基于等效结构应力的地铁车辆焊接构架疲劳寿命分析  

Fatigue life analysis of metro vehicle welded frame based on equivalent structural stress

作　　者：李岐峰 张旭[1] LI Qi-feng;ZHANG Xu(School of Locomotive and Rolling Stock Engineering,Dalian Jiaotong University,Dalian 116028,China)

机构地区：[1]大连交通大学机车车辆工程学院,辽宁大连116028

出　　处：《电力机车与城轨车辆》2022年第1期35-39,共5页Electric Locomotives & Mass Transit Vehicles

摘　　要：文章针对地铁车辆焊接构架焊接部位的疲劳失效问题,首先建立构架有限元模型,选取5条危险焊缝,按照疲劳试验的载荷计算得到焊缝结构应力分布特点,其中焊缝最大等效结构应力点为77.5 MPa;然后根据结构应力法中98%可靠度,-2σ应力水平下的S-N曲线计算焊缝疲劳寿命,5条焊缝的累积损伤均小于1,满足疲劳设计寿命要求;最后使用等效初始裂纹替代法选取焊缝1和焊缝4进行有初始裂纹的疲劳寿命分析,结果显示具有初始裂纹的焊接部位剩余寿命符合预期。Aiming at fatigue failure of metro vehicle frame welding parts, firstly the finite element model of frame is established. Five dangerous welds are selected, and stress distribution characteristics of weld structure are calculated according to fatigue test load. The maximum equivalent structural stress point of weld is 77.5 MPa. Then fatigue life is calculated according to the S-N curve of 98% reliability and stress level of-2σ in the structural stress method, and total damage of five welds is less than 1, which meets fatigue design life requirements. Finally fatigue life analysis with initial cracks is performed by using equivalent initial crack substitution method to select weld 1 and weld 4. The results show that remaining life of welding parts is in line with expectations when there is an initial crack.

关 键 词：焊接构架 等效结构应力 疲劳寿命 剩余寿命 

分 类 号：U270.331.8[机械工程—车辆工程]