外拘束对铝合金薄板结构焊接变形的影响  

Influence of External Restraint on Welding Distortion of Aluminum Alloy Thin-plate Structures

作　　者：梁伟[1] 郑颖 邓德安[2] LIANG Wei;ZHENG Ying;DENG Dean(College of Mechatronics&Automotive Engineering,Chongqing Jiaotong University,Chongqing 400074;College of Materials Science and Engineering,Chongqing University,Chongqing 400044)

机构地区：[1]重庆交通大学机电与车辆工程学院,重庆400074 [2]重庆大学材料科学与工程学院,重庆400044

出　　处：《机械工程学报》2021年第6期70-77,共8页Journal of Mechanical Engineering

基　　金：国家自然科学基金资助项目(51375518)。

摘　　要：采用热-弹-塑性有限元法与基于固有应变理论的弹性有限元法相结合的计算方法,模拟不同板厚铝合金(A6061)薄板结构的焊接变形。同时,基于数值模拟结果,讨论外部拘束对焊接变形的影响。在计算方法上采用两步集成计算方法,第一步采用热-弹-塑性有限元法计算薄板结构中典型焊接接头的固有变形,第二步将各个接头的固有变形转化成相应的固有应变代入到基于固有应变理论的弹性有限元模型中计算了薄板结构的总体变形。热-弹-塑性有限元计算结果表明,在本研究的模型中,外部拘束对T字接头的纵向收缩力(Tendon force)的影响很小,对横向收缩有一定影响,对角变形有显著影响。弹性有限元计算结果表明,在不产生屈曲变形的情况下,外部约束可以有效地减小焊接结构的面外变形,但是在发生屈曲变形的情况下,外部约束并不能防止薄板焊接结构的失稳变形。The purpose of this paper is to illustrate the effect of external constraints on the welding deformation of thin-plate panel welding structures based on the numerical simulation results. In this study, the welding deformation of aluminum alloy(A6061) thin-plate structure with different thickness was simulated by the computational procedure combining the thermal elastic plastic finite element method(FEM) with the elastic FEM based on the theory of inherent strain. The thermal elastic plastic FEM was used to calculate the inherent deformation of typical joints in the thin-plate structure in the first step, and the elastic FEM based on the theory of the inherent strain is used to calculate the overall deformation of the thin plate structure in the second step. The result obtained from the thermal elastic plastic FEM shows that the external constraint has a little influence on the longitudinal shrinkage force(Tendon Force), a certain influence on the transverse shrinkage, and a significant effect on angular distortion of T-joint. The result calculated by the elastic FEM indicates that the external constraint can effectively reduce the out-of-plane deformation of the thin-plate welded structure when buckling deformation does not occur, while it cannot prevent the unstable deformation of the thin plate welded structure when buckling distortion happens.

关 键 词：焊接变形 屈曲变形 固有应变 数值模拟 铝合金 

分 类 号：TG404[金属学及工艺—焊接]