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1、浙江大學(xué)機(jī)械與能源工程學(xué)院博士學(xué)位論文航空薄壁件精密銑削加工變形的預(yù)測理論及方法研究姓名：白萬金申請學(xué)位級別：博士專業(yè)：機(jī)械制造及其自動化指導(dǎo)教師：柯映林;董輝躍20081201浙江大學(xué)博士學(xué)位論文關(guān)鍵詞：薄壁件；數(shù)控銑削加工：加工變形；局部彈性變形；有限元模擬；切削力；切削溫度；熱力耦合；加工穩(wěn)定性；殘余應(yīng)力本論文研究得到了國家自然科學(xué)基金重點(diǎn)項(xiàng)目(50435020)及國家863高技術(shù)研究發(fā)展計劃(2006AA042147)的資助Ⅱ摘要ABSTRACTAtpresent，airframesarewidelymadeofmonolithicthin‘walledc
2、omponentsforthesakeofweightreducingandstrengthratioimprovement．However,duetofactorssuch勰cuttingforceinducedflexibledeflection,dynamicvibrationandnon-uniformresidualstressdistributioninduceddistortion,precisionmachiningoftheselow-rigiditythin-walledpartshasbeenprovidingaseriouschalleng
3、eforengineers．Inthisarticle，themodelsandmethodsforpredictingtheprecisionmillingdeformationerrorsaresystematicallyinvestedbymeansoftheoreticanalysis，mechanicsmodeling，fiuiteelementsimulationandexperimentsverification．Firstly,basedonlargedeformationtheoryandvirtualworkprinciple，athree—d
4、imensional(3-D)themao-elastic—plasticcoupledfiniteelementanalysis(FEA)modelisconstructedtoinvestigatethehigh—speedmilling(HSM)processesof7050-T7451aluminumalloy．SeveralkeyFEAtechniques，such弱finiteelementmeshmodel，materialconstitutivemodel，chipseparationcriteria，frictionsonthetool-chip
5、interfaceand3-Dheatconductiongoverningequations，areanalyzedandimplementedtoimprovetheaccuracyandefficiencyoftheFEAsimulation．AHSMcaseissimulatedwiththe3一DFEAmodel．Thedetailedcalculatedresultsarepresentedandanalyzed，includingthechip’Sgeometricshapeanditsevolutionprocesses，thestress，str
6、ain,cuttingforces，andtemperaturedistributionsintheworkpiece，toolandchip，弱well弱theresidualstressesdistributionsonthemachinedsurface．Secondly,basedontwotypicalcuttingforcepredictingmodels，namelytherigidmodelandtheflexiblemodel，anumericalsimulationprocedureisdevelopedtoevaluatecuttingfor
7、cesunderdifferentcuttingconditions．Theprecisionandvalidityofthepredictionmodelsareverifiedbythemillingforceexperimentalmeasurements．Then,asemi—artificialthermocoupledeviceisdevelopedtoexplorethedynamiccuttingtemperaturevariationrulesinhigh—speedmillingofA17050·T7451aluminumalloy．Also，
8、acutt
