Band Gaps of Three-Dimensional Phononic Crystal with Anisotropic Spheres

Abstract Three-dimensional (3D) locally resonant phononic crystals (LRPCs) are studied with the aim of optimising the sub-wavelength band gaps of such composites. By analysing their effective acoustic properties, it has been found that the effective acoustic speed of the composite will drop to zero when local resonance arise, and will increase monotonically when Bragg scattering effects occur. Moreover, if the matrix is a low-shear-speed medium, local resonators can significantly reduce the effective acoustic speed of the composite and, therefore, lower the frequency where Bragg scattering effects occur. Hence, a specific LRPC with alternating elastic and fluid matrices is proposed, whose resonance and Bragg gaps are already close in frequency. The fluid matrix behaves as a wave filter, which prevents the shear waves from propagating in the composite. By using the layer-multiple-scattering theory, the coupling behaviour of local resonance and Bragg scattering band gaps has been investigated. Both gaps are enhanced when they move closer to each other. Finally, a gap-coupled case is obtained that displays a broad sub-wavelength band gap. Such proposal excels at the application of underwater acoustic materials since the arrangement of structure can be handily adjusted for tuning the frequency of coupled gap.

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Band Gaps in Three-Dimensional Layer-by-Layer Phononic Crystal

Journal of Vibration and Acoustics ◽

10.1115/1.4023825 ◽

2013 ◽

Vol 135 (4) ◽

Cited By ~ 10

Author(s):

N. Aravantinos-Zafiris ◽

M. M. Sigalas

Keyword(s):

Time Domain ◽

Finite Difference Time Domain ◽

Periodic Boundary ◽

Phononic Crystal ◽

Three Dimensional ◽

Periodic Boundary Conditions ◽

Band Gaps ◽

Layer By Layer ◽

Phononic Band Gaps ◽

Difference Time

In this work, we numerically investigate the existence of phononic band gaps in the layer-by-layer rods structure. For the numerical calculations the finite difference time domain method was used and the transmission, as well as the band structure (using periodic boundary conditions and the Bloch theorem), was calculated. Several different materials (considered as the rods materials) were examined and the effects of all the geometric parameters of the structure were also numerically investigated. The results show that this structure seems to have very promising features as a phononic crystal giving, under certain conditions, a full 3D band gap. Taking into account that it is already known for its use as a photonic crystal, a certain belief for its use simultaneously as a photonic and phononic crystal rises.

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Flexural Wave Band Gaps in Phononic Crystal Thick Plates with Defects

10.26678/abcm.diname2019.din2019-0002 ◽

2019 ◽

Author(s):

Edson Jansen Pedrosa de Miranda Junior ◽

Jose Maria Campos dos Santos

Keyword(s):

Phononic Crystal ◽

Band Gaps ◽

Flexural Wave ◽

Wave Band ◽

Thick Plates

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The Voigt effects in the anisotropic photonic band gaps of three-dimensional magnetized plasma photonic crystals doped by the uniaxial material

Optics Communications ◽

10.1016/j.optcom.2013.06.011 ◽

2013 ◽

Vol 307 ◽

pp. 86-95 ◽

Cited By ~ 6

Author(s):

Hai-Feng Zhang ◽

Shao-Bin Liu ◽

Bing-Xiang Li

Keyword(s):

Photonic Crystals ◽

Three Dimensional ◽

Magnetized Plasma ◽

Band Gaps ◽

Photonic Band Gaps ◽

Plasma Photonic Crystals ◽

Photonic Band

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Lamb wave band gaps in locally resonant phononic crystal strip waveguides

Physics Letters A ◽

10.1016/j.physleta.2011.10.064 ◽

2012 ◽

Vol 376 (4) ◽

pp. 579-583 ◽

Cited By ~ 24

Author(s):

Yuanwei Yao ◽

Fugen Wu ◽

Xin Zhang ◽

Zhilin Hou

Keyword(s):

Lamb Wave ◽

Phononic Crystal ◽

Band Gaps ◽

Wave Band

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Thermal Design of Highly-Efficient Thermoelectric Materials With Atomic-Scale Three-Dimensional Phononic Crystals

Volume 10: Mechanics of Solids and Structures, Parts A and B ◽

10.1115/imece2007-43538 ◽

2007 ◽

Author(s):

Jean-Numa Gillet ◽

Yann Chalopin ◽

Sebastian Volz

Keyword(s):

Thermal Conductivity ◽

Bulk Material ◽

Phononic Crystal ◽

Three Dimensional ◽

Mean Free Path ◽

Dispersion Curves ◽

Phononic Crystals ◽

Thermal Design ◽

Atomic Scale ◽

Thermal Insulating

Owing to their thermal insulating properties, superlattices have been extensively studied. A breakthrough in the performance of thermoelectric devices was achieved by using superlattice materials. The problem of those nanostructured materials is that they mainly affect heat transfer in only one direction. In this paper, the concept of canceling heat conduction in the three spatial directions by using atomic-scale three-dimensional (3D) phononic crystals is explored. A period of our atomic-scale 3D phononic crystal is made up of a large number of diamond-like cells of silicon atoms, which form a square supercell. At the center of each supercell, we substitute a smaller number of Si diamond-like cells by other diamond-like cells, which are composed of germanium atoms. This elementary heterostructure is periodically repeated to form a Si/Ge 3D nanostructure. To obtain different atomic configurations of the phononic crystal, the number of Ge diamond-like cells at the center of each supercell can be varied by substitution of Si diamond-like cells. The dispersion curves of those atomic configurations can be computed by lattice dynamics. With a general equation, the thermal conductivity of our atomic-scale 3D phononic crystal can be derived from the dispersion curves. The thermal conductivity can be reduced by at least one order of magnitude in an atomic-scale 3D phononic crystal compared to a bulk material. This reduction is due to the decrease of the phonon group velocities without taking into account that of the phonon average mean free path.

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