1、題目專業(yè)班級姓名學號指導教師湖北文理學院畢業(yè)設計（論文）英文翻譯有限元熱分析的陶瓷離合器車輛工程XxxXxxx2010138xx職稱Xxx副教授2014年2月25日FethermalanalysisofaceramicclutchIntroductionAbrasivedryrunningvehicleclutchesareforceclosurecouplings.Torqueandspeedtransmissionareensuredbythefrictionalforcegeneratedbetweentwopressedsurfaces.Reasonsfortheapplication

2、ofceramicasafrictionmediumincludegoodheatandwearresistaneeproperties,whichprovidetheopportunitytodrivehigherpressures,andalowdensity.Thus,anincreasingpowerdensityisenabledwithaparallelminimizationofconstructionspace.MeasurementswithafirstprototypeofaclutchdiskusingceramicfacingswereperformedatKarlsr

3、uheUniversityinalaboratoryspecializedinpassengercardrivesystemtesting.Inthecourseofanalysisthefiniteelement(FE)modelwastobeconstructedwiththeknowledgeofmeasurementdataandmeasurementconditions.Calculationswereintendedtodeterminethetemperaturedistributionoftheclutchdiskanditsenvironmentateachmomentint

4、imecorrespondingtomeasurements.Itisessentialtobefamiliarwiththetemperaturerangeinordertoexaminethewearcharacteristicsofthesystem.Thus,importantinformationisderivedfrommeasurementdata.Incriticalloadcases,thehighestexpectedtemperaturesmustbeforecastinspaceandtimeinordertoprotectmeasuringinstrumentsclo

5、setothelocationofheatgeneration.Thegoalofthisstudyistoanalyzeandmodifytheclutchsystemtoprovidebetteroperatingconditionsbyimprovingtheheatconductionandconvectionofthesystemortoincreasetheamountoftheenergyconvertedintofrictionalheat.Furthermore,itisdesiredtofindbetterdesignsolutionsformoreefficientclu

6、tchsystems.CalculationswereperformedbytheCosmosDesignStarsoftware.Duringmodeldevelopment,greatcarehadtobetakenforpropersimplificationofgeometry,theselectionofelementsizes,andthecorrectadjustmentoftimestepsduetothesubstantialhardwarerequirementsfortransientcalculations.Changesinthermalparameterssucha

7、sthesurfaceheatconvectioncoefficientandthermalloadhadtobetakenintoconsiderationonanon-goingbasisintermsoftimeandlocation.Thetwosidesoftheanalyzedtestclutchsystemcanonlybemanagedbytwoindependentmodelslinkedbyheatpartition,accordingtothehypothesisthatthecontacttemperaturemustbeidenticalonbothsideswhil

8、ethereispropercontactbetweenthemanditsvaluemustbeadjustedbyiteration.Calculationsrevealedthattheheatpartitionchangedbycycleanditdifferedalongtheinnerandoutercontactrings.Asaresultofthedifferentcoolingcharacteristicsbetweentheceramicandsteelside,aheat?owislaunchedfromtheceramicsidetothesteelside.This

9、heatflowwasalsodeterminedbyiteration,itsvaluealsochangesbycycleanddiffersalongtheinnerandoutercontactrings.FirstprototypeofaclutchusingengineeringceramicsasfrictionmaterialTheexaminedclutchdiskwasdevelopedaccordingtothespecificceramic”productdevelopmentprocessestablishedattheInstituteforProductDevel

10、opment(IPEK)attheUniversityofKarlsruhe.Thisdevelopmentprocessalreadyhasthepossibilityforconnectiontoarealtransmissionshaft;further,ithasacushionspringdeviceforthefacingsallowinggoodstartbehaviour.Abrasiveclutchesmustcomplywiththefollowingbasicrequirements:hightorquetransmissionaccordingtohighfrictio

