Harnessing uniaxial tension to tune Poisson's ratio and wave propagation in soft porous phononic crystals: an experimental study

Soft Matter ◽  
2019 ◽  
Vol 15 (14) ◽  
pp. 2921-2927 ◽  
Author(s):  
Nan Gao ◽  
Jian Li ◽  
Rong-hao Bao ◽  
Wei-qiu Chen
Keyword(s):  
Experimental Study ◽  
Wave Propagation ◽  
Uniaxial Tension ◽  
Poisson’S Ratio ◽  
Phononic Crystal ◽  
Phononic Crystals ◽  
Band Gaps ◽  
Poisson's Ratio ◽  
Elliptical Holes

In this work, we investigate the effect of regulation of uniaxial tension on the band gaps in 2D soft phononic crystal with criss-crossed elliptical holes via experiments.

Elastic Dispersion Analysis of Two Dimensional Phononic Crystals Composed of Auxetic Materials

2015 ◽  
Author(s):  
Geng-Ting Liu ◽  
Chia-Nien Tsai ◽  
I-Ling Chang ◽  
Lien-Wen Chen
Keyword(s):  
Elastic Wave ◽  
Poisson’S Ratio ◽  
Periodic Structures ◽  
Phononic Crystal ◽  
Expansion Method ◽  
Phononic Crystals ◽  
Poisson's Ratio ◽  
Square Lattice ◽  
Two Dimensional ◽  
Auxetic Materials

The wave propagations of two dimensional phononic crystals composed of auxetic materials are studied. The periodic structures consist of square lattice air cylinders in a solid background made of auxetic material. The finite element method and plane wave expansion method are used to obtain the band structures of the phononic crystals. The effects of Poisson’s ratio on the elastic wave propagation within the phononic crystal are investigated. The negative Poisson’s ratio of the auxetic material is shown to have significant effect on the dispersion of the elastic wave within the periodic structures. The results reveal that the phononic crystals composed of auxetic materials can have a great potential for the design of novel acoustic devices.

scholarly journals “Fuzzy Band Gaps”: A Physically Motivated Indicator of Bloch Wave Evanescence in Phononic Systems

Crystals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 66
Author(s):  
Connor D. Pierce ◽  
Kathryn H. Matlack
Keyword(s):  
Wave Propagation ◽  
Dispersion Relation ◽  
Quantitative Measure ◽  
Bloch Wave ◽  
Phononic Crystals ◽  
Wave Transmission ◽  
Band Gaps ◽  
Dissipative Systems ◽  
Frequency Range ◽  
Wave Modes

Phononic crystals (PCs) have been widely reported to exhibit band gaps, which for non-dissipative systems are well defined from the dispersion relation as a frequency range in which no propagating (i.e., non-decaying) wave modes exist. However, the notion of a band gap is less clear in dissipative systems, as all wave modes exhibit attenuation. Various measures have been proposed to quantify the “evanescence” of frequency ranges and/or wave propagation directions, but these measures are not based on measurable physical quantities. Furthermore, in finite systems created by truncating a PC, wave propagation is strongly attenuated but not completely forbidden, and a quantitative measure that predicts wave transmission in a finite PC from the infinite dispersion relation is elusive. In this paper, we propose an “evanescence indicator” for PCs with 1D periodicity that relates the decay component of the Bloch wavevector to the transmitted wave amplitude through a finite PC. When plotted over a frequency range of interest, this indicator reveals frequency regions of strongly attenuated wave propagation, which are dubbed “fuzzy band gaps” due to the smooth (rather than abrupt) transition between evanescent and propagating wave characteristics. The indicator is capable of identifying polarized fuzzy band gaps, including fuzzy band gaps which exists with respect to “hybrid” polarizations which consist of multiple simultaneous polarizations. We validate the indicator using simulations and experiments of wave transmission through highly viscoelastic and finite phononic crystals.

Locally resonant effective phononic crystals for subwavelength vibration control of torsional cylindrical waves

2021 ◽  
pp. 1-30
Author(s):  
Ignacio Arretche ◽  
Kathryn Matlack
Keyword(s):  
Wave Propagation ◽  
Plane Wave ◽  
Effective Properties ◽  
Equations Of Motion ◽  
Phononic Crystal ◽  
Phononic Crystals ◽  
Unit Cell ◽  
Periodic Coefficients ◽  
Bloch Theorem ◽  
Plane Wave Propagation

