铁路钢轨打磨目标型面研究

STUDY ON RAIL GOAL PROFILE BY GRINDING

  • 摘要: 提出一种基于轮轨接触界面法向间隙的钢轨踏面设计方法,寻找了重载线路上较小轮轨接触应力水平的钢轨打磨目标型面,为新铺设钢轨预打磨及预防性打磨方案的设计提供理论依据。根据三维非赫兹滚动接触理论寻找了轨头的优化范围,在此范围内能保证轮对动态横移过程中,轮轨接触点附近最小法向间隙的钢轨轨头外形。针对重载线路轮轨伤损严重的问题,利用目前的方法对现有的60kg/m钢轨进行了优化设计。利用车辆-轨道耦合动力学理论及三维弹性体非赫兹滚动接触理论对优化前后钢轨踏面与原车轮接触时静态接触性能及动态接触性能进行了分析。结果表明,优化后轮轨界面之间具有较好的“共形”接触特性,在不降低车轮其他动力学性能的情况下,钢轨踏面优化后的轮轨接触应力显著地降低,并且使左右轮轨磨耗程度趋于均衡,可以有效降低轮轨磨耗与滚动接触疲劳。

     

    Abstract: An optimization method is put forward for the design of a rail goal profile based on the normal gap of the wheel and rail. Such a grinding rail goal profile is obtained by grinding and can be widely applied to heavy haul railways to efficiently reduce the contact stress level of wheels/rails. The optimization scope of the rail head is determined based on the theory of three-dimensional elastic bodies rolling contact with non-Hertzian. In the scope, the minimum gap forms between the original wheel and the improved rail when the wheelset shifts transversely. To mitigate the damage of the wheels and rails served in heavy haul freight railways, the present method is utilized to optimize the profile of CHN60 rail. The theory of vehicle and track coupling dynamics and three-dimensional elastic bodies rolling contact with non-Hertzian are used to analyze the contact behavior of the wheel/rail before and after the rail profile optimization in a static and dynamic state. The results show that the optimized rail profile is in good conformal contact with LM wheel, which reduces wheel-rail contact stress significantly without sacrificing the dynamic performance, and the wear status of the right wheel-rail and the left one are close. Therefore, the wear and rolling contact fatigue of the wheels and the rails served in heavy haul railways can be decreased effectively by using the optimized rail.

     

/

返回文章
返回