Using ultrasonic guided wave mode cutoff for corrosion detection and classification

The use of guided wave mode cutoff as a feature for the detection and quantification of corrosion in plate and pipe structures was studied. To examine the nature of the interaction between guided waves and a corrosion region, the theory for traction free plates was first examined. From the theory, features were chosen that have a potential for corrosion detection and classification. A series of experiment were then conducted to establish the validity of the proposed features. Two methods were explored as possible means for determining the cutoff frequencies in the test specimens. The first uses a tone burst system to generate modes close to the cutoff region. The second uses a shock excitation system.