Acoustic Emission Crack Localization: 2D Grid-Search Inversion

Acoustic emission (AE) testing listens for the elastic wave bursts that damage itself releases — crack growth, fibre fracture, dislocation slip — and localizes the source purely from when each sensor hears it. This 2D companion to the 3D acoustic-emission simulator keeps the same real time-difference-of-arrival physics but computes it independently: the elastic burst's amplitude is modelled explicitly with 2D cylindrical spreading and material attenuation, so a weaker or more distant arrival crosses each sensor's fixed detection threshold late — a systematic bias distinct from random timing jitter — and can even drop out entirely if attenuation is high enough. Instead of the 3D version's closed-form linear solve, the source position here is recovered with a coarse-to-fine brute-force grid search over the candidate-position residual, the same class of nonlinear inversion real multi-sensor AE and seismic-location systems fall back on when more than the minimum number of sensors are in play. A dedicated arrival-time-vs-distance strip beneath the map — a genuinely 2D-native diagnostic with no 3D equivalent — makes the detection-latency bias visible as a graph, not just a localization-error number.