Coupling Vibration Model of Wind-train-track-bridge System

A coupling dynamic analysis model of wind-vehicle-track-bridge(WTTB) system is presented in this paper in the time domain. In the model, wind is regarded as a stationary stochastic process. The vehicle is regarded as the multiple rigid body system, and all kinds of movements of the car body, bogie and wheel-set and various sorts of non-linear factors in vehicle suspension system are fully considered. The rails are modeled as Euler beams supported by a discrete-elastic foundation of three layers with sleepers and ballasts included. The bridge is modeled through finite element method using different kinds of finite elements such as beam elements, truss elements, plate element, and others. Fluctuating wind velocity and track irregularities are the most important excitations for the WTTB system. An explicit-implicit hybrid dynamic integration method is introduced and a computational program WTTBDAS is developed. The proposed framework is finally applied to vehicles moving on the railway long-span bridge under in cross-wind. The dynamic responses of the bridge, the track and the vehicles in cross winds are calculated. The dynamic responses of bridge, vehicle and track subsystem is analyzed and discussed under different wind loads case, respectively. The results demonstrate that the wind loads acting on the vehicles have significant influence on the dynamic responses of WTTB system and the wind loads acting on the bridge have great influence on the dynamic responses of bridge but little influence on the dynamic responses of train and track subsystem. The mean and turbulent winds should be taken into account in the dynamic analysis of WTTB system.