Tuning characteristic of band gap and waveguide in a multi-stub locally resonant phononic crystal plate

Abstract

In this paper, the tuning characteristics of band gaps and waveguides in a locally resonant phononic crystal structure, consisting of multiple square stubs deposited on a thin homogeneous plate, are investigated. Using the finite element method and supercell technique, the dispersion relationships and power transmission spectra of those structures are calculated. In contrast to a system of one square stub, systems of multiple square stubs show wide band gaps at lower frequencies and an increased quantity of band gaps at higher frequencies. The vibration modes of the band gap edges are analyzed to clarify the mechanism of the generation of the lowest band gap. Additionally, the influence of the stubs arrangement on the band gaps in multi-stub systems is investigated. The arrangements of the stubs were found to influence the band gaps; this is critical to understand for practical applications. Based on this finding, a novel method to form defect scatterers by changing the arrangement of square stubs in a multi-stub perfect phononic crystal plate was developed. Defect bands can be induced by creating defects inside the original complete band gaps. The frequency can then be tuned by changing the defect scatterers’ stub arrangement. These results will help in fabricating devices such as acoustic filters and waveguides whose band frequency can be modulated.

Acoustic isolation of disc‐shaped modes using periodic corrugated plate‐based phononic crystal

“…5b. In comparison to previous cavity designs reported in the literature and using similar calculation method [2,6,7], the proposed structure enables to achieve the much higher Q factor with minimal phononic crystal size.…”

“…The acoustic energy with frequencies in the band gaps may be localised in the defect and therefore the propagation can be engineered. In the case of locally resonant structural unit cells, the phononic crystals can exhibit band gaps with a lattice constant smaller than the relevant wavelength [4][5][6][7]. The eigenfrequencies of the localised modes generally depend on the precise geometrical properties (such as size or shape) and the composition of the supporting structure.…”

“…The eigenfrequencies of the localised modes generally depend on the precise geometrical properties (such as size or shape) and the composition of the supporting structure. Many authors have studied the defect states in such phononic crystals and demonstrated their usefulness as waveguides, filters, and cavity modes [6,7].…”

Highly confined radial contour modes in phononic crystal plate based on pillars with cap layers

“…Many authors have studied the defect states in such phononic crystals and demonstrated their usefulness as waveguides, filters, and cavity modes. [23][24][25][26][27][28][29][30][31][32][33][34][35][36] In a recent paper, 37 we have proposed a phononic crystal based on 1D grooves placed periodically in one direction and surmounted by disc shaped thin metallic films deposited periodically on each groove. This platform enabled us to obtain highly confined disc shaped radial contour modes, characterized by their high Q factor and surface mode nature.…”

Emergent wave phenomena in coupled elastic bars: from extreme attenuation to realization of elastodynamic switches

“…With the modification of Newton’s second law 14 , the periodic elastic composite may be homogenized and designed to exhibit frequency dependent effective properties 15 , 16 . Those effective properties lead to efficient wave manipulation and result in applications such as enhanced wave damping 17 , wave guides 18 , noise filters 19 and cloaking 20 , 21 .…”