Flaw detection in rotating structures by Lamb waves

Rotor damage detection is crucial in order to ensure safe operation of aircraft. We present a technique that detects defects in rotating propellers. A pulsed Nd:YAG laser is scanned across an aluminum sample that rotates at 415 rpm to generate ultrasound while a LDV picks up data. We detected the presence of a surface breaking rectangular notch, determined its position, and calculated its size.