saej2730v001

__________________________________________________________________________________________________________________________________________SAETechnicalStandardsBoardRulesprovidethat:“ThisreportispublishedbySAEtoadvancethestateoftechnicalandengineeringsciences.Theuseofthisreportisentirelyvoluntary,anditsapplicabilityandsuitabilityforanyparticularuse,includinganypatentinfringementarisingtherefrom,isthesoleresponsibilityoftheuser.”SAEreviewseachtechnicalreportatleasteveryfiveyearsatwhichtimeitmaybereaffirmed,revised,orcancelled.SAEinvitesyourwrittencommentsandsuggestions.Copyright©2006SAEInternationalAllrightsreserved.Nopartofthispublicationmaybereproduced,storedinaretrievalsystemortransmitted,inanyformorbyanymeans,electronic,mechanical,photocopying,recording,orotherwise,withoutthepriorwrittenpermissionofSAE.TOPLACEADOCUMENTORDER:Tel:877-606-7323(insideUSAandCanada)Tel:724-776-4970(outsideUSA)Fax:724-776-0790Email:CustomerService@sae.orgSAEWEBADDRESS:http://www.sae.orgJ2730ISSUEDAUG2006SURFACEVEHICLERECOMMENDEDPRACTICEIssued2006-08DynamicCleatTestwithPerpendicularandInclinedCleatsRATIONALEThisRecommendedPracticewasdevelopedaspartofasetofRecommendedPracticesintendedtoallowmodelerstodeterminetheparametersrequiredbyanyofthecommontiremodelsforcalculatingspindleloadsgiventheroadsurfaceprofile.Thesedocumentsprovidethenecessarydatafromasinglesetofexperimentalresults,thus,eliminatingduplicatetesting.TABLEOFCONTENTS1.Scope............................................................................................................................................................22.References....................................................................................................................................................22.1ApplicablePublications.................................................................................................................................23.Definitions.....................................................................................................................................................33.1TheParallelAxisTireCoordinateSystem....................................................................................................33.2TheTireForcesandMoments......................................................................................................................43.3TravelDistances...........................................................................................................................................63.4Test...............................................................................................................................................................63.5TestProgram................................................................................................................................................64.Nomenclature................................................................................................................................................65.LaboratoryQualitySystemRequirement......................................................................................................66.Apparatus......................................................................................................................................................76.1EnvironmentalVibrationandIsolation..........................................................................................................76.2LoadingSystem..........................................................................................................................................156.3MeasuringSystem......................................................................................................................................156.4DataAcquisition..........................................................................................................................................176.5TestSurface................................................................................................................................................176.6TestCleats..................................................................................................................................................186.7TestSpace..................................................................................................................................................197.Calibration...................................................................................................................................................198.PreparationofApparatus............................................................................................................................199.SelectionandPreparationofTestTires.....................................................