A0 Mode Excitation and Defect Detection in Aluminum Beam Structure

Abstract

Abstract As a method to realize the defect detection in beam structure, this paper constructs an EMAT-laser detection system to detect the notch defect in an aluminum beam. EMAT is designed as a transmitter to generate single Lamb wave mode. A high precision laser detector is used as a receiver to obtain the received signals. The defect is localized and quantified with the help of space-frequency-wavenumber analysis. The evaluated depth of the defect is 2.006 mm, while the actual size is 2 mm. It shows good agreement between the evaluated result and actual size, the error is only 0.3%. This method also can be used in the evaluation of defect in other materials.