11、ncoefficients,highcomfort(novibrationsthroughself-inducedchattering),homogeneoustemperaturedistribution,lowwearcharacteristic.Acriticalelementoftheswitchistheabrasivedisk.Withregardtothedesignutmostcaremustbetakentoselecttherightmaterial.Ahighandconstantfrictioncoefficient,wearresistaneeandthermalre

12、sistaneearedesiredcharacteristics.Theclutchdiskhasinsteadofthegenerallyappliedring-shapedabrasiveinlettworowsofSSIC(assintered)ceramicpellets.Thesepelletsareplacedon6separatesegments.Thesegmentsare?xedtothecentralhubbyrivets.Eachsegmentconsistsof4plates,2workingasfacingspringsand2ascarriers.Measurem

13、entsMeasurementswereperformedatthedepartmentofpowertraindevelopmentoftheInstituteforProductDevelopment(IPEK)attheKarlsruheUniversity(TH)ResearchUniversity,whereacategoryIVcomponenttestrigisusedfortestsofnewfrictionalmaterialsandexaminationsofnewmaterialsinrealclutchdisks.Realconditionsareappliedbyth

14、esimulationofdrivingresistanee(e.g.startingintheplane,startingatthehill).ItisacomponenttestrigleveledonthefourthpositionofthetribologicaltestingenvironmentInordertogiveanideaofdimensions:theequipmentlengthisabout4-5m.Thetwoelectricmotorsandtheaxialforcearecontrolledindependentlybycomputer;therebyman

15、yoperationalstatescanberealized.Thisenablestheequipmenttocompleteamyriadoftribologicalmeasurementsallwhileproperlymodelingtheoperationofaclutchdiskinapassengercar.ItisalsoequippedwithanautomaticITmeasurementsystem.Measurablequantitiesincludethefollowing:twoheavy-dutyelectricmotors(150KW,BaumullerDS1

16、60L-305),devicesuitableforexertingaxialforce,torquemeter(MannerSensortelemetrieMF100),axialforcemeter,steeldiskinfriction,replaceableheadtoaffixthedevicetobetested,temperaturealongtwodifferentradiiat0.4mmbelowtheabrasivesurfaceofthesteeldisk(OmegaHJMTSS-IM100U-150-2000,J-typeiro-constantanthermocoup

17、les),revolutionsperminuteforbothsides(PolyteneLSV065).Thegreatestchallengeoutoftheseistemperaturemeasurementaswewouldliketoknowthetemperatureoftherevolvingsteeldisk.Thetwothermoelementsplacedinthesteeldiskforwarddatatothecomputerthroughawirelessbluetoothsystemandareplaced0.4mmbelowtheabrasivesurface

18、ofthesteeldiskonthetwooppositearcsoftheclutchdisk.3.2.MeasurementprocessDuetocomponentanalysesandcostreductiononlyonesideoftheclutchdiskismountedwithceramicfacings.Thus,theclutchdiskanditsfittingwillbereferredtoastheceramicside,andtheabrasivesteeldiskwithitsenvironmentrevolvingtogetherwillbereferred

19、toasthesteelside.Inthecourseofmeasurements,datawerecollectedatasamplingfrequencyof100and1000HZ.Measurementswereconductedaccordingtothetimecurves.Themeasurementstartsbyincreasingtherevolutionsperminuteofthesteelside(thedrivingside)toaspecificvalue(1500rpmhere).Thentheceramicside(thedrivenside),heldat

20、zerorpm,ispushedtowardsthesteeldiskandtheaxialforceisapplieduntiladesignatedvalueisreached(nominally4200Nhere).Uponreachingthedesignatedaxialforcetheceramicsideisreleasedandthetwosidesstarttosynchronize.Afewsecondsaftersynchronization,theaxialloadisdiscontinuedandaftersometimeboththesteelandtheceram

