Methodology for Stress Concentration Analysis in Corrosion Pits Using the Finite Element Method

Abstract

This paper aims to propose a methodology for stress concentration analysis in corrosion pits measured by surface topography techniques, such as interferometry. A filter was proposed to smooth the measured profile of pits, remaining the same aspect ratio (a/2c). There was an increase in the stress concentration factor ($K_t$) for discretized pit models compared with ellipsoidal pit models. The increase was already expected, since there is a pronounced effect of secondary pits in the $K_t$. The effect of the pit surface profile was more pronounced than a/2c in the $K_t$. The maximum stress was at the maximum pit depth, or it was dislocated to secondary pits, depending on the pit geometry. The $K_t$ for measured pits is possibly even greater, considering the real pit profiles.