Wheel-rail wear characteristics of intercity EMUs on curve in worn stages

The CRH6A intercity electric multiple units (EMUs) were examined in this study. Based on the measured wheel-rail profiles after wear, the vehicle dynamics model was established by the multi-body dynamics software Universal Mechanism. Wheel-rail interaction forces and position parameters of wheelset were calculated on curves. In the nonlinear finite element software ABAQUS, the wheel-rail three-dimensional rolling contact model was established based on the arbitrary Lagrangian Eulerian method, and the wheel-rail contact stress and slip characteristics were investigated. A fast calculation method of wear rate at the contact area on wheel surface was proposed according to the Archard wear model. The wear characteristics of contact areas were investigated under the interactions of new wheel, initial-worn stage wheel and wheel worn to limit with new rail and worn rail on curves. Research results show that under the interactions of new wheel and worn rail, initial-worn stage wheel and new rail, and wheel worn to limit and new rail, the maximum normal contact stresses reach 2 017, 1 803 and 1 668 MPa, respectively, which are 20% higher than those under the interactions of new wheel and new rail, initial-worn stage wheel and worn rail, and wheel worn to limit and worn rail. Under the interactions of new wheel and worn rail, initial-worn stage wheel and new rail, and initial-worn stage wheel and worn rail, the two-points contact, three-points contact, and four-points contact appear on the wheel surface. When multi-points contact appears, the contact points at the flange encounter stress concentration and high wear rates. Moreover, the maximum wear rates reach 2.60×10^-5, 3.82×10^-5 and 3.52×10^-5 mm·s^-1, respectively, which are higher than that under the interactions of new wheel and new rail, wheel worn to limit and new rail, and wheel worn to limit and worn rail. Under the interactions of wheel worn to limit and new rail, and wheel worn to limit and worn rail, the wheel wear rates are relatively small. It also shows that the wear rate of wheel in the later-worn stage is relatively low. The wear of rail gauge corner severely aggravates the flange wear of new wheel, and the initial worn stage wheel shows a high wear rate on the flange. Reprofiling cycle of wheel and grinding cycle of rail should be coordinated and the wear of flange in the initial-worn stage should be reduced by oiling or using other methods.3 tabs, 13 figs, 30 refs.