Parallel Co-Simulation Method for Railway Vehicle-Track Dynamics

Abstract

This paper introduces a new parallel co-simulation method to study vehicle-track dynamic interactions. The new method uses the transmission control protocol/internet protocol (TCP/IP) to enable co-simulation between a detailed in-house track dynamics simulation package and a commercial vehicle system dynamics simulation package. The exchanged information are wheel-rail contact forces and rail kinematics. Then, the message passing interface (MPI) technique is used to enable the model to process track dynamics simulations and vehicle dynamics simulations in parallel. The parallel co-simulation technique has multiple advantages: (1) access to the advantages of both in-house and commercial simulation packages; (2) new model parts can be easily added in as new parallel processes; and (3) saving of computing time. The original track model used in this paper was significantly improved in terms of computing speed. The improved model is now more than ten times faster than the original model. Two simulations were conducted to model a locomotive negotiating a section of track with and without unsupported sleepers. The results show that the vertical rail deflections, wheel-rail contact forces and vehicle suspension forces are evidently larger when unsupported sleepers are present. The simulations have demonstrated the effectiveness of the proposed parallel co-simulation method for vehicle-track dynamic interaction studies.