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《復(fù)合材料層合板lamb波脫層缺陷檢測分析-(5742)》由會員上傳分享，免費在線閱讀，更多相關(guān)內(nèi)容在行業(yè)資料-天天文庫。
1、重慶大學(xué)碩士學(xué)位論文II英文摘要ABSTRACTWiththerapiddevelopmentofindustrialtechnology,therequirementsforengineeringapplicationmaterialpropertiesarebecomingincreasinglyhigher.Compositeiswidelyusedinindustrialfieldbecauseoftheadvantageofhigherstrength,biggerelasticitymodulusandlighterquality.
2、Thehealthofcompositestructuresisdirectlyrelatedtotheintegrityandsecurityofsystem.Inthecompositelaminates,themostcommondefectsarefiberbreakage,matrixcrack,anddelaminationandthemostdifficultforexaminationistheinternaldelamination,andthisdefectseriouslyaffectsthecharacteristics
3、ofthecompositematerial.Meanwhile,itbearssafetyrisksduringitsusage.Therearemanylargeaccidentsmadebydelaminationinhomeandabroad.Therefore,delaminationexaminationtothecompositematerialisverysignificant.ThispaperusingLambwavetoexaminedelaminationdefects,analyzingthepropagationpr
4、incipleofLambwaveinthecompositeandconductingfiniteelementsimulation,usingthetimereversalmethodandwaveletanalysismethodtoachievefreebaselinepurpose,anddisplayingcompositedelaminationdefectsintwo-dimensionalimageaccordingtoprobabilityimaging.Firstly,thispaperstudiespropagation
5、theoryequationandthedetectingprincipleofLambwaveinthecompositeplate,obtainsthedisperseequation,drawsoutthedispersioncurves,makesthedetailedtheoreticalanalysisaboutthetimereversalmethod（TRP）,andestablishesfreebaselinedelaminationexaminationbasiswithTRPprincipleandwaveletanaly
6、sismethod.Byanalyzingthefocusingsignalaftertimereversalprocessingandcomparingthedifferencebetweentheoriginalinputsignalsandfocusingsignal,weproposetime-reversefocusedpropertyevaluationindexesaboutthefocusingsignalsandwaveletothernesscoefficientevaluationindexes,andtheywillbe
7、usedasanimportantparameterinimagingdamageinthefollowingsection.Basedonthestudyabouttheorymethod,byusingthefiniteelementanalysissoftwareABAQUS,webuildthepropagationmodelofLambwaveincompositeplate,thencarryoutdeepstudyonthepropagationcharacteristicsofguidedwavesontheIII重慶大學(xué)碩士學(xué)
8、位論文one-dimensionalLinepropagationmodelandtwo-dimensionalPlanepropagationmod
