摘要
采用虚拟仪器和NI数据采集卡搭建了一种以小孔法为核心的残余应力测试系统,分析了7A52铝合金VPPA-MIG复合焊后残余应力的分布情况.为降低弹性模量误差对最终测量结果的影响,通过实测复合焊接接头不同区域的弹性模量,拟合弹性模量随测量点位置变化的曲线来修正弹性模量误差.针对10 mm厚7A52铝合金板材,完成了VPPA-MIG复合焊接残余应力测试试验.结果表明,焊缝两侧各区域上的残余应力分布基本关于焊缝对称,熔合区出现最大拉应力,最大横向残余应力σy与纵向残余应力σx分别为118和223 MPa.从熔合区至热影响区,残余应力均为拉应力,逐渐减小且高于焊缝中心的残余应力.与单MIG焊相比,复合焊的最大横向残余应力与纵向残余应力大于MIG焊,但高应力区比MIG焊窄.
A residual stress testing system based on hole-drilling method was designed by virtual instrument and NI data acquisition card to analyze the welding residual stress distribution for 7A52 aluminum alloyplates after the process of VPPA-MIG hybrid welding.To reduce the impact of elastic modulus error on the final measurement results,the elastic modulus is derived from curve that is fit to data measured in different hybrid welded joint areas.The experiment of VPPAMIG welding residual stress measurement was carried out on 10 mm thick 7A52 aluminum alloy plates.The results show that the distribution of residual stresses on two sides of weld is basically symmetrical along the weld center.Maximum tensile stresses exist in the fusion zone,and the maximum transverse residual stressσy and the maximum longitudinal residual stressσx are 118 and 223 MPa,respectively.From fusion zone to heat affected zone,residual stresses are all tensile stresses,which become smaller gradually and are higher than the residual stresses in the weld center.Compared with the result of MIG welding,the maximum transverse residual stress and the maximum longitudinal residual stress of VPPA-MIG hybrid welding are higher,but the high-stress area of VPPA-MIG hybrid welding are narrower.
作者
甘世明
韩永全
陈芙蓉
李小飞
GAN Shiming;HAN Yongquan;CHEN Furong;LI Xiaofei(Materials Forming Key Laboratory,Inner Mongolia University of Technology,Hohhot 010051,China;College of Mechanical Engineering,Inner Mongolia University of Technology,Hohhot 010051,China)
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2019年第5期13-17,23,I0002,共7页
Transactions of The China Welding Institution
基金
国家自然科学基金资助项目(51665044)
