缺口应力法在机车焊接构架疲劳分析中的应用  

Application of Notch Stress Method in Fatigue Analysis of Locomotive Welded Frame

作　　者：刘旭[1] 张开林[1] 姚远[1] 张俊[2] 

机构地区：[1]西南交通大学牵引动力国家重点实验室,四川成都610031 [2]南车株洲电力机车有限公司,湖南株洲412001

出　　处：《铁道学报》2015年第1期24-29,共6页Journal of the China Railway Society

基　　金：国家自然科学基金(51205324)

摘　　要：为了关注焊接接头的局部力学特征,引入弹性缺口应力法分析复杂焊接结构的疲劳强度。文章采用Neuber应力平均概念衡量微观约束效应,并探讨了虚拟缺口圆的构造理论和参数选取;提出在缺口应力的有限元分析中,局部模型的边界条件控制采用节点力法比位移法更能有效避免应力集中和应力分布不均。运用缺口应力法对设计阶段的机车焊接构架进行了疲劳分析,通过建立构架整体三维粘接模型和局部缺口模型,分析了焊接接头的缺口应力和累积损伤。本文为机车关键焊接部件的疲劳评估提供了一种新的方法。In order to study the local mechanical properties of welded j oints,the elastic notch stress method is used to analyze the fatigue strength of a complex welded structure.The paper assesses the micro-structural notch support effect with the Neuber’s stress averaging approach,and discusses the modeling theory and pa-rameter selection of the fictitious notch rounding.The paper presents that,in the analysis of notch stress with FEM,when it comes to controlling the boundary conditions of the local model,the use of the nodal force can better avoid stress concentration and uneven stress distribution than the displacement method.Fatigue analysis by notch stress method is performed on the locomotive welded frame in the design stage.Notch stress and cu-mulative damage for welding joints are calculated through the establishment of the 3D overall model and sub-model.This paper provides a new method for the fatigue assessment of key welded structures of locomotives.

关 键 词：缺口应力法 焊接构架 有限元 

分 类 号：U260.3[机械工程—车辆工程] TG407[交通运输工程—载运工具运用工程]