Simultaneous Localization and Classification of Acoustic Emission Sources in Plates using a Guided Wave-Based Sparse Reconstruction

Abstract

This paper presents an approach for localizing and classifying acoustic emission (AE) events in isotropic plate-like structures. A sparse reconstruction method is used to extract the parameters of a modeled AE event that best describe a recorded AE event. Here, the location and A0/S0 amplitude ratio at the source of the AE event are extracted. A classification based on the amplitude ratio is used to determine if an event is out-of-plane (OP) or in-plane (IP). The orientation (OP or IP) may be used to infer the damage mechanism; for instance, impact or crack. By extracting the amplitude ratio at the source, any propagation effects are removed, which yields a more accurate evaluation of the source orientation. This is in contrast to previous studies that measure this parameter at a distance from the source. The approach is validated through experimentally simulated AE events in an aluminum plate. Events are simulated using pencil lead breaks on both the plate surface and the cross-section of the plate edge to generate OP and IP motions. The ability to both localize and classify the two cases of simulated events is demonstrated. Lastly, the approach is shown to be computationally efficient, taking on the order of 1 second to run on a desktop computer.