Residual stress effects on the fatigue life of an externally grooved thick-walled pressure vessel

摘要

To ensure the structural integrity of a thick-walled pressure vessel containing residual stresses induced by the autofrettage process, a fatigue life evaluation of the pressure vessel was performed based on the local strain approach. Residual stress distribution due to autofrettage loading were calculated using an elastic-plastic finite element stress analysis. The tangential residual stress varied from compression at the inside radius to tension near the outside radius, showing a high stress concentration at the groove root. The local stresses and local strains calculated by the elastic-plastic analysis were applied to the fatigue life evaluation of the pressure vessel. Reasonable agreement was found between the predicted and the experimental fatigue lives of the pressure vessel within factors of 3-4, depending on autofrettage level and the fatigue damage parameter.