Abstract: A new optimization method is put forward for railway wheel profiles based on the target function including using wheel/rail normal gap as parameters. Taking the wheel/rail counterpart, LMa/CHN60 of China railway at high speed, as an example, the new optimization method is used to improve the profile of LMa. It is found that the improved profile of LMa by using this method is in good conformal contact with CHN60 rail，which reduces wheel/rail contact stress and rolling contact fatigue. 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 railway vehicle. The numerical results show that the distribution of the contact points of the wheel and rail is relatively uniform and extensive on the wheel tread and the rail top, compared to the LMa in contact with CHN60 rail, and the maximum normal pressure of the wheel/rail can be reduced effectively without sacrificing the dynamic performance.

Key words: Contact stress, Optimization, Wheel profile, Wheel/rail normal gap