中文摘要：

基于高速气体金属电弧焊（GMAW）驼峰焊道形成过程的实验观测结果，充分考虑熔池中后向液体流的动量和热焓，在熔池表面变形方程中加入后向液体流的动能项，并将熔滴热焓分布在整个熔池表面层，建立了高速GMAW驼峰焊道形成过程的数值分析模型．模拟了一定焊接条件下的驼峰焊道形成过程及其三维形状与尺寸，与实测结果进行了对比，证明本文模型能够较好地模拟高速GMAW过程，可定量分析驼峰焊道形成过程．

英文摘要：

High speed GMAW （gas metal arc welding） is an effective way to improve the welding productivity, however, its application is usually limited by the occurrence of several weld bead defects, such as humping bead. Based on the experimental results, a mathematical model is developed to analyze the forming mechanism of humping bead for high speed GMAW through considering both the momentum and heat content of the backward flowing molten jet in weld pools. One term related to the momentum of backward jet is added to the equation of weld pool surface deformation, and the heat content of overheated droplets is distributed within the layer covering the whole pool. The humping bead forming process and its dimension and 3D geometry are numerically simulated, and compared with the experimental measurement under some welding conditions. It is found that the model can describe and characterize the humping formation in high speed GMAW quantitatively.