Experimental characterisation of the bound acoustic surface modes supported by honeycomb and hexagonal hole arrays.
Sci Rep
; 9(1): 15773, 2019 Oct 31.
Article
em En
| MEDLINE
| ID: mdl-31673035
ABSTRACT
The Dirac point and associated linear dispersion exhibited in the band structure of bound (non-radiative) acoustic surface modes supported on a honeycomb array of holes is explored. An aluminium plate with a honeycomb lattice of periodic sub-wavelength perforations is characterised by local pressure field measurements above the sample surface to obtain the full band-structure of bound modes. The local pressure fields of the bound modes at the K and M symmetry points are imaged, and the losses at frequencies near the Dirac frequency are shown to increase monotonically as the mode travels through the K point at the Dirac frequency on the honeycomb lattice. Results are contrasted with those from a simple hexagonal array of similar holes, and both experimentally obtained dispersion relations are shown to agree well with the predictions of a numerical model.
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Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article