Non-Crack-Growth Acoustic Emission Observed in Controlled-Stress-Intensity-Factor High-Cycle-Fatigue Tests

Acoustic emission (AE) was monitored during stress intensity factor (SIF)-controlled high-cycle fatigue (HCF) tests on an aluminum 2024-T3 specimen with a crack growing at its center. The SIF control implemented in such manner that growth could be slowed down and even inhibited while the experiment continued. In beginning, specific type of AE signal observed allowed to grow up approximately 9.4 mm length. Subsequently, load reduced order value tip inhibit growth. signals were recorded when stopped growing, although signature these different from those as discussed text. gist phenomenon reported this article is strong still growing. These latter due rubbing clapping faying surfaces. Travel analysis consistently performed ensure originating crack, though not necessarily tip. addition, absorbing clay wave dams built around region boundary reflections grip noise. Fast Fourier Transform (FFT) Choi–Williams (CWT) classify signals. It related clearly Strong S0-mode Lamb components crack-growth signals, whereas A0-mode dominated non-crack-growth Pearson correlation clustering compare non-crack We propose fatigue-crack surfaces may undergo and/or cyclic loading thus produce are registered by system hits, actually understanding very important for design structural health monitoring (SHM) based AE-hit capture interpretation.