【摘要】 车轮扁疤是铁道车辆车轮踏面的缺陷形式之一,对轮轨动力和运用安全有明显的影响.本文建立了弹性车辆系统动力学模型,且将车轮扁疤伤损考虑为车轮轮径变化.利用数值仿真,研究了车轮扁疤伤损对高速列车轮轨冲击力、轮对振动及轮轨接触性能等的影响,并结合列车运行安全性指标得到了不同速度等级下车轮扁疤长度安全限值.结果表明,弹性车辆系统模型可以准确体现轮对旋转运动特征.车轮扁疤伤损对轮轨系统垂向和横向均产生冲击作用,对轮轨系统垂向冲击作用尤为明显,将显著增大轮对旋转振动频率及其倍频对应的振动能量,且会激起轮对中高频弹性共振.车轮出现40mm扁疤时,随着车轮旋转运动,轮轨接触点向轮背侧出现周期性横移,轮轨接触斑面积最大可达142mm2,轮轨纵向和横向蠕滑率分别增大4%和16%.轮轨力、轮对振动加速度及轮轨磨耗指数均会随车轮扁疤长度的增加而增大.当列车运行速度在300km/h及以下时,车轮扁疤长度需限制在30mm;当列车运行速度达到350km/h时,车轮扁疤长度需限定在25mm.更多还原

【Abstract】 Wheel flat is one of wheel tread defect forms of railway vehicles,and it has significant influence on the wheel/rail dynamic and operation safety.In order to study the influence,the elastic dynamic model of vehicle system and the model of wheel flat which considered the change of wheel radius are established.With the numerical method,the influence of wheel flat on wheel-set vibration,wheel/rail impact force and contact performance is analyzed,and the safety limit value of wheel flat length is obtained in different speeds.The results show that the designed elastic vehicle system model can accurately reflect the wheel-set rotation characteristics.The wheel flat causes impacts on the wheel/rail system in both vertical and lateral directions,and the dynamic responses in vertical are more obvious.The vibration energy in frequency of wheel-set rotationwill significantly increase because of the impact of wheel flat.When the length of wheel flat is 40 mm,with the wheel-set rotation,the contact area of wheel/rail up to 142 mm2,the longitudinal and lateral creepage increased by 4%and 16%respectively.The amplitudes of wheel/rail vertical contact force,the wheel-set acceleration and wheel/rail wear number will increase as the increasing of the wheel flat length.When the operation speed is 300 km/h and below,the length of wheel flat should be limited to 30 mm,and 25 mm is the limit value of wheel flat length when the speed is 350 km/h.更多还原