Identification of damage locations based on operating deflection shape

Abstract

Vibration-based damage detection methods have attracted a lot of investigations. Damage detection using natural frequencies or mode shapes is an efficient way to detect damages in static structures, but it cannot be directly extended to operating structures. In this paper, we present a new method based on operating deflection shape (ODS). The ODS of a damaged plate-like structure excited by a harmonic force is calculated using wavelet numerical method. The performance of wavelet numerical method is verified to analyse eigenvalue problem. Based on high-performance numerical simulation, the possibility of ODS in the prediction of damage locations is then investigated. Two typical plates with damages are given and the corresponding ODS are analysed using interval wavelet transform. It is found that the predicted results are in good agreement with the actual results and noise immunity of the method is relative robustness. Moreover, the interval wavelet transform has the ability to decrease boundary distortion phenomenon for the finite-length data of ODS. The present method provides a new way to detect damages in structures for operating conditions.