Band Gap Properties of Piezoelectric/Viscous Liquid Phononic Crystals

2011 ◽  
Author(s):  
Yi-Ze Wang ◽  
Kazuaki Inaba ◽  
Feng-Ming Li ◽  
Kikuo Kishimoto
Keyword(s):  
Band Gap ◽  
Viscous Liquid ◽  
Phononic Crystals ◽  
Viscous Damping ◽  
Viscous Effects ◽  
Filling Fraction ◽  
Damping Parameter ◽  
Out Of Plane ◽  
Gap Characteristics ◽  
Gap Width

The viscous effects on the band gap characteristics of the piezoelectric/viscous liquid phononic crystals are studied. The expressions of the generalized eigenvalue equation for the cylindrical phononic crystals are derived. Numerical calculations are performed to discuss the band gap characteristics with different filling ratios and viscous damping parameters. Form the results, it can be observed that the out-of-plane mode will appear, which caused by the viscous effects. Both of the real and imaginary parts of frequencies will increase with the filling fraction becoming larger. The maximum of the normalized band gap width is achieved by f = 0.5. Furthermore, the band gap edges become higher with the viscous damping parameter increasing, especially for higher band gaps.

Full Band-Gap Silicon Phononic Crystals for Surface Acoustic Waves

2006 ◽  
Author(s):  
Saeed Mohammadi ◽  
Abdelkrim Khelif ◽  
Ryan Westafer ◽  
Eric Massey ◽  
William D. Hunt ◽  
...  
Keyword(s):  
Band Gap ◽  
Acoustic Waves ◽  
Phononic Crystal ◽  
Surface Acoustic Waves ◽  
Hexagonal Lattice ◽  
Phononic Crystals ◽  
Bulk Wave ◽  
Filling Fraction ◽  
Phononic Band Gap ◽  
Wide Range

Periodic elastic structures, called phononic crystals, show interesting frequency domain characteristics that can greatly influence the performance of acoustic and ultrasonic devices for several applications. Phononic crystals are acoustic counterparts of the extensively-investigated photonic crystals that are made by varying material properties periodically. Here we demonstrate the existence of phononic band-gaps for surface acoustic waves (SAWs) in a half-space of two dimensional phononic crystals consisting of hexagonal (honeycomb) arrangement of air cylinders in a crystalline Silicon background with low filling fraction. A theoretical calculation of band structure for bulk wave using finite element method is also achieved and shows that there is no complete phononic band gap in the case of the low filling fraction. Fabrication of the holes in Silicon is done by optical lithography and deep Silicon dry etching. In the experimental characterization, we have used slanted finger interdigitated transducers deposited on a thin layer of Zinc oxide (sputtered on top of the phononic crystal structure to excite elastic surface waves in Silicon) to cover a wide range of frequencies. We believe this to be the first reported demonstration of phononic band-gap for SAWs in a hexagonal lattice phononic crystal at such a high frequency.

Band gap characteristics of friction stir additive manufactured phononic crystals

2022 ◽  
Author(s):  
Z.J. Tan ◽  
Zhao Zhang
Keyword(s):  
Additive Manufacturing ◽  
Band Gap ◽  
Temperature Rise ◽  
Phononic Crystals ◽  
Inertia Moment ◽  
Welding Temperature ◽  
Rotating Speed ◽  
Friction Stir ◽  
Gap Characteristics ◽  
Lower Temperature

Abstract Additive Manufacturing (AM) is widely used to fabricate phononic crystals (PnCs) in recent years. Friction Stir Additive Manufacturing (FSAM) is a new-type solid state fabrication technology which is fusion free with low distortions. FSAM was selected to fabricate the designed PnCs. The manufactured specimen was distorted due to the temperature rise in the manufacturing process and the band gaps (BGs) were changed with the distortions. Results indicate that the band gap of the PnCs moves to be in higher frequency domain due to the residual distortions of the manufactured PnCs. The residual distortion of FSAM PnCs is 2.77 times smaller in comparison with the Tungsten Inert Gas (TIG) welding. So, the differences of the band gap between the designed PnCs and the FSAM specimen are only in the range of 0.15%- 0.55% due to the lower temperature rise in FSAM. The further analysis shows that the change of the BGs is caused by the growth of the inertia moment for the FSAM PnCs. With the increase of the rotating speed in FSAM, the residual distortion of the FSAM PnCs is increased due to the increase of the welding temperature. This can lead to the increase of the inertia moment, which is the key reason for the increase of the BG characteristics of the FSAM PnCs.

