A NEW DAMAGE INDEX FOR STRUCTURAL DAMAGE IDENTIFICATION BY MEANS OF WAVELET RESIDUAL FORCE

In this paper a new method is presented for structural damage identification. First, the damaged structure is excited by short duration impact acceleration and then, the recorded structural displacement time history responses under free vibration conditions are analyzed by Continuous Wavelet Transform (CWT) and Wavelet Residual Force (WRF) is calculated. Finally, an effective damage-sensitive index is proposed to localize structural damage with a high level of accuracy. The presented method is applied to three numerical examples, namely a fifteen-story shear frame, a concrete cantilever beam and a four-story, two-bay plane steel frame, under different damage patterns, to detect structural damage either in free noise or noisy states. In addition, some comparative studies are carried out to compare the presented index with other relative indices. Obtained results, not only illustrate the good performance of the presented approach for damage identification in engineering structures, but also introduce it as a stable and viable strategy especially when the input data are contaminated with different levels of random noises.