Abstract:
The influence of weak roughness of mechanically free elastic waveguide surfaces on propagation of normal shear wave is investigated. Thin layers of variable thickness are virtually separated in near-surface areas. Distribution functions of elastic shears are introduced in separated elastic layers (hypotheses MELS). Introduction of hypotheses MELS will make the study of wave processes in waveguides with complicated properties and sophisticated characteristic roughness of the material of the waveguide and its surfaces more convenient. It is shown that in contrast to perfectly smooth surfaces, weak roughness of the mechanically free surfaces leads to distortion of propagating normal waves. Partial localization of wave energy occurs in near-surface layers of the waveguide. Frequency zones of silence of newly formed waves (as well as zones of frequency bandwidth) appear as well.
Keywords:instability of normal waves, weakly rough surfaces, delay frequency, internal resonance.
