Time Saving Simulation of Long Train Derailment

This article presents a new method in determining long train derailment. A new strategy for building train models with large number of wagons has been developed. Previous studies have shown that in a train model, some of the details in the model of the wagons neighboring the wagon under study play minor role in dynamic behavior of the spotted wagon. To reduce the size of the overall model, one would tend to eliminate some of the details of the complex neighboring model having minor effect on overall behavior and trade a small approximation in results for large saving in computation time. In this research this idea is used to develop a train model with one full detail wagon model linked in a train model with a large number of wagons having 3 degrees of freedom. The 3 degrees of freedom wagon models are considered to have yaw, lateral and longitudinal motions. The detailed wagon model has 48 degrees of freedom including nonlinear springs, dampers and friction on sliding surfaces. Nonlinear equations of motion for train were developed using Newton-Euler method. The model was then used to simulate train behavior in passing a bend or applying severe brakes at different speeds. The results show very good agreement with the results of models with full degrees of freedoms in all wagons. The computation time is tremendously decreased in the new method.