Random vibration analysis of coupled vehicle-bridge systems

This paper investigates the random responses of a coupled vehicle-bridge system due to track irregularities. The train model consists of 9 vehicles, and each vehicle is constructed by a rigid body, two bogies and four wheels, while the bridge is modeled by three-dimensional Euler beam elements. The equations of motion of the train and bridge are built respectively. Based on the displacement compatibility condition of the interface with track irregularities, the equation of motion of the coupled system can be achieved by eliminating the dependent DOFs. When the track irregularities are regarded as stationary random processes, the stochastic analysis of the coupled system is carried out by using pseudo-excitation method (PEM), and a mean extreme value estimation of the non-stationary responses is proposed. In the numerical example, the results are compared with those obtained by the Monte Carlo method. The influence of the rail roughness on the vehicle and bridge coupled system were discussed, and the variation of the mean extreme value of the responses with moving speed is preliminarily explored.