单缆式焊丝GMAW电弧物理行为的数值模拟

Numerical Simulation of Arc Physical Behavior in Gas Metal Arc Welding with a Single Cable-typed Wire

采用Gambit软件建立了单缆式焊丝熔化极气体保护焊(GMAW)电弧三维数值模型,研究了焊接电流对单缆式焊丝GMAW电弧的电流密度、电磁场、温度场、速度场和压力场分布特征的影响。结果表明:缆式焊丝GMAW电弧的电流密度、电磁场、温度场、速度场和电弧压力最大值均随着焊接电流的增大而显著增加。缆式焊丝GMAW电弧电流密度和温度最大值位于焊丝阳极端部。电弧等离子流速最大值位于弧柱区。随着焊接电流的增加,电弧最大压力位置由速度入口向阳极区转变。在相同的焊接工艺参数条件下,三维数值模拟所得电弧形态与高速摄像系统拍摄的电弧形态吻合,验证了模拟所选三维模型的准确性。

This paper reports the numerical simulation for the arc physical behavior in gas metal arc welding (GMAW) with a single cable-typed wire,using a three-dimensional numerical model of arc established by Gambit software.We explored from the simulation results the welding current dependences of the distribution characteristics with respect to current density,electromagnetic field,temperature field,velocity field and pressure field of GMAW arc.The results showed that all the maximums in current density,electromagnetic field,temperature field,velocity field and pressure field had obvious positive correlation with the welding current.It was found that the maximum current density and highest temperature of arc occurred on the tip of single cable-typed wire,while the maximum velocity of plasma arc was located on the arc column area.Meanwhile,the transfer of location of the highest arc pressure from velocity inlet to wire tip induced by the increasing welding current was also observed.Under the same welding process parameter,the accuracy and validity of the established simulation model could be verified by a good coincidence between the simulated arc shape and the actual arc shape taken by high-speed camera system.