Dynamic Analysis of Multi-layer Beam Structure of Rail Track System Under a Moving Load Based on Mode Decomposition

In this study, the dynamic responses of railway track multi-layer beam structure system under a moving load, which is connected by Winkler springs, are analyzed. It is noted that since track structure beams with consistent boundary conditions in mathematical sense have the same mode, the mode decomposition can be carried out in the same way. By adopting this approach, the dynamic coupling equations of track structure multi-layer beam system with the same vibration mode under a moving load can be decoupled. The closed vibration solutions of the displacement of the beams at each layer of the track system are presented and some are obtained by observing the form of solutions. The track structure multi-storey beam system model can be further used in the analysis of track system structural displacement, as well as the high-speed railway system and railway-bridge coupled system dynamics. It is found that the multi-layer system of CRTS-II simply supported beam bridge system and CRTS-II track system can be degenerated into triple simply supported beams with Winkler connection and double free beams on Winkler foundation, which is of great significance to engineering practice.