三维数字光弹性基本方法的研究和应用

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1、Y1532080三维数字光弹性基本方法的研究和应用Studyofthe3DDigitalPhotoelasticityMethodandItsApplication博卜学位论文一级学科：学科专业：研究生：指导教师：力学固体力学张丽娜计欣华教授天津大学机械工程学院二零零八年六月ABSTRACTPhotoelascityisaneffectivemethodtosolvetwo—dimensionalandthree—dimensionalstressanalysisinengineeringandafocustoday．Stres

2、scomponentsatanypointofthethree—dimensionalmodelcanbecalculatedbyit．Withthedevelopmentofcomputertechnique，automaticwhole—fieldmeasurementofphotoelasticityhasbeenfocused．Basedontheworkwhichwasreportedbefore，someurgentproblemsofdigitalphotoelasticityhavebeendiscussed，a

3、ndautomaticdataprocessingandstressseparationofphotoelasticityalerealized．Theproblemofisoclinicandisochromaticinteractionisimportantinphase—shiftingtechniquesinphotoelasticity．Atechniquenamedeight—stepphaseshiftingtechniqueispresentedtosolvetheproblemofisoclinicfringe

4、patterninfluencedbyisochromaticfringepattemsofintegerorderandhalf-integerorder．Isoclinicparameterintherangeof【0，州2】ofthefrozensliceisgivenbythemethod．Basedontheeight-stepphaseshiftingtechnique，threemethodstodeterminingthefirstprincipalstressdirectionoftheslicearedisc

5、ussed．1soclinicangleinformationofwhole--fieldfirstprincipal··stressdirectioncanbeanalyzedandobtainedbytworulesofarctancalculation．Thefeasibilityofthismethodwasprovedbytheexperimentsofdiskandringunderradialcompression．Theinfluenceoftimeedgeeffectisanalyzed．Onthepremis

6、eofexitingtimeedgeeffect，mechanicmodelisfoundedandprovedbysimulationandexperiment．Twomethodsforerasingtimeedgeeffectareputforwardintheexperiments．Automatictechniqueofstressseparationisdisc弩sedafterobtainingthevalueanddirectionofsecondaryprincipalstressofeveryfrozensl

7、ice．Three．dimensionalcontactstressofturbinebetweenrootsandrimsareanalyzedbythethree．dimensionaldigitalphotoelasticity．SixstresscomponentsandequivalentVonMisesstressofanypointinthemodelarecalculatedandthecontactareaofrootsandrimsarediscussed．Finally，theloadingvaluesof

8、everytoothofrimsareobtained．Three．dimensionaldigitalphotoelasticitycanbeusedwidelyinengineeringfieldandthefieldofapplicationiSwiden