Numerical Modeling and Experimental Analysis of Water Jet Spot Welding and Friction Stir Spot Welding: A Comparative Study

In this work, a finite element method was implemented to comparatively study the welding of AA6061-T6 aluminum alloy sheets by water jet spot welding and friction stir spot welding processes. The Johnson–Cook (J–C) model was applied to define the mechanical and thermal behaviors of the material during both welding processes. The simulation results showed good agreement with the experimental measurements. The process of jet impact on the flyer plate surface occurred on a short time scale which made it challenging to experimentally study the dynamic of this process. Therefore, a simulation was of great importance to consider this phenomenon. The water jet pressure and velocity, as well as the strain and stress distribution on the flyer plate surface, were thoroughly analyzed. The depression growth during the primary impact of the water jet was also studied. Regarding the FSSW process, mechanical characteristics such as stress and strain distribution, material flow, as well as the force and torque variation on the workpiece were investigated. Finally, the hardness profile and the temperature distribution in the joint area were compared in both welding processes.