Residual stresses and FCP prediction in FSW through a continuous FE model

Residual stresses prediction is definitively a relevant and open issue in welding processes. In the last years, different numerical models are proposed by many researchers to predict the residual stress field in FSW butt joint. However, most of these works are based on properly tuned analytical models and neglect the effect of the mechanical action due to the presence of the tool pin. In the present paper, a continuous 3D FE model, which was previously developed by some of the authors, was used to simulate the FSW process of butt joints with a single block approach, and predict the residual stress field by considering both thermal and mechanical actions. Then, the residual stress effect on the fatigue life was estimated through fatigue crack propagation (FCP) tests in compact tension specimens. Encouraging results were found out leading to a few interesting conclusions that have to be properly verified in the future.