重载铁路钢轨抗疲劳型面的设计与应用

Design and Application of Rail Anti-fatigue Profile for Heavy Haul Railway

为了改善轮轨接触关系,基于三次插值样条曲线方法,通过降低钢轨轨肩-轨距边廓形,设计了重载铁路小半径曲线钢轨抗疲劳型面。结合重载运输条件下的车辆-轨道动力学模型,根据接触点位置、轮轨接触斑面积、横向力、脱轨系数、轮重减载率、磨耗指数等参数,确定了重载铁路钢轨打磨铣磨基准型面并进行现场应用。基准型面为:钢轨轨肩-轨距边廓形降低的起点在由轨顶中心向近轨距边方向移动5 mm的位置,廓形改变范围覆盖起点至轨距边侧磨点,改变范围内最大廓形弧面下降量出现在轨顶中心向轨距边26 mm处,且最大弧面下降量为0.6、0.7 mm。现场试验结果表明:该基准型面使得轮轨垂向、横向力均有所降低,轮轨接触关系改善,接触点位置稳定;预测的裂纹萌生寿命延长了16.3%~47.2%,满足改善车辆运行状态、延长重载铁路钢轨使用寿命等需求。

In order to improve the wheel rail contact relationship,based on the cubic interpolation spline curve method,a small radius curve rail anti fatigue profile for heavy haul railway was designed by reducing the rail shoulder-gauge edge profile.Combining with the vehicle track dynamics model under heavy haul transportation conditions,the benchmark profile for grinding and milling of heavy haul railway rails was determined and applied on site according to parameters such as contact point position,wheel-rail contact area,lateral force,derailment coefficient,wheel load reduction rate,and wear index.The reference profile is that the reduction starting point of the rail shoulder-gauge edge profile is moved by 5 mm from the center of the rail top towards the near gauge edge direction,and the range of profile change covers the starting point to the side wear point on the gauge edge.The maximum reduction of the profile arc surface within the change range occurs at 26 mm from the center of the rail top towards the gauge edge,and the maximum reduction of the arc surface is 0.6、0.7 mm.The on-site test results show that the benchmark surface reduces the vertical and lateral forces between the wheel and rail,improves the wheel-rail contact relationship,and stabilizes the contact point position.The predicted crack initiation life has been extended by 16.3%~47.2%,which could meet the needs of improving vehicle operating conditions and extending the service life of heavy haul railway rails.