Spectral variational multiscale model for transient dynamics of phononic crystals and acoustic metamaterials

AbstractPhononic crystals and acoustic metamaterials are periodic structures whose effective properties can be tailored at will to achieve extreme control on wave propagation. Their refractive index is obtained from the homogenization of the infinite periodic system, but it is possible to locally change the properties of a finite crystal in such a way that it results in an effective gradient of the refractive index. In such case the propagation of waves can be accurately described by means of ray theory, and different refractive devices can be designed in the framework of wave propagation in inhomogeneous media. In this paper we review the different devices that have been studied for the control of both bulk and guided acoustic waves based on graded phononic crystals.

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Introduction to Phononic Crystals and Acoustic Metamaterials

Acoustic Metamaterials and Phononic Crystals - Springer Series in Solid-State Sciences ◽

10.1007/978-3-642-31232-8_1 ◽

2012 ◽

pp. 1-12 ◽

Cited By ~ 6

Author(s):

Pierre A. Deymier

Keyword(s):

Phononic Crystals ◽

Acoustic Metamaterials

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Characteristics of Band Gap and Low-frequency Wave Propagation of Mechanically Tunable Phononic Crystals with Scatterers in Periodic Porous Elastomeric Matrices

Journal of Applied Mechanics ◽

10.1115/1.4049516 ◽

2021 ◽

pp. 1-34

Author(s):

Shaowu Ning ◽

Dongyang Chu ◽

Fengyuan Yang ◽

Heng Jiang ◽

Zhanli Liu ◽

...

Keyword(s):

Wave Propagation ◽

Coupling Effect ◽

Low Frequency ◽

Phononic Crystals ◽

Band Gaps ◽

Dynamic Responses ◽

Acoustic Metamaterials ◽

Frequency Wave ◽

Strong Coupling Effect ◽

The Matrix

Abstract The characteristics of passive responses and fixed band gaps of phononic crystals (PnCs) limit their possible applications. For overcoming this shortcoming, a class of tunable PnCs comprised of multiple scatterers and soft periodic porous elastomeric matrices are designed to manipulate the band structures and directionality of wave propagation through the applied deformation. During deformation, some tunable factors such as the coupling effect of scatterer and hole in the matrix, geometric and material nonlinearities, and the rearrangement of scatterer are activated by deformation to tune the dynamic responses of PnCs. The roles of these tunable factors in the manipulation of dynamic responses of PnCs are investigated in detail. The numerical results indicate that the tunability of the dynamic characteristic of PnCs is the result of the comprehensive function of these tunable factors mentioned above. The strong coupling effect between the hole in the matrix and the scatterer contributes to the formation of band gaps. The geometric nonlinearity of matrix and rearrangement of scatterer induced by deformation can simultaneously tune the band gaps and the directionality of wave propagation. However, the matrix's material nonlinearity only adjusts the band gaps of PnCs and does not affect the directionality of wave propagation in them. The research extends our understanding of the formation mechanism of band gaps of PnCs and provides an excellent opportunity for the design of the optimized tunable PnCs and acoustic metamaterials.

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