Optimization of stationary shoulder friction stir welding numerical model based on instantaneous velocity center

During the friction stir welding process, the motion of the stirring tool is divided into two parts: the rotational motion and the lateral feed, both of which influence the temperature distribution, material flow, and slip rate. The effect of the rotational motion in numerical simulations is usually the focus of research, but the changes in material flow, slip, and heat generation due to welding speed are usually neglected. In this study, the numerical model of stationary shoulder friction stir welding (SSFSW) was developed to optimize the effect of welding speed on heat generation and material flow based on the instantaneous velocity center (IVC), and the relationship between n/v and IVC were discussed. The instantaneous velocity center distance was inversely proportional to n/v, and its magnitude affected the difference in temperature between the AS and RS.