Current Practice and Applications of Acoustic Emission

Abstract

Acoustic emission (AE) is a technique that is often misunderstood and misrepresented, but is fast emerging as a powerful method in terms of damage assessment and structural health monitoring (SHM). Early pioneers of the technique during the late 196O’s through to the early 1980’s such as Dunegan, Pollock, Wadley, Scruby, Birchon, Schofield, Beattie, Proctor, Harris and Ono produced outstanding scientific analyses despite the limitation of their equipment and indeed many of today’s researchers are revisiting this work. AE is currently experiencing an increase in popularity due to recent advances in high-speed digital waveform-based AE instrumentation which permits vast numbers of AE waveform signals to be digitised and stored for analysis. Coupled with improvements in high fidelity, high sensitivity broadband sensors and the development of advanced PC based signal analysis software; these advances have given rise to recent work that has been directed at an enhanced understanding of AE signal propagation in terms of guided acoustic modes. The approach, more recently designated “Modal Acoustic Emission”, offers the potential to depart from the traditional reliance on statistical analysis and significantly improve the structural monitoring capabilities of AE.