Investigation on the transient rolling contact behaviour of corrugated rail considering material work hardening

The process of work hardening in the corrugation zone of the steel rail results in an uneven distribution of hardness, with higher hardness in the corrugation troughs and lower hardness in the corrugation crests. To study the influence of hardness on the rolling contact behavior of the wheel-rail at corrugation zone, a three-dimensional wheel-rail transient rolling contact finite element model is established based on the measured corrugation and hardness distribution of the rail to reveal the influence of the non-uniform distribution of hardness at corrugation zone on the wheel-rail contact state and the wear and fatigue of the rail surface. The results indicate that: (1) work hardening in the corrugation zone leads to an increase in equivalent stress and strain within the contact patch between the wheel and rail. However, due to the increase in yield strength, plastic deformation and residual strain are somewhat reduced; (2) The uneven distribution of hardness in the corrugation zone results in an elevation of longitudinal shear strain between the wheel and rail, which may initiate tangential fatigue cracks and spalling of the steel rail surface; (3) the wear on the rail surface is large near the wave crest and small near the wave trough, work hardening will change the wear difference between the wave crest and wave trough while reducing the wear, resulting in the “peak shaving and valley filling” phenomenon developing faster in the early wave wear period and slower in the later period.