An efficient solution method for train-track-tunnel coupled differential quadrature finite element dynamic model

Aiming at the complexity of train-track-tunnel system, differential quadrature finite element (DQFEM) with both P-convergence and H-convergence is used to establish a refined dynamic model of train-track-tunnel coupled system. To solve the problem of low calculation efficiency of train-track-tunnel system, this paper improves the cyclic calculation method and adopts linear superposition method to decompose the train-track system into vehicle-track system. At the same time, the infrastructure is expressed the as Green function in discrete form, and infrastructure is coupled with the train-track system by the interface interaction force. The reliability of the proposed train-track-tunnel coupled dynamic model based on DQFEM is verified by comparing with FEM model from in time- and frequency-domain. Furthermore, by comparing with the traditional solution method, the accuracy and efficiency of the proposed solution method is demonstrated. In the numerical example, the distribution of the train-track-tunnel dynamic response and the influence of the vibration isolation track is analyzed in detail. The conclusions have practical value for the design of the railway structure with vibration reduction in subway system.