Three-dimensional elastic–plastic stress analysis of wheel–rail rolling contact

A finite element model with the implementation of an advanced cyclic plasticity theory was used to study the three-dimensional elastic–plastic rolling contact stresses of wheel and rail. Three-dimensional rolling contact was simulated by multiple translations of the normal pressure and tangential tractions across the rail surface. The contact area, normal contact pressure and tangential tractions were calculated by the Kalker's program CONTACT. The finite element simulations were conducted to investigate the influence of partial slip condition and varying contact load on the rolling contact stresses and deformations. The results show that the partial slip condition or the creepage has a greater effect on the residual strains than on the residual stresses. While the residual strains and surface displacements increase at a reduced rate with increasing rolling passes, the residual stresses stabilize after a limited number of rolling passes. The present simulation results also indicate that a varying normal contact force results in a plastic deformation induced wavy rolling contact surface profile. Such a wavy surface profile evolves with rolling history and tends to stabilize due to the decaying ratchetting rate. The residual stresses and strains near the wave trough of the residual wavy deformation are higher than those near the wave crest of the residual wavy deformation. The wave depth of the residual wavy deformation increases with an increase of creepage.

Research highlights▶ A three-dimensional elastic–plastic finite element model of wheel–rail rolling contact is developed. ▶ The creepage has a greater effect on the residual strains than on the residual stresses. ▶ A varying contact force results in a plastic deformation induced wavy contact surface profile. ▶ Such a wavy profile evolves with rolling history and tends to stabilize due to the decaying ratchetting rate. ▶ The wave depth of the wavy profile increases with increasing the creepage.