New strategy of solid/fluid coupling during numerical simulation of thermo-mechanical processes

In this study, numerical methods are developed to simulate thermomechanical processes, taking into account both the fluid flows in the molten pool and the deformations of the solid parts. The methods are based on a new strategy of solid/fluid coupling. They allow to simulate the formation of the molten pool by taking into account the fluid flows through both effects of the surface tension (curvature effect and Marangoni effect) and the buoyancy. An ALE approach is used to follow the evolution of the free surface. The effects of the deformations in the base metal on the fluid flows in the molten pool (solid/fluid interaction) is ensured by imposing the velocities of the solid nodes during the thermo-fluid simulation. As an application, a thermo-fluid-mechanical simulation of laser welding is carried out. It is found that the solid/fluid interaction has a minor effect on simulation results. (C) 2020 Elsevier Ltd. All rights reserved.