Effect of Pitting Corrosion on the Stress Intensity Factor Magnitude and Distribution

摘要

The fracture and fatigue performance of corroded steel components show significant degradation in both the crack initiation and propagation stage. This study is aimed to research the fracture behavior degradation mechanism of corroded steel members through investigating the effects of pits on stress intensity factor magnitude and distribution. The numerical simulation method was adopted, and a series of specimens with different sizes and shapes of corrosion pits were modeled. It was found that the pitting-degradation models would show a more intense displacement and stress field. A greater value of stress intensity factor SIF could be observed in model interior when the specimens were attacked by corrosion pits. The SIF distribution characteristic along thickness direction was affected by ratios of pit depth to radius. According to SIF numerical results, the premature fracture and shorter fatigue life induced by corrosion pits could be attributed to the higher SIF value compared with non-corrosion one.