激光-电弧复合焊接7075-T6铝合金裂纹扩展分析  

Fatigue life prediction of laser-MIG hybrid welded 7075-T6 Al alloy joints

作　　者：吴圣川[1,2] 周鑫淼[1] 张卫华[2] 余啸[1] 徐晓波[1] 

机构地区：[1]合肥工业大学材料科学与工程学院,合肥230009 [2]西南交通大学牵引动力国家重点实验室,成都610031

出　　处：《焊接学报》2013年第2期5-8,113,共4页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51005068);牵引动力国家重点实验室自主课题资助项目(2012TPL_T18);汽车车身先进设计制造国家重点实验室开放基金资助项目(31115030)

摘　　要：研究了7075-T6铝合金薄板激光复合焊焊接接头疲劳裂纹扩展寿命.同时通过试验建立了不同热输入与弹性模量之间的函数关系并预测了给定热输入下的疲劳寿命.基于改进的Forman公式,提出了一种考虑7075-T6复合焊接头性能差异性、应力强度因子门槛值、裂纹扩展驱动力以及残余应力等多因素耦合的接头寿命预测模型.通过有限元模拟仿真并结合裂纹扩展和接头拉伸试验,对提出的模型进行了验证.结果表明,该模型预报的接头寿命与试验结果吻合较好.Fatigue crack propogation life of laser-MIG hybrid welded 7075-T6 Al alloy thin plate was investigated,and the relation of heat input and elastic modulus was established by experiments.Moreover,the fatigue life was predicted with different heat input.Based on the improved forman equation,an integrated fatigue life model was formulated with the coupling effect of the property difference,threshold of stress intensity factor,driving force of cracking and residual stress of hybrid welded 7075-T6 joints.This novel model was then validated through real fracture propagation,tensile tests and finite element simulation.It has been proved that the predicted fatigue life shows a good agreement with experimental results.

关 键 词：激光-电弧复合焊 高强铝合金 疲劳寿命预测 残余应力 弹性模量 

分 类 号：TG405[金属学及工艺—焊接]