High-Frequency Spectra of SH GuidedWaves in Continuously Layered Plates

The spectra of SH guided waves in an isotropic continuously layered plate with arbitrary profile of the limiting slowness ŝ(y) across the plate are explicitly analyzed for high frequencies ω in the framework of “adiabatic” approximation. Dispersion equations and their solutions are analytically found for free, clamped or free-clamped faces of the plate. The positions of horizontal asymptotes for dispersion branches are determined by extreme points y _i of the dependence ŝ(y) including also inflection points and “linear” (non-extreme) min/max points. In the vicinity of all asymptotic levels, apart from the upper one, spectra form specific ladder-like patterns. Explicit asymptotics of dispersion curves are derived for a series of particular local dependencies ŝ(y) in the vicinity of points y _i .