Calculation of Wheel Wear Based on Semi-Hertzian Contact

To study the effect of wheel/rail contact theory on wheel wear calculation, wheel/rail contact stress and contact patch were analyzed using the semi-Hertzian contact theory, the Hertzian contact theory and the CONTACT program of Kalker's exact theory. Then, the creep forces under semi-Hertzian contact were solved by Kalker's simplified theory using the numerical program FASTSIM, and the wear depths of wheel profile were calculated based on Archard wear model. The results indicate that the contact patch and maximal contact stress calculated by semi-Hertzian theory are more closer to CONTACT's than that by Hertzian theory, because the varied curvatures in contact patch are considered in the semi-Hertzian theory; the error of creep forces between semi-Hertzian theory and CONTACT does not exceed 18%, except the lateral creep force in large spin creep condition; the computing time of the FASTSIM algorithm based on semi-Hertzian theory is 6 times that based on Hertzian theory and 1/166 of the CONTACT's; and, the wheel wear depth calculated by semi-Hertzian theory agrees well with CONTACT's when the elastic velocity is considered.