Abstract：In order to research the vertical dynamic interaction of low-to-medium speed (LMS) maglev train-bridge system, this study establishes two types of coupling vibration analysis models for LMS maglev train-bridge system based on two simplified maglev train models, considering (proportional–integral–derivative) PID active suspension control system and modal superposition method. The simulation models were compared and verified based on the bridge dynamic filed test in Changsha LMS maglev commercial line. Based on the simulation model of no.2, the vertical coupling vibration characteristics of LMS maglev train-bridge system were analyzed though the bridge A, B and C with different heights of girder. The research shows that simplifying the maglev train to a uniform load model can accurately simulate the actual situation. The decrease of bridge rigidity may lead to the increase of electromagnetic levitation force acting on the vehicle and the bridge, as well as larger dynamic responses of the maglev train and the bridge. The spectrum distribution of the levitation force for low-speed running is discrete, and its distribution for normal-speed running is concentrated. The resonance of LMS maglev train-bridge vertical system can be induced by the self- frequency of the levitation force, and the resonance frequency is relatively low.
