城轨车辆长期服役过程中关键部件疲劳寿命性能研究

Study on the Fatigue Life of Key Components of Urban Rail Vehicles in Long-term Service

为了研究城轨地铁车辆长期大负载运行对关键部件疲劳寿命的影响,文章跟踪测试了实际服役状态下某地铁车辆转向架、车体关键部位的动应力,获得了动应力幅值与列车载重变化的关系,并依据Miner线性疲劳累计损伤法则计算了各测点的每日等效应力。结果表明,车体和转向架关键部位的应力幅值与列车载重具有强关联性,构架纵梁与横梁连接焊缝和牵引拉杆座焊缝的等效应力最大值超过70 MPa,构架空气弹簧座焊缝和一系弹簧座焊缝的等效应力维持在较高水平。

In this article,to study the impact of the long-term large loading running of urban rail and metro vehicles on the fatigue life of their key components,the follow-up tests are carried out to measure the dynamic stress on key components of bogie and carbody of the vehicles in actual service of a certain metro so as to obtain the relationship between the dynamic stress amplitude and the load variation of train,and the daily equivalent stress of each test point is calculated according to the linear fatigue cumulative damage rule by Miner.The result shows that there is a strong correlation between the stress amplitude of key components of carbody and bogie and the load of train,that the maximum equivalent stress of the weld joint connecting the longitudinal sill and the transom of bogie and the weld joint connecting the traction rod seat exceeds 70 MPa,and that the equivalent stress of the weld joint of the air spring seat and the weld joint of the primary spring seat on the frame is maintained at a high level.