地铁车轮凹形磨耗对轮轨接触及动力学性能的影响

Influence of Hollow-Worn Wheels on Wheel-Rail Contact and Dynamic Performance of Metro Vehicle

对某地铁线路的车轮磨耗进行测试,发现车轮存在严重的踏面凹形磨耗。利用多体动力学软件SIMPACK建立车辆系统动力学仿真模型,研究凹形磨耗车轮与CHN60钢轨匹配时的轮轨接触特性以及车辆动力学性能,采用基于安定图的表面疲劳指数评价轮轨滚动接触疲劳特性。计算结果表明,车轮凹形磨耗使轮轨接触点对由连续分布变得分散集中,增大了滚动圆半径差和等效锥度,会降低车辆的非线性临界速度,但提升了车辆的曲线通过性能以及横向平稳性,对垂向平稳性几乎没有影响。凹形磨耗的发展增大了轮轨接触压力,使得R≤2000m的曲线高轨侧车轮轮缘根部及钢轨轨距角处易产生滚动接触疲劳;R≤500 m的曲线低轨侧车轮假轮缘内侧与钢轨轨顶外侧有出现滚动接触疲劳的可能性。

The worn wheel profiles of one metro line are measured and the wheel hollow wear is found to be serious.The dynamic simulation model of metro vehicle is established with the SIMPACK multibody software to investigate the wheel-rail contact behaviour and vehicle dynamic performance when matching the hollow-worn wheels with the CHN60 rail profile,and the surface fatigue index based on shakedown map is used to evaluate the wheel-rail rolling contact fatigue.The results indicate that the hollow wear turns the wheel-rail contact points from continuous distribution into concentrated distribution at intervals,which increases the rolling radius difference and equivalent conicity,thus reduces the nonlinear critical speed but improves the curving performance and lateral ride quality of the vehicle without affecting the vertical ride quality.The development of the hollow wear deteriorates the wheel-rail contact relationship and increases the wheel-rail contact pressure,which makes the rolling contact fatigue easy to occur on the wheel flange root and rail gauge corner of high rail side of curves with R≤2000 m.For the low rail side of curves with R≤500 m,the rolling contact fatigue is possible to occur between the inner side of the wheel false flange and the outer side of the rail top.