Numerical modeling methodologies for friction stir welding process

Friction stir welding (FSW) is a solid-state joining process and is performed in three stages, viz., plunging, dwelling, and welding. In the plunging stage, a nonconsumable rotating tool plunges onto the workpiece surface to generate heat. Further, during dwelling the tool rotates in its position to further increase the heat generation. Finally, the rotating tool traverses along the abutting edge to perform welding. Numerical modeling has become an efficient tool for the analysis of any manufacturing process. Three different modeling techniques, viz., Lagrangian, Eulerian, and Coupled Eulerian and Lagrangian (CEL) analyses have been discussed to simulate FSW. Each method is distinct in its own way and is capable of simulating FSW. Comparison of these methods in terms of implementation and methodology has been discussed to provide insight into their capabilities. Lagrangian method is implemented by using DEFORM-3D coupled with a remeshing technique to tackle mesh distortion. ANSYS Fluent is used to implement Eulerian method, and this method is the least time consuming among the three. CEL exploits the advantages of Lagrangian and Eulerian technique and is implemented through ABAQUS/Explicit. This method requires higher computation time but can predict volumetric defects.