Localization of Acoustic Emission Source in Plates Using Wavelet Transform

Acoustic Emission (AE) techniques for crack detection, leak andloose part monitoring in different engineering applications are gaining muchinterest due to their potential capabilities for online detection without theneed of operational shutdown. However, many issues remain challenging toimplement this technique efficiently in industrial setting. This paper presentsan implementation of this technique to detect an acoustic emission source in plateswith different materials and geometrical configurations. The time of arrival (TOA)for lamb wave fundamental modes S0 and A0 wereexperimentally determined using a pencil-lead break test. Moreover, time-frequencyanalysis was conducted and group velocity dispersion curves were overplayed to clearlyidentify the modes of the acoustic emission (AE) signal and locate its source.For relatively larger plates, the wavelet transform (WT) analysis shows theability of this technique to identify the time of arrival (TOA) of wave modesgiving an acceptable accuracy in source localization. However, the wavelettransform (WT) analysis of relatively smaller plates shows some difficulties toidentify the characteristics of the acoustic emission signal due to reflection ofthe acoustic emission wave at the plate edges. A summary of the results ispresented in this paper.