| Abstract Scope |
A three-dimensional quasi-steady model for Gas Metal Arc Welding (GMAW) of thin steel plates is developed using a finite volume method in an arc-fixed reference frame, in which the workpiece translates at the welding travel speed. The model fully couples heat transfer, local fluid flow in the weld pool, and free-surface deformation, so bead geometry is predicted rather than prescribed. The model incorporates temperature-dependent material properties including latent heat of fusion, a double-ellipsoid volumetric heat source, Marangoni and electromagnetic forces, and nonlinear combined convection–radiation surface boundary conditions. Butt weld experiments were conducted on thin steel plates of different widths, instrumented with thermocouples. The quasi-steady moving-frame equivalence is used to compare the predicted temperature distribution directly against measured thermal cycles, and post-weld characterization of fusion zone and bead geometry provides independent validation. The validated framework is used to examine how plate width influences weld pool flow, penetration and bead shape, and it is also applied to dissimilar welds. |