Excitation efficiency analysis and mode selection on ultrasonic guided wave mixing

Wave mixing of ultrasonic guided wave has attracted considerable attention because of its potential for localizing micro-damage in plate-like structures. Non-zero power flux and phase-velocity matching are regarded as the necessary conditions for generating cumulative harmonics. However, selecting a high-efficiency Lamb mode with obvious difference or sum harmonics remains problematic in practice. In this paper, experiment and numerical simulations have been performed to investigate the excitation efficiency of mode pairs that satisfy resonance conditions. The result shown that a mode pair (S0 mode at 1.2MHz and S0 mode at 3.0MHz can generate the S2 mode at 4.2MHz) has more obvious harmonics than other mode pairs. We could find that the potential of the excitation efficiency simulation on selecting mode pairs with obviously harmonics.