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国内目前正在设计、研制30 t轴重铁路货车,原用于21 t、25 t轴重转向架的交叉支撑装置拟用于该型车辆。运用环境(轴重)改变后,在多大程度上改变了转向架交叉支撑装置的疲劳寿命,对于车辆尚处于设计阶段而不能通过实测车辆线路动应力来评估车辆结构强度的交叉支撑装置来说,需要寻求一种新的研究方法来实现疲劳寿命预测目的。由此,在建立三种轴重货车系统动力学模型基础上,详细研究三种轴重货车交叉支撑装置的径向力峰值和均值特性,获得交叉支撑装置受力方向与状态,揭示出轴重、运行速度、线路曲线半径以及线路等级等因素对交叉支撑装置载荷的影响特点。为预测30 t轴重货车交叉支撑装置的疲劳寿命问题,依据交叉支撑装置径向力与轴向应力之间线性对应关系,提出等效载荷计算方法以及等效载荷与疲劳寿命之间对应关系。等效载荷计算方法考虑了各载荷水平和出现频次对等效载荷的贡献。在分别计算21 t、25 t和30 t轴重货车交叉支撑装置等效载荷前提下,预测了30 t轴重货车交叉支撑装置疲劳寿命所占21 t、25 t轴重货车交叉支撑装置疲劳寿命的比率。研究结果表明,30 t轴重货车交叉支撑装置的疲劳寿命约分别为21 t、25 t轴重的76%、92%左右。采用等效载荷预测轴重对货车交叉支撑装置疲劳寿命影响的研究方法对解决类似工程问题提供了新的方式,具有良好的工程实用价值,是将车辆动力学研究和结构强度研究有机结合的新研究思路。
At present, China is designing and developing a 30t axle railway truck. The original cross-support device for 21t and 25t axle bogies is intended for this type of vehicle. After the change of the operating environment (axle weight), the fatigue life of the bracing device is changed. For the cross supporting device which can not assess the vehicle structural strength by the measured dynamic stress of the vehicle while the vehicle is still in the design stage, Need to seek a new research method to achieve the purpose of fatigue life prediction. Therefore, based on the establishment of the dynamic model of three axle truck systems, the peak force and mean value of the radial force of the three axle truck cross support devices are studied in detail, the force direction and state of the cross support device are obtained, and the axle load , Running speed, line curve radius and line grade and other factors on the impact of cross-support device load characteristics. In order to predict the fatigue life of cross-support device with 30 t axle, the equivalent load calculation method and the corresponding relationship between equivalent load and fatigue life are proposed according to the linear relationship between radial force and axial stress of cross support device. The equivalent load calculation method takes into account the contribution of each load level and occurrence frequency to the equivalent load. The 21 t, 25 t and 30 t axle equivalent weight of truck cross-supports were calculated respectively, and the fatigue life of cross-supports of 30 t-axle trucks was predicted to be 21 t. The ratio. The results show that the fatigue life of the 30 t-axle truck cross-supports is about 21 t, 76% and 25% of the 25 t axle load, respectively. The research method that using equivalent load to predict the influence of axle load on the fatigue life of truck cross-support device provides a new way to solve similar engineering problems and has good engineering practical value. It is a new method that combines vehicle dynamics research and structural strength research Research ideas.