高速列车轴箱弹簧载荷特性与疲劳损伤

以某型高速列车轴箱弹簧为研究对象, 通过载荷标定方法制作了弹簧载荷测试传感器, 安装于动力转向架, 通过在线路测试得到了轴箱弹簧载荷时间历程; 结合车载陀螺仪信号, 分析了启动牵引、制动停车、高低速直线、进出坡道、曲线通过等典型工况下的轴箱弹簧载荷特性; 根据轴箱弹簧载荷的变化特点, 将测试载荷分解为趋势载荷和动态载荷, 并在统计基础上给出轴箱弹簧一定运用里程下的载荷谱, 确定了载荷幅值与载荷作用频次的对应关系, 根据损伤一致性准则, 分析了载荷谱各级载荷造成的损伤比重与轴箱弹簧疲劳损伤随列车运行速度增大的变化规律。分析结果表明: 轴箱弹簧载荷与应变呈线性关系, 其传递系数为9.45×10-5 kN-1; 与非动力侧轴箱弹簧相比, 动力侧轴箱弹簧载荷幅值变化受电机扭矩载荷的影响较大, 在列车启动阶段, 电机输出扭矩达到最大值, 动力侧与非动力侧轴箱弹簧的载荷分别为-7.42、1.26 kN; 列车速度由240 km·h-1增大至350 km·h-1时, 轴箱弹簧趋势载荷由-0.6 kN变化至-2.0 kN, 最大动态载荷由1.53 kN增大至1.86 kN, 增大了22%;动力侧轴箱弹簧在列车低速、高速运行时所产生的疲劳损伤比重分别为0.79、0.75;列车运行速度提高会使轴箱弹簧高幅值载荷产生的疲劳损伤比重略有降低, 这与非动力侧疲劳损伤比重分布特点相吻合; 动力侧和非动力侧轴箱弹簧疲劳损伤随着列车运行速度增大均呈现出先减小后增大的变化趋势, 在列车速度为300 km·h-1附近时达到最小疲劳损伤, 动力侧与非动力侧轴箱弹簧的疲劳损伤分别为0.110、0.004。 

Axle box spring load characteristics and fatigue damage of high-speed train

Taking the axle box spring of high-speed train as the research object, the spring load test sensor installed on the power bogie was made through the load calibration method. The load-time history of axle box spring was obtained from line test. Combined with a vehicular gyroscope signal, the spring load characteristics of axle box were analyzed under typical working conditions, such as traction, braking, straight line with high or low speed, in and out of ramp, and curve line. According to the change characteristics of axle box spring load, the test load was decomposed into the trend load and dynamic load. On the basis of statistics, the load spectrum of axle box spring under certain mileage was given, the corresponding relationship between load amplitude and its frequency was determined. According to the damage consistency criterion, the damage proportion of load spectrum at all levels and the variation rule of fatigue damage of axle box spring with the increase of train speed were analyzed. Analysis result shows that the axle box spring load is linear with strain, and its transfer coefficient is 94.5 kN-1. Compared with the non-power side axle box spring, the load amplitude of power side axle box spring is greatly influenced by the torque load of motor. During train start-up phase, the motor output torque reaches the maximum value. The loads on the power and non-power side axle box springs are-7.42 and 1.26 kN. When the train speed increases from 240 to 350 km·h-1, the axle box spring trend load varies from-0.6 to-2.0 kN, and the maximum dynamic load increases from 1.53 to 1.86 kN, which increases by 22%. The fatigue damage proportions of power side axle box spring are 0.79 and 0.75 when the train is in low and high speeds. The increase of train speed will slightly reduce the fatigue damage proportion caused by the high amplitude load of axle box spring, which is consistent with the distribution characteristics of non-power side fatigue damage proportion. The fatigue damages of both power and non-power side axle box springs tend to decrease first and then increase finally as the train speed increases. The fatigue damage reaches the minimum value when the train speed is around 300 km·h-1, and the fatigue damages of power and non-power side axle box springs are 0.110 and 0.004 respectively.