基于應力波和時頻分析的復合材料結(jié)構(gòu)損傷監(jiān)測和識別.pdf

1、南京航空航天大學碩士學位論文基于應力波和時頻分析的復合材料結(jié)構(gòu)損傷監(jiān)測和識別姓名：嚴剛申請學位級別：碩士專業(yè)：飛行器設(shè)計指導教師：周麗20051201基于應力波和時頻分析的復合材料結(jié)構(gòu)損傷監(jiān)測和識別iiAbstractAbstractOneofthecriticaltasksintheresearchofstructuralintegrityffuture’saircraftistocontinuouslyonlinemonitthea

2、dvancedcompositestructurein(near)realtime.Thisstudypresentsapreliminarystudyonthepiezoelectricbasedbuiltinstructuralhealthmonitingsystemwhichcanbeintegratedseamlesslyintothecompositestructure.Adamagedetectionidentificati

3、onmethodusingLambwavestimefrequencyanalysisisproposedfcontinuouslymonitingofcompositesdetectingthedamageinnearrealtimelocalizingitaccuratelysizingitapproximatelyvisualizingitfinally.InthisstudyLambwavespropagatinginaniso

4、tropiclaminatesarefirstmodeledanalyticallyusinghigherderplatetheythedirectiondependentdispersionrelationsofthewavesareestablished.Finiteelementanalysisisemployedtosimulatethewavepropagationinanisotropiccompositestructure

5、.Wavelettransfmisappliedtothewavesignalsactuatedsensedbypiezoelectrictransducersinthetimefrequencydomaintoextracttheacteristicinfmationsuchastimearrivaltomeasuretheactualwavegroupvelocitiespropagatingincompositelaminates

6、comparethemwiththeresultsgivenbyplatethey.Combinedwiththetheeticallycomputedactuallymeasuredwavevelocityageicalgithmsoptimizationtechniqueisemployedtoidentifythelocationsizeofthedamage.Adamageimagingapproachisadoptedimpr

7、ovedtoimagethedamage.Theapplicabilityeffectivenessoftheproposedmethodisdemonstratedbyexperimentalstudies.ThisresearchissupptedbytheNationalNaturalScienceFoundationofChinaunderGrantNo.10572058bytheScienceFoundationofAeron