滚动接触疲劳载荷对铁轨表面接触疲劳裂纹应力强度因子的影响

为研究轮轨滚动接触疲劳（Rolling Contact Fatigue，RCF）载荷对铁轨表面裂纹应力强度因子的影响，以UIC60铁轨轮廓尺寸为依据建立轮轨接触的三维有限元模型，通过改变RCF载荷大小、轮轨表面摩擦因数和接触中心位置等轮轨接触的输入参数，计算铁轨表面接触裂纹尖端的应力强度因子，分析RCF载荷对铁轨表面接触疲劳裂纹的影响. 结果表明RCF载荷作为控制铁轨表面接触裂纹的重要因素，其变化直接导致裂纹尖端应力强度因子的变化，从而改变裂纹的扩展状况；为减缓铁轨表面裂纹的扩展，可以针对载荷采取均匀分布载重量、使用润滑剂降低轮轨摩擦因数等相应措施.

Influence of rolling contact fatigue loads on stress intensity factors of rail surface contact fatigue crack

To analyze the influence of wheel-rail Rolling Contact Fatigue(RCF) loads on stress intensity factors of rail surface crack, a 3D finite element model is built with respect of the profile of UIC60 rail. By changing the input parameters about the wheel-rail contact such as RCF loads, friction factors between rail and wheel, position of contact center and so on, the stress intensity factors of the rail surface crack tip are calculated to analyze the influence of RCF loads on the contact fatigue of rail surface crack. The results indicate that the RCF loads are the main factor of controlling rail surface crack, their change will lead to the change of stress intensity factors of the crack tip and the crack propagation will be changed consequently. The measures such as uniform distribution of loading weight, application of lubricant to reduce wheel-rail friction factors and so on can be taken to decrease the propagation of rail surface crack.