Hybrid Dynamics Model of the Train–Rail–Bridge System Based on the Transfer Matrix Method.

The traditional dynamic analysis method is less efficient in the global and local vibrations analysis of long-span bridge structures. Therefore, to meet the need for an efficient solution of the refined analysis model of the train–track–bridge coupled system (TTBCS), a new hybrid dynamic model of the TTBCS based on the transfer matrix method (TMM) is proposed in this paper. It can solve the local high-frequency vibration response of the track structure and the global and local vibrations responses of the bridge structure simultaneously, accurately, and efficiently. First, according to the periodic characteristics of track and bridge structure, the periodic repeating parts are divided into cellular structures. For the bridge subsystem, fine cells are established to achieve the accurate solution of local vibration, and the rest of the super element cells are established by model condensation technology, which can significantly reduce the number of cells and save the transmission time. The state vector transfer model of the track and bridge subsystem is established based on the TMM, and the coupling calculation is realized by combining rail bridge force. The train system adopts the model of 10 degrees of freedom and realizes the coupling with the rail system through the wheel–rail interaction force. With the movement of train load, the track and bridge cells established by the hybrid dynamic model approach (HMA) dynamically update the arrangement information, which not only realizes the calculation of ultra-long track based on a fixed number of track cells, but also moves the fine cell models of bridge with the change of load position. These dynamic update measures reduce both the number of cells and transfer solutions, save the transfer time, and further improve the calculation efficiency. Taking CRH-2 EMU passing through a 3-span simply supported steel truss bridge as an example, the results and time-consuming of the direct stiffness method, TMM, and HMA are compared, and the accuracy and efficiency of the hybrid model are proved. [ABSTRACT FROM AUTHOR]