Relative reflection intensity of Lamb waves from elliptically-shaped damages in metallic plates

To improve the reliability and sensitivity of techniques using Lamb waves, the influences of Lamb wave dispersion, the shape of damage, the excitation frequency in wave signals, and the incident angle of the Lamb wave on the relative reflection intensity (RRI) from through-thickness elliptically-shaped damages in an aluminum plate are investigated systematically by employing a powerful Chebyshev pseudospectral Mindlin plate element. The A₀ Lamb wave mode is chosen, although the conclusions in this work should also be applicable to the S₀ mode. The obtained numerical results show that the dispersion of the Lamb wave has no obvious effect on the RRI, whereas the other parameters mentioned above have a remarkable influence on the RRI from elliptically-shaped damages. The results obtained can be helpful for understanding the complex interactions between Lamb waves and various areas of damage, and for improving the design of actuator/sensor placements and input wave signals.