21、icsidesrevoIvingatthesamespeedaresloweddown.Thisisdeemedtobeonemeasurementcycle.Tencyclesarecompletedinthecourseofasinglemeasurement.Duringapplicationoftheaxialforcetheceramicsideisheldatzerorpmuntilthedesiredforceisreachedtoensuresynchronizationoccursatnearlythesametimeofeachcycle.Thisisunfavorable

22、fromtheviewpointofbothmeasurementsandcalculations.Measurementsareusuallyconductedbychangingonly3parameters:thespeed,theaxialloadandtheinertia.Thefollowingfiguresareappliedinvariouscombinations:speedn:700,1100and1500(rpm),axialforceF:4200,6400and8400(N)and2inertiaI:1,1.25and1.5(kgm).Experimentalmeasu

23、rementsarelaunchedwithapprox.10-15minintervals,duringwhichthesystemcoolsdowntoabout30-401C.Thismakescalculationsdifficult,astheexacttemperaturedistributionofthesystemisnotknownatthecommencementofthemeasurement.However,itcanbeassumedthataperiodof10-15minissufficientforanearlyhomogeneoustemperaturedis

24、tributiontobeproduced.Theparametersforthefollowingsimulationhavebeenchosenforanintermediatecasewithaspeedn=1500rpm,anaxialforceF=4200NandaninertiaI=1kgm2.CalculationsofheatgenerationThemechanicalenergyconsumedduringthefrictionoftwobodiesistransformedintoheat.Thegeneratedheatcanbecalculatedbythefollo

25、wingsimpleformula:Q=卩FVW/.wheremisthethefrictionalcoefficient;vistheslidingvelocity;Fistheforceperpendicularlycompressingthesurfaces.Andtheheatfluxdensitypersurfaceunitis2q=卩卩VWm.wherepisthethepressurecalculatedasaratiooftheforceandthecontactingsurface.Astheceramictabletsareplacedattwodifferentradii

26、alongtheclutchdisk,theheatgeneratedmustbecalculatedseparatelyforeachradii.Slidingcanbedividedintotwosections.Inthefirstsection,theceramicsideiskeptinastationarypositionbybraking,meanwhiletheaxialloadisincreased;thereforecompressionchangesinthecourseoftimewhilethespeeddiffereneebetweenthetwosidesisco

27、nstant.Inthesecondsection(atsynchronization)thespeeddiffereneeisequalizedwhiletheforcevalueisconstant,sovelocitychangesintime.Onthebasisthereof,theheatgeneratedisQi=小叩mpA恤肝Qj=W-v2ir)|f)-A2ramThenominalcontactareaistheaggregateofthecontactingsurfacesofthe24and18ceramictabletsonthegivenring.Thediamete

28、rofceramictabletsis:脈=16mm*兒訶=24-0.004825m3=18-嘗兀=0.003619in2Calculationswereperformedfortheloadcasetobecharacterizedbythefollowingparameters:nnux=1500rpm而執(zhí)=4200NJ=1kgm3Basedonexperimentalmeasurementsaconstantfrictioncoefficientof0.4wasestablished.p=0.4(consr)Thevelocitycanbecalculatedwiththeknowled

29、geoftheradiusandthespeed.門=0.094mr2=0.07mf%評L=4詐bUs2兄5忻熬汀2廠tn60=Surfacepressurecanbecalculatedasaratiooftheaxialforceandthecontactingsurface.Thisproducesthesamefigureforeachceramicpellet,assuminganevenloaddistribution.p.,.,=m=0.496MPaThus,themaximumvaluesofthegeneratedheatareQ=0.414.84960000.004825=

30、14177W=0.4H-4960000.003619=7919W.Inthefirstsectionofsliding,thegeneratedheatisrisingduetotheincreaseoftheloadforce;inthesecondsection,itisdecreasingduetotheequalizationofthespeeddifferenee.Itisnecessarytoknowthetimeofeachslidingsectioninordertobeabletospecifythegeneratedheattimecurve.Thesecanbedeter

