Damage location diagnosis of urban rail transit bridge based on vehicle-induced vibration responses

Abstract

For the urban rail transit bridges, vehicle load has obvious repeatability and regularity, and the vibration amplitude of the bridges under the vehicle action is much larger than that during the period of not being open to traffic, which is more conducive to the appearance of structural damage. This paper attempts to use vehicle-induced vibration responses to diagnose damages for urban rail transit bridges. Firstly, the vehicle-rail-bridge coupling finite element model was established based on the engineering background of a typical urban rail transit bridge. Then, through dynamic time history analysis, the vibration responses of bridge and vehicle before and after damage were obtained. Finally, the sensitivity to damage of acceleration responses from measuring points on both bridge and vehicle was compared, and a damage diagnosis method based on the difference of acceleration responses from different measuring points of bridge and vehicle structure was proposed. The results show that the difference of acceleration response between the measured points of bridge, wheelset and bogie before and after damage can be used to locate damage, and the vehicle-induced vibration data as a medium can provide a new way for rapid diagnosis of damage location for urban rail transit bridges.