基于摩擦自激理论的单侧钢轨波磨机理分析

Analysis of Unilateral Rail Corrugation Mechanism Based on Friction Self-Excited Theory

为了分析重载铁路曲线地段钢轨波磨的产生原因,基于摩擦自激振动理论建立小半径曲线轮轨三维接触精细化模型,讨论了不同扣件刚度、摩擦系数、超高对轮轨系统不稳定摩擦自激振动的影响,揭示了单侧钢轨波磨产生的内在原因,并通过轮轨瞬态动力学方法,分析了单侧钢轨波磨的传递及演化过程.结果表明:超高和实际运行速度的不匹配是曲线内股钢轨首先产生波磨的主要原因;内股钢轨波磨产生后会导致轮轨系统不稳定,并将振动传递至外股钢轨,从而诱发小半径曲线地段两侧钢轨均产生波磨;适当地提高扣件垂横向刚度、控制轮轨摩擦系数在0.4以下,能够有效地降低轮轨系统发生不稳定振动的趋势,从而抑制波磨发展.

In order to analyze the causes of rail corrugation in curve section of heavy haul railway,a refined wheel-rail three-dimensional contact model is established based on the friction self-excited vibration theory.The influences of different stiffness,friction coefficient and superelevation on the unstable friction self-excited vibration of wheel-rail system were discussed,and the internal causes of single rail corrugation were revealed,and the transmission and evolution process of single rail corrugation were analyzed by means of the explicit dynamic model.The results show that the mismatch between superelevation and actual running speed is the main cause of unilateral rail corrugation.The corrugation of the inner rail will lead to the instability of the wheel/rail system,and the vibration will be transmitted to the outer rail,which will induce corrugation of the rails on both sides of the small radius curve section.By properly improving the vertical and lateral stiffness of fasteners and controlling the wheel-rail friction coefficient below 0.4,the tendency of unstable vibration of wheel-rail system can be effectively reduced,and the development of ripples can be restrained.