Abstract
Arc welding phenomena have been theoretically investigated by using various numerical models, which have been proposed and developed together with rapid progress of the computer technologies. However, most of the numerical models are two-dimensional axial symmetric models that are available only for stationary arc on the flat plate. Actual welding processes applied to the manufacturing field are carried out with various joint geometries and the welding arc moves on the base metal. Therefore, they should be non-axial symmetric phenomena and it is required to be discussed with a three-dimensional (3D) model. In this research, TIG arc characteristics in V-groove welding are numerically investigated by using our 3D numerical model. It is shown that both heat input and arc pressure on the groove surface are significantly different from the flat plate surface. In the groove heat input and arc pressure are varied sensitively with location and aiming of the TIG torch. Experimental results show the validity of calculation results of TIG arc heat input distribution on the groove surface.