钢轨铣磨和打磨对钢轨滚动接触疲劳和磨耗的影响

Influence of Rail Milling and Grinding on Rail Rolling Contact Fatigue and Wear

根据重载铁路小半径曲线区段和运行车辆实际参数,建立实参数轨道-车辆多体动力学仿真模型,分析钢轨铣磨前后和打磨后的轮轨关系、滚动接触疲劳和钢轨磨耗耦合竞争关系。结果表明:钢轨铣磨能有效去除轨面病害,但不能有效改善轮轨关系;钢轨打磨可有效改善轮轨接触关系,降低轮轨横向力、轮轨振动加速度和法向接触应力,有效控制病害发展。对于小曲线半径区段,上股钢轨铣磨前以磨耗为主,铣磨后磨耗减小但疲劳伤损严重,打磨后钢轨疲劳损伤和磨耗基本达到平衡;下股钢轨铣磨前疲劳损伤大且磨耗快,铣磨后与打磨后的疲劳损伤、磨耗指数均明显下降。建议对较严重的钢轨滚动接触疲劳实施先铣磨后打磨的综合维修,最大程度延缓钢轨病害和磨耗的发展。

Based on the small radius curve section of heavy haul railways and the actual parameters of operating vehicles,a multi body dynamic simulation model of real parameter track-vehicle was established to analyze the wheel rail relationship,rolling contact fatigue and rail wear coupling competition relationship before and after rail milling and after grinding.The results show that rail milling can effectively remove rail surface defects,but it cannot effectively improve the wheel-rail relationship.Rail grinding can effectively improve the wheel-rail contact relationship,reduce the lateral force,vibration acceleration,and normal contact stress of the wheel-rail,and effectively control the development of diseases.For the small curve radius section,the upper rail is mainly worn before milling,and the wear decreases but the fatigue damage is severe after milling.After grinding,the fatigue damage and wear of the rail basically reach a balance.The fatigue damage and wear of the lower steel rail are significant and fast before milling,while the fatigue damage and wear index after milling and grinding are significantly reduced.It is recommended to implement a comprehensive maintenance of milling followed by grinding for more severe rail rolling contact fatigue,in order to minimize the development of rail diseases and wear.