Prediction of Stress Corrosion Cracking by Nonlinear Ultrasonic Guided Wave Technology

Reliable diagnosis of stress corrosion cracking (SCC) in aircraft components at an early stage is critical for maintaining mission readiness and safety. One of the primary challenges associated with maintenance management for aircraft components is that SCC does not grow at a steady rate over the life of the component, but rather the majority of the remaining useful life is spent before macroscale SCC initiates. Many traditional inspection technologies failed to effectively detect microscopic SCC in aircraft components. FBS proposes a novel nonlinear ultrasonic guided wave inspection approach and device for detecting microscopic SCC at an extremely early stage along with guided wave imaging capability of accurately identifying and characterizing macroscale SCC. Nonlinear guided waves are sensitive to microstructure change of the material and can be utilized to evaluate material properties even before the initiation of macroscale SCC. Linear guided wave scan can be used to generate damage imaging of SCC at a later stage. Another benefit of guided wave inspection is that it is able to perform long-distance inspection of hidden or inaccessible regions of the aircraft, and the sensors can be completely contained within the airframe.