Vertical Resonance Simulation of Superconducting Electrodynamic Suspension Train/Bridge Coupled System

The superconducting electrodynamic suspension (EDS) train, with speed over 600 km/h, has the advantages of a lightweight, large suspension gap (up to 100 mm), stable suspension, etc. Therefore, it is expected to become one main form of the next generation of high-speed and ultra-high-speed manned rail transit. The bridge will vibrate and deform when the train passes through the bridge. And the vibration and deformation of the bridge will affect the dynamic response of the train as well. Therefore, the train and the bridge will form an interaction system. And under a certain running speed, train/bridge coupled resonance will occur, directly affecting the train's safety and comfort. In this article, the MLX01 superconducting EDS train is taken as the research object, established a 14-degree of freedom (DOF) dynamic model for vertical and pitching vibration analysis of a superconducting EDS train and established a single-span Euler–Bernoulli simply supported bridge. Nonlinear levitation forces connect the train and bridge subsystem to form a superconducting EDS train/bridge coupled vertical dynamic model. Simulation calculation explores the effects of train speed and bridge damping ratio on the superconducting EDS train/bridge coupled system's vertical resonance response. The results show that the train speed and the bridge's natural frequency are two main factors affecting the vertical resonance of the train/bridge. In train operation, the first resonance speed should be avoided. Increasing the damping ratio of the bridge cannot prevent the train/bridge resonance, but it can weaken the dynamic response of the bridge during resonance, and properly increasing the damping ratio of the bridge is conducive to the stability of train operation.