Investigation of High-Frequency Guided Wave Modes Applicability in Defect Detection Using Phased Array Ultrasonic Transducer.

An ultrasonic phased array scanning method was used for lamb wave evaluation of surface and in-depth defects in a steel plate. The ultrasonic guided wave modes resulting from a phased array transducer were modeled using finite element method. The experimental results showed that the high-frequency A0 mode gives acceptable sensitivity and resolution for small diameter through-thickness and surface defects. The sectorial scanning showed better axial resolution rather than spatial resolution. [ABSTRACT FROM AUTHOR]