Wave propagation based damage detection and localization

摘要

This paper presents damage localization methodologies using local or wave propagation based techniques.First,a smart layer for damage detection and localization is described.The smart layer consists of a matrix of piezoelectric elements which are driven in the pulse-echomode.This smart layer can be used formonitoring thickness changes and delaminations in composite materials.Secondly,a laser-based method for detecting and localizing of discontinuities in panels is discussed.Specifically,Lamb waves in thin plates are generated and detected using laser ultrasonics.The location and relative size of the discontinuity is determined via a signal processing procedure involving a time-frequency-representation and a special correlation applied in the group velocityfrequency domain.Finally,an autonomous technique for monitoring of overhead transmission lines based on guided waves is presented.