车辆转向架转臂定位节点疲劳寿命可靠性研究

Study on Fatigue Life Reliability of Vehicle Bogie Arm Positioning Node

[目的]基于虚拟仿真疲劳试验技术,对某型车辆转向架的转臂定位节点进行疲劳寿命分析及可靠性评估,以提高车辆稳定性并保障列车安全运行。[方法]利用ABAQUS软件建立转臂定位节点有限元模型,获取应力应变数据;通过FE-SAFE软件设置橡胶材料的疲劳参数,进行疲劳寿命仿真分析;采用图检验法对伪失效疲劳寿命进行分布假设检验,选取最优寿命分布;利用寿命分布参数值与应力水平之间的关系拟合出适合的函数关系式,对正常应力水平下转臂定位节点的疲劳寿命进行可靠性评估。[结果及结论]转臂定位节点在正常应力水平下仅有橡胶衬套将产生疲劳损伤;橡胶衬套最下端为伪失效疲劳寿命值最低的区域,也是最先发生破坏的区域;现场试验与疲劳仿真结果验证了转臂定位节点有限元模型的准确性;确定了最优的正态寿命分布;正常应力水平下,转臂定位节点可靠度为0.9时的疲劳寿命循环次数大约为21万次。

[Objective]Based on the virtual simulation fatigue test technology,fatigue life analysis and reliability evaluation of the bogie arm positioning node of a certain type of vehicle are carried out to improve the vehicle stability and guarantee the train operation safety.[Method]ABAQUS software is used to establish a finite element model of the arm positioning node and obtain the stress and strain data.FE-SAFE software is used to set the fatigue parameters of rubber material,simulate and analyze its fatigue life.Graph test method is used to test the distribution hypothesis of pseudo-failure fatigue life and to select the optimal life distribution.The relation between the life distribution parameters and the stress level is used to fit a proper functional relation and evaluate the reliability of the arm positioning node fatigue life under normal stress level.[Result&Conclusion]Under normal stress level,only the rubber bushing in arm positioning node will have fatigue damage.The bottom end of the rubber bushing is the area with the lowest pseudo-failure fatigue life value,and is also the area where the damage occurs first.On-site test and fatigue simulation results verify the accuracy of the finite element model of arm positioning node.The optimal normal life distribution is determined.Under normal stress level,the number of fatigue life cycles is about 210,000 when the reliability of the arm positioning node is 0.9.