Corrosion Damage Monitoring Using Guided Lamb Waves

In this paper, a Guided Lamb Wave (GLW) technique using piezoelectric transducers is presented to detect and monitor corrosion damage in an aluminum panel. An electro-chemical etching method was applied to simulate corrosion damage in the test article. A signal processing approach using time-based analysis was demonstrated to measure amplitude change and phase shift of GLW signals captured in the aluminum specimen. Damage Index (DI) for each sensor network was calculated based on the time-domain signal processing method. From the DI information, damage profile maps were produced by using a tomographic algorithm. Corrosion damage location and its size were identified from an integrated damage profile map. The severity of the corrosion damage was examined based on the phase shift of a fundamental anti-symmetric mode (A0) in the GLW signals. The experimental results show the capability of the proposed corrosion monitoring technique based on the GLW approach.