................................................199.1SelectionofTiresforGoodComparability..................................................................................................199.2InflationPressure........................................................................................................................................19SAEJ2730IssuedAUG2006-2-9.3TirePreparation..........................................................................................................................................209.4SampleSize................................................................................................................................................2010.TestProcedure............................................................................................................................................2010.1TireMounting..............................................................................................................................................2010.2LoadedRadiusDetermination....................................................................................................................2010.3TestSpeeds................................................................................................................................................2010.4Test.............................................................................................................................................................2111.DataProcessingandReporting..................................................................................................................2112.DataRepeatabilityandReproducibility.......................................................................................................23Figure1TheSAEParallelAxisSystem......................................................................................................................4Figure2SAEParallelAxisSystemForcesandMoments..........................................................................................5Figure3TestMachineSchematic...............................................................................................................................7Figure4IllustrationoftheAmplitudeEffectofaMachineResonance.......................................................................8Figure5IllustrationofthePhaseEffectofaMachineResonance.............................................................................9Figure6InputtinganFY”ImpulsewithaModalHammer..........................................................................................10Figure7InputtinganFX”ImpulsewithaModalHammer..........................................................................................10Figure8InputtinganFZ”ImpulsewithaModalHammer..........................................................................................11Figure9InputtingbothFY”andMX”ImpulseswithaModalHammer........................................................................11Figure10InputtingbothFY”andMZ”ImpulseswithaModalHammer........................................................................12Figure11InputtinganFY”ImpulseintotheBackPathwithaModalHammer...........................................................13Figure12InputtinganFX”ImpulseintotheBackPathwithaModalHammer...........................................................13Figure13InputtinganFZ”ImpulseintotheBackPathwithaModalHammer............................................................14Figure14InputtingbothFY”andMZ”ImpulsesintotheBackPathwithaModalHammer..........................................14Figure15InputtingbothFY”andMX”ImpulsesintotheBackPathwithaModalHammer.........................................15Figure16CrossSectionalViewofMounted90°Cleat...............................................................................................18Figure17ExampleDataforTwoChannels................................................................................................................22Table1SymbolsDefined...........................................................................................................................................6Table2MinimumLoadCellCapacitiesBasedonForceandMoment....................................................................16Table3LoadCellCapacityExample.......................................................................................................................17Table4DataFileLayout.........................................................................................................................................221.SCOPEThisSAERecommendedPracticedescribesatestmethodformeasuringtheforcesandmomentsgeneratedatahighfrequencyresponsespindlewhenarollingtireimpactsacleat.Thecleatisconfiguredeitherwithitscrestperpendicular,90°,tothepathofthetireoroptionallywithitscrestinclinedatanangletothepathofthetire.Thecarriagetowhichthespindleisattachedisrigidlyconstrainedinpositionduringeachtestconditionsoastoprovideagoodapproximationtofixedloadedradiusoperation.Themethoddiscussedinthisdocumentprovidesimpactforceandmomenttimehistoriesessentiallyfreefromvariationsduetotirenon-uniformities.Themethodappliestoanysizetiresolongastheequipmentisproperlyscaledtoconductthemeasurementsfortheintendedtesttire.Thedataaresuitableforuseindeterminingparametersforroadloadmodelsandforcomparativeevaluationsofthemeasuredpropertiesinresearchanddevelopment.NOTE:Herein,roadloadmodelsaremodelsforpredictingforcesappliedtothevehiclespindlesduringoperationoverirregularsurfaces,pavedorotherwise.Withinthecontextofthisdocument,forcesappliedtotheroadorterrainsurfacearenotconsidered.2.REFERENCES2.1ApplicablePublicationsThefollowingpublicationsformpartofthespecificationtotheextentspecifiedherein.Unlessotherwiseindicatedthelatestrevisionsofallpublicationsshallapply.SAEJ2730IssuedAUG2006-3-2.1.1SAEPublicationsAvailablefromSAE,400CommonwealthDrive,Warrendale,PA15096-0001,Tel:877-606-7323(insideUSAandCanada)or724-776-4970(outsideUSA),www.sae.org.SAEJ2047TirePerformanceTechnologySAEJ2429Free-RollingCorneringTestforTruckandBusTiresSAEJ2710ModalTestingandIdentificationofLowerOrderTireNaturalFrequenciesofRadialTiresSAEJ2717TeststoDefineTireSize(Geometry),MassandInertiasSAE2001-01-0790DynamicForceMeasurementSystem(DFMS)forTires,G.R.PottsandE.F.Knuth,2001SAE770870TheEffectofTireBreak-inonForceandMomentProperties,K.D.Marshall,R.L.Phelps,M.G.Pottinger,andW.Pelz,1977SAE810066TheEffectofAgingonForceandMomentPropertiesofRadialTires,M.G.PottingerandK.D.Marshall2.1.2RubberManufacturersAssociationPublicationAvailablefromRubberManufacturersAssociation,1400KStreet,NW,Suite900,Washington,DC20005,Tel:202-682-4800,www.rma.org.OSHAStandard1910.177ServicingMulti-pieceandSinglePieceRimWheels(availableinwallchartformas#TTMP—7/95)2.1.3ISOPublicationAvailablefromANSI,25West43rdStreet,NewYork,NY10036-8002,Tel:212-642-4900,www.ansi.org.ISOStandard17025GeneralRequirementsfortheCompetenceofTestingandCalibrationLaboratories3.DEFINITIONSThedefinitionsthatfollowareofspecialmeaninginthisdocumentandareeithernotcontainedinotherRecommendedPracticesorarewordedsomewhatdifferentlyinthispractice.3.1TheParallelAxisTireCoordinateSystemThissystemistheonedefinedinSAEJ2710extendedtoallowtirerotation.Theloadedtireforthepurposeofthisdocumentisdefinedasatire/wheelassemblyattachedtothespindle.Thespindleisconsideredtobesubstantiallyrigidlysupportedinthelongitudinal,lateral,andverticaldirections1.Thetireisfreetorotateaboutthespindle.Thetireisloadedincontactwiththereaction(testmachine)surfacesoastoproduceatirefootprint.Theprincipaldirectionsaredefinedintermsofaright-handedCartesiancoordinatesystemwithitsoriginattheintersectionofthespindleandthewheelplane.ThethreeaxesaredefinedasfollowsandillustratedinFigure1.1Theverticaldirectionissometimesreferredtoasthenormalorradialdirectiondependentonthecontext.SAEJ2730IssuedAUG2006-4-X”Y”Z”SpindleωX”Y”Z”SpindleX”Y”Z”X”Y”Z”SpindleωFIGURE1-THESAEPARALLELAXISSYSTEM3.1.1ParallelSystemLongitudinalAxis,X”TheparallelsystemlongitudinalaxisisparalleltotheSAEX’—AxisasdefinedinSAEJ2047.ItispositiveinthedirectionofrollingasindicatedinFigure1.3.1.2ParallelSystemLateralAxis,Y”TheparallelsystemlateralaxisisparalleltotheSAEY’—AxisasdefinedinSAEJ2047.ItspositivesenseistotherightasviewedfrombehindtheY”—Z”Plane.NOTE:Inthecaseofatirewithoutinclination,asassumedinthisdocument,Y”liesalongthespindlecenterlinewithapositivesensetotheright.3.1.3ParallelSystemVerticalAxis,Z”Theparallelsystemverticalaxisisperpendiculartotheroadplanewithapositivesenseintotheroadsurface.ItisparalleltotheSAEZ’—AxisasdefinedinSAEJ2047,buttheoriginoftheverticalaxisisatthecenterofthetirenotattheroadsurface.NOTE:ThetireisassumedtohavenoinclinationinthisdocumentinwhichcaseZ”liesinthewheelplane.3.1.4SpinVelocity,ωThetirespinvelocityisaboutthespindle,whichiscoincidentwiththeY”—Axisinthecaseconsideredinthisdocument.3.2TheTireForcesandMomentsInthisdocument,theforcesandmomentsoriginateattheoriginofthedoubleprimedaxissystem.TheyareshowninFigure2andaredefinedbelow.Theyareconsideredasbeingforcesandmomentsappliedtothespindlebythevibratingtire/wheelassembly.AfterthissectionanduseinTable1,theseforcesandmomentsaresimplyreferredtoastireforcesandmoments.Thisisdoneforreasonsofsimplicity.Inthedefinitions,theseforcesandmomentsarenamedtoclearlyassociatethemwiththeparallelaxissystem.Thesearetheonlyforcesandmomentsunderdiscussioninthisdocument.SAEJ2730IssuedAUG2006-5-FX”FY”FZ”SpindleMX”MY”MZ”FX”FY”FZ”SpindleFX”FY”FZ”SpindleMX”MY”MZ”MX”MY”MZ”MX”MY”MZ”MX”MY”MZ”FIGURE2-SAEPARALLELAXISSYSTEMFORCESANDMOMENTS3.2.1ParallelAxisLongitudinalForce,Fx”TheparallelaxislongitudinalforceisalongtheX”—Axis.ItispositiveinthedirectionofthepositiveX”—Axis.Theforceactsfromthetireontothespindle.3.2.2ParallelAxisLateralForce,Fy”TheparallelaxislateralforceisalongtheY”—Axis.ItispositiveinthedirectionofthepositiveY”—Axis.Theforceactsfromthetireontothespindle.3.2.3ParallelAxisNormalForce,Fz”TheparallelaxisnormalforceisalongtheZ”—Axis.ItispositiveinthedirectionofthepositiveZ”—Axis.Theforceactsfromthetireontothespindle.3.2.4ParallelAxisOverturningMoment,Mx”TheparallelaxisoverturningmomentisabouttheX”—Axis.ItispositiveclockwiseaboutthepositivebranchoftheX”—Axis.Themomentactsfromthetireontothespindle.3.2.5ParallelAxisRollingResistanceMoment,My”TheparallelaxisrollingresistancemomentisabouttheY”—Axis.ItispositiveclockwiseaboutthepositivebranchoftheY”—Axis.Themomentactsfromthetireontothespindle.23.2.6ParallelAxisAligningMoment,MZ”TheparallelaxisaligningmomentisabouttheZ”—Axis.ItispositiveclockwiseaboutthepositivebranchoftheZ”—Axis.Themomentactsfromthetireontothespindle.2Therollingresistancemomentisincludedforcompleteness,butisneithermeasurednorutilizedinthisdocument.SAEJ2730IssuedAUG2006-6-3.3TravelDistances3.3.1AngularDisplacementoftheTire,ΦTheangulardisplacementaboutthespindledefinedtobezeroattheinstantthedataacquisitiontriggeroccurs.3.4TestATestisexecutionoftheproceduredescribedinthisdocumentonetimeononetireatasinglesetofconditions.3.5TestProgramATestProgramisadesignedexperimentinvolvingasetofthetestsdescribedinthispractice.34.NOMENCLATURETable1liststhesymbolsusedinthisdocument.ForfurtherinformationonitemsnotinSection4ofthispracticepleaseseeSAEJ2047.TABLE1-SYMBOLSDEFINEDSymbolDefinedTermFX”ParallelSystemLongitudinalForceFY”ParallelSystemLateralForceFZ”ParallelSystemNormalForceΦTireAngularDisplacementMX”ParallelSystemOverturningMomentMY”ParallelSystemRollingResistanceMomentMZ”ParallelSystemAligningMomentpInflationPressureRlTireLoadedRadiustTimeVTestVelocityωTireSpinVelocityΩTestRoadwaySpinVelocity5.LABORATORYQUALITY-SYSTEMREQUIREMENTThelaboratoryperformingtheproceduresspecifiedinthisdocumentshallhaveaqualitysystemeitherconformingtoISO17025orwhichcanbeshowntobefunctionallyequivalenttoISO17025.Theelementsofsuchasystemareassumedbelowandarenot,therefore,specificallycalledoutwithinthispractice.3Therearemanyexperimentalpossibilities:repeatedtestsofthesametire,testsofthesametireundermultipletestconditions,testsoftireswithdifferentspecifications(designdetails),applicationofthistestaspartofaseriesofdifferenttests,etc.SAEJ2730IssuedAUG2006-7-6.APPARATUSTherequiredapparatusconsistsofatestmachinewitharoundtestsurfacecapableofrollingtesttiresatthevelocitiesdefinedinthetestconditions,Section10.3TestSpeeds.Thetestsurfaceshallallowmountingoftestcleatsoneatatime,asspecifiedinthispractice.Themachineshallhaveaninstrumentedspindlecapableofmeasuringthreeforces(FX”,FY”,andFZ”)andtwomoments(MX”andMZ”)developedduringtireimpactwithatestcleat.Theinstrumentationalsomeasurestireangulardisplacement,Φ,usingabsoluteencoders.Figure3isaschematicofsuchamachine.Appropriatedata-acquisitionequipmentisconsideredtobepartoftheapparatus.Thespacehousingtheloadingmachineisalsoconsideredtobepartoftheapparatus.Vibrationinitiatedbythetire/cleatimpactprocessandoutsidesourcesissoimportantinthisdocumentthatvibrationrequirementsarediscussedexplicitlyinSection6.1,thefirstsubsectioninthispartofthepractice.++ωΦRoadwheelTireCleatFixedDistanceΩ++ωΦRoadwheelTireCleatFixedDistance++ωΦRoadwheelTireCleatFixedDistance++ωΦRoadwheelTireCleat++ωΦRoadwheelTire++ωΦRoadwheel++ωΦ++ωΦ++ω++ω+++++++ωΦRoadwheelTireCleatFixedDistanceΩFIGURE3-TESTMACHINESCHEMATIC46.1EnvironmentalVibrationandIsolationTire/cleatimpactinthecaseofarigidlyconstrainedspindle,asisusedinthistest,generatesverysignificantdynamicforces.Theinstrumentedspindlewillrespondtoforcesignalsregardlessofwhethertheyreachitdirectlyfromthetire/wheelsystem,asisdesired,fromthetestsurfacethroughthemachineframe,orfromasourceinthelaboratoryenvironmentthroughthefloorandthenthemachineframe.Themachine’splannedenvironmentshouldbetestedforsignificantstructurebornevibrationarisingfromthelaboratoryenvironmentpriortoinstallation.5Ifnosuchvibrationisfound,themachinecanbemountedonanormalfoundation.Ifsignificant,environmentally-associated,vibrationsarediscovered,twocoursesareopen.Thefirstistoascertainwhetherornottherearepredictableperiodswhentheenvironmentalvibrationsareatalowenoughleveltopermittesting.Isthereenoughusabletimetopermitadequatemachineuse?Ifenoughusabletimeexists,anoperationalscheduleadjustmentmayresolvetheproblem.Ifschedulingcan’tmitigatetheproblem,asecondcourseisasfollows,anadequatevibrationisolatedmachinefoundationshouldbedesignedbyamachineisolationexpert,andthecleatimpactmachineinstalledonit.Inverybadcasesbothisolationandschedulingmayhavetobepursued.Inanycase,environmentalvibrationmonitorin