scholarly journals Recent Advances in Non-Traditional Elastic Wave Manipulation by Macroscopic Artificial Structures

2020 ◽  
Vol 10 (2) ◽  
pp. 547 ◽  
Author(s):  
Jeonghoon Park ◽  
Dongwoo Lee ◽  
Junsuk Rho
Keyword(s):  
Elastic Wave ◽  
Elastic Waves ◽  
Acoustic Waves ◽  
Electromagnetic Waves ◽  
Gradient Index ◽  
Bragg Scattering ◽  
Elastic Materials ◽  
Artificial Structures ◽  
Elastic Metamaterials ◽  
Gradient Index Lens

Metamaterials are composed of arrays of subwavelength-sized artificial structures; these architectures give rise to novel characteristics that can be exploited to manipulate electromagnetic waves and acoustic waves. They have been also used to manipulate elastic waves, but such waves have a coupling property, so metamaterials for elastic waves uses a different method than for electromagnetic and acoustic waves. Since researches on this type of metamaterials is sparse, this paper reviews studies that used elastic materials to manipulate elastic waves, and introduces applications using extraordinary characteristics induced by metamaterials. Bragg scattering and local resonances have been exploited to introduce a locally resonant elastic metamaterial, a gradient-index lens, a hyperlens, and elastic cloaking. The principles and applications of metasurfaces that can overcome the disadvantages of bulky elastic metamaterials are discussed.

scholarly journals Numerical Modelling and Optimization of Two-Dimensional Phononic Band Gaps in Elastic Metamaterials with Square Inclusions

2021 ◽  
Vol 11 (7) ◽  
pp. 3124
Author(s):  
Alya Alhammadi ◽  
Jin-You Lu ◽  
Mahra Almheiri ◽  
Fatima Alzaabi ◽  
Zineb Matouk ◽  
...  
Keyword(s):  
Elastic Wave ◽  
Tungsten Carbide ◽  
Composite Structure ◽  
Elastic Waves ◽  
Wave Attenuation ◽  
Low Frequency ◽  
Filling Fraction ◽  
Carbide Composite ◽  
Elastic Metamaterials ◽  
Tungsten Carbide Composite

A numerical simulation study on elastic wave propagation of a phononic composite structure consisting of epoxy and tungsten carbide is presented for low-frequency elastic wave attenuation applications. The calculated dispersion curves of the epoxy/tungsten carbide composite show that the propagation of elastic waves is prohibited inside the periodic structure over a frequency range. To achieve a wide bandgap, the elastic composite structure can be optimized by changing its dimensions and arrangement, including size, number, and rotation angle of square inclusions. The simulation results show that increasing the number of inclusions and the filling fraction of the unit cell significantly broaden the phononic bandgap compared to other geometric tunings. Additionally, a nonmonotonic relationship between the bandwidth and filling fraction of the composite was found, and this relationship results from spacing among inclusions and inclusion sizes causing different effects on Bragg scatterings and localized resonances of elastic waves. Moreover, the calculated transmission spectra of the epoxy/tungsten carbide composite structure verify its low-frequency bandgap behavior.

Transformation Method to Control Shear Horizontal Waves

2015 ◽  
Vol 07 (03) ◽  
pp. 1550049 ◽  
Author(s):  
Yongquan Liu ◽  
Wei Liu ◽  
Bing Li ◽  
Xianyue Su
Keyword(s):  
Elastic Waves ◽  
Acoustic Waves ◽  
Electromagnetic Waves ◽  
Effective Medium Theory ◽  
Transformation Method ◽  
Sh Waves ◽  
Medium Theory ◽  
Out Of Plane ◽  
Linear Transformation Method ◽  
Shear Horizontal

The transformation method is of great interest to control electromagnetic waves and acoustic waves in recent years, but it does not always work to manipulate elastic waves. In this paper, a detailed analysis of controlling the shear horizontal (SH) wave, which is a special form of elastic waves, is presented by employing the transformation method. Two scenarios of setting needed materials are provided, and the equivalence of them is proved theoretically. To reduce the complexity of required material parameters, the case of a changing out-of-plane coordinate is studied. The linear transformation method and the effective medium theory are introduced to control SH waves by using homogeneous and isotropic materials. Moreover, numerical simulations confirm the validity of this approach even in the cases of anisotropic and inhomogeneous background media, which are rarely investigated before. Finally, the multiple transformations method is proposed as a strategy of designing multi-domain and multi-function devices.

