THE SECOND-ORDER PROPERTIES OF SH WAVE IN AN ISOTROPIC SOLID

摘要

The second harmonics of SH wave that occur within an isotropic plate with two free boundaries are determined by second-order perturbation theory. The results show, in general, that the total second harmonic acoustic field pattern is symmetric and the second harmonics do not have nonlinearity. However, the second harmonic resonant phenomenon occurs and the harmonic waves possess the characteristics of space accumulation once the phase velocity of SH wave equals the longitudinal one of elastic medium. Moreover, the analytical expressions of the second harmonic waves are obtained.