–MeasuretheircomplexstiffnessStep3:CalculateOperatingForces:Step4:MeasureNoiseTransferFunctions:[H]=[NTF]Step5:CalculatePathContributions-Calculatecontributions,modify,recalculate,auralize...dttXtXtXBA)()()(StructureBorneNoise:MountStiffnessMethod)(KKXKFo]F][H[PoDemoMountStiffnessImpedanceMatrixMethodopvopaHF1ExperimentaldeterminationofOperationalaccelerationsonpassive/bodysideExperimentaldeterminationofAccelerancematrixofpassive/bodysideCalculatingOperationalForcesusinginverseAccelerancematrixandOperationalaccelerationFHavOperationaltestsLaboratorytests1F2FnF…….…….1a2aia1iama…….ForcesateachMountPassiveSideIndicatorsatleastateachMountpassiveside{aop}:ImpedanceMatrixmethodQXFPFFAP]F][H[PoFMeasureBody-sideOperatingAccelerations[Ao]-MeasureatmultiplelocationstimedataMeasureInertanceFunctions[HI]=[A]/[F]-RemoveEngine,suspension-Choosepathsofinterests-Measure/Exciteonbestlocations-InvestigatequalityofmatrixInvertMatrix[HI]-Calculatecomplexspectrumofeachforce-InvestigateconditioningofmatrixCalculateForces[Fo]=[HI]-1[Ao]MeasureNoiseTransferFunctions:[H]=[NTF]-Measureusingvibro-acousticreciprocity-MeasurewithEngine,SuspensionremovedCalculatePathContributions-Calculatecontributions,modify,recalculate,auralize...DemoAirborneSubstitutionMethod