A study of the Acoustic Emission simulation method: addressing the issue of dimensionality in the propagation medium modeling

Abstract

A reliable numerical reproduction of acoustic emission (AE) tests requires a clear understanding of simulating the AE process. Here, we perform a comparative study of Pencil-Lead Break (PLB) tests on polymethyl methacrylate (PMMA) plates using two-dimensional (2D) and three-dimensional (3D) finite element models, with emphasis on how the propagation medium is represented. A Hsu–Nielsen source is applied at the plate center, and responses are recorded at multiple locations along the plate symmetry axis. Sensors are modeled as perfect-contact sensors, neglecting the sensor effect. Thus, a 2D model with an axisymmetry assumption can be established only to reproduce the direct-wave response. While 2D modeling greatly reduces computational cost, particularly for large plates whose in-plane dimensions far exceed thickness, noticeable discrepancies arise between 2D- and 3D-simulated signals. The direct waveforms are highly consistent, but differences appear after the direct-wave arrival. To clarify the origin of these discrepancies, we investigate the influences of plate size and geometry, mesh configuration, and sensor–source distance. In addition, we evaluate commonly used AE features to identify conditions under which 2D simulations remain valid. These findings provide practical guidance on the limitations and appropriate use of 2D models for interpreting PLB-based AE responses.