Propagation Characteristic in 2D Phononic Crystals with Bending Linear Defect

2012 ◽  
Vol 217-219 ◽  
pp. 2566-2570
Author(s):  
Guang Hui Fan ◽  
De Xun Zhao ◽  
Jiao He ◽  
Ying Kai Liu
Keyword(s):  
Acoustic Wave ◽  
Plane Wave ◽  
Phononic Crystal ◽  
Defect Mode ◽  
Propagation Characteristic ◽  
Phononic Crystals ◽  
Plane Wave Expansion ◽  
Linear Defect ◽  
Plane Wave Method ◽  
The Waves

The band gap of 2D perfect and defect phononic crystal are calculated by using plane-wave expansion (PWE) and supercell plane wave method, which is consist of Al2O3 embedded in the epoxy resin with a square arrangement. Compared to the perfect, the gap of defect will become wider. As the size of defect length ld varied, the band structure changed. It is found that the acoustic wave only propagates along the path of defect when the propagation of acoustic wave is simulated on the 900 bending defect phononic crystals by matlab. It means that the waves are localized. So the defect mode of phononic crystal can be used as acoustic waveguide along the specific path.

Transmission Properties in 2D Phononic Crystal Thin Plate with Linear Defect

2013 ◽  
Vol 652-654 ◽  
pp. 1383-1387
Author(s):  
Guang Hui Fan ◽  
De Xun Zhao ◽  
Jiao He ◽  
Ying Kai Liu
Keyword(s):  
Plane Wave ◽  
Band Gap ◽  
Thin Plate ◽  
Phononic Crystal ◽  
Plane Wave Expansion ◽  
Linear Defect ◽  
Filling Fraction ◽  
Plane Wave Method ◽  
Gap Width ◽  
Band Gap Width

The band gap of 2D perfect phononic crystal thin plate was investigated by plane-wave expansion (PWE), which is consist of copper embedded in the organic glass with a square arrangement. The band gap of straight linear defect, branching linear defect, and symmetrical linear defect are calculated by supercell plane wave method respectively. It is found that the bandwidth of defect structure will become narrow. Especially there is little band gap appearing for straight linear defect. As the filling fraction varied, the band gap width and the band gap number changed.

scholarly journals Design and Optimization of a Novel SAW Gyroscope Structure Based on Amplitude Modulation with 1-D Phononic Crystals

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1485
Author(s):  
Fei Ge ◽  
Liye Zhao ◽  
Yang Zhang
Keyword(s):  
Signal Processing ◽  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Amplitude Modulation ◽  
Phononic Crystal ◽  
Defect Mode ◽  
High Sensitivity ◽  
Phononic Crystals ◽  
Linear Range ◽  
One Dimensional

Surface acoustic wave gyroscopes (SAWGs), as a kind of all-solid-state micro-electro-mechanical system (MEMS) gyroscopes, can work normally under extremely high-impact environmental conditions. Among the current SAWGs, amplitude-modulated gyroscopes (AMGs) are all based on the same gyro effect, which was proved weak, and their sensitivity and intensity of the output are both lower than frequency-modulated gyroscopes (FMGs). However, because FMGs need to process a series of frequency signals, their signal processing and circuits are far less straightforward and simple than AMGs. In order to own both high-sensitivity and simple signal processing, a novel surface acoustic traveling wave gyroscope based on amplitude modulation is proposed, using one-dimensional phononic crystals (PCs) in this paper. In view of its specific structure, the proposed gyroscope consists of a surface acoustic wave oscillator and a surface acoustic wave delay line within a one-dimensional phononic crystal with a high-Q defect mode. In this paper, the working principle is analyzed theoretically through the partial wave method (PWM), and the gyroscopes with different numbers of PCs are also designed and studied by using the finite element method (FEM) and multiphysics simulation. The research results demonstrate that under a 1 V oscillator voltage output, the higher sensitivity of −23.1 mV·(rad/s)−1 in the linear range from −8 rad/s to 8 rad/s is reached when the gyro with three PC walls, and the wider linear range from −15 rad/s to 17.5 rad/s with the sensitivity of −6.7 mV·(rad/s)−1 with only one PC wall. Compared with the existing AMGs using metal dots to enhance the gyro effect, the sensitivity of the proposed gyro is increased by 15 to 112 times, and the linear range is increased by 4.6 to 186 times, even without the enhancement of the metal dots.

Acoustic wave frequency filtering in constant total length phononic crystals of Al/Pb multilayer

2021 ◽  
Author(s):  
Chittaranjan Nayak ◽  
Mehdi Solaimani ◽  
Alireza Aghajamali ◽  
Arafa H. Aly
Keyword(s):  
Acoustic Wave ◽  
Phononic Crystal ◽  
Phononic Crystals ◽  
Geometrical Parameters ◽  
One Dimensional ◽  
Internal Geometry ◽  
Total Length ◽  
Acoustic Filters ◽  
System Length ◽  
Phononic Band Gaps

In this study, we have scrutinized the frequency gap generation by changing the geometrical parameters of a one-dimensional phononic crystal. For this purpose, we have calculated the transmission coefficient of an incident acoustic wave by using the transfer matrix method. We have retained and fixed the total length of the system and changed the system internal geometry not to increase the system length too much. Another reason was to adjust the phononic band gaps and get the desired transmission properties by finding the optimum internal geometry without increasing or decreasing the total length of phononic crystals. In addition, we also propose few structures with the opportunity of applications in acoustical devices such as sonic reflectors. Our results can also be of high interest to design acoustic filters in the case that transmission of certain frequencies is necessary.