31、minedfrommeasurementdataseries.Synchronizationtimecanbeeasilydeterminedfromthespeedoftheceramicside.Speedincreaseislinear.Forceincreaseisnon-Iinear.Forthesakeofsimplicity,forceincreasewassubstitutedbyastraightlineincalculationssothattheareabelowthestraightlineisnearlyidenticalwiththeareameasuredbelo

32、wthecurve.Thus,thetimediffereneebetweenthetwoterminalpointsofthestraightlineisthetimeofthefirstslidingsection.Theabove-mentionedmethodwasappliedforeachcycleandtheiraveragewasspecified.Basedontheseresults,thefollowingvaluesweredeterminedforslidingtimes:fotcpapplyingtime冷汀=2.8ssynchronisationtime燈：門二0

33、.92sNowthetimecurveofheatgenerationcanbeproduced.Thesamecurvewasusedineachcycleastherewerenosignificantdifferencesbetweenparametersineachcycle.Thegeneratedheat-calculatedthisway-willappearasthermalloadinthethermalmodel.Itmustbedistributedappropriatelybetweenthecontactingsurfacesbytakingintoconsidera

34、tionheatpartition.Heatpartitionrequiresthecontacttemperaturestobeidenticalatbothsurfaces.Correctadjustmentrequiresrepeatediterations.有限元熱分析的陶瓷離合器1引言磨料空轉車輛離合器是力封閉聯(lián)軸器。扭矩和高速傳輸被壓緊表面之間產(chǎn)生的摩擦力所保證。應用陶瓷是因為它作為摩擦介質(zhì)具有好耐熱和耐磨損性能，提供了機會以驅(qū)動更高的壓力，以及一個低的密度。因此，一個提功率密度啟用了一個平行的最小化建筑空間。測量使用陶瓷飾面離合器盤的第一個原型在卡爾斯魯厄大學的一個實驗室專門從事

35、客車驅(qū)動系統(tǒng)進行了測試執(zhí)行。在分析過程中的有限元（F巳模型是將與測量數(shù)據(jù)和測量條件的知識所構成。計算的目的是要確定在離合器盤上溫度的分布以及環(huán)境中的在每一時刻的及時測量目。至關重要的是熟悉的溫度范圍，為了檢驗該系統(tǒng)的耐磨特性。因此，重要信息從測量數(shù)據(jù)中得出。在臨界負載的情況下，預計最高溫度必須在時間和空間上進行預測，為保護接近發(fā)熱體的位置測量工具的。本研究的目的是分析和修改該離合器系統(tǒng)通過改進，以提供更好的工作條件熱傳導和系統(tǒng)或增加轉化成摩擦熱的能量的對流。此外，人們希望找到更有效的更好的離合器系統(tǒng)設計方案。計算是由宇宙星空的設計的軟件進行的。在模型開發(fā)階段，非常謹慎，必須采取幾何元素，選擇適

36、當?shù)暮喕叽?，并且由于正確調(diào)整的時間步長大量的硬件要求瞬態(tài)計算。熱物性參數(shù)的改變，如表面熱對流化系數(shù)和熱負荷，必須考慮到到在一個持續(xù)的基礎上在時間和地點方面。離合器系統(tǒng)的分析測試這兩方面，只能通過加熱隔板連接的兩個獨立的模型來管理，根據(jù)該假說認為，接觸溫度必須是在兩個相同的雙方，同時他們要有適當接觸，其價值需通過迭代來進行調(diào)整。計算顯示，該熱分區(qū)按周期變化，它沿不同的內(nèi)，外接觸環(huán)。在不同的冷卻特性下，在陶瓷和鋼之間的結果是不同的，熱流從陶瓷側面向鋼側流動。此熱流也通過迭代確定；它的價值也改變了周期和不同沿著所述內(nèi)和外接觸環(huán)。2采用工程陶瓷作為摩擦材料的第一個原型機這款檢查過的離合器盤是根據(jù)“特

