Damage detection of composite laminated structure by discrete wavelet transform and CorV method

A damage detection method under random excitation is proposed. The multiple-level discrete wavelet decomposition is first conducted to decompose the random vibration responses. The reconstructed signal of the final level which involves the lowest mode vibration is then adopted to calculate the CorV(cross correlation function amplitude vector) of the structure. The second order difference between the shift of CorVs of the intact and damaged structure is used as damage indicator. The feasibility and capability of this method are verified by numerical simulation of damage detection for a cantilevered composite laminate. In the damage detection, the superiority of the proposed method is demonstrated by comparison of damage detection results obtained using original vibration signal and the reconstructed signal respectively. The anti-noise ability of this approach is also verified by adding measuring noise into the original vibration response and the damage positions are also located correctly.