Abstract: In view of the fatigue fracture of the axle box spring of an electric locomotive, fracture analysis, dynamic stress test and finite element simulation were used to explore the fracture causes. The results show that the spring failure is fatigue fracture failure mode, and the crack source starts from the contact wear position of the first and the second ring. The frequency of the 19th order polygon of the wheel coincides with the 3rd order modal main frequency of the spring, resulting in resonance, which increases the fatigue equivalent stress of the spring. The excessive stress and the decrease of the fatigue strength caused by wear are the causes for the premature fatigue failure of the spring.

Key words: vehicle engineering; spring; dynamic stress; mode; resonance

摘要： 针对某型电力机车轴箱弹簧出现疲劳断裂的现象，采用断口分析，线路动应力测试以及有限元仿真探究其断裂原因。结果表明：弹簧失效为疲劳断裂失效模式，裂纹源始于第1圈、第2圈之间的接触磨损位置；车轮第19阶不圆频率与弹簧第3阶模态主频重合，从而发生共振导致弹簧的疲劳等效应力增大；过大的应力以及因磨损造成的疲劳强度降低是造成弹簧过早出现疲劳失效的原因。

关键词: 车辆工程；弹簧；动应力；模态；共振