小半径曲线内轨波磨外轨无波磨原因的研究

目的研究铁路小半径曲线线路内轨有波磨而外轨无波磨的原因。方法根据轮轨系统摩擦自激振动导致钢轨波磨的观点,建立了由车轮、钢轨和轨枕组成的轮轨系统摩擦自激振动模型。在模型中,车轮与钢轨接触几何关系使用车辆通过R=350 m曲线时的SIMPACK车辆动力学仿真计算获得的数值,钢轨与轨枕、轨枕与道床之间的连接用弹簧和阻尼单元组来模拟。应用复特征值方法对该模型发生摩擦自激振动的趋势进行了数值分析。结果小半径曲线内轨和车轮的接触角较小,在饱和蠕滑力(即摩擦力)作用下容易发生摩擦自激振动,因而容易出现波磨;外轨和车轮因为接触角较大,在饱和蠕滑力作用下不容易发生摩擦自激振动,因而极少出现波磨。数值预测结果与波磨发生的实际情况一致。结论轮轨蠕滑力饱和以及轮轨接触角是引起小半径曲线内外轨波磨差异的两个主要因素,其中轮轨蠕滑力饱和(即轮轨滑动)是决定性因素,如果轮轨蠕滑力不饱和,则轮轨系统就不会发生摩擦自激振动,因而就不会出现波磨。

Causes of low Rail Corrugation and Little high Rail Corrugation in Minor Radius Curve Route

The work aims to study causes of inner rail corrugation and little outer rail corrugation in minor radius curve route. A frictional self-induced vibration model was established for wheel-rail system consisting of a wheel, a rail and several sleepers was established based upon the opinion that rail corrugation was caused by frictional self-induced vibration of the wheel-rail system. In the model, the contact geometrical relationship between the wheel and rail was set to values from SIMPACK vehicle dynamics simulating calculation when a vehicle passed through a R=350 m curve, connections between steel rail and sleeper, sleeper and ballast bed were simulated with two different springs and damping element groups. Generation tendency of frictional self-induced vibration was analyzed numerically for the model in complex eigenvalue method. As contact angle between low rail and wheel was small in minor-radius curve, the frictional self-induced vibration might easily took place under the effects of saturated creep force (i.e., frictional force), hence corrugation might easily occurred; as contact angle between high rail and wheel was big, the frictional self-induced vibration might not easily took place under the effects of saturated creep force (i.e., frictional force), hence corrugation seldom occurred. Numerical prediction results were consistent with actual situation of corrugation. Saturation of creep force and contact angle between the wheel and rail are two main factors leading to difference between inner rail and outer rail in minor-radius curve. Saturation of creep force, which suggests that the wheel slips on the rail, is the decisive factor. If the wheel-rail creep force is not saturated, frictional self-induced vibration will not occur in the wheel-rail system, thus no rail corrugation occurs as well.