Resonance-induced band gaps of elastic waves traveling along corrugated-plate sidewalls

Abstract

We investigate elastic waves propagating along a sidewall of periodically corrugated plates. It is found that high-order transverse modes are involved in resonances when the period and thickness of the plate are close in value. In addition to the Bragg resonances caused by the same transverse modes, there are different types of resonances generated by the interaction between different transverse modes (called non-Bragg resonances). A graphical method is proposed to predict the transverse mode resonances and the related frequency gaps are confirmed by finite element simulations. Mode component analyses for the Bragg and non-Bragg gaps show that only the fundamental mode dominates the Bragg resonance, whereas both fundamental and first-order modes participate in the non-Bragg resonances. Moreover, the band gaps can be modulated by the phase shift and amplitude of corrugations, which provides an efficient method for realizing elastic wave filtering applications.