Enhancement of Lamb-EMAT Signal Using a Modified One-Side Pitch-Catch Design

Abstract

This study presents a modified one-side pitch-catch electromagnetic acoustic transducer (EMAT), the optimized design improves the horizontal static magnetic field excitation and helps to enhance the generation and reception of the Lamb wave. A coupling model is applied to characterise and analyse the new design in detail. The model indicates that the optimized magnetic field with an increased peak flux density compared to the traditional magnetic configuration of EMAT. As a result, the transduction efficiency of the one-side pitch-catch design is dramatically improved ingeneration and reception process. Experiments verify that a measurement system using the modified one-side pitch-catch design is improved by a factor of 3.3, when compared to conventional one-side pitch-catch design.

Keywords

• EMAT
• Lamb waves
• magnetic circuit optimization
• one–side pitch–catch