摘要
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。
China is seeing to develop the 30 t axle load railway freight car, and according to the schedule, the crossbar set used in K2 and K6 truck in which the axle load are 21 t and 25 t respectively should be used in the 30t axle load truck. Therefore, the influence of the axle load increasing to the service life of the crossbar set would be researched in advance. With the establishment for the dynamic models of three types of railway freight cars, the P64 （21 t axle load）, C80 （25 t axle load） and M95 （30 t axle load）, the cross bars in the three type of freight car dynamic models are set to 6 degrees of freedom （DOFs）, the influences of the axle load on the freight car to the maximum force and average load on the cross bar are studied, and the forces status of the cross bar are also obtained. Farthermore, the influences of other factors such as vehicle operating velocity, curve radius and railway level to the dynamic characteristics of the cross bar are researched. Moreover, in order to predict the influence of the axle load increasing to the service life of the crossbar set, a method to calculate the equivalent loads of the crossbar set is advanced. The calculating measure contains the contribution of the load level and load acting frequency to the equivalent loads. By use of the equivalent loads of crossbar set under the three type of the freight car and the service life of the crossbar set, the service life of the crossbar set under 30 t axle load freight car is predicted. The results show that the service life of the crossbar set under 25 t and 30 t axle load freight car are decreased to 82,6% and 76,2% of the former respectively, The way advanced is a new method to study the influence of the axle load to the structure service life aider integrating the vehicle system dynamics and the structural stress, and it is very helpful to solve the similar engineering problems.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2008年第3期16-21,共6页
Journal of Mechanical Engineering
基金
国家自然科学基金(50575020)。
关键词
等效载荷
疲劳寿命
轴重
交叉支撑装置
货车
车辆系统动力学
Equivalent load Service life Axle load Crossbar set Railway freight car Vehicle system dynamics
