Experimental verification of acoustic source localization technique in heterogeneous plates

Acoustic source localization (ASL) in a structure by analyzing the recorded signals at the receivers is an important process in nondestructive testing for various applications. In spite of recent research advances on this topic some challenges still remain when the plate becomes heterogeneous. Heterogeneous structures are found in natural materials as well as in engineered synthetic materials. The wave propagation direction deviates from a straight line when it propagates through a heterogeneous structure due to refraction at the interface. This paper combines the law of refraction and TDOA technique to localize the acoustic source. No complicated nonlinear equation solution is required and thus it avoids the problem of multiplicity and wrong solution. The process of acoustic emission source localization is fast and easy for structural health monitoring. Positioning a set of sensor clusters in every one of different media media constituting the heterogeneous structure is required. It enables acoustic source localization in a heterogeneous plate of unknown material properties. The technique works well for homogeneous and multi-layered heterogeneous plate structures. The experiment results show that the new acoustic source localization technique of heterogeneous plate can localize the acoustic source accurately.