Effects of spallation on rail thermo-elasto-plasticity in wheel-rail sliding contact

A finite element model with rail spallations in wheel-rail sliding contact was established by using the finite element software ANSYS, the material nonlinearity was considered, the impact behaviors of wheel-rail contact were calculated when the wheels passed through the rail spallations, and the influences of length and depth of rail spalling area, friction coefficient and sliding speed on the thermo-elasto-plasticity of rail spalling area were analyzed by transient analysis. Analysis result shows when the length of spalling area is 2 cm and the depth is 4 mm, the equivalent plastic strain of rail reaches to the maximum, and the value in the rear of spalling area is 3-4 times as large as the value in the front. When the length of spalling area is 2 cm and the depth is 6 mm, the plastic deformation reaches to the maximum, and the value in the rear is about twice as large as the value in the front. The contact stress reduces with the increase of friction coefficient, while the frictional rising temperature, equivalent plastic strain, plastic deformation, equivalent stress and longitudinal shear stress of rail increase. When the friction coefficient is bigger than 0.3, the growth of equivalent stress and longitudinal shear stress becomes slower as the increase of fraction coefficient. When the sliding speed is equal to 3 m·s-1, or is not less than 6 m·s-1, the stress, deformation and temperature of rail are in most unfavorable conditions. © 2016, Editorial Department of Journal of Traffic and Transportation Engineering. All right reserved.