Numerical simulation of a coupled GMAW process model

Abstract

Abstract With the help of numerical simulations of welding processes, precise predictions can be made and, if necessary, elaborate test series for the production of complex components can be reduced. Since the interactions between the arc and the workpiece surface play a central role, a coupled consideration of these sub-areas leads to a reduction of the assumptions on the model side. Therefore, a coupled GMAW process model has been developed, which consists of the partial models of the arc (finite volume method) and the weld pool (smoothed particle hydrodynamics method), and by combining them with a suitable coupling algorithm, the mutual dependence is taken into account. In this paper, the development of the coupled model will be presented. This contribution is funded within the DFG project FU 307/18-1. First, welding tests were carried out to determine boundary conditions and validation parameters. With the help of these values, a further developed, three-dimensional GMAW arc model could be validated. Furthermore, a particle-based weld pool model was developed taking the material transition into account. These partial models were coupled on the side of the arc by varying the distribution of the heat flux density, the arc pressure and the shear stress, and on the side of the weld pool by changing the surface topology of the workpiece. By comparing the dimensions of the melt zones, it was finally possible to verify the overall model and 
determine its high validity.