Sonic Wave Band Gaps in Two-Dimensional Phononic Crystals Consisting of Hollow Mercury Columns Immersed in a Water Host, and Arranged in Simple Lattices

2014 ◽  
Vol 875-877 ◽  
pp. 512-517
Author(s):  
Yong Gang Xie ◽  
Jian Bing Chen ◽  
Gai Jing Huangfu ◽  
Hai Yang
Keyword(s):  
Cross Sections ◽  
Phononic Crystals ◽  
Band Gaps ◽  
Wave Band ◽  
Two Dimensional ◽  
Frequency Filtering ◽  
Filling Fraction ◽  
Water Columns ◽  
Sonic Wave ◽  
Gap Width

In this paper, band gaps for two-dimensional phononic crystals consisting of hollow square water columns immersed in a mercury host are investigated by plane-wave-expansion (PWE) method, in which cross sections of the scattering objects are hollow-square and hollow water columns are arranged in simple lattices (square, and triangular lattices). In order to regulate band gaps, we alter inner side lengths of hollow-square column, and change the filling ratio at the same time. From the results, It can be found that the band gap width and the number of the bad gaps can be changed by lattice shapes and corresponding filling fraction. This could be very useful in the design of phononic crystals band gaps and frequency filtering.

Study on Filling Fraction of Bandgap Lowest Starting Frequency of one Dimension Phononic Crystals

2012 ◽  
Vol 518-523 ◽  
pp. 3865-3868
Author(s):  
Zhuo Fei Song ◽  
Qiang Song Wang ◽  
Zai Qiang Feng ◽  
Zi Dong Wang
Keyword(s):  
Elastic Modulus ◽  
Band Gap ◽  
Calculation Method ◽  
Phononic Crystals ◽  
One Dimension ◽  
Filling Fraction

A calculation method of lowest band gap starting frequency corresponding to filling fraction of fixed periodic size one dimension phononic crystals are given, found the filling fraction only correlation with the density of two materials, but no correlation with elastic modulus, furthermore found no correlation with periodic size.

Active tuning of the vibration band gap characteristics of periodic laminated composite metamaterial beams

2020 ◽  
Vol 31 (6) ◽  
pp. 843-859 ◽  
Author(s):  
Tao Ren ◽  
Chunchuan Liu ◽  
Fengming Li ◽  
Chuanzeng Zhang
Keyword(s):  
Band Gap ◽  
Piezoelectric Actuator ◽  
Composite Beam ◽  
Laminated Composite ◽  
Dynamic Responses ◽  
Vibration Band ◽  
Gap Characteristics ◽  
Laminated Composite Beam ◽  
Gap Width ◽  
Band Gap Width

A novel strategy is proposed to investigate the vibration band-gap and active tuning characteristics of the laminated composite metamaterial beams. The piezoelectric actuator/sensor pairs are periodically placed along the laminated composite beam axis so that the vibration frequency band-gap and active tuning characteristics can be induced. The dynamic equations of the laminated composite metamaterial beams bonded by the piezoelectric actuator/sensor pairs are established based on the Euler–Bernoulli beam theory. The negative proportional feedback control strategy is employed to provide the positive active control stiffness for the piezoelectric actuator/sensor patches. The spectral element method is used to calculate the dynamic responses of the laminated composite metamaterial beams with the periodically placed piezoelectric patches, and the calculation accuracy for the dynamic responses is validated by the finite element method. The results demonstrating the high-performance vibration band-gap properties in the low-frequency ranges can be achieved by properly designing the sizes and the number of the piezoelectric patches. Moreover, the vibration band-gap characteristics, especially the band-gap width and the normalized band-gap width with respect to the considered excitation frequency range, can be significantly changed by tuning the structural parameters of the piezoelectric actuators and sensors. In addition, the cross-ply angle of the laminated composite metamaterial beams has significant influences on the band-gap characteristics and the vibration reduction performance of the laminated composite beam structures.

scholarly journals Second Order Approximation for Band Gap Characterization of One-Dimensional Dielectric Omnidirectional Reflector

2003 ◽  
Vol 12 (02) ◽  
pp. 263-275 ◽  
Author(s):  
J. Prawiharjo ◽  
A. A. Iskandar ◽  
M. O. Tjia ◽  
E. van Groesen
Keyword(s):  
Band Gap ◽  
Order Approximