治理滚动接触疲劳伤损钢轨的打磨廓形设计及效果评价

Design and Effect Evaluation of Grinding Profile for Treatment of Rolling Contact Fatigue Damage Rail

针对我国普速铁路普遍存在的钢轨滚动接触疲劳伤损情况,对滚动接触疲劳伤损的形成机理和分类进行了论述。以经典的轮轨接触几何学和轮轨接触力学为理论依据,对无侧磨且带有疲劳伤损的曲线地段钢轨进行了打磨廓形优化设计,并通过仿真计算分析评价了廓形优化设计的效果。结果表明:廓形优化设计后轮轨接触点分布趋于集中,且基本位于轨顶中心附近区域;轮轨接触应力有所减小,曲下股减小约9.11%、曲上股轨顶面减小约20.28%、曲上股工作边减小约39.33%;轮轨磨耗指数有所增大,曲下股增大约27.57%、曲上股轨顶面增大约3.14%、曲上股工作边增大约282.26%,有利于加速曲上股钢轨形成侧磨;车辆运行安全性指标有一定的改善,轮重减载率降低约11.43%,脱轨系数降低约7.50%。

The forming mechanism and classification of rolling contact fatigue damage of rails in general speed railway in China were discussed.Based on the classical wheel-rail contact geometry and wheel-rail contact mechanics,the grinding profile optimization design of rail with fatigue damage in curve section without side wear was carried out,and the effect of profile optimization design was evaluated by simulation calculation and analysis.The results show that the distribution of wheel-rail contact points tends to be concentrated after profile optimization design,and basically lies near the center of rail top.The wheel-rail contact stress is reduced by 9.11%,20.28%and 39.33%,respectively,for the lower curved strand,the top surface of the upper curved strand,the working edge of the upper curved strand.The wheel-rail wear index increases,the lower curved strand increases by 27.57%,the top surface of the upper curved strand increases by 3.14%,and the working edge of the upper curved strand increases by 282.26%,which is beneficial to accelerate the formation of side wear of the curved upper strand.The safety index of vehicle operation has been improved,the wheel load shedding rate is reduced by 11.43%,and the derailment coefficient is reduced by 7.50%.