VIBRATION OF COUPLED TRAIN AND LONG SPAN BRIDGE SYSTEM UNDER WIND ACTION

A framework for performing dynamic analysis of coupled train and long span bridge system under wind action is presented in this paper. A dynamic model of wind-train-bridge system is established, in which 27-degrees-of-freedom are considered for the 4-axle train, and the modal superposition technique is adopted for the bridge model. The wind forces, including steady-state, buffeting and self-excited forces acting on the bridge, and steady-state, buffeting ones acting on the train, are generated in time domain using computer simulation techniques. The proposed framework is then applied to a real long span steel truss arch bridge with a train composed of two locomotives and 5 passenger coaches under wind action. The histories of dynamic response with and without wind loads are drawn for comparing, and the three dimensional responses of train-bridge system versus train speed and wind velocity are shown. The results show that wind has great influences on the train-bridge system, to which great attention should be paid.