Abstract:
The influence of a weak longitudinal inhomogeneity on normal shear waves under different mechanical boundary conditions is investigated. It is shown, that for clamped smooth surfaces of isotropic elastic layer, occurs asymmetric localization of wave energy near the mid-surface layer. On the other side, for mechanically free smooth surfaces, near-surface localization of wave energy appears near mechanically free surfaces of the waveguide, but more intense localization appears again near the mid-surface layer. In both cases, due to the influence of material inhomogeneity on the normal wave, some distortion of amplitude and phase functions occur due to the change of formation coefficients (of frequencies). In both cases of boundary conditions, the weak inhomogeneity of the material leads to presence of frequency zones of transmission or prohibition of the formed wave. It is shown, that it is possible internal resonance in some higher forms.
Keywords:inhomogeneous waveguide, instability of normal wave, band of frequency delay.
