VALIDATION OF A COMPUTER SIMULATION OF FORCED-STEERING RAIL VEHICLES

SUMMARY

The validation of rail vehicle lateral dynamic behaviour in curves is a difficult task and has been virtually neglected in the past. Forced-steering designs have been proposed to improve significantly the curving performance of rail vehicles without sacrificing stability margins. To predict the curving behaviour of these vehicles, a dynamic curving model has been developed. This computer model simulates a rail vehicle traversing a spiral transition followed by a circular curve, and features automatic generation of the equations of motion with significant non-linearities included. Validation of the model has been accomplished by comparing its results to experimental data obtained for a prototype forced-steering vehicle. The model includes 37 degrees-of-freedom with 60 suspension elements including 12 non-linear elements. Comparisons between the experimental results and the simulations corroborate the validity of the simulation model DYNCURV. Although the characteristics of the sliding pads and particularly their coefficients of friction were difficult to predict, good agreement between the experiments and the simulations was obtained. To further improve the simulation, a better knowledge of the sliding pad dynamic behaviour is required.