钢轨三维弹塑性滚动接触应力

用有限元法建立了钢轨三维弹塑性滚动接触计算模型，分析钢轨材料屈服强度对钢轨残余应力和应变的影响．模型中考虑了钢轨的几何形状和边界条件，通过在钢轨表面反复施加移动赫兹法向压力和切向力模拟车轮的反复滚动作用．结果表明：最大等效塑性应变和剪应变均发生在钢轨接触表面，此处易萌生裂纹；钢轨接触表面附近材料塑性变形流线趋势与现场观测到的裂纹方向一致；钢轨材料屈服强度越高，材料的累积塑性变形越小，钢轨的最大残余应力越接近于表面．

Three-Dimensional Elastic-Plastic Rolling Contact Stresses in Rail

A three-dimensional elastic-plastic model of wheel-rail rolling contact was established by finite element method to investigate the effect of yield stress of rail material on residual stresses and strains in the rail. In the model, the geometry and boundary conditions of the rail were taken into account. Repeated wheel rolling and sliding were simulated by multiple translations of normal and tangential surface tractions with Hertz form across rail running surface. The results show that the maximum equivalent plastic strain and shear strain occur on the contact surface, where the cracks initiate easily. The plastic flow direction in the rail near the contact surface is consistent with that observed in the field. An increase in yield stress of rail materials leads to a decrease in residual deformation, and drives the location of the absolute values of the maximum residual stresses to the contact surface.