桿狀構(gòu)件導(dǎo)波檢測(cè)的有限元模擬.pdf

1、華中科技大學(xué)碩士學(xué)位論文桿狀構(gòu)件導(dǎo)波檢測(cè)的有限元模擬姓名：陳衛(wèi)東申請(qǐng)學(xué)位級(jí)別：碩士專(zhuān)業(yè)：測(cè)試計(jì)量技術(shù)及儀器指導(dǎo)教師：武新軍康宜華20090509II華中科技大學(xué)碩士學(xué)位論文AbstractTheguidedwavestechnologyhasbecamearesearchfocusasitcaninspectoverlongdistancefromasingleposition.ThethesisissupptedbyNationalH

2、ighTechnologyResearchDevelopmentProgramofChina.Indertoprovideabasisfthedevelopmentofguidedwavesinspectionsystemanalysisofsignalrecognitionguidedwavesintherodshapedcomponentsisdetailedinvestigatedwiththefiniteelementmodel

3、ing.TheacteristicsofguidedwavesintherodshapedcomponentsisanalyzedwhichshowsthatbetterdetectionresultscanbeachievedwhenusingL(01)modeoflowfrequencies.Thefiniteelementmodelingofguidedwavesisdiscussedindetail.Throughcompari

4、ngofthethreemodelstheprincipleofmodelionispresented.Theexcitationreceptionofdifferentmodewavesisalsoproposed.Thesecondpartfocusesonthedetectionofdefectsinrodshapedcomponents.Thecrackdetectionofasteelrodissimulatedwhosere

5、sultscoincidewithexperimentalresultsshowingthatthefiniteelementmodelingofguidedwavesdetectioninrodshapedcomponentsisfeasible.Thentheeffectofdepthaxialextentcircumferentialextentofdefectsinrodshapedcomponentsisdetailedsim

6、ulatedwhichprovidesomeusefulresultsfthequantitativeevaluationofdefects.Thelastpartofthisthesisstudiesguidedwavespropagationindefmedrodshapedcomponents.Thesimulationresultsshowthatbendsoftherodshapedcomponentswouldarouses

7、mallechoes.Thedegreeofbendingcouldbeidentifiedbythesizeofechoesthebendinglengthcanbedeterminedbythetimeoftheechoeslast.Theclearechoescausedbydiameterchangedstructuresofrodshapedcomponentsindicatethatdiameterchangedstruct

8、uresmakeagreatimpactonthepropagationofguidedwaves.Furtheranalysisshowsthatdefectsinrodshapedcomponentscouldbemeclearlyidentifiedbythetimetheechoesreached.Keywds:GuidedWavesRodshapedComponentsFiniteElementModelingNonDestr