非赫兹型滚滑接触荷载作用下钢轨体内应力状态模拟分析

Simulation Analysis of Rail Stress State Under Non Hertz Rolling Sliding Contact Load

基于迹线法、Kalker的三维非赫兹滚动接触理论和半空间势函数理论解,分析不同接触荷载与接触状态下的轮轨接触差异。结果表明:接触荷载类型、饱和度、摩擦因数都是影响钢轨体内应力分布的重要因素;接触荷载类型主要影响钢轨体内的应力水平,对最大von Mises等效应力发生的位置没有影响;接触斑内黏滑分布和纵向应力整体分布情况主要由饱和度控制;摩擦因数越大,蠕滑饱和时最大von Mises等效应力越大,且越容易发生在表层;与非赫兹型接触荷载+部分滑动状态相比,赫兹型接触荷载+全滑动状态的最大von Mises等效应力更大且更易发生在表层,相同加载次数下钢轨会产生更大的塑性变形。以赫兹型接触荷载+全滑动状态为前提的简化轮轨接触疲劳预测模型得到的疲劳预测结果偏于保守。

Based on the trace method,Kalker’s three-dimensional non Hertz rolling contact theory and the semi space potential function theory,the difference of wheel-rail contact under different contact loads and contact states was analyzed.The results show that the type of contact load,saturation and friction coefficient are important factors affecting the stress distribution in the rail.The type of contact load mainly affects the stress level in the rail body,but has no effect on the location of the maximum von Mises equivalent stress.The distribution of stick slip and longitudinal stress in the contact spot is mainly controlled by saturation.The larger the friction coefficient is,the greater the maximum von Mises equivalent stress of creep saturation will be,which is likely to occur in the surface layer.Compared with the non Hertz contact load+partial sliding state,the maximum von Mises equivalent stress of Hertz contact load+full sliding state is larger and more likely to occur in the surface,and the rail will produce greater plastic deformation under the same loading times.The fatigue prediction results of the simplified wheel rail contact fatigue prediction model are conservative,which is on the premise of Hertz contact load and full sliding state.