高速车轮非圆化磨耗对轴箱端盖异常振动影响初探

国内现有某高速列车在运营一段时间后，轴箱端盖的连接螺栓经常发生松动现象。为寻找轴箱端盖螺栓松动的原因，分别对车轮表面磨耗状态及列车关键部件振动特性进行测试，系统地分析轴箱显著频率振动与车轮非圆化磨耗之间的相关性；根据车轮多边形及关键部件的振动特征，对轴箱端盖和一系减振器进行模态测试，对轮对和构架进行有限元模态分析，并通过观察轴箱振动显著频段内轴箱端盖变形，初步分析了轴箱端盖螺栓易松动的原因。结论如下：轴箱振动能量主要集中在314～372 Hz和514～600 Hz的频率范围内，该频率段分别对应车轮的11～13阶多边形磨耗和18～21阶多边形磨耗产生的激励频率范围。轴箱在314～372 Hz的振动显著频率与减振器在221～436 Hz的固有模态群相互耦合，轮对和构架在514～600 Hz的固有模态群相互耦合，这两种模态耦合关系是导致轴箱端盖异常振动，后期发展为螺栓松动的主要原因。

Influence of Wheel Non-circular Wear on Axle Box Cover Abnormal Vibration in High-speed Train

After a certain period of operation of a high-speed train, the bolts of the axle box cover of the train get loosened. To analyze the problem, the wheel wear status and the key components of the bogie vibration are monitored focusing on the relationship between the abnormal vibration of axle box and non-circular wear of the wheels. Meanwhile, the modes of the axle box cover and the primary damper are measured, the modes of the wheelset and the bogie frame are calculated by using finite element method, the deformation shapes of the axle box cover are analyzed in the frequencies which axle box vibrate evidently. The causes of the loosening of these bolts are discussed. The results of the tests show that vibrations in the axle box are concentrated in the 314-372 Hz range and the 514-600 Hz range, which respectively correspond to the 11th to 13th polygonal wear of the wheel and to the 18th to 21th polygonal wear of the wheel. The 314-372 Hz range is close to the natural frequency of the primary damper, which falls in the 221-436 Hz range. The 514-600 Hz range is also close to the natural frequency of the bogie frame and wheelset. These two cases are the main causes of the abnormal vibration of the axle box cover of a high-speed train, which in turn leads to bolts loosening.