Damage Localization of Bridge in the Presence of Road Profile using Vibration Measurement of the Passing Vehicle

Direct damage localization of bridge involves the use of a large number of vibration sensors on the structure, which is often costly and time-consuming. Through vehicle bridge interaction, dynamic response of a passing vehicle includes the bridge response which may be used for extracting bridge modal parameters. In this paper, transmissibility measurement of the vehicle response is dedicated to localize indirectly the bridge damage. As the sensor is embedded on the axle of the vehicle, recording the signal is fulfilled during the vehicle passage and there is no need to stop the vehicle. There is white noise assumption in most other techniques. But excitation characteristics are not considered in this method; which is another advantage. Since the road profile may cause modal parameter identification to be difficult, subtracting the acceleration signals from two identical axles is used here in order to remove the influence of road profile. In the numerical simulation by finite element method, the bridge model is accompanied by road profile and three vehicles are assumed to be 2DOF systems of mass-spring-damper. By solving the vehicle-bridge interaction equations simultaneously and then removing the effect of road profile, the estimation of bridge mode shape would be possible. Then, by considering bridge damage, the vehicle-bridge interaction equations are solved once more and the damage localization is fulfilled using the changes in the mode shape curvature. Results of numerical simulations indicated the capability of the proposed method in the presence of measured noise.