Observation of nonlinear acoustic effects at isotropic solid-solid interfaces

The second harmonic generation of SV shear waves at isotropic solid-solid i nterfaces is experimentally studied. The amplitude of shear waves is measur ed for the interfaces of glass-air, glass-iron, glass-copper, and glass-alu minum. The measured angular relation of amplitude of the second harmonic wa ve is compared with theory and the agreement is reasonably good. The influe nce of the physical state of the interface on second harmonic generation is also observed. It is found that the second harmonic generation is sensitiv e to the interface state. (C) 2001 Acoustical Society of America.