Analysis of Acoustic Emission Output from Propagating Fatigue Crack

Acoustic emission (AE) is a very useful approach in detecting and characterizing fatigue damage growth in general and crack initiation and propagation in particular. Numerous studies have been conducted dealing with correlations of AE output and fracture mechanics and fatigue damage parameters [1–9]. It has been shown that under monotonie loading AE can detect yielding and that the cumulative AE output from a notched specimen is directly related to the stress intensity factor [10]. However, such correlations between AE and damage may not be easy to establish because of the influence of loading, material, geometric and noise factors. In application of the AE method, discrimination between signal and noise is of paramount importance.