Multiphysics modeling of pulsed laser welding

Laser beam welding is largely used in industrial manufacturing because of the advantages it provides such as high-quality welds. Nevertheless, depending on the operating conditions, porosities or unwanted deformations can be produced during welding operations. In order to understand and control the responsible underlying mechanisms, numerical models are developed in a unique finite element formalism. All models are based on experimental characterizations. First of all, a thermal-hydraulic model is developed to predict the dimensions of the melted zones and the heat-affected zones as well as the mechanisms of porosities formation for a Ti6VAl4 alloy. A thermal-mechanical model including metallurgical phase changes is then developed in order to predict the residual states of stress and strain. The heat source is calibrated with an optimization procedure based on thermal-hydraulic analysis. Indeed, an equivalent approach is used to reduce the computational time for thermal-mechanical computations. Finally, this model is applied to a study case and numerical results are discussed and compared with experimental data.