The Influence of Vibratory Treatment on the Fatigue Life of Welds: A Comparison with Thermal Stress Relief

A comparison has been made between the fatigue lives of welded specimens a) in the as welded condition b) after heat treatment, and c) after post-weld vibration. By comparison with the as-welded specimens, the fatigue lives of the thermally relieved specimens were found to decrease by 43%, while the vibration treated specimens showed an increase of between 17% and 30%. While these findings are interesting in that they offer a way of extending the fatigue lives of welded joints, they confirm the view that the mechanism of residual stress relieving in the vibratory stress relief (VSR) method, and its relationship with fatigue life is poorly understood.