Effects of Combined Thermal Autofrettage and Wire-winding on the Structural Performance of Thick-walled Cylinders

Thermal autofrettage is a promising approach for generating beneficial residual stress patterns in thick cylinders subjected to internal pressure. However, its effectiveness is constrained by the allowable thermal gradient, as excessive temperature differences can negatively impact the mechanical and microstructural properties of the material. To overcome these limitations, this study proposes a combined approach that integrates thermal autofrettage with wire-winding prestressing. Analytical and numerical approaches, supplemented by ASME code provisions, are applied to investigate the impact of the integrated procedure on the cylinders' resistance to yielding and fatigue life. The results indicate that the combined technique significantly increases the yield onset pressure and enhances the fatigue life of the vessel compared to stand-alone thermal autofrettage and an untreated ‘monobloc cylinder’.