构架管接头焊缝参数对疲劳缺口应力的影响  

The Influence of Weld Parameters of Frame Tube Joints on Fatigue Notch Stress

作　　者：刘斌[1] 张开林[1] 刘旭[1] 杨畅 LIU Bin ZHANG Kai-lin LIU Xul YANG Chang(Traction Power State Key Laboratory, Southwest Jiaotong University, Sichuan Chengdu 610031, China Chinese Zhongche Chengdu Locomotive Vehicle Co Ltd, Sichuan Chengdu 610057, China)

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]中国中车成都机车车辆有限公司,四川成都610057

出　　处：《机械设计与制造》2017年第7期65-69,共5页Machinery Design & Manufacture

基　　金：国家自然基金资助项目(51205324);牵引动力国家重点实验室资助研究课题资助项目(2015TPL_T10)

摘　　要：为了克服整体法进行焊接结构强度设计时造成的母材强度过剩,焊缝强度不足的问题,采用局部缺口应力法,分析了焊缝各局部参数对疲劳应力的影响程度;目的是在不改变整体结构参数的前提下,通过优化焊缝设计参数,实现焊接结构疲劳强度的提高。文章以某动车焊接构架为研究对象,建立了横梁管焊接接头的多尺度模型。以参数化的1mm虚拟缺口模型分析了各焊缝参数变化以及砂轮打磨半径对于缺口应力集中系数的影响规律,结果表明焊趾角度的影响较焊喉深度更为显著,而砂轮磨削的最佳半径为6mm。以构架整体模型分析了焊接接头在各疲劳工况下的实际受力情况,联合各向缺口应力集中系数并采用形状改变能密度准则计算了管接头焊趾处的多轴等效缺口应力。通过与原焊缝设计参数相比较,减小15°的焊趾角度能够降低10%的疲劳缺口应力,6mm的磨削半径则能够降低超过20%的疲劳缺口应力。In order to overcome the problem of strength surplus of base metal and insufficient strength of weld caused by using global approach when design of the structure strength, the local notch stress approach in this paper is used to study the effect degree of weld parameters to fatigue stress, which purpose is to improve the fatigue strength by optimizing weld parameters but without changing overall structure. It chooses a welded frame of powered bogie as the research object, then the multi-scale models of tube-to-plate joint from the frame are established. In a pararneterized local notch model of lmm fictitious radii,the variation of stress concentration factors（ SCF ）are analyzed with different weld parameters and burr grinding radii, it shows that weld toe angle has more significant influence on SCF than weld throat depth, and the 6ram grinding radius is considered the most reasonable. The force situation of tube-to-plate joint in some actual cases are got by overall FE model, and then the multi axis equivalent notch stress is calculated which also combined the notch SCF and distortional strain energy criterion. Comparing with the result of original weld design parameter, the fatigue notch stress will reduce 10% when the toe angle decrease 15% and the 6mm grinding radius can lead to fatigue stress reduced more than 20%.

关 键 词：疲劳缺口应力 焊缝参数 多尺度模型 管接头 焊接构架 砂轮打磨 

分 类 号：TH16[机械工程—机械制造及自动化]