建筑用对接铝合金薄板应力模拟及焊接变形机理研究

Research on Stress Simulation and Welding Deformation Mechanism of Butt-joined Aluminum Alloy Sheets for Construction

针对铝合金薄板焊后应力问题,通过力场模拟结果,设计合理的焊接工装,能达到减小焊件变形的目的,对铝合金薄板焊件的质量控制有着极为重要的意义。利用有限元分析软件,分别对铝合金薄板进行应力分布和温度场的有限元数值分析。结果表明:在焊缝及其附近区域,纵向残余应力为拉应力,在远离焊缝区表现为压应力。在焊缝中心处,残余拉应力的峰值约为0.95σ_(s)。焊接残余应力模拟结果与实际结果基本吻合。根据铝合金薄板焊后残余应力的分布特征及铝合金TIG焊时常出现的缺陷,设计了双向预置应力的焊接工装。

Aiming at the post-weld stress problem of aluminum alloy sheets,a reasonable design of welding tooling can achieve the purpose of reducing the deformation of the weldment through the simulation results of the force field,which is extremely important for the quality control of the aluminum alloy sheet weldment.Using finite element analysis software,a finite element numerical simulation of the stress distribution in the TIG welding process of aluminum alloy sheets was carried out.The simulation results show that the longitudinal residual stress in the weld and its vicinity is tensile stress,and it appears as compressive stress in the area away from the weld.At the center of the weld,the peak value of the residual tensile stress is about 0.95σ_(s).The simulation results of welding residual stress are basically consistent with the actual results.According to the distribution characteristics of residual stress after welding of aluminum alloy sheets and the defects that often occur in aluminum alloy TIG welding,a welding tool with bidirectional prestress is designed.