Features of non-linear transformation of the acoustic waves at oblique incidence on a plane boundary between two solids

The features of non-linear transformation of longitudinal and shear acoustic waves with vertical polarization (SV-waves) when they fall at the angle of 45o to the plane boundary between two rough environments were studied. Studies were made by the spectral method measuring the generation efficiency of the amplitude of the first, second and third longitudinal and shear acoustic harmonics, reflected and transmitted through a flat interface between two solids, depending on the external pressure applied to the boundary. The amplitudes of the harmonics nonmonotonically depend on the external static pressure applied to the border. The results were in agreement with the analysis indicate the presence of a strong non-linearity of the structure at the boundary between two media due to the mechanisms of contact Hertz and hysteresis non-linearity and can be used in the diagnosis of the quality of the welds.