Locating acoustic emission sources in pseudo-triaxial experiments with the shortest path and orthogonal constraint

Acoustic waves in the pseudo-triaxial experiment system experience refraction phenomena. The conventional assumption that acoustic waves propagate along a straight line in traditional methods can lead to significant errors in localization results. To the end, this paper presents a method for locating acoustic emission (AE) sources in pseudo-triaxial experiments using shortest paths and orthogonal constraints. The approach consists of three main steps: (1) establishing control equations for refraction paths from AE sources to sensor locations; (2) calculating refraction point locations using the shortest travel principle and orthogonal constraints; (3) determining source coordinates using Taylor's first-order expansion. The results from laboratory AE experiments demonstrate that the average localization accuracy of the new method is only 6.5 mm, which is 66% more precise than the accuracy (19.4 mm) of the traditional method. Furthermore, simulation results indicate that the new method is not affected by the refraction ratio of the media and maintains the highest positioning accuracy across various arrival and velocity errors.