Damage detection in a bridge structure under traffic loads

Abstract

This paper proposes a damage detection approach for a structure under moving vehicular loads. The dynamic response reconstruction technique in the wavelet domain is extended in the scenario where a structure is subject to moving vehicular loads. The transmissibility matrix between two sets of response vectors of the structure is formulated using the unit impulse response function in the wavelet domain with the moving loads at different locations. Measured acceleration responses from the structure in the damaged state are used for the identification and the damage detection procedure is conducted without the knowledge of the time-histories of the moving loads and properties of the moving vehicle. A dynamic response sensitivity-based method is used for the structural damage identification and the adaptive Tikhonov regularization technique is adopted to improve the identification results when noise effect is included in the measurements. Numerical studies on a three-dimensional box-section girder subject to a two-axle three-dimensional vehicle are conducted to validate the proposed approach of damage identification of a structure under moving loads. The simulated damage can be effectively identified even with 10% noise in the measurements.