(西安交通大学 材料科学与工程学院，西安 710049)
摘 要: 针对铝合金5A12有限薄板钨极惰性气体(TIG)焊接过程存在非准稳态的特点，提出了考虑热源预热作用及移动效应的二维高斯热源修正模型，并采用修正的二维高斯热源模型对其焊接热过程、焊接残余角变形和纵向残余应力进行数值模拟及研究，同时比较数值模拟及实验结果。实验结果表明：利用修正的二维高斯模型能较好地反映有限薄板的焊接特点，所计算的接头熔合区形状、热循环曲线与实验结果吻合良好。焊接残余角变形及焊接纵向残余应力也得到了与实验值较接近的模拟结果。利用此修正的二维高斯模型可提高焊接温度场、焊接纵向残余应力与变形数值模拟的准确性。
关键字: 热源模型；有限尺寸；预热；残余应力；残余变形
（School of Materials Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China）
Abstract:The characteristics of the quasi-steady-state during tungsten inert gas (TIG) welding process on 5A12 aluminum alloy sheet with limited size were analyzed. The welding process, residual angular deformation and longitudinal residual stress were numerically simulated and studied using the modified two-dimonsional Gaussian heating source model. The numerical simulation results were compared with experimental results. The results show that the numerical results by the modified two-dimensional Gaussian model reflect well the limited plate welding characteristics. The shape of joint fusion zone and thermal cycle curve calculated agree well with the experimental results. And the welding residual deformation and longitudinal welding residual stress are closer with the experimental value of the simulation results. The welding temperature field, welding longitudinal residual stress and deformation can be simulated accurately using the modified two-dimensional Gaussian model.
Key words: heating source model; limited size; preheating; residual stress; residual deformation
