基于主S-N曲线法的板边焊接接头疲劳评估  

Fatigue evaluation of plate edge welded joints based on master S-N curve method

作　　者：徐继鑫 窦飞 桂志远 李明君 聂春戈[2] XU Jixin;DOU Fei;GUI Zhiyuan;LI Mingjun;NIE Chunge(CRRC.Dalian Co.,Ltd,Dalian 116022,Liaoning,China;School of Locomotive&Rolling Stock Engineering,Dalian Jiaotong University,Dalian 116028,Liaoning,China)

机构地区：[1]中车大连机车车辆有限公司,辽宁大连116022 [2]大连交通大学机车车辆工程学院,辽宁大连116028

出　　处：《计算机辅助工程》2024年第4期44-48,共5页Computer Aided Engineering

基　　金：国家高速列车青岛技术创新中心项目(CXKY-02-01-02(2020))。

摘　　要：基于主S-N曲线的常规计算流程在评估板边焊接接头时存在难以计算疲劳控制应力的问题,提出3种可能的计算方案并进行对比分析。方案I通过定义虚拟焊线计算焊趾结构应力,但由于焊趾区域应力梯度过大,导致应力值对网格尺寸非常敏感;方案II和III的计算结果具有网格不敏感特性,同时与疲劳试验数据吻合良好,证明适用性。基于方案II和III,对某型号机车底架板边接头的疲劳开裂问题进行分析。结果表明:方案III只利用焊趾附近2倍板厚范围内的网格进行计算,更适用于几何特征和应力状态复杂的工程结构。The conventional calculation process based on the master S-N curve has the problem that it is difficult to calculate the fatigue control stress when evaluating the welded joints at the plate edge,and three possible calculation schemes are proposed and compared and analyzed.Scheme I calculates the structural stress of the weld toe by defining the virtual weld wire,but the stress value is very sensitive to the mesh size due to the excessive stress gradient in the weld toe area.The calculated results of schemes II and III are not sensitive to mesh,and at the same time,they are in good agreement with the fatigue test data,which proves the applicability.Based on schemes II and III,the fatigue cracking problem of the plate side joint of a certain type of locomotive chassis is analyzed.The results show that scheme III only uses the grid in the range of 2 times the plate thickness near the weld toe for calculation,which is more suitable for engineering structures with complex geometric features and stress states.

关 键 词：板边接头 疲劳寿命 结构应力 主S-N曲线 有限元 

分 类 号：TG407[金属学及工艺—焊接] TB115.1[理学—数学]