In-Situ Surface Acoustic Wave Monitoring of Fatigue Crack Initiation and Propagation
Material degradation due to pitting corrosion and fatigue crack initiation from pits may trigger widespread fatigue damage in aging aircraft structures. Since corrosion damage is often hidden, the corrosion pits and initiated cracks can remain undetected by surface inspection techniques for long service periods. Therefore, the ability to predict the initiation and propagation of surface damage originating from pitting corrosion is of great importance for the timely maintenance of aging airplanes . Recently, we reported a microradiographic method quantifying pitting corrosion  and fatigue life prediction model  based on the measured pit depth. These have been applied successfully to A1-2024-T3 alloy.