A novel multi-segment path analysis-based technique for acoustic emission source localization in complex solid media

Abstract

Abstract. FastWay is a novel method for source localization of acoustic emissions (AE) in complex solid media. It uses the fastest, rather than the shortest wave path between the AE source and the recording sensors. In this paper we investigate the potential of this method for acoustic emission source localization in concrete structures. To consider the influence on the wave propagation of both the concrete heterogeneity and the possible cracks present in the tested specimen, a heterogeneous velocity model was selected and a multi-segment path analysis based on this model was performed. After validating the model numerically using simulated AE sources, laboratory experiments were conducted on a small concrete beam (152 mm × 152 mm × 533 mm) with a predefined notch cut to serve as a material discontinuity (crack). Artificial AE sources using pencil-lead breaks were applied on a 25.4 mm × 25.4 point grid mapped on the surface of the beam. To evaluate the performance of FastWay, a set of sources randomly selected were picked and localization results using both FastWay and Geiger's method compared. The results obtained show that FastWay performs more reliably and accurately than Geiger's algorithm even in the presence of cracks and air inclusions. No major influence of these two factors was seen on the localization results. The influence considered the most crucial, however, is of the velocity model which strongly depends on the complex internal structure of the tested specimen.