Optimal design of wheel profiles based on weighed wheel/rail gap

A direct optimization method for railway wheel profiles is put forward based on the weighed normal gap between wheel and rail at the contact point. Taking the wheel/rail counterpart, wheel LMa and rail CHN60 of China railway, as an example, the new optimization method is used to improve the profile of wheel LMa. The coupling dynamics theory of the vehicle and track is also used to investigate the effect of the improved profile on the dynamical behavior of the vehicle, and the rolling contact theory is hired to analysis the influence of the optimized wheel profile under the wheel/rail contact status. The numerical results illustrate that the improved wheelset of LMa has superior curving behavior. It is found that the improved profile of LMa with this method is in good conformal contact with rail CHN60, and the distribution of contact points of the wheel and rail is relatively uniform and extensive on the wheel tread and rail top, compared to the LMa in the same case before its optimization. After the profile optimization of the wheelset, the maximum normal pressure of the wheel/rail is greatly lowered when the vehicle runs on the tangent track, and the wear index of the wheel/rail is largely reduced without sacrificing the dynamic performance of the wheelset.

Research highlights▶ A forward solution method for design wheel profiles is developed. ▶ The method has fast computation speed and preferable convergence. ▶ The coupling dynamics theory of the vehicle and track is used in the optimization loop. ▶ The improved profile can reduce normal pressure of the wheel/rail without sacrificing the dynamic performance.