车轮扁疤激励下高铁轴箱系统振动特性研究

Vibration Characteristics of High‑Speed Train Axle‑Box System Excited by Wheel Flat

以某型高速列车轮对和轴箱轴承为研究对象,构建包含轮对轴箱轴承的车辆-轨道耦合动力学模型,研究在京津线轨道不平顺激扰及车轮扁疤激扰工况下轴箱系统内部结构的接触振动特性。结果表明:当车轮出现扁疤缺陷时会引起轴箱在垂向和横向的高频振动;随着车轮扁疤长度的增加,轴箱轴承滚子与外圈接触载荷高频段所占成分逐渐增加,引起轴承滚子与外圈的中高频激振,加速轴承的疲劳破坏;扁疤长度超过30 mm时,0号滚道区域的接触载荷变化较大,扁疤长度50 mm处轴箱轴承滚子与外圈接触载荷均值与扁疤长度10 mm处滚子与外圈接触载荷均值的最大值相比增加了33.38%;当列车运行速度在250 km/h左右时,车轮扁疤长度安全阈应限制在30 mm以内,尽量降低车轮较长扁疤引起的轮轨结构高频振动。

Taking the wheelset and axle-box bearings of a high-speed train as research objects,the vehicle track coupling dynamics model including the wheelset and axle-box bearings are built to study the contact vibration characteristics of the internal structure of axle-box bearings under the track excitation of Beijing-Tianjin rail and wheel flat.The results show that when the flat defect of the wheel occurs,it causes high-frequency vibration of the axle-box in the vertical and lateral directions.With the increase of wheel flat scar length,the high-frequency component of the roller-outer raceway contact load increases,which causes the medium and high-frequency excitation of the bearing rollers and outer raceways,and accelerates the fatigue failure of the bearings.When the flat length exceeds 30 mm,the contact load in No.0 raceway area changes greatly.Compared with the maximum roller-outer raceway contact load at the flat length of 10 mm,the average roller-outer raceway contact load at the flat length of 50 mm increases by 33.38%.When the train speed is about 250 km/h,the safety threshold of wheel flat length should be limited to 30 mm to minimize the high-frequency vibration on the wheel-rail structure caused by long wheel flat.