Structural Damage Localization in a Suspension Bridge Under Seismic Excitation

In this paper we present the application of the Interpolation Damage Detection Method (IDDM) to the numerical model of a suspension bridge having a long span truss-stiffened deck. The method, which belongs to Level II damage identification method, can identify the presence and the location of a damage based on acceleration responses of the structure before and after a damaging event without explicit knowledge of the modal properties of the structure. Emphasis is placed on the influence of noise in recorded signals on the reliability of the results given by the IDDM method. The response of the suspension bridge to seismic excitation is computed from the model and artificially corrupted with random noise characteristic of two families of MEMS accelerometers, in order to simulate real conditions. The reliability of the results has been checked for different damage scenarios.