TRAIN-BRIDGE INTERACTION ANALYSIS OF LINEAR INDUCTION MOTOR DRIVEN TRANSIT SYSTEM

Linear Induction Motor driven transit system (LIM system) has many merits and it has potential to be developed in cities. Based on the analysis of the electromagnetic force generated by the vehicle motor, a dynamic model for analyzing the vibrations of the LIM train-bridge system is established. Taking a 3-span simply-supported bridge as an engineering background, the dynamic responses of the LIM train-bridge system are calculated using a specific computer program. Then the vibration influences of different operating conditions on the LIM system are discussed and the dynamic performances of the LIM train and the bridge are evaluated. The calculated results show that the track irregularities influence the electromagnetic force of the the axle suspending LIM train significantly. In addition, the setting of the electromagnetic gap, the value and the direction of the electromagnetic force, and the vehicle speed have definite influences on the dynamic responses, especially the vertical vibrations of the train-bridge system. When the LIM train is passing the bridge, the dynamic performance indices of the vehicles meet the requirements of the running safety and stability, and the dynamic performance indices of the bridge meet the requirements of the criterion too.