Train braking simulation with wheel-rail adhesion model

Abstract

This paper modelled the vehicles in conventional Longitudinal Train Dynamics (LTD) as 2D models that considers suspensions and wheel-rail contact. The Polach model was used as the adhesion model for faster computing speeds. A 2D train model was developed and solved using a parallel computing technique called Message Passing Interface. A train with the configuration of 1 locomotive + 120 wagons + 1 locomotive + 120 wagons was simulated in three different braking scenarios: emergency brake, full-service brake and minimum service brake. The same simulations were also conducted using a LTD model and the results are compared with those of the 2D train model. The comparisons indicate that: (1) wheelset rotational inertia needs to be considered in LTD models to achieve matched results with the 2D train model; (2) in most cases, simulated coupler forces from the 2D train model are slightly lower than those from the LTD model; (3) during minimum service brake and full-service brake, the differences of simulated coupler forces between the two models are lower than 100 kN; and (4) during emergency brake, a maximum difference of 266 kN was simulated, which accounts for 35% of the maximum force simulated by the LTD model.