车轮踏面三维扁疤轮轨系统冲击振动研究

Study on Wheel/Rail Impact Dynamics with Three Dimensional Wheel Flat Model

车轮扁疤是铁道机车车辆轮对踏面常见的一种擦伤,对轮轨系统振动和结构损伤等有十分重要的影响.既有工作主要是在考虑车轮扁疤附加冲击速度或者扁疤形状引起的轮径变化的基础上,研究车轮扁疤引起的轮轨冲击振动特性.在建立包含扁疤长度和宽度及深度的车轮踏面三维扁疤模型和车辆-轨道耦合系统动力学模型的基础上,考虑轮对旋转走行和轮轨接触几何关系,研究高速车辆-轨道系统三维车轮扁疤轮轨冲击振动特征.结果表明,扁疤长度一定时,扁疤宽度越宽轮轨冲击振动越激烈,宽度越小轮轨冲击越弱.车轮扁疤宽度与长度之比越接近1,轮轨冲击力峰值对扁疤冲击临界速度越敏感.在一定扁疤长度范围内,长度小但宽度大的扁疤引起的轮轨冲击振动,比长度大但宽度小的扁疤引起的轮轨冲击振动大.研究结果对全面揭示车轮扁疤轮轨冲击振动特征和扁疤轮轨接触走行关系等具有良好的理论意义.

Wheel flat is one kind of faults of wheelset and has great effect on the wheel/rail system dynamics and damages. In the most of presented studies, the impact velocity or the radius variable because of the wheel flat were taken into account to research the wheel/rail system impact characteristics. In the presented paper, included the length, width and depth, a 3 dimensional wheel flat model on wheel profile is established. The wheel rotating and wheel/rail contact geometries are included in the model. Based on a high speed vehicle/rail coupling system dynamics model, the effect of the wheel flat on the wheel/rail dynamics are investigated. The results show that the width of the wheel flat has great influence on the wheel/rail dynamics. The ratio between the width and length of the flat has great effect on the wheel rail impact too. The wheel/rail impacting dynamics with larger width and shorter length flat is more severe than that of the flat with smaller width and longer length. The wheel/rail contact geometry when the wheel passes through the flat area are presented. It is useful of the results to comprehensively understand the wheel/rail impacting mechanics and effects.