Abstract: The numerical simulation of arc was carried out for both conventional melt inert gas (MIG) welding and ultrasonic assisted melt inert gas (U-MIG) welding. Based on the model established by Fluent, the arc shape, temperature field, and potential distribution were simulated. The study found that the shape of the arc changed when ultrasonic was added radially; the high-temperature area of the arc stretched, and the temperature peak increased. But as the current increased, the increase in temperature decreased. In addition, under the same conditions, the potential of U-MIG decreased and the pressure on the workpiece increased. To verify the accuracy of the simulation results, welding experiments under identical conditions were carried out, and a high-speed camera was used to collect dynamic pictures of the arc. The simulation results were in a favorable agreement with the experimental results, which provided a certain reference value for ultrasonic assisted arc welding.

Key words: numerical simulation, welding arc, ultrasonic arc welding, arc temperature

摘要： 对传统的熔化极惰性气体保护（MIG）焊和超声波辅助熔化极惰性气体保护（U-MIG）焊电弧进行了数值模拟。基于Fluent软件建立的模型，对电弧形状、温度场和电势分布进行了模拟。研究发现，径向添加超声波后，电弧的形状发生了变化；电弧的高温区域拉长，温度峰值增大。但随着电流的增大，温度的升高幅度减小。此外，在相同的条件下，U-MIG的电位降低，工件上的压力增加。为了验证仿真结果的准确性，进行了相同条件下的焊接实验，并利用高速摄像机采集电弧的动态图像。仿真结果与实验结果吻合良好，为超声辅助电弧焊提供了一定的参考价值。

关键词: 数值模拟，焊接电弧，超声波弧焊，电弧温度