Assessment of collision-induced derailment of single wheelset on curved tracks by rail removing and lateral impact

Significant lateral and vertical impact forces can cause a derailment on the curved tracks. In this work, we try to indicate the similarities and differences between derailment modes on the curved track due to the lateral impact, considering the position and importance of the impact force itself and the rail removal. The obtained results may be used to design the passive safety systems. A wheelset with six degrees of freedom is considered, and the impact force is applied as a step function for both considered scenarios. In a curve with a large radius (above 4000 meters), the derailment modes become similar to the straight track. In the smaller radius curves, it is seen that the anti-clockwise derailment is more likely. But this derailment process takes more time in comparison with the clockwise (toward the center of the curves) derailment. The higher velocity of the wheelset leads to a shorter derailment time. In the case of the rail removal, velocity above 50 m/s affects the derailment significantly, and removing the outer rail in the curved track cause derailment while removing the inner rail will not cause derailment under any circumstances.