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.

scholarly journals Modelling Propagating Bloch Waves in Magnetoelectroelastic Phononic Structures with Kagomé Lattice Using the Improved Plane Wave Expansion

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 586 ◽  
Author(s):  
Edson Jansen Pedrosa de Miranda ◽  
Samuel Filgueiras Rodrigues ◽  
Clodualdo Aranas ◽  
Hélio Vitor Cantanhêde da Silva ◽  
Eden Santos Silva ◽  
...  
Keyword(s):  
Plane Wave ◽  
Transverse Isotropy ◽  
Phononic Crystal ◽  
Plane Wave Expansion ◽  
Kagome Lattice ◽  
Dispersion Diagram ◽  
Kagomé Lattice ◽  
Wave Expansion ◽  
Piezomagnetic Effects ◽  
Classical Elasticity Theory

We studied the dispersion diagram of a 2D magnetoelectroelastic phononic crystal (MPnC) with Kagomé lattice. The MPnC is composed of BaTiO3–CoFe2O4 circular scatterers embedded in a polymeric matrix. The improved plane wave expansion (IPWE) approach was used to calculate the dispersion diagram (only propagating modes) of the MPnC considering the classical elasticity theory, solid with transverse isotropy and wave propagation in the xy plane. Complete Bragg-type forbidden bands were observed for XY and Z modes. The piezoelectric and the piezomagnetic effects significantly influenced the forbidden band widths and localizations. This investigation can be valuable for elastic wave manipulation using smart phononic crystals with piezoelectric and piezomagnetic effects.

scholarly journals Use of Transient Time Response as a Measure to Characterize Phononic Crystal Sensors

2018 ◽  
Author(s):  
Simon Villa-Arango ◽  
David Betancur Sánchez ◽  
Róbinson Torres ◽  
Panayiotis Kyriacou
Keyword(s):  
Transient Response ◽  
Composite Structures ◽  
Phononic Crystal ◽  
Defect Mode ◽  
Lithium Carbonate ◽  
Phononic Crystals ◽  
Transient Time ◽  
Frequency Measurements ◽  
Periodic Composite ◽  
The Impact

Phononic crystals are periodic composite structures with specific resonant features that are gaining strength in the field as liquid sensors. The introduction of a structural defect in an otherwise periodic regular arrangement can generate a resonant mode, also called defect mode, inside the characteristic band gaps of phononic crystals. The morphology, as well as the frequency in which these defect modes appear, can give useful information on the composition and properties of an analyte. Currently, only gain, and frequency measurements are performed using phononic crystal sensors. Other measurements like the transient response have been implemented in resonant sensors such as quartz microbalances showing great results and proving to be a great complimentary measure to the gain and frequency measurements. In the present paper, a study of the feasibility of using the transient response as a measure to acquire additional information about the analyte is presented. Theoretical studies using the transmission line model were realized to show the impact of variations in the concentration of an analyte, in this case, lithium carbonate solutions, in the transient time of the system. Experimental realizations were also performed showing that the proposed measurement scheme presents significant changes in the resulting data, indicating the potential use of this measure in phononic crystal sensors. This proposed measure could be implemented as a stand-alone measure or as a compliment to current sensing modalities.

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.

scholarly journals Using PWE/FE Method to Calculate the Band Structures of the Semi-Infinite PCs: Periodic in x–y Plane and Finite in z -direction

2017 ◽  
Vol 42 (4) ◽  
pp. 735-742 ◽  
Author(s):  
Denghui Qian ◽  
Zhiyu Shi
Keyword(s):  
Finite Element ◽  
Band Structure ◽  
Plane Wave ◽  
Composite Structures ◽  
Phononic Crystal ◽  
Plane Wave Expansion ◽  
Fe Method ◽  
Band Structures ◽  
Wave Expansion ◽  
Elastic Composite

Abstract This paper introduces the concept of semi-infinite phononic crystal (PC) on account of the infinite periodicity in x-y plane and finiteness in z-direction. The plane wave expansion and finite element methods are coupled and formulized to calculate the band structures of the proposed periodic elastic composite structures based on the typical geometric properties. First, the coupled plane wave expansion and finite element (PWE/FE) method is applied to calculate the band structures of the Pb/rubber, steel/epoxy and steel/aluminum semi-infinite PCs with cylindrical scatters. Then, it is used to calculate the band structure of the Pb/rubber semi-infinite PC with cubic scatter. Last, the band structure of the rubbercoated Pb/epoxy three-component semi-infinite PC is calculated by the proposed method. Besides, all the results are compared with those calculated by the finite element (FE) method implemented by adopting COMSOL Multiphysics. Numerical results and further analysis demonstrate that the proposed PWE/FE method has strong applicability and high accuracy.

Study on the Vibration Reduction of Phononic Crystal Structural Plate

2014 ◽  
Vol 543-547 ◽  
pp. 3900-3903
Author(s):  
Yu Yang He ◽  
Xiao Xiong Jin
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Wave Propagation ◽  
Plane Wave ◽  
Elastic Wave ◽  
Band Gap ◽  
Phononic Crystal ◽  
Vibration Reduction ◽  
Plane Wave Expansion ◽  
Crystal Structural

Plane wave expansion (PWE) method and finite element method (FEM) are applied to analyze the vibration reduction characteristic of the phononic crystal structural plate, and the results of two methods are consistent. The range of band gap is acquired, which certain frequent elastic wave propagation is forbidden.

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