Simulation Solution Method for Long and Heavy-Haul Trains Negotiating Elastic Curved Tracks

To solve the synchronisation simulation problem for long trains and continuous elastic tracks, a representative case employing a train curving negotiation is used. A heavy-haul train-track coupled dynamic model is used to analyse the dynamic performance of the track structure with a 30 t axle-load train, when a coupler compressive force is applied to it. As implified principle is presented to simulate the dynamic interaction between the long heavy-haul train and the track. The general concept behind this method is replacing the large train-track coupled dynamic system by a finite number of three dimensional vehicle models, considering the foundation structure elasticity under the corresponding models. Thus, the motion freedom of the system can be significantly reduced.The results indicate that a long train can be treated as a shorter mixed train, composed of a single-mass vehicle model and a three-dimensional wagon model. As only one wagon is simulated by the detailed dynamics model, with the front and rear connected wagons considered as a single-mass model, conservative results are obtained. As the train negotiates a 400 m radius curve, simultaneously bearing a 2 200 kN coupler force, the lateral and vertical wheel-rail forces in the outer wheel of the wagon are underestimated by about 24% and 4% respectively, relative to the results calculated using a train model composed of several three-dimensional wagons. Correspondingly, the lateral and vertical displacement of outer rail are sequentially underestimated by nearly 20% and 8%. When a single-mass model is used at the ends of the train, and the number of the additional wagons simulated by the three-dimensional dynamic model is 3, both the wheel-rail dynamic interaction of the middle target wagon and the track dynamic behaviour, can be reflected accurately.