Baseline-free damage localization of structures under unknown seismic excitations based on strain transmissibility and wavelet transform of strain mode

Abstract

The necessity of baseline data in current damage detection methodologies limits their applications in practice, so it is essential to implement baseline-free damage detection of structures. In this paper, a baseline-free damage detection method is proposed based on the combination of structural strain transmissibility and wavelet transform of strain mode shape. First, the strain mode shape of a structure is identified based on the transmissibility of structural strain responses under seismic excitation. Then, by considering the sensitivity of wavelet analysis to the abrupt-change signal, the strain mode shape abnormality at the damage location is amplified by wavelet transform to accomplish damage detection. Two numerical simulation examples for structural damage detection have demonstrated the proposed method. Moreover, a structural damage detection experiment of a lab cable-stayed bridge tower model under shaking table also verified the proposed method.