轮轨非线性几何接触对铁道车辆稳定性影响的研究

Influences of Wheel/Rail Nonlinear Rolling Contact Geometry for Vehicle Stability

与一般的机械系统相比,铁道车辆系统有着特殊的轮轨接触关系。尽管在理论上轮轨接触的几何关系是确定的,但是它具有很强的非线性特征,在高速运行条件下对铁道车辆运行稳定性有很大的影响。分析了轮轨滚动接触的几何线性和非线性参数表达,并通过车辆临界速度分叉图讨论了它们对车辆运行稳定性的影响。分析结果显示:随着车轮踏面名义等效锥度的减小,会使车辆线性临界速度和非线性临界速度增大;而在名义等效锥度大致相同时,轮轨接触的几何非线性参数的变化对车辆的动力学响应有比较大的影响,随着它的减小,速度分叉图中轮对横移幅值小的临界速度明显减小。从现场实测数据分析也能得到相似的结果。

Compared to the general mechanical systems,there is a special wheel/rail contact interface in railway vehicle system.Though wheel/rail rolling contact geometry is explicit in theory,it also owns strictly nonlinear characteristics,which affect the stability of railway vehicle system in high-speed running condition.In this paper,the geometric linear and non-linear parameters of wheel/rail rolling contact geometry are studied,their influences on the stability of railway vehicle system are discussed by analyzing the critical velocity bifurcation.Analytic result shows that the critical velocity bifurcation curves will move right with the decrease of nominal equivalent conicity,namely the linear and nonlinear critical velocity will increase;when their nominal equivalent conicity are roughly the same,the nonlinear parameters will affect the dynamic response of the vehicle,and the critical velocity will be significantly reduced with the decrease ofλN,1.The results are verified by an analysis of the measured data.