Characteristics extraction of acoustic emission signal based on wavelet packet decomposition

Acoustic emission (AE) is defined as the class of phenomena whereby transient elastic wave is generated by the rapid release of energy from a localized source of damage, which is well known as a highly sensitive technique to detect various types of damage, such as crack propagation in structure. Since most information of the failure in structure is contained in AE signal, this paper attempts to study the AE more carefully based on FEM and wavelet packet decomposition (WPD). Firstly, the FEM is implemented to simulate the properties of AE source mechanism, and propagation in three different kinds of structures, including an isotropic plate, thin-walled cylinder structure, and an anisotropic plate. Then the WPD is introduced to extract the characteristics of AE signals obtained from the FE simulation. The results of this study illustrate the effectiveness of FEM to model AE wave propagation problems, and carrying out characteristics extraction of acoustic emission signals based on wavelet packet decomposition.