37、定的陶瓷”產(chǎn)品而開發(fā)的，此材料的研發(fā)過程在流程在卡爾斯魯厄大學的InstituteforProductDevelopment（IPEK）雜志上發(fā)表過。此開發(fā)過程已經(jīng)具有的可能性，用于連接到一個真實的傳動軸；甚至，它為面板有一個好的初始行為起到一個很好的緩沖作用。磨料配件必須符合以下基本要求：根據(jù)高摩擦系數(shù)高扭矩傳遞高舒適度（通過自感應抖動無共振）均勻的溫度分布低磨損特性開關的一個關鍵因素是摩擦面.在設計極限方面，必須謹慎采取選擇合適的材料。高而恒定的摩擦系數(shù)，耐磨損和耐熱性是理想的特性。離合器圓盤能代替通常應用環(huán)形磨料入口兩排SSIC勺（燒結）陶瓷顆粒。這些小球被放置在6個單獨的段位。該段由鉚

38、釘固定到中心輪轂。每個段由4片組成，2個工作面對著彈簧和2個作為載體。3測量3.1測量設備測量是在卡爾斯魯厄大學（TH）研究型大學的動力傳動系完成的，同時也是用于測試新的摩擦材料和新材料在實際離合器片中檢測的地方。真實情況是通過驅(qū)動電阻的仿真應用（例如，開始在平面上，開始于山）的試驗裝置。這是一個組件試驗臺夷為平地在摩擦測試環(huán)境的第四位。為了給維度的概念：設備長度大約4-5m。兩臺電動機和軸向力是由計算機獨立控制；因此許多運營可實現(xiàn)的狀態(tài)。這使得設備來完成一個摩擦學測量無數(shù)，而所有正確建模在乘用車上的離合器盤的操作。它還配備用自動的IT測量系統(tǒng)。可測量的量包括以下內(nèi)容：2個重型電機（150千瓦

39、，Baume米勒DS160L-305）設備適用于施加軸向力扭力計（SensortelemetrieMF100）軸力計鋼盤的摩擦可更換的頭部貼上設備進行測試溫度沿兩個不同的半徑處為0.4mm以下的鋼盤（歐米茄HJMTSS-IM100U-磨料表面150-2000，J鐵康銅熱電偶）每分鐘轉數(shù)為雙方（PolytecLSV065）。這里最大的挑戰(zhàn)是這些我們想知道的旋轉鋼盤面上溫度的測量。兩個熱元件放置在鋼盤通過無線藍牙數(shù)據(jù)轉發(fā)給計算機系統(tǒng)和被放置為0.4mm以下的研磨面鋼盤上的兩個相對的圓弧的離合器盤。3.2測量過程為了測量由組分分析和降低成本的一側離合器盤安裝用陶瓷襯片，由此，離合器磁盤及其配件將被稱

40、為陶瓷側，而磨具鋼盤與它的環(huán)境一起旋轉會簡稱為鋼側。在測量時，數(shù)據(jù)的過程中收集在100和1000Hz的采樣頻率。在測量開始通過增加每轉鋼側（驅(qū)動側）的分鐘為一個特定值（這里是1500轉）。然后在陶瓷側（驅(qū)動側），在保持零轉速下被推向鋼盤和軸向力應用，直到一個指定的值為止（名義上4200N在這里）。當?shù)竭_所指定的軸向力的陶瓷側是釋放和雙方開始同步。幾秒鐘在同步之后，在軸向載荷終止和后一段時間都在鋼和陶瓷兩側繞轉在相同的速度會慢下來。這被視為一個測量周期。十個周期中的一個過程中完成單次測量。在應用程序中的軸向力陶瓷側被保持在零轉速，直至所需的力達到以確保發(fā)生同步于幾乎每種相同的時間周期。這是不利的從兩者的觀點出發(fā)，測量目和計算。測