Characteristics of Wheel-rail Dynamic Interaction of Heavy Haul Railways due to the Rail Welding Joint

In order to investigate the wheel-rail interaction performance of a heavy haul freight car passing through the rail welding joint,a vertical coupled model between 30t-axle-load freight car and track has been established on the basis of vehicle-track coupled dynamics theory. In this model,the harmonic wave was adopted to simulate rail welding joint irregularity. The wheel-rail dynamic indices are analyzed at the speed of 120 km / h. The effects of wave length and depth on the wheel-rail dynamic performance are discussed specifically. Results show that according to the existing railway standard of welded rail,the change of wheel-rail interaction force is not remarkable. The wheel-rail vertical force exceeds the limited value of 250 kN under the case that the length and depth of long wave are 1 m and 0. 3 mm,and the length and depth of short wave are 0. 1 m and 0. 4 mm. The wheel will jump off the rail if the short wave depth is more than 0. 7 mm. Furthermore,under the case that the length and depth of short wave is 0. 2 m and 0. 6 mm,the wheel-rail vertical force is bigger than 250 kN. If the depth of short wave is more than 1. 6 mm,the phenomenon of wheel jumping off the rail will appears.