Abstract: The full wave form acquisition of acoustic emission (AE) signal provides the possibility of source location based on waveform analysis. The time differences between several sensors are commonly used for AE source location; and the accuracy of time differences has a direct influence on the location accuracy. Based on the wavelet transform cross correlation, the time delay estimation of AE signal is studied. Firstly, through wavelet analysis, signals are decomposed into a series of time-domain signals, each of which covers a specific octave frequency band. Then, the frequency band of meaningful signals were ascertained, based on which the wavelet coefficients of corresponding frequency band after being decomposed were extracted. Finally, the method of cross correlation was applied to reconstruct the signals, to calculate the arrival time of AE waves and to locate the AE source. The results indicate that: compared with the AE monitoring experimental results, the newly proposed AE location method using cross correlation based on wavelet transform can effectively improve the location accuracy of AE source; so as to provide an effective way for AE source inversion.

Key words: wavelet transform, acoustic emission (AE), cross correlation technique, time delay estimation, source location