Finite Element Analysis of Thermo-mechanical Contact Fatigue Crack in Rail

An oblique surface crack in rail under wheel-rail full slip contact loading and frictional heating is analyzed by finite element simulations. In the present thermo-mechanical coupling finite element model, the heat-convection between the rail and ambient, heat transfer between the crack surfaces, and temperature-dependent material properties are taken into consideration. The effects of the frictional coefficients of wheel-rail contact and crack surfaces and the crack orientation on the stress intensity factors are investigated. The results reveal that the values of stress intensity factors K-1 and K-2 obtained by the thermo-mechanical coupling simulation are lower than those by the only mechanical simulation. But the value of the stress intensity factor range Delta K-2 for the former is higher. Reducing the wheel-rail contact surface frictional coefficient, increasing the crack-face frictional coefficient and avoiding the small angle of crack can restrict the rail surface crack growth.