Characterization of surface damage of a solid plate under tensile loading using nonlinear Rayleigh waves

This letter reports experimental observation of a direct correlation between the acoustic nonlinearity parameter (NP) measured with nonlinear Rayleigh waves and the accumulation of plasticity damage in an AZ31 magnesium alloy plate specimen. Rayleigh waves are generated and detected with wedge transducers, and the NPs are measured at different stress levels. The results show that there is a significant increase in the NPs with monotonic tensile loads surpassing the material's yielding stress. The research suggests an effective nondestructive evaluation method to track the surface damage in metals.