Coupling effects of strain rate and fatigue damage on wheel-rail rolling contact behaviour: a dynamic finite element simulation

A comprehensive 3-D explicit finite element (FE) model was established to investigate the frictional wheel-rail rolling contact responses in this study, in which the strain rate effect and initial fatigue damage of wheel/rail materials were taken into account via inputting relevant stress-strain response curves. Four friction exploitation levels were included to examine the dynamic contact responses in terms of contact load, contact patch area, creep characteristic, and stress/strain state. It is found that the nodal velocities on the rail surface at the trailing and leading edges of the contact patch are in opposite directions once the slip occurs. The strain rate hardening effect will significantly increase the Mises stress and suppress the plastic deformation of the wheel and rail at high creep levels, while the Mises stress will decrease with the increase of fatigue damage but the plastic strain will increase correspondingly.