Combination of Longitudinal Train Dynamics and Multibody Simulation: Comparison of Co-Simulation with Other Modelling Strategies

The present work aims to benchmark co-simulation architectures against other modelling strategies that can be adopted to combine longitudinal train dynamics and multibody simulations. The comparison of the modelling strategies is performed on a reference train-track operation scenario extracted from an international benchmark, building a detailed multibody model of a group of four wagons. The rest of the train composition is considered in the multibody environment with different approaches, namely a straightforward model applying the in-train forces obtained from a preliminary longitudinal train dynamics simulation, a mixed multibody model where the remaining wagons are modelled as single degree of freedom masses and a multibody model replacing wagon sets with a single big mass. It is found that the multibody models which do not need to exchange data with a separate longitudinal train dynamics module can easily consider the effect of the lateral component of the in-train forces on the derailment ratio, while ensuring lower times for the model setup and simulation with respect to co-simulation architectures.