COUPLED EULERIAN-LAGRANGIAN THERMOMECHANICAL MODEL TO PREDICT RESIDUAL STRESS DURING ADDITIVE FRICTION STIR DEPOSITION OF ALUMINUM 6061

Additive friction stir deposition (AFSD) is a solid-state additive manufacturing process that is increasing in popularity thanks to the absence of high temperature effects in the deposited material. Due to the large amount of material flow, conventional Lagrangian (finite element) models are incapable of capturing realistic material physics involved in the process. Alternatively, although Eulerian (computational fluid dynamics) models capture large material flow, they cannot predict the mechanical (stress-strain) response of the material. Existing AFSD modeling works in the literature either apply simplifying assumptions or do not predict the mechanical response of the material. To address this research gap, a coupled Eulerian-Lagrangian (CEL) model is developed to simulate AFSD of aluminum 6061 and predict the thermomechanical response of the material during and after deposition. This physics-based model captures the influences of significant material flow, adiabatic heating due to plastic deformation and frictional heating during deposition and reasonably predicts temperature and residual stress.