Research of High Accuracy Detection on Plates with Electromagnetic Ultrasonic Lamb Wave

Due to the particularity of electromagnetic ultrasonic lamb wave excitation, it is difficult to satisfy demand for GJB 3384-98 which requires the Lamb wave detecting device to detect through-holes whose diameter is 1mm and groove whose depth is 0.4mm in a 4mm thick plate. In this paper, the detection capability of Lamb wave is analyzed to find a proper working point satisfying the demand detection. In addition, considering the low signal-to-noise ratio, the receiver matching circuit is redesigned to enhance the echo signal. Finally, a detecting platform is set, and the experiments shows the effectiveness of the method.