Influence of the creep curve on the wheel-rail contact characteristics in small radius curve of metro

In order to reduce the damage of rail and prolong the rail service life at the small radius curve of metro, the appropriate wheel rail friction coefficient and Kalker's weight coefficient were proposed. Firstly, based on the vehicle-track coupling dynamics theory, dynamics model at the small radius curve of metro was established by SIMPACK software. Considering the coupling relationship between wear and rolling contact fatigue, a rail damage model was established. Secondly, according to the dynamic calculation results under standard working conditions, the characteristics of dynamic interaction and damage of inner and outer rails were studied. Thirdly, 50 matching schemes of wheel-rail friction coefficient and Kalker's weight coefficient were set up, and the influence of friction coefficient and Kalker's weight coefficient on wheel-rail dynamic interaction and damage characteristics was analyzed. Finally, vehicle operation safety and rail damage characteristics were comprehensively considered, and the matching scheme of wheel-rail friction coefficient and Kalker's weight coefficient was proposed. The results show that the damage of the inner rail is abrasion under the standard working condition. The wear degree of the outer rail is greater than that of the inner rail, and the service life of the outer rail is shorter considering the accumulated fatigue damage on the rail of transition curve. The smaller the Kalker's weight coefficient, the smaller the wheel-rail lateral force, derailment coefficient and the lateral vibration acceleration of the car body the influences of friction coefficient on wheel-rail dynamic behavior, wear and fatigue damage. It is suggested that the friction coefficient of wheel and rail should not be greater than 0.2, and the Kalker's weight coefficient should not be greater than 0.1. At this condition, the maximum wear index of both inner and outer rail is less than 100 N, the wear damage of rails is almost non-existent and the maximum fatigue damage of inner rail and outer rail is 0, which greatly improves the service life of rail. © 2020, Central South University Press. All right reserved.