Detection of second harmonic components of Lamb waves passed through fatigue tested magnesium plate

Lamb waves are transmitted into pure magnesium plate which is carried out fatigue test and the second harmonic components generated from the plates are detected. Second harmonic components had increased as the number of fatigue test cycles producing the stress faults was increased. At 100 thousand and 200 thousand cycles, second harmonic components had increased by approximately 3 dB and 6 dB respectively compared with an unstressed plate.