Dynamic interaction analysis of bridges induced by a low-to-medium–speed maglev train

Abstract

The structure of low-to-medium–speed maglev trains significantly differs from that of traditional wheel/rail trains, leading to significant differences between the coupling vibration mechanism of the train and bridge systems. To determine the vertical dynamic interaction of the low-to-medium–speed maglev train–bridge system, a dynamic interaction model was established and studied, based on a proportional–integral–derivative active suspension control system and modal superposition method. The simulation model was validated through bridge dynamic field tests on the Changsha low-to-medium–speed maglev commercial line. The vertical dynamic characteristics of the system were analyzed for bridges with different girder heights. Subsequently, the mechanism of the vertical resonance of the bridge induced by the maglev train was analyzed carefully. The results show that reducing the bridge rigidity increases the electromagnetic levitation force, thereby increasing the dynamic response. The low-speed resonance in the bridge is caused by the circulation loading frequency of the adjacent electromagnetic force, whereas the normal-speed resonance is induced by the self-frequency of the electromagnetic levitation force.