地铁线路上一种钢轨波磨现象的成因分析

Cause Analysis of a Kind of Rail Corrugation Phenomenon on Metro Line

针对地铁线路直缓点附近区间上的一种特殊钢轨波磨现象,根据现场条件建立车辆-轨道系统数值模型,并对模型的有效性进行了验证;运用数值模型分析上述线路区间的轮轨界面黏滑特性,解释了该类钢轨波磨的形成原因;结合轮轨系统动力响应特性,分析促使钢轨波磨生成和发展的波长固定属性的成立条件。结果表明:在线路直缓点附近区间,导向轮对和从动轮对内外侧轮轨界面均会发生横向黏滑运动,而轮轨界面发生纵向黏滑运动的概率较低,且黏滑运动的交替发生,导致了钢轨表面初始波磨的形成;当导向轮对和从动轮对内外侧车轮经过线路直缓点时,外侧轮轨接触表现为轮缘-轨距角接触,且接触形式的改变造成了轮轨系统法向力的波动,说明直缓点的存在赋予了轮轨横向黏滑运动的相位同步特征,能够保持钢轨波磨的波长固定属性,因此,钢轨波磨最终形成并不断发展,而且内轨表现为轨面波磨,外轨表现为侧面波磨,这与实测区间波磨现象一致。

Aiming at a special rail corrugation phenomenon near the point of tangent to spiral of metro line,a numerical model of vehicle-track system was established according to the field conditions,and the validity of the model was verified.The stick-slip characteristics of wheel-rail interface were analyzed by the numerical model,and the cause of rail corrugation was explained.Combined with the dynamic response characteristics of wheel-rail system,the establishment condition of the fixed-wavelength attribute that promoted the generation and development of rail corrugation was investigated.The results show that,in the interval near the point of tangent to spiral of the line,lateral stick-slip motion will occur at the inside and outside wheel-rail interfaces of guiding wheelset and driven wheelset,while the probability of longitudinal stick-slip motion at the wheel-rail interfaces is low,and the alternate occurrence of stick-slip motion leads to the formation of initial corrugation on the rail surface.When the inner and outer wheels of guiding wheelset and driven wheelset pass through the line point of tangent to spiral,the outside wheel-rail contact is characterized by the wheel flange-rail gauge angle contact,and the variation of contact type causes the fluctuation of normal force of wheel-rail system,which shows that the existence of the point of tangent to spiral gives the phase synchronization characteristic of wheel-rail lateral stick-slip motion,and can maintain the fixed-wavelength attribute of rail corrugation.Therefore,the rail corrugation is finally formed and continuously developed,and the inner rail is characterized by rail surface corrugation and the outer rail is characterized by side corrugation,which are consistent with the corrugation phenomena in the measured interval.