Structural damage assessment based on spatial analysis of wavelet packet signature

A damage identification technique based on spatial analysis of wavelet packet signature (WPS) was proposed, which requires that the acceleration responses before and after damage have been beforehand available. The square ratio of the WPS was calculated through a proper level of wavelet packet analysis. The spatial curvature index of square ratio was computed to judge the damage location in the model. A numerical example of a simply-supported beam was presented for verification. The results show the spatial curvature index can be used to locate both single and multiple damages existing in the structure. The reliability of the index is not affected even at the presence of 30dB measurement noise. An experimental study on a simply supported beam was conducted and the test results validate the effectiveness of the method.