Analytical Method for Calculating Dynamic Response of Coupled Train-Bridge System Based on Duhamel Integral

In order to shorten the computation time of solving the dynamic response of a coupled train-bridge system, the modal decomposition method is used to decompose the train subsystem and bridge subsystem in the coupled system. Assuming that the vehicle-bridge interaction forces change linearly within each time step, the dynamic response of the system during this period is obtained by Duhamel integral. Based on this theory, a new method is proposed to analyze the dynamic response of the coupled train-bridge system. The proposed method is then used to analyze a 4-axle train passing through a 32 m simply-supported beam at a constant speed. The results show that the dynamic responses obtained by the proposed method for the coupled train-bridge system are very close to those obtained by the Newmark-β method, and the relative error at every extreme points is less than 1%. Compared with the Newmark-β method, the proposed method can increase the time interval of integration by at least 5-10 times while ensuring the precision.