2. Physical phenomena and their modeling

The focus here is on the mechanical and metallurgical consequences of a welding process. It is beyond the scope of this article to describe the physical phenomena associated with heat input (electric arc, laser-material interaction, etc.) or to analyze the flow in the molten bath. The heat input is modelled solely from a thermal point of view, using an appropriately shaped heat source. Convection phenomena in the liquid bath are taken into account simply by artificially increasing thermal conductivity at the corresponding temperatures. Similarly, the electrothermal couplings involved in resistance welding processes, extensively described in the article of the same treaty [49] , will not be detailed here.

The various physical phenomena involved and their coupling are shown in figure...