A finite element model for surface and volumetric defects in the FSW process using a coupled Eulerian-Lagrangian approach

The friction stir welding (FSW) process is often associated with various defects, which may develop due to the inappropriate choice of process parameters. The visualisation of the defects is often impossible by means of simple experiments. The present work develops a finite element model using a coupled Eulerian-Lagrangian (CEL) approach to investigate commonly occurred defects in the FSW process. The numerical model is framed, in general, to predict multiple defects such as the improper joining of substrates, formation of tunnel defect, excessive flash, voids and other surface irregularities. In principle, the flow of material within and out of the solution domain allows predicting both the surface and subsurface defects. A suitable comparison between simulation and experiments shows the robustness of the developed model.