CRH5动车组车轮低温概率疲劳寿命研究

摘要

为了研究CRH5动车组车轮在低温环境下的概率疲劳寿命,对比AASHO、ECCS以及CPM三种外推方法,并使用CPM方法获得了ER8钢材在-40℃低温环境下的概率疲劳寿命曲线,同时结合车辆系统动力学仿真及车轮有限元分析,获得了车轮在该温度下运行的概率疲劳寿命.结果表明:车轮踏面下2 mm的轮辋部位是车轮的危险部位,易萌生疲劳裂纹,且低温下车轮的疲劳寿命水平较低,在p、c皆为50%水平下,车轮在-40℃时的寿命为1740 km,相比常温下降约23%,可见低温环境对车轮疲劳寿命存在严重的影响.%In order to investigate the probabilistic fatigue lifes of wheels for the CRH5 EMU,this paper followed by the comparisons with three extrapolation methods of AASHO,ECCS and CPM,applied CPM method to obtain the p-c-S-N curves of ER8 steel at-40℃temperature and used dynamic and finite element simulation to get probabilistic fatigue lifes of the wheels at-40 ℃. The results show that:the positions 2mm under the wheel treads are the dangerous points to initiate cracks. Besides,the fatigue lifes of wheels under low temperature are insufficient for it is of only 1 740 km under survival rate p and confidence c are 50%. It decreases 23% compared with the life under normal temperature,that is to say,low temperature has a strong impact on fatigue lifes of wheels.