Abstract: A modified Kik-Piotrowski method which is able to consider the yaw angle of the wheelset and multi-point contact is established in order to study the dynamic behavior of the vehicle with tread worn-wheel. Combining the vehicle-track coupled dynamics, wheel-rail dynamic interaction is investigated for the CRH2 EMU with tread hollow-worn wheel running on the straight line. Results show that the modified Kik-Piotrowski method can be used to accurately simulate the multi-point and non-Hertzian contact between worn wheel and rail; both the predicted wheel-rail contact patch and the wheel-rail contact force have good agreements with CONTACT. The contact patch is distributed in two discontinuous areas at the boundary of the main wear region of the wheel tread, and instantaneous two-point wheel-rail contact occurs when the contact patch switches from one area to another area. The impact effect induced by the variation of wheel-rail contact point is not significant due to the transition of the two-point wheel-rail contact. Compared with the dynamic response of the vehicle without worn-wheel, the wheel-rail forces are slightly affected by the tread hollow-worn wheel, the effect on the wheel-rail lateral force is more significant than that on the wheel-rail vertical force. Both the wheel-rail vertical force and the wheel-rail lateral force are increased to a certain extent at the high frequencies.

Key words: Kik-Piotrowski method, multi-point contact, non-Hertzian contact, tread hollow-worn wheel, vehicle-track coupled dynamics