One-way Lamb mixing method in thin plates with randomly distributed micro-cracks

Abstract It is crucial to detect and evaluate early material degradation caused by micro-cracks in key engineering structures. This paper investigates the resonant behavior of one-way Lamb mixing waves in thin plates with randomly distributed micro-cracks by numerical simulations. It is found that when the resonance condition ω S 0 / ω A 0 = 2 κ / ( κ + 1 ) is satisfied, a resonant A0 mode wave can be generated by a pair of A0 and S0 mode waves mixed in the micro-crack damage region. Meanwhile, it is manifested that the acoustic nonlinearity parameter increases with the crack density and the length of the micro-crack region, which is also related to the resonant frequency. Furthermore, it is proven that the location of the micro-crack region can be determined by the time-domain signals of the resonant wave. This study numerically reveals that the one-way Lamb mixing method is feasible to quantitatively identify micro-crack damage in thin plates.