Abstract Locally resonant materials allow for wave propagation control in the sub-wavelength regime. Even though these materials do not need periodicity, they are usually designed as periodic systems since this allows for the application of the Bloch theorem and analysis of the entire system based on a single unit cell. However, geometries that are invariant to translation result in equations of motion with periodic coefficients only if we assume plane wave propagation. When wave fronts are cylindrical or spherical, a system realized through tessellation of a unit cell does not result in periodic coefficients and the Bloch theorem cannot be applied. Therefore, most studies of periodic locally resonant systems are limited to plane wave propagation. In this paper, we address this limitation by introducing a locally resonant effective phononic crystal composed of a radially-varying matrix with attached torsional resonators. This material is not geometrically periodic but exhibits effective periodicity, i.e. its equations of motion are invariant to radial translations, allowing the Bloch theorem to be applied to radially propagating torsional waves. We show that this material can be analyzed under the already developed framework for metamaterials. To show the importance of using an effectively periodic system, we compare its behavior to a system that is not effectively periodic but has geometric periodicity. We show considerable differences in transmission as well as in the negative effective properties of these two systems. Locally resonant effective phononic crystals open possibilities for subwavelength elastic wave control in the near field of sources.

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

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.

Effect of longitudinal stress on wave propagation in width-constrained elastic plates with arbitrary Poisson's ratio

2015 ◽  
Vol 252 (7) ◽  
pp. 1615-1619 ◽  
Author(s):  
Paweł Sobieszczyk ◽  
Marcin Majka ◽  
Dominika Kuźma ◽  
Teik-Cheng Lim ◽  
Piotr Zieliński
Keyword(s):  
Wave Propagation ◽  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Elastic Plates ◽  
Longitudinal Stress

Research on the large band gaps in multilayer radial phononic crystal structure

2016 ◽  
Vol 30 (10) ◽  
pp. 1650108 ◽  
Author(s):  
Nansha Gao ◽  
Jiu Hui Wu ◽  
Dong Guan
Keyword(s):  
Crystal Structure ◽  
Finite Element Method ◽  
Phononic Crystal ◽  
Phononic Crystals ◽  
Band Gaps ◽  
Transmission Spectra ◽  
Intermediate Mass ◽  
Displacement Fields ◽  
Vibration Coupling ◽  
Single Material

In this paper, we study the band gaps (BGs) of new proposed radial phononic crystal (RPC) structure composed of multilayer sections. The band structure, transmission spectra and eigenmode displacement fields of the multilayer RPC are calculated by using finite element method (FEM). Due to the vibration coupling effects between thin circular plate and intermediate mass, the RPC structure can exhibit large BGs, which can be effectively shifted by changing the different geometry values. This study shows that multilayer RPC can unfold larger and lower BGs than traditional phononic crystals (PCs) and RPC can be composed of single material.

P0-11 Experimental Study of Complete Band Gaps and Waveguiding Inside Phononic Crystal Slabs

2007 ◽  
Author(s):  
F.-L. Hsiao ◽  
A. Khelif ◽  
H. Moubchir ◽  
A. Choujaa ◽  
C.-C. Chen ◽  
...  
Keyword(s):  
Experimental Study ◽  
Phononic Crystal ◽  
Band Gaps

Surface Acoustic Wave Band Gaps and Phononic Structures on Thin Solid Plates

2005 ◽  
Author(s):  
Xinya Zhang ◽  
Ted Jackson ◽  
Emmanuel Lafound ◽  
Pierre Deymier ◽  
Jerome Vasseur
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Acoustic Waves ◽  
Phononic Crystal ◽  
Surface Acoustic Waves ◽  
Phononic Crystals ◽  
Band Gaps ◽  
Laser Ultrasonics ◽  
Thin Plates ◽  
Wave Band

Novel phononic crystal structures on thin plates for material science applications in ultrasonic range (~ MHz) are described. Phononic crystals are created by a periodic arrangement of two or more materials displaying a strong contrast in their elastic properties and density. Because of the artificial periodic elastic structures of phononic crystals, there can exist frequency ranges in which waves cannot propagate, giving rise to phononic band gaps which are analogous to photonic band gaps for electromagnetic waves in the well-documented photonic crystals. In the past decades, the phononic structures and acoustic band gaps based on bulk materials have been researched in length. However few investigations have been performed on phononic structures on thin plates to form surface acoustic wave band gaps. In this presentation, we report a new approach: patterning two dimensional membranes to form phononic crystals, searching for specific acoustic transport properties and surface acoustic waves band gaps through a series of deliberate designs and experimental characterizations. The proposed phononic crystals are numerically simulated through a three-dimensional plane wave expansion (PWE) method and experimentally characterized by a laser ultrasonics instrument that has been developed in our laboratory.

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