基于切断技术的固有变形获取方法研究  

Method to Obtain Inherent Deformation of Welded Joint Based on the Cutting Technique

作　　者：梁伟[1,2] 孙晓露[1] LIANG Wei;SUN Xiaolu(College of Mechatronics&Automotive Engineering,Chongqing Jiao Tong University,Chongqing 400074;State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin 150001)

机构地区：[1]重庆交通大学机电与车辆工程学院,重庆400074 [2]哈尔滨工业大学先进焊接与连接国家重点实验室,哈尔滨150001

出　　处：《机械工程学报》2020年第8期92-98,共7页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51375518);先进焊接与连接国家重点实验室基金(AWJ-16-Z03)资助项目。

摘　　要：固有变形逆解析法是一种获取焊接接头固有变形的新方法。但是,采用该方法来获得铝合金或高强钢等轻量化结构材料的薄板焊接接头固有变形时,由于焊接过程中产生几何非线性现象的倾向大,逆解析过程中常常出现收敛困难而无法获得固有变形。针对这一问题,研究提出了一种借助于切断手段的方法来消除因几何非线性引起的收敛性问题。文中以钨极惰性气体保护焊和熔化极惰性气体保护焊加工铝合金薄板接头为例,采用提出的"切断法"与"逆解析方法"相结合的新方法来获得了焊接接头固有变形,并在此基础上运用固有应变法再现了原尺寸铝合金焊接接头的焊接变形。通过比较分别由试验法、热-弹-塑性方法和固有应变法得到的焊接变形结果发现,尽管不同焊接方法对变形模式和变形量影响显著,但是利用提出的算法获得的固有变形值得到的焊接变形均能较好地再现热-弹-塑性有限元计算得到的结果。Inverse analysis method based on the elastic finite element method and measuring technique is a new method to obtain the inherent deformations of a welded joint.However,when it is used to obtain the inherent deformation of the thin-plate welded joint made of lightweight structural materials such as aluminium alloy or high-strength steel,the tendency of geometric non-linearity occurring during the welding process is large,and convergence is often difficult in the reverse analysis process.Facing this problem,a improved method under the help of cutting technique is proposed to overcome the convergence problem caused by geometric non-linearity.In the current study,two thin-plate joints performed by tungsten inert gas welding(TIG)and melt inert gas welding(MIG)welding process respectively,which have complete different deformation modes,are taken as examples to obtain inherent deformations by the proposed method.Results show that the new method combining the cutting technique and the reverse analysis method can effectively obtain the inherent deformation of the thin-plate welded joint.Using the inherent deformations obtained by the new method,we accurately reproduce the welding deformations of two joints performed by TIG and MIG welding process,and match both the results predicted by thermal elastic plastic FEM and the experimental measurements.

关 键 词：切断法 逆解析 屈曲变形 固有应变 

分 类 号：TG404[金属学及工艺—焊接]