A Structural Damage Detection Approach Based on Response Sensitivity for Bridges Subjected to Moving Vehicles

In this paper, a model of a railway simply-supported beam bridge subjected to a moving vehicle is established. The Newmark integration method is used to calculate the dynamic response of the bridge under moving vehicle. Suppose that the flexural stiffness of the ith element of the beam decreases when damage occurs, the sensitivity of dynamic response of bridge or vehicle with respect to the damage factor is investigated. The damage can be identified by the finite element model updating method based on dynamic response sensitivity. The effects of measurement noise, measured response type and location and vehicle speed on the identified results are discussed. It is found that the damages can be identified successfully and accurately by only a few measured accelerations. The proposed detection approach is insensitive to measurement noise and train speed, and the acceleration measurement seems to give better identified results than displacement measurement.