Vibration of coupled train and cable-stayed bridge systems in cross winds

This paper presents a framework for performing dynamic analysis of coupled train and cable-stayed bridge systems in cross winds. A three-dimensional finite element model is used to represent a long span cable-stayed bridge with a highway at the upper level and two railway tracks at the lower level of the bridge deck. Wind forces acting on the bridge, including both buffeting and self-excited forces, are generated in the time domain using a fast spectral representation method and measured aerodynamic coefficients and flutter derivatives. Each 4-axle vehicle in a train is modeled by a 27-degrees-of-freedom dynamic system. Wind forces acting on the train, including both steady and unsteady aerodynamic forces, are simulated in the time domain, taking into account the effects of vehicle speed and the spatial correlation with wind forces on the bridge. The dynamic interaction between the bridge and train is realized through the contact forces between the wheels and track with track irregularities and wheel hunting included. The proposed framework is then applied to a real long span cable-stayed bridge with a train consisting of two locomotives and 10 passenger coaches in cross winds. The results demonstrate that the proposed framework and the associated computer program can efficiently predict the dynamic response of coupled train and cable-stayed bridge systems subjected to cross winds.