Corrosion pit-induced stress concentration in spherical pressure vessel

This paper aims to investigate the effect of pitting corrosion on stress concentration factor (SCF) for a spherical pressure vessel subjected to internal pressure. Stress concentration at semi-elliptical corrosion pit and secondary pit nucleated at bottom of the semi-elliptical base pit are examined systematically by conducting a series of axisymmetric finite element models. SCF occurs at the bottom of the semi-elliptical pits and increases as pit depth enhances but decreases as pit width enlarges. Pit aspect ratio is a principal parameter affecting stress. Presence of a premature pit at the bottom of base pit intensifies the stress distribution and SCF.