Two-dimensional finite element simulation of material flow in the friction stir welding process

Solid mechanics based finite element models and computational procedures have been developed by the authors to study and simulate the friction stir welding process. In this paper, two-dimensional simulation results of the material flow pattern and spatial velocity field around the rotating tool pin during welding, and the positions of material particles around the pin after welding, are presented. Material flow pattern predictions are found to compare favorably with experimental observations. Simulation results suggest that material particles in front of the tool pin tend to pass and get behind the rotating pin from the retreating side of the pin. Similarities between predicted velocity fields based on two different tool-workpiece interface models are described in detail, and implications of these findings (e.g., to fluid dynamics based models) are discussed.