EngineMount_opt

EngineMountSystemOptimizationUsingLMSDADSandOptimusOverviewGoalsDetermineoptimummountlocationsandstiffnessesforanenginemountsystemanddeterminethesystemresponseduetoidle,enginerun-up,androughroadshake.StrategyUsea6DegreeofFreedom(DOF)modeltodeterminePowertrainrigidmodes,optimizemodesforidleresponse,andanalyzeresponseduetotheotherexcitations.EigenModeAnalysismxmymzIxIxyIzxIxyIyIyzIzxIyzIzK11K21K31K41K51K61K12K22K32K42K52K62K13K23K33K43K53K63K14K24K34K44K54K64K15K25K35K45K55K65K16K26K36K46K56K66xyzFxFyFzExEyEz::::::::::::EquationofMotionProcessOverview•BuildPowertrainmountsysteminDADS,usinginitialestimatesformountlocationsandstiffnesses•RunDOEinOptimustofindparametersensitivities•UseOptimustooptimizefortheidlestrategy•Findsystemresponsestoidle,enginerun-upandroughroad,basedonoptimizeddesign.OptimizingforIdlefn=ωn/2πωn=(k/m)1/2IsolationRegionsAmplificationRegionsExcitationFrequencyEx.I4Firing-2EO@600rpmidle=20HzFt/Fofn1fn21100.010.1HzToimproveisolationatidle,makethemountassoftaspossible,tomakethenaturalfrequencyofthePTonthemountsaslowaspossible.OptimizingforIdleIdleexcitationisduetocombustion,whichisarollcoupleabouttheTRA.Todesignforgoodidleweusea6DOFmodelandsetthefollowingconditions:Optimizingforidle•RollMode10Hz•BounceMode10Hz•RollandBounceModede-coupledfromeachother•Rollde-coupledfromallothermodesBuildingtheSysteminDADS-InputParameters•Establishpreliminarymountlocationsandstiffnesses•Connectmountstopowertrainandvehicleusingbushingelements•Use3pointlinkstoconnectmountstopowertrain,toallowforrotationalmovement•Inputpowertraincenterofgravityandmomentsofinertia•InputidleexcitationBuildingtheSysteminDADS-InputParametersIdleexcitationcanbemodeledorshakingforcesappliedtoenginecenterofgravityToModelIdleExcitationNeed:•connectingrodlength•connectingrodmass•pistonmass•cylinderfiringorder•crankmass•crankradiusBuildingtheSysteminDADS-InputParametersInthisexample,apendulumtorquerollaxissystemismodeledforaFWDI4engine.Mountlocationsareselectedabovethepowertrain,withoneontheengineside,andoneonthetransmissionside.Atorquerestrictorislocatedatthebottomofthepowertrain,alongthecenterofgravity.=PowertraincenterofgravityTRAzxyPowertrainModelIdleModelInitialResultsEigenfrequencyVectorsFREQXYZE1(~pitch)E2(~roll)E3(~yaw)6.5831-0.058625690.9947313020.0840990935.89205E-06-4.1342E-057.9683E-056.85570.180495486-0.022928230.983308208-9.1749E-050.0007113050.0003610161.62990.9427584830.0005540060.333468645-0.00016741-0.002183644.74156E-055.4960.8753184710.0486711-0.48108980.0001488940.0009170830.0006624119.36120.99770508-0.06615210.012814085-0.000489280.001458527-0.0064734319.5766-0.11079835-0.08990646-0.98880692-0.04255870.0036732860.008757519•Resultsshowrollmodeislow(1.63Hz),butcoupledwithfore-afttranslation•Primarybouncemodeishigh(19.57Hz),butsignificantenergyisinthesecondarybouncemodeat6.86Hz.•Inputx,y,andzlocationrangesforeachmountExample(1000to1100,-500to-450,700to850)mm•Inputx,yandzstaticstiffnessrangesforeachmountExample(100to200,50to80,100to250)N/mm•Inputx:y,x:z,y:zstiffnessratiosforeachmountExample(1.5to3:1:2.5to5)DOEInputs•RollMode10Hz•BounceMode10Hz•RollandBounceModede-coupledfromeachother•Rollde-coupledfromallothermodesDOEandOptimizationModelTaguchiDOEResponseSurfaceRollModeFactorSensitivitiesChartshowsonlyprimaryfactors.Interactionswerealsoreviewed.TaguchiDOEResponseSurfaceBounceModeFactorSensitivitiesChartshowsonlyprimaryfactors.Interactionswerealsoreviewed.Inputs•DOEInputsandgoals•DOEresponsesurfaceOutputs•Recommendedmountlocations•Recommendedmountstiffnesses•InputforDADSModelOptimizationModelSampleOptimizationProgressionDADsIdleSystemModelResultsOptimizedUnitVectorsOriginalUnitVectorsFREQXYZE1(~pitch)E2(~roll)E3(~yaw)6.5831-0.058625690.9947313020.0840990935.89205E-06-4.1342E-057.9683E-056.85570.180495486-0.022928230.983308208-9.1749E-050.0007113050.0003610161.62990.9427584830.0005540060.333468645-0.00016741-0.002183644.74156E-055.4960.8753184710.0486711-0.48108980.0001488940.0009170830.0006624119.36120.99770508-0.06615210.012814085-0.000489280.001458527-0.0064734319.5766-0.11079835-0.08990646-0.98880692-0.04255870.0036732860.008757519FREQXYZE1(~pitch)E2(~roll)E3(~yaw)8.0392-0.514787950.00633134-0.064593020.00002387-0.00030087-0.0001110410.1907-0.33117211-0.36622021-0.00035590.00108042-0.000958660.0078764718.8840.020100270.35436395-0.91609561-0.036299110.001531380.008076232.53450.62766151-0.003900990.740194820.00014758-0.00382694-0.000372076.8441-0.200072590.415569970.64594682-0.000127240.000226690.00006746.7120.067600550.85172589-0.241243730.000158-0.000155210.00008153DesignforAccelerationForceduetotorquepre-loadStiffnessatidle-noloadStiffnessunderdrivetorquecanbemuchgreaterthanstiffnessatidle.FδAloweridlestiffnesscanincreasestiffnessunderpre-load.Increasingidlestiffnessprovidesforlowerstiffnessundertorque.However,thisisdirectlycountertogoodidleisolationdesign.DesignforAccelerationIncreasingthemaximumprogressionreducesthestiffnes