Damage Detection on a Cable Stayed Bridge Using Wave Propagation Analysis

Abstract : The Global Search Method (GSM) is being proposed for global evaluation of complex structures. This method is based on the analysis of the flexural wave propagation and the comparison of the real structure responses to those from a calibrated simulation model representing the non-damaged condition. Then, the differences are associated to changes in the structural parameters (stiffness, damping, mass, and geometry) or the boundary conditions, and related to a specific region or location within the structure to locate damage and quantify its overall structural effect. The effectiveness of the GSM was evaluated on a cable stayed bridge where damage was simulated when a cable was removed during rehabilitation, dynamic tests were done using a Falling Weight Deflectometer to control the dynamic impact load and previously analogous tests were done to calibrate the finite element model. Results show that the GSM has the ability to identify and quantify damage, where sensitivity increases when the sensors are closer to damage. In the bridge case, damage could not be detected when the distance of the sensors was greater than 65 meters from damage because of signal attenuation.