高速列车车轮偏心磨耗的形成机理与发展规律

Formation mechanism and progression pattern of eccentric wear of high-speed train wheels

为了研究高速列车车轮偏心磨耗的形成机理,根据现场测试和多体动力学仿真结果,建立了高速列车车轮-钢轨系统有限元模型,采用瞬时动态仿真分析了车轮残余静不平衡对轮轨法向接触力的影响;对最高速度为250 km·h^(-1)动车组列车的运营速度进行现场测试,计算了列车匀速运行区间的平均速度;基于摩擦功周期性波动引起轮轨非均匀磨耗的观点,分析了车轮残余静不平衡量对轮轨接触力的影响,研究了车轮偏心磨耗的成因;通过改变轮轨有限元模型中车轮辐板上特定区域的材料密度来模拟残余静不平衡量,研究了偏心磨耗与残余静不平衡量大小的关系;通过重新编译有限元模型节点坐标来模拟偏心磨耗后车轮踏面的真实轮廓,研究了车轮偏心磨耗的发展规律。仿真结果表明:当高速列车以237 km·h^(-1)的速度匀速运行时,车轮残余静不平衡会引起轮轨系统发生约24 Hz的振动,导致轮轨法向接触力周期性变化,引起车轮踏面发生1阶非圆磨耗,即车轮偏心磨耗;随着磨耗的不断加深,轮轨系统约48、72 Hz的振动被激励,引起2、3阶车轮多边形磨耗;当磨耗后的车轮踏面最大径跳大于0.15 mm时,在0~150 Hz的频率范围内,72 Hz的振动强度最大,导致车轮3阶多边形磨耗迅速增加;降低车轮残余静不平衡量可减缓1阶非圆车轮的形成。

To investigate the generation mechanism of the eccentric wear of high-speed train wheels,a high-speed wheel-rail finite element model was established based on the results of a field test and multibody dynamics-based simulation,and the impacts of residual static unbalance of wheels on wheel-rail normal contact forces were analyzed by transient dynamic simulation.The field test was performed on the operational speed of a multiple-unit train with a maximum operational speed of 250 km·h^(-1)to determine the average speed of the train travelling in a uniform speed interval.Based on the viewpoint that the periodic fluctuations of frictional work result in uneven wheel-rail wear,the impacts of residual static unbalance of wheels on wheel-rail contact forces were analyzed,and the causes of the eccentric wear of wheels were explored.The residual static unbalance was simulated by adjusting the material density in the specific area on the wheel plate in the wheel-rail finite element model to investigate the relationship between the eccentric wear and the level of residual static unbalance.By recompiling the node coordinates in the finite element model to investigate the progression pattern of the eccentric wear of wheels,the eccentric wear of the actual wheel tread contour was simulated.Simulation results show that when the high-speed train travels at a uniform speed of 237 km·h^(-1),the residual static unbalance of the wheels causes the wheel-rail system to vibrate at around 24 Hz,resulting in the periodic changes in wheel-rail normal contact forces and 1-order out-of-roundness wear of the wheel tread(that is,the eccentric wear of the wheels).With the progression of the wear,the vibrations at about 48 Hz and 72 Hz are stimulated in the wheel-rail system,which causes 2-or 3-order polygonal wear of wheels.When the maximum radial runout value of the worn wheel tread is greater than 0.15 mm,the vibration intensity is the greatest at 72 Hz within the frequency range of 0-150 Hz,resulting in the rapid progression of the 3-order polygonal wear of wheels.The formation of 1-order out-of-roundness wheels can be attenuated by reducing the amount of residual static unbalance of wheels.2 tabs,11 figs,29 refs.