Modeling and simulation of keyhole-based welding as multi-domain problem using the extended finite element method

Abstract In this article, we demonstrate the flexibility of a multi-domain approach combined with the extended finite element method by addressing the modeling and simulation of keyhole-based welding. The welding process is modeled by the heat equation where the keyhole geometry and the interface separating molten and solid area are represented by two independent level set functions, separating the domain into three time-dependent subdomains. The keyhole shape is computed by an analytical approach based on the energy balance at the keyhole wall and its shape is assumed to be fixed. The solid-liquid interface is considered as free boundary whose evolution is described by the two-phase Stefan problem. The coupled problem including the two discontinuities is solved using a multi-domain XFEM implementation. The simulated results are shown together with experimental data on different welded materials.