Acousticemissionsourcelocationanddamagedetectioninametallicstructureusingagraph-theory-basedgeodesicapproach

摘要

Ageodesic-basedapproachusingLambwavesisproposedtolocatetheacousticemission(AE)sourceanddamageinanisotropicmetallicstructure.InthecaseoftheAE(passive)technique,theelasticwavestaketheshortestpathfromthesourcetothesensorarraydistributedinthestructure.ThegeodesicsarecomputedonthemeshedsurfaceofthestructureusinggraphtheorybasedonDijkstra’salgorithm.Bypropagatingthewavesinreversevirtuallyfromthesesensorsalongthegeodesicpathandbylocatingthefrstintersectionpointofthesewaves,onecangettheAEsourcelocation.Thesameapproachisextendedfordetectionofdamageinastructure.Thewaveresponsematrixofthegivensensorconfgurationforthehealthyandthedamagedstructureisobtainedexperimentally.Thehealthyanddamageresponsematrixiscomparedandtheirdifferencegivestheinformationabouttherefectionofwavesfromthedamage.Thesewavesarebackpropagatedfromthesensorsandtheabovemethodisusedtolocatethedamagebyfndingthepointwhereintersectionofgeodesicsoccurs.Inthiswork,thegeodesicapproachisshowntobesuitabletoobtainapracticablesourcelocationsolutioninamoregeneralset-uponanyarbitrarysurfacecontainingfnitediscontinuities.Experimentswereconductedonaluminumspecimensofsimpleandcomplexgeometrytovalidatethisnewmethod.