The EIFS distribution for anodized and pre-corroded 7010-T7651 under constant amplitude loading

This paper reports results from SICAS, an experimental programme to evaluate the effectiveness of the equivalent initial flaw size (EIFS) approach in managing the structural integrity effects of pitting corrosion. Fatigue crack growth and life tests were conducted on anodized and pre-corroded 7010-T7651. The corrosion pits that initiated fatigue were then measured using the SEM. These data were analysed statistically to identify the pit geometric parameter(s) that influenced fatigue life. Projected pit area had the strongest effect, while pit depth and pit width were each statistically insignificant. The EIFS distribution for corroded 7010-T7651 was then calculated. Examination of the probability distribution of the ratio of EIFS area to pit area allowed the derivation of a scatter factor that gave safely conservative fatigue life predictions for the corroded material.