Suppression of front and back surface reflections in ultrasonic analytic-signal responses from composites.

Pulse-echo ultrasound testing is the most prevalent method for inspection of composite materials in industry although evolving designs combined with the anisotropic nature of composites demands the constant development of more advanced signal-processing techniques and testing equipment. One problem that is frequently encountered in ultrasonic inspection, in pulse-echo mode, is the masking effect that occurs due to the strong surface reflections. This can prove critical for the detection of near-surface defects and accurate ply-tracking of the first and last two plies.