An Efficient Iterative Method for Vehicle-Track Nonlinear Coupled Dynamic Analysis Based on Explicit and Implicit Algorithms

This paper aims to study the dynamic response of nonlinear vehicle-track coupled systems, accounting for the coupling of nonlinear wheel-rail contact forces.

We presents an efficient iterative solution method based on implicit-explicit integration algorithms, by which can adjust the positions of the vehicle subsystem and the dynamic response matrix of the track subsystem. Both relaxation and Aitken acceleration techniques are adopted to iteratively update. The computational accuracy of the proposed method is confirmed by the results in literature.

Results reveal that acceleration convergence methods enhances both computational efficiency and iterative calculation stability. The relaxation method is found to be sensitive to the relaxation factor, and an optimal range of 0.6 ~ 0.8 is determined, while Aitken acceleration method generally exhibit a stable convergence. Besides, the proposed method is easy to implement, and feasible in handling multi-vehicle formations and long-term vehicle operations.

The study on the influence of the number for vehicle marshalling on the wheel pair acceleration, wheel-rail force and rail acceleration reveals it is reasonable to set the number of vehicle marshalling as 1 to ensure computational accuracy to simplify coupling system.