Damage identification based on wavelet packet analysis method

A new structure damage identification method is proposed based on wavelet packet analysis of the time domain response. It is known that the distribution of the wavelet packet node energy of response varies if the structure is damaged. The presented identification approach considers the variation rate of variance (VRV) of each node energy distribution as the damage detection index. Through decompositions of the time domain responses of intact and damaged structures using the wavelet packet transformation, the location and the degree of damage in the structure can be identified. Both the simulated and experimental studies on damage identifications are carried out for beam structure with crack based on the proposed method. The identification results show that the presented method is able to identify damages more accurately in the case of noise contamination compared with the previous methods.