Residual Stress Analysis in Wire-Arc Additive Manufacturing (WAAM) Using Numerical Simulations

Wire Arc Additive Manufacturing (WAAM) is a direct energy deposition process that utilizes welding technology to print engineering components layer by layer. Despite its advantages, such as a high deposition rate and cost-effectiveness, WAAM introduces significant thermal gradients that lead to residual stresses and distortion. These factors can compromise the structural integrity and performance of printed components, making accurate prediction and developing mitigation strategies are crucial for industrial applications.

This study focuses on the numerical simulation of the residual stress formation in WAAM-manufactured 316L stainless steel component, particularly in a T-joint configuration. A 3D finite element (FE) model was developed to analyse both thermal and mechanical aspects of the process, incorporating detailed clamping conditions and material properties. The thermal model was calibrated using temperature data from several surface and embedded thermocouples.

The mechanical model, validated against experimental measurements, simulated distortion and residual stress profiles using different strain hardening models, including isotropic, kinematic, and combined isotropic-kinematic approaches.

This study provides insights into optimizing WAAM parameters to minimize residual stresses and distortion. The findings underscore the significance of advanced numerical models in predicting WAAM-induced residual stresses, offering valuable tools for fast process optimization of large-scale components which are necessary for the industrial uptake of this novel technology.