电力机车车体关键部件疲劳全寿命评估方法  

Life-cycle assessment method for key parts of an electric locomotive body

作　　者：曾燕军 金希红 朱涛[3] 刘宏也 张华海 ZENG Yanjun;JIN Xihong;ZHU Tao;LIU Hongye;ZHANG Huahai(The State Key Laboratory of High Power AC Drive Electric Locomotive Systems Integration,Zhuzhou,Hunan 412001,China;R&D Center,CRRC Zhuzhou Locomotive Co.,Ltd.,Zhuzhou,Hunan 412001,China;State Key Laboratory of Traction Power,Southwest Jiaotong University,Chengdu,Sichuan 610031,China)

机构地区：[1]大功率交流传动电力机车系统集成国家重点实验室,湖南株洲412001 [2]中车株洲电力机车有限公司产品研发中心,湖南株洲412001 [3]西南交通大学牵引动力国家重点实验室,四川成都610031

出　　处：《机车电传动》2022年第6期10-16,共7页Electric Drive for Locomotives

基　　金：国家自然科学基金项目(52175123);中国中车股份有限公司科技研究开发计划项目(2018CJA002-1)。

摘　　要：针对电力机车车体在线路循环激励作用下的疲劳裂纹失效问题,对关键部件进行了动应变测试,结合标准载荷,研究了其疲劳全寿命。首先,以某电力机车车体为研究对象,对关键部件进行了线路动应变测试,并对测试数据进行低通滤波;其次,对滤波结果进行雨流计数,基于国际焊接协会(International Institute of Welding,IIW)标准确定测点焊缝材料参数,并按照Palmgren-Miner线性累积损伤理论进行了关键部件疲劳裂纹萌生寿命计算;然后,以车体枕梁和垂向减振器安装座的底架局部结构为例,建立了关键部件裂纹扩展仿真子模型,并基于EN 12663标准确定了子模型载荷工况;最后,在垂向减振器动应变测点位置插入初始裂纹,基于断裂力学方法计算了疲劳裂纹扩展寿命,从而获取了车体垂向减振器安装座疲劳全寿命数据。研究结果表明,电力机车车体垂向减振器安装座在既有线路上的疲劳裂纹萌生寿命为6.86×10^(7)公里;具有2 mm表面半长、0.8 mm深的初始半椭圆型表面裂纹的电力机车车体,在EN 12663标准要求的载荷条件下,至少还能承受4.18×10^(7)次载荷循环才会完全丧失承载能力。研究结果为必要的车体结构改进提供了可靠的试验和仿真依据,为评定机车运营中车体的安全可靠性提供了极强的指导作用和参考价值。In respect of the fatigue crack failure of the electric locomotive body under the cyclic excitation, the dynamic strain test was carried out on the key parts, and the fatigue life of the locomotive body was researched based on standard loads. Firstly, the body of an electric locomotive was taken as the research object, the dynamic strain test of the key parts was carried out, and the test data were filtered by low-pass filter. Secondly, the rainflow counting was carried out on the filtering results, and the parameters of the welding material at the measuring point were determined based on the IIW(International Institute of Welding) standard. The fatigue crack initiation life of the key parts was calculated according to the Palmgren-Miner linear cumulative damage theory. Then, the body bolsters and the local structure of the underframe of the vertical damper holder were taken as examples, the sub-model of crack propagation simulation of key parts was established, and the load conditions of the sub-model were determined based on the EN 12663 standard. Finally, the initial crack was inserted at the dynamic strain measuring point of the vertical damper, and the fatigue crack propagation life was calculated based on the fracture mechanics, thereby obtaining the fatigue life data of the vertical damper holder of the body. The results show that the fatigue crack initiation life of the vertical damper holder is 6.86×10^(7) km. Under the load conditions required by the EN 12663 standard, the electric locomotive body with an initial semi-elliptical surface crack of 2 mm in half length and 0.8 mm in depth can bear at least 4.18×10^(7) load cycles before it completely loses its bearing capacity. The research results provide reliable test and simulation basis for the necessary improvement of the body structure, as well as a strong guidance and reference value for the evaluating the safety and reliability of the body in locomotive operation.

关 键 词：车辆工程 电力机车 车体 动应变测试 损伤累积 断裂力学 裂纹扩展仿真 

分 类 号：U260.32[机械工程—车辆工程]