Analysis of AE signals by wavelet transform
Ni Qing Qing; Misada Yasuharu
Abstract:The analysis of acoustic emission (AE) signals is presented by using the wavelet transform, which is a representative method of the time frequency analysis, and its properties are discussed. Five analyzing wavelets are used in order to obtain the best suitable one for AE signals. It is shown that Gabor wavelet can make a good decomposition of AE signals, and gives the peaks of frequency that are in good agreement with the results by Fourier analysis. The properly spaced intervals for sampling AE signals are obtained. Furthermore, the analysis using Gabor wavelet provides much time information, such as microfracture time, relation of matrix cracking and fiber break at a fiber break age, etc., which are impossible to be evaluated by Fourier analysis. Key Words:wavelet transform, acoustic emission, frequency, fracture, spectrum, composites