Advanced studies on locomotive dynamics behaviour utilising co-simulation between multibody and train dynamics packages

As heavy haul trains become longer and heavier, the resulting in-train forces are also being increased. However, locomotive dynamics studies are commonly focused on the dynamics of individual locomotives, which means that in-train forces are not attached to the locomotive or, in other words, external forces due to train configuration are not fully considered. Some published studies do apply an approximation of lateral coupler forces to replicate a locomotive’s dynamics in curves. This is very important for the analysis of locomotive dynamics given the significant variations in coupler forces when transiting a curve. However, this approach does not fully depict the real situation because it is necessary to also take account of vertical components of coupler forces along with locomotive pitch dynamics in order to correctly analyse the outcomes. One of the techniques to investigate such behaviour in vehicle dynamics studies is to use a cosimulation approach. This paper describes a methodology for the development of co-simulation between the multibody software and an in-house train dynamics code, as well as presenting numerical experiments for locomotive dynamics studies based on the developed methodology.