The impact responses of the wheel-rail system with a wheel flat

The vertical wheel-rail impact responses induced by a wheel flat were simulated based on a dynamic finite element (D-FE) model using Ls-dyna/explicit code. Influences of the inertia effect, strain rate effect and temperature effect on the wheel-rail impact responses were discussed, respectively. The results indicate that the D-FE model can well describe the wheel-rail rolling contact behavior, and the wheel-rail impact responses are sensitive to train speed and flat length. The strain rate effect is revealed to have no contribution to the vertical impact force but has great influences on the von Mises equivalent stress and equivalent plastic strain. The temperature effect can reduce the magnitudes of maximum impact force and von Mises equivalent stress, and exacerbate the plastic deformation.