Modeling the Residual Stress Evolution in Wire-Arc Directed Energy Deposition with Interlayer Machining Interventions

Wire-Arc Directed Energy Deposition (Wire-Arc DED) is a promising metal additive manufacturing process due to its high deposition rate and ability to produce large parts. However, residual stress and geometric accuracy challenges persist. While interlayer machining in Wire-Arc DED has shown potential to improve geometric accuracy and mechanical properties, its impact on residual stress in the hybrid process remains unexplored. In this regard, developing accurate models is crucial for understanding and optimizing the residual stress in Hybrid Wire-Arc DED. This paper investigates the challenge of predicting the residual stress in Hybrid Wire-Arc DED using the Finite Element Method. Interlayer milling interventions are simulated by modelling material removal as a predominantly geometric effect through element deactivation, excluding the thermo-mechanical effects of cutting. We demonstrate the limitations of this approach through simulations and experiments, highlighting the need for improvements in modelling the residual stress induced by interlayer machining in Hybrid Wire-Arc DED.