Effect of load redistribution of a steel truss bridge due to fracture of a truss member on vibration-based fault detection

摘要

This study is intended to investigate how damage in a steel truss member results in load redistribution and the fault detection from the traffic-induced vibration data of the bridge. A damage experiment is carried out on a real nine-span-continuous steel-truss bridge. Stress redistribution of truss members due to cut in a diagonal member was observed under live load as well as dead load. Frequencies and damping constants led to a low fault-detection performance. Nonetheless there exists a possibility to detect a fault utilizing changes in frequencies and damping constants, of which success substantially varies amongmodes. On the other handan improved performance in fault detection was observed by the damage-sensitive feature derived from linear system parameters of an AR model.