Influence of individual wheel profiles on the assessment of running dynamics of a rail vehicle by numerical simulation: a case study

It is well known that wheel wear degrades the dynamic performance of the rail vehicles, especially in regard to the issue customarily known as ‘running stability’ and resulting in the evaluation of the vehicle’s critical speed. Past research addressed this problem mainly from the viewpoint of the influence on the vehicle performance of the wear pattern. The aim of this work is to investigate the influence of individual wheel profiles measured on a rail vehicle on the vehicle’s dynamics in the context of multibody (MB) simulations. The EN14363-based method, bifurcation map and the decreasing speed approach were implemented, and two new criteria were proposed based on the bifurcation map and decreasing speed schemes. Six methods were compared for assessing the vehicle’s critical speed for a case study. The results show that different assumptions made in the MB simulations for the wheel profiles may have a significant effect on the assessment of system dynamics and that some of the methods used for the calculation of the vehicle’s critical speed are more sensitive to the combination of profiles used. Therefore, the consideration of the peculiarity of each wheel profile is desirable for a detailed dynamics assessment of a vehicle in service.