Physical Model of a Weld Bead Deposit on an Inclined or Horizontal Support Applied for Wire and Arc Additive Manufacturing

The present work is carried out in the framework of the WAS project [1] which deals with the WAAM process. The process relies on an automatized welding process in which a part is built by a successively deposed metal bead. Under a two-dimensional hypothesis, we propose a physically based bead topology model using the equilibrium between the hydrostatic pressure and the capillarity force. This equilibrium can be described by the Young-Laplace equation [2]. The proposed model can also estimate a bead topology that is deposed on a horizontal or inclined support. To do so, the Young equation is used to balance the forces at the tri-phase point [3]. Moreover, the bead topology model requires a deposed melted metal volume. By modeling a gas metal arc welding (GMAW) power generator system [4], the volume can be estimated and used as a physical parameter for the bead topology model. Combining the topology and the power generator models, the resulting synergy enables to simulate the topology of a weld bead of a WAAM process. In addition to the modelling, experimental profiles of the beads are used to validate the model.