A numerical study of Lamb wave localisation in thin plates using a passive co-linear phased array

Abstract

Lamb waves have become increasingly popular in the field of aerospace vehicle non-destructive testing and evaluation as well as structural health monitoring. These guided waves possess the ability to travel long distances and exhibit a notable inclination to interact with existing damage. This work has numerically explored the use of a passive co-linear phased array to localise emission sources over a wide range of variables. Three localisation methods are explored, namely, reverse beamforming, wavefront curvature ranging, and hyperbolic lateration. It was shown that both reverse beamforming and wavefront curvature ranging could localise an emission with <1% error in both range and bearing, while hyperbolic lateration was significantly worse. A relationship between bearing error and bearing was demonstrated, presenting the ability to develop new methods with correction factors that can localise emissions with even greater accuracy.