外文翻译-汽车复合材料悬架摆臂的实验分析 英文版.pdf

EXPERIMENTALANALYSISOFACOMPOSITEAUTOMOTIVESUSPENSIONARMMPINFOLDANDGCALVERTUNIVERSITYOFWARWICK/ROVERGROUPGAYDON,UKRECEIVED11NOVEMBER1992；REVISED26MARCH1993INAPPLICATIONSWHEREWEIGHTSAVINGANDPARTSINTEGRATIONCANBEACHIEVED,THEROVERGROUPHASBEENINVESTIGATINGTHEDESIGNANDMANUFACTUREOFCOMPONENTSFROMCOMPOSITEMATERIALSTHEMETHODSUSEDINTHEDIFFERENTSTEPSINTHEDESIGNTOMANUFACTURECYCLEINTHEHIGHVOLUMEAUTOMOTIVEINDUSTRYARERELATIVELYWELLKNOWNFORASTEELCOMPONENT,BUTARENOTSOWELLESTABLISHEDFORACOMPOSITECOMPONENTADESIGNMETHODOLOGYFORCOMPOSITESHASBEENEMERGINGINWHICHAPRINCIPALPROCEDUREISDESIGNANALYSISONEOFTHEMOSTESTABLISHEDMETHODSOFANALYSISISTHATUSINGTHEFINITEELEMENTTECHNIQUE,ANDTHISISBEINGSUPPLEMENTEDWITHEXPERIMENTALTESTSONPROTOTYPESUSINGPHOTOELASTICANALYSISANDSTRESSPATTERNANALYSISBYTHERMALEMISSION,COUPLEDWITHCONVENTIONALSTRAINGAUGEMONITORINGLITTLEWORKHASBEENUNDERTAKENTOCORRELATETHERESULTSOBTAINEDFROMTHESEDIFFERENTTESTMETHODSANDTOCOMPARETHERESULTSWITHMEASUREMENTSMADEONANACTUALCOMPONENTTHISPAPERPRESENTSSOMEOFTHEWORKUNDERTAKENCONCERNINGTHEANALYSISANDTESTINGOFACOMPOSITEAUTOMOTIVESUSPENSIONARMTHERESULTSOBTAINEDFROMTHETHREEDIFFERENTANALYSISTECHNIQUESARECOMPAREDWITHEXPERIMENTALTESTRESULTS,ANDTHEIRACCURACYISDISCUSSEDKEYWORDSAUTMOTIVESUSPENSIONARM；STRESSANALYSIS；FINITEELEMENTMETHOD；PHOTOELASTICANALYSIS；SPATE；STRAINGAUGES；SHEETMOULDINGCOMPOUNDSOLANDDEWILDESTATETHATCOMPOSITEMATERIALSHAVEBEENUSEDINCREASINGLYASSTRUCTURALMATERIALSAREASONFORTHIS,ISTHATCOMPOSITEMATERIALSHAVEHIGHSTRENGTHTOWEIGHTANDHIGHSTIFFNESSTOWEIGHTRATIOSWHICHCANSIGNIFICANTLYREDUCETHEWEIGHTOFASTRUCTUREPERHAPSTHEMOSTIMPORTANTFEATUREOFCOMPOSITEMATERIALSISTHATTHEIRMECHANICALPOPERTIESCANBETAILOREDTOMEETASPECIFICCRITERIONHOWEVER,JOHNSONETALSUGGESTTHATCOMPOSITEDESIGN,ANALYSISANDFABRICATIONTECHNOLOGYMUSTUNDERGOMAJORDEVELOPMENTSANDSUCCESSFULDEMONSTRATIONSBEFORESIGNIFICANTSTRUCTURALCOMPONENTSWILLBEINCORPORATEDINPRODUCTIONAUTOMOBILESANDTRUCKSCOMPOSITEMATERIALSHAVETOCOMPETEWITHSTEELWITHINTHEENGINEERINGENVIRONMENTWITHINTHEAUTOMOTIVEINDUSTRYTHISREQUIRESACERTAINAMOUNTOFTECHNOLOGYTRANSFERFROMPLACESSUCHASTHEADVANCEDTECHNOLOGYCENTREATTHEUNIVERSITYOFWARWICK,WHICHWORKWITHMATERIALMANUFACTURERSANDAUTOMOTIVEENGINEERSTOENABLEUNDERSTANDINGABOUTTHESEMATERIALSASANALTERNATIVETOTHETRADITIONALMATERIALSSUCHASSTEELIFCOMPOSITESARETOCOMPETEWITHTRADITIONALMATERIALSINAREALSENSE,THENAUTOMOTIVEDESIGNERSNEEDTOBEFULLYAWARE00104361/94/01005905OFTHEIRSTRENGTHSANDLIMITATIONSSOTHATTHEYCANBEONEOFPERHAPSMANYOPTIONSCONSIDEREDATTHECONCEPTSTAGEOFTHEDESIGNFORTHISTOHAPPENAUTOMOTIVEENGINEERSNEEDTOCATCHUPONTHETECHNIQUESOFDESIGNING,TESTINGANDMANUFACTURINGCOMPONENTSFROMCOMPOSITESTHISWILLINCLUDEUNDERSTANDINGHOWVARIOUSMETHODSSUCHASFINITEELEMENTFEANALYSIS,STRESSPATTERNANALYSISBYTHERMALEMISSIONSPATEANDPHOTOELASTICANALYSISCANBEAPPLIEDTOCOMPOSITECOMPONENTSINTHEIRDESIGNANDDEVELOPMENTTHUSFARLITTLEWORKAPPEARSTOHAVEBEENUNDERTAKENTOSTUDYWHETHERTHERESULTSOBTAINEDFROMTHESEDIFFERENTANALYSISMETHODSCORRELATEWITHONEANOTHERORWITHACTUALEXPERIMENTALRESULTSOBTAINEDFROMTESTINGAREALCOMPONENTINORDERTOSTUDYTHEAPPLICATIONANDCORRELATIONOFTHEDIFFERENTANALYSISMETHODSTOCOMPOSITEMATERIALS,ACOMPOSITECOMPONENTANAUTOMOTIVELOWERSUSPENSIONARMWASMANUFACTUREDTHISCOMPOSITECOMPONENTWASANALYSEDBYTHETHREEMETHODSDESCRIBEDABOVEANDALSOTESTEDUNDERREALISTICLOADINGCONDITIONS,WITHEXPERIMENTALRESULTSBEINGOBTAINEDFROMSTRAINGAUGES1994BUTTERWORTHHEINEMANNKTDCOMPOSITESVOLUME25NUMBER1199459,BALLJOINTHOUSINGFIG1THECOMPOSITESUSPENSIONARMDESIGNTHEEXISTINGSTEELLOWERSUSPENSIONARMCONSISTSOFNINEPIECESWELDEDTOGETHERWHILSTTHEREDESIGNEDCOMPOSITECOMPONENTWHICHCANBESEENINFIG1ISASINGLEMOULDEDPARTTHEMATERIALUSEDTOMANUFACTURETHESUSPENSIONARMWASASHEETMOULDINGCOMPOUNDSMC,COMPRISINGAPOLYESTERRESINBONDINGAGENTWITHA30CONTENTOFRANDOMLYARRANGEDSHORTGLASSFIBRESANDCALCIUMCARBONATEFIILERTHEWEIGHTOFTHESTEELSUSPENSIONARMIS253KGWHILSTTHEREDESIGNEDSMCSUSPENSIONARMCOMPLETEWITHBUSHESANDBALLJOINTWEIGHS15KGTHEMATERIALPROPERTIESUSEDFORTHECOMPOSITESUSPENSIONARMINTHESEANALYSES,OBTAINEDFROMTESTSCARRIEDOUTATROVERSMATERIALSLABORATORY,WEREYOUNGSMODULUS105GPA,POISSONSRATIO026ANDDENSITY18X106KGMM3EXPERIMENTALTECHNIQUESPRIORTOUNDERTAKINGEXPERIMENTALANALYSISOFANACTUALENGINEERINGCOMPONENT,SOMEINITIALVALIDATIONWORKWASREQUIREDTOGAINCONFIDENCEINTHETECHNIQUESWHENAPPLIEDTOSHEETMOULDINGCOMPOUNDTHEREFORE,FIATPLATES,BEAMSANDDISCSCONSTRUCTEDFROMSMCWEREANALYSEDUNDERVARIOUSLOADINGCONDITIONSBEFOREPROGRESSINGONTOTHEDESIGNEDCOMPONENTMOSTVALIDATIONTESTSWERECARRIEDOUTUSINGSTRAINGAUGEDSPECIMENSTOCORRELATEWITHTHEFINITEELEMENTANALYSISRESULTSALTHOUGHITISRECOGNIZEDTHATSMCISNOTANISOTROPIEMATERIALDUETOSOMEFIBREORIENTATIONDURINGPROCESSING,FORTHEPURPOSESOFANALYSISTHEMATERIALWASASSUMEDTOBEISOTROPICALSO,WHENTHEACTUALSMCSUSPENSIONARMWASCUTUPANDEXAMINED,SIGNIFICANTFIBREDISTRIBUTIONWASOBSERVEDINTHERIBSITISFELTTHATTHECORRELATIONBETWEENTHEEXPERIMENTALANDANALYSISRESULTSVALIDATEDTHISASSUMPTIONINTHECASEOFTHISPARTICULARCOMPONENTSTRAINGAUGETESTSBEFOREUNDERTAKINGTHEEXPERIMENTALTESTWORK,THECOMPOSITECOMPONENTWASMOUNTEDVIAITSRUBBERMOUNTINGBUSHESONTOARELATIVELYINFINITELYSTIFFSTRUCTUREITISVERYDIFFICULTTOCOVERALLOFTHELOADINGCONDITIONSWHENCONDUCTINGEXPERIMENTALTESTSANDTHUSAWORSTCASESCENARIOISUSUALLYASSUMEDTHEWORSTCASELOADINGCONDITIONONSUSPENSIONCOMPONENTSISKNOWNASPOTHOLEBRAKETHISATTEMPTSTOSIMULATETHEVEHICLEFALLINGINTOADEEPPOTHOLEAT30MPHWITHTHEBRAKESFULLYAPPLIEDATTHEPOINTOFIMPACTTHERESULTANTFORE/AFTANDLATERALLOADSARETHENCALCULATEDBASEDONTHEWEIGHTANDVELOCITYOFTHEVEHICLEDUETOTHELIMITATIONSOFTHETESTRIGTHEFULLPOTHOLELOADSCOULDNOTBEAPPLIEDTOTHECOMPONENT,ANDTHUSREDUCEDLOADSWITHTHESAMERESULTANTDIRECTIONASTHEPOTHOLELOADSWEREAPPLIEDANDTHERESULTSSCALEDTHELOADSAPPLIEDFORTHEFULLPOTHOLEBRAKECASEWERE242KNINXAND82KNINY,ANDFORTHEREDUCEDLOADCASEWERE59KNINXAND202KNINYSEEFIG1THESTRAINGAUGESUSEDCONSISTEDOFSIXTHREEAXISROSETTEGAUGESAND13SINGLEGRIDGAUGES,WITH25MMGRIDLENGTHS,CHOSENTOFITINTOTHERADIIOFTHECOMPONENTINANATTEMPTTOMEASURETHEMAXIMUMSTRAIN,GAUGESWERESITUATEDNEARTHEBALLJOINTHOUSING,WHERETHELOADSWEREAPPLIED,ANDAROUNDTHERADIIOFTHEBODYMOUNTINGBUSHES,WHERETHECOMPONENTWOULDBEMOUNTEDTOTHECARSUBFRAMEADDITIONALSTRAINGAUGESWERESITUATEDONSOMEOFTHESTRENGTHENINGRIBSANDCLOSETOTHEANTIROLLBARMOUNTINGPOSITIONSPATEANALYSISSTRESSPATTERNANALYSISBYTHERMALEMISSIONSPATECANBEUSEDTODETERMINETHESURFACESTRESSESOFCOMPONENTSBYSTUDYINGTHESMALLCHANGESINTEMPERATUREDUETOCYCLICLOADINGCONDITIONSSPATEEQUIPMENTCOMPRISESADETECTORUNITWITHSCANNINGHEAD,ANANALOGUESIGNALPROCESSINGUNITANDADIGITALELECTRONICDATAUNITTHESYSTEMWORKSBYDETECTINGTHEMINUTETEMPERATURECHANGESWHICHOCCURWHENASTRUCTUREISCYCLICALLYLOADEDTHEINFRAREDDETECTORSCANSTHESTRUCTUREANDCORRELATESTHEMEASUREDOUTPUTWITHAREFERENCESIGNALFROMTHELOADINGSYSTEMANELECTRONICDATAPROCESSINGSYSTEMCORRELATESTHEDETECTEDSTRESSINDUCEDTHERMALFLUCTUATIONSWITHTHELOADINGREFERENCESIGNALACOLOURCONTOURMAPOFTHESUMOFTHEPRINCIPALSTRESSESCR4ISTHENPLOTTED,TOGETHERWITHABARCHARTGIVINGACTUALVALUESTHISCORRELATIONOFSIGNALSEFFECTIVELYELIMINATESALLSIGNALFREQUENCIESOTHERTHANTHOSECAUSEDBYTHELOADINGSYSTEM,IE,ALLAMBIENTTEMPERATUREFLUCTUATIONSTHESPATESYSTEMHASATEMPERATURERESOLUTIONOF0001C,ANDASPATIALRESOLUTIONOFLESSTHANIMMTHISTYPEOFANALYSISHASBEENSHOWNBYANUMBEROFAUTHORSTMTOALSOBEAPPLICABLETONONISOTROPICMATERIALSSUCHASCOMPOSITES,ANDTHESMALLERRORS6DEMONSTRATEDFROMSUCHSTUDIESWHENCOMPAREDWITHTHEORETICALORFERESULTSAREFELTTOBEDUETOINACCURACIESINTHEMATERIALDATAUSED4ITISAPPARENTFROMTHESTUDIESUNDERTAKENTHATTHEUSEOFTHERMOELASTICSTRESSANALYSISTOEVALUATESTRESSESANDSTRAINSINANISOTROPICCOMPOSITEMATERIALSISMORECOMPLEXTHANFORISOTROPICMATERIALSHOWEVER,ITHASBEENSHOWNTHATTHETECHNIQUECANPROVIDEVALUABLEQUALITATIVEINFORMATIONONSTRESSDISTRIBUTION,EFFECTSOFSURFACEDEFECTSANDCRACKGROWTHPREDICTIONSITHASALSOBEENDEMONSTRATEDTHAT,GIVENACCURATEDETAILSOFMATERIALPROPERTIESINCLUDINGEXPANSIONCOEFFICIENTS,QUANTITATIVERESULTSCANBEOBTAINEDDEPENDINGUPONTHEDEGREEOFANISOTROPYOFTHEMATERIALPRIORTOUNDERTAKINGAFULLSPATEANALYSISOFTHESUSPENSIONARMITWASNECESSARYTODETERMINEACALIBRATIONFACTORFORTHEMATERIALUSEDTHISCANBEACHIEVEDINTWOWAYS,EITHERBYLOADINGADISCOFTHEMATERIALINCOMPRESSIONANDCOMPARINGTHESPATEOUTPUTWITHTHETHEORETI60COMPOSITESNUMBER11994CALSOLUTION,ORBYSTRAINGAUGINGDIRECTLYONTOTHECOMPONENTINANAREAOFEVENSTRESSDISTRIBUTION,THEREBYOBTAININGADIRECTCOMPARISONWITHTHESPATEOUTPUTBOTHMETHODSWEREUSEDINTHISCASE,BUTDIRECTCALIBRATIONWITHSTRAINGAUGESCANOVERCOMEALOTOFTHEPROBLEMS,THUSALLOWINGSIGNIFICANTINFORMATIONTOBEOBTAINEDFROMTHESPATEOUTPUTPHOTOELASTICANALYSISTHEMAJORITYOFPHOTOELASTICWORKINVESTIGATINGTHEMACROMECHANICALBEHAVIOUROFCOMPOSITEMATERIALSHASBEENUNDERTAKENUSINGPHOTOELASTICCOATINGTECHNIQUESTHISISDONETOAVOIDTHECOMPLEXITIESOFCONSTRUCTINGAPHOTOELASTICMODELWITHANISOTROPICPROPERTIESANDTHUSCONSTRUCTINGACOMPOSITELIKETHEORIGINALWHICHWOULDLOSEITSTRANSPARENCYANDCOULDNOTBEANALYSEDHOWEVER,FORCOMPLEXFIBRELAYUPSTHISWOULDBETHEONLYMETHODOFCONDUCTINGPHOTOELASTICANALYSIS,ANDTHUSSOMERESEARCHHASBEENUNDERTAKENINVESTIGATINGTHEUSEOFTHEACTUALCOMPOSITESJ730REASONABLERESULTSHAVEBEENOBTAINEDFROMSUCHANALYSES,BUTWITHLIMITATIONSDUETOTHENECESSITYFORTRANSPARENCYWITHINTHECOMPOSITEHOWEVER,THECOMPOSITECOMPONENTCONSIDEREDINTHISSTUDYWASMANUFACTUREDFROMSMCANDTHEMATERIALWASASSUMEDTOBEISOTROPIC,THUSSIMPLIFYINGTHECREATIONOFAPHOTOELASTICMODELATHREEDIMENSIONALEPOXYRESINMODELOFTHESUSPENSIONARMWASCONSTRUCTEDFORTHEPHOTOELASTICANALYSISTHEMODELWASTHENLOADEDINAREPRESENTATIVEMANNER,WITHSCALEDDOWNLOADS,ANDSUBJECTEDTOASTRESSFREEZINGCYCLETHISINVOLVESHEATINGTHEMODELUPTOTHEMATERIALSGLASSTRANSITIONTEMPERATURE,ATWHICHPOINTTHEYOUNGSMODULUSCHANGES,ANDTHEMODELDEFORMSUNDERTHEAPPLIEDLOADSTHEMODELISTHENSLOWLYCOOLED,AVOIDINGANYUNEVENTEMPERATUREDISTRIBUTIONWHICHCOULDRESULTINUNWANTEDTHERMALSTRESSESDURINGTHECOOLINGCYCLETHEDEFORMATIONSANDSTRESSESARELOCKEDINTOTHEMODELWHENVIEWEDUNDERPOLARIZEDLIGHTTHETHREEDIMENSIONALMODELISAJUMBLEOFINTERFERENCEFRINGESINORDERTODETERMINEBOTHMAGNITUDEANDDIRECTIONOFTHEPRINCIPALSTRESSESATANYPOINT,ASLICEISREMOVEDANDOBSERVEDUNDERPOLARIZEDLIGHTBYCOUNTINGTHEFRINGESTHESTRESSESINTHEMODELCANBECALCULATEDANDCONVERTEDINTOACTUALSTRESSINTHECOMPONENTTHISISDONEBYMEANSOFPROPORTIONALITY,BETWEENTHEMODELANDCOMPONENTMATERIALS,A