EXPERIMENTAL STUDIES ON DAMAGE LOCATION OF THE LONG-SPAN TRUSS STEEL BRIDGE MODEL BASED ON SDLV METHOD UNDER AMBIENT EXCITATION

According to the truss steel bridges employed in China, a simply supported truss steel bridge model has been built for health monitoring. A simple FEM was established with Matlab as the reference numerical model based on the perfect match of the first several modal parameters with the results of the experiment. The accelerations of the damaged bridge at the sensor locations are collected from sensors installed on the nodes of model while the accelerations of the undamaged bridge are obtained from the Matlab reference model. The modal parameters were obtained using NeXT-ERA method. Elements between sensors were identified using the Stochastic Damage Locating Vector method. Simulation of multi-damage case and experiment of single damage case were performed respectively, and the results of them obviously indicated that the method was effective when the extent of damage reached a certain level. At last, preliminary studies about accurate damage location were introduced.