重载铁路钢轨磨耗分布发展计算模型及影响因素研究

A study on the calculation model and influence factors of rail wear distribution for heavy haul railway

建立了钢轨磨耗数值计算模型,可实现磨耗具体分布及发展的定量预测分析。对货车轴重、速度及材料硬度对钢轨磨耗分布发展的影响进行了系统研究,弥补了既有研究多采用定性指标、无法定量分析对磨耗分布发展的影响的不足。主要结论:(1)轴重影响:直线运行时,随轴重的增加钢轨磨耗均呈马鞍状分布且马鞍状特征愈发显著,波峰磨耗深度逐渐增大而波谷磨耗深度逐渐减小,磨耗量总体呈增大趋势。曲线运行时两轨磨耗分布差异较大,随轴重的增加钢轨磨耗分布特征保持一致,幅值呈增大趋势。(2)速度影响:直线运行时,随车速的提高钢轨磨耗向轨头内侧扩展加宽,分布区域磨耗深度均呈增大趋势。曲线运行时,随车速的提高外轨轨肩磨耗幅值先减小后增大而轨顶磨耗变化较小,内轨磨耗明显下降。相对轴重而言车速对磨耗的影响更显著,从减磨角度同等条件下宜优先发展大轴重货车来实现扩能增效,并尽量减少重车方向大幅提速。(3)材料硬度影响:增大轮轨硬度对磨耗分布区域和形状影响不明显,但可显著降低磨耗幅值和磨耗量。但硬度过高易加速疲劳伤损,不一定能延长使用寿命。

A numerical model was established,which can predict the wear distribution and development quantificationally.The influences of axle load,running speed and material hardness on rail wear distribution and development were studied systematically.This work solves the problems of lacking quantitative analysis in previous research.The major conclusions are as follows.①Influences of axle load:in the tangent section,with the axle load increasing,the rail wear are all distributed like saddle and the saddle feature becomes more obvious.The crest wear depth increases and the trough wear depth decreases.The wear loss tends to increase as a whole.In the curved section,the wear distribution is significantly different between the two rails.With the axle load increasing,the rail wear distribution characteristics remain almost the same,and the magnitude tends to increase.②Influences of speed:in the tangent section,with the vehicle speed increasing,the rail wear extends towards the inner side,and the wear depth increases over the distribution zone.In the curved section,with the speed increasing,the wear magnitude around the shoulder of outer rail decreases firstly and then increases,while the wear magnitude on the top of outer rail changes slightly.The wear magnitude of the inner rail decreases obviously.Compared with axle load,the influence of vehicle speed on wear is more significant.From the perspective of slowing down wear,priority should be given to developing heavy-axle load freight vehicle to expand the capacity of the heavy haul railway.Meanwhile,the speed of loaded vehicle should not be increased greatly.③Influences of material hardness:Increasing the hardness will not influence the wear distribution zone and shape significantly,but can reduce the wear magnitude notably.However,excessive high hardness will accelerate fatigue damage and may not prolong the life-span of rail.