According to the features of tread fatigue crack tip,a blunt-shaped model of tread fatigue cracks is presented.Adopting the fracture parameters as crack tip displacement,crack propagation of U75V steel tread fatigue is analyzed in elastic-plastic case.The results show a large plastic zone lines near the crack tip and elastic-plastic fracture mechanics should be used to analyze features of tread fatigue crack propagation.Crack tip sliding displacement is affected by wheel load,friction coefficient of wheel/r...