Sonic Gradient Index Lens in Water

2010 ◽  
Author(s):  
Theodore P. Martin ◽  
Michael Nicholas ◽  
Gregory J. Orris ◽  
Liang-Wu Cai ◽  
Daniel Torrent ◽  
...  
Keyword(s):  
Gradient Index ◽  
Gradient Index Lens

Three-Dimensional Spatial Image Forming Using Gradient-Index Lens Arrays.

2002 ◽  
Vol 30 (12) ◽  
pp. 731-736
Author(s):  
Fumio OKANO ◽  
Jun ARAI ◽  
Makoto OKUI
Keyword(s):  
Three Dimensional ◽  
Gradient Index ◽  
Spatial Image ◽  
Gradient Index Lens

scholarly journals Two-photon microscopy with simultaneous standard and extended depth of field using a tunable acoustic gradient-index lens

2009 ◽  
Vol 34 (11) ◽  
pp. 1684 ◽  
Author(s):  
Nicolas Olivier ◽  
Alexandre Mermillod-Blondin ◽  
Craig B. Arnold ◽  
Emmanuel Beaurepaire
Keyword(s):  
Depth Of Field ◽  
Gradient Index ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
Gradient Index Lens ◽  
Extended Depth Of Field

A CALIBRATED MODEL SEISMIC SYSTEM

Geophysics ◽  
1972 ◽  
Vol 37 (3) ◽  
pp. 445-455 ◽  
Author(s):  
C. N. G. Dampney ◽  
B. B. Mohanty ◽  
G. F. West
Keyword(s):  
Wave Propagation ◽  
Elastic Wave ◽  
Elastic Waves ◽  
Critical Examination ◽  
Two Dimensional ◽  
Linear Filtering ◽  
Analog Model ◽  
Basic Assumptions ◽  
Electronic Circuitry ◽  
Seismic System

Simple electronic circuitry and axially polarized ceramic transducers are employed to generate and detect elastic waves in a two‐dimensional analog model. The absence of reverberation and the basic simplicity. of construction underlie the advantages of this system. If the form of the fundamental wavelet in the model itself, as modified by the linear filtering effects of the remainder of the system, can be found, then calibration is achieved. This permits direct comparison of theoretical and experimental seismograms for a given model if its impulse response is known. A technique is developed for calibration and verified by comparing Lamb’s theoretical and experimental seismograms for elastic wave propagation over the edge of a half plate. This comparison also allows a critical examination of the basic assumptions inherent in a model seismic system.

Fiber compatible fast acousto‐optic modulator using a gradient index lens as the interaction medium

1993 ◽  
Vol 62 (26) ◽  
pp. 3402-3404 ◽  
Author(s):  
I. Abdulhalim ◽  
C. N. Pannell ◽  
D. N. Payne
Keyword(s):  
Gradient Index ◽  
Acousto Optic Modulator ◽  
Gradient Index Lens

Numerical simulation for coupled nonlinear Schrödinger–Korteweg–de Vries and Maccari systems of equations

2021 ◽  
pp. 2150339
Author(s):  
Lanre Akinyemi ◽  
Pundikala Veeresha ◽  
Samuel Oluwatosin Ajibola
Keyword(s):  
Numerical Simulation ◽  
Plasma Physics ◽  
Acoustic Waves ◽  
Electromagnetic Waves ◽  
Nonlinear Partial Differential Equations ◽  
Transform Method ◽  
Langmuir Waves ◽  
Suggested Approach ◽  
Nonlinear Schrödinger ◽  
De Vries

The primary goal of this paper is to seek solutions to the coupled nonlinear partial differential equations (CNPDEs) by the use of q-homotopy analysis transform method (q-HATM). The CNPDEs considered are the coupled nonlinear Schrödinger–Korteweg–de Vries (CNLS-KdV) and the coupled nonlinear Maccari (CNLM) systems. As a basis for explaining the interactive wave propagation of electromagnetic waves in plasma physics, Langmuir waves and dust-acoustic waves, the CNLS-KdV model has emerged as a model for defining various types of wave phenomena in mathematical physics, and so forth. The CNLM model is a nonlinear system that explains the dynamics of isolated waves, restricted in a small part of space, in several fields like nonlinear optics, hydrodynamic and plasma physics. We construct the solutions (bright soliton) of these models through q-HATM and present the numerical simulation in form of plots and tables. The solutions obtained by the suggested approach are provided in a refined converging series. The outcomes confirm that the proposed solutions procedure is highly methodological, accurate and easy to study CNPDEs.

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