不同铸造缺陷下的L-B型制动梁闸瓦托疲劳寿命预测  

Fatigue Life Prediction of Brake Head of L-B Type Brake Beam with Different Casting Defects

作　　者：俞正宽 朱涛[1] 肖守讷[1] 阳光武[1] 杨冰[1] YU Zhengkuan;ZHU Tao;XIAO Shoune;YANG Guangwu;YANG Bing(State Key Laboratory of Traction Power,Southwest Jiaotong University,Chengdu 610031 Sichuan,China)

机构地区：[1]西南交通大学牵引动力学国家重点实验室,成都610031

出　　处：《铁道机车车辆》2021年第5期38-42,共5页Railway Locomotive & Car

基　　金：国家自然科学基金(51675446);国家自然科学基金联合基金项目(U1534209)。

摘　　要：为了更准确地评估不同铸造缺陷下L-B型制动梁闸瓦托结构的疲劳寿命,建立了闭环的闸瓦托结构疲劳寿命分析方法。首先,根据制动梁结构的受力特点,对制动梁结构进行了有限元分析,得到了闸瓦托结构的应力及其结构薄弱部位;然后,对闸瓦托所用材料的S-N曲线进行参数估计,推导得到了不同铸造缺陷下的闸瓦托结构的S-N曲线表达式和对应的曲线;最后,以标准疲劳载荷谱为输入,对比分析了不同缺陷状态下闸瓦托的疲劳寿命。研究结果表明:闸瓦托的疲劳寿命随着铸造缺陷的增加而降低,在无缺陷和小缺陷的理想状态下,闸瓦托接近于无限寿命;在中等铸造缺陷下,闸瓦托寿命急剧减小,对应里程约为224万km;在大的铸造缺陷下,闸瓦托的使用寿命小于100万km,低于标准规定的160万km。研究成果为闸瓦托结构的疲劳寿命预测、生产制造和检修维护提供了一定的理论和工程运用指导。In order to evaluate accurately the fatigue life of brake head of L-B type brake beam with different casting defects,a closedloop fatigue life analysis method of it is established.Firstly,according to the stress characteristics of the brake beam structure,the finite element analysis of the brake beam structure is carried out,and the stress and weak parts of the brake head are obtained;then,the parameters of the S-N curve of the materials used in the brake head are estimated,and the S-N curve expression and corresponding curve of the brake head with different casting defects are deduced;finally,taking the standard fatigue load spectrum as the input,the fatigue life of brake head with different defect states is compared and analyzed.The results show that the fatigue life of brake head decreases with the increase of casting defects,under the ideal state of no defects and small defects,the brake head is close to infinite life;under medium casting defects,the service life of brake head decreases sharply,and the corresponding mileage is about 2.24 million kilometers;under large casting defects,the service life of the brake head is less than 1 million kilometers,which is lower than 1.6 million kilometers specified in the standard.The research results provide a certain theoretical and engineering guidance for the fatigue life prediction,production,manufacturing,overhaul and maintenance of the brake head.

关 键 词：闸瓦托 铸造缺陷 S-N曲线 疲劳寿命 

分 类 号：U270.35[机械工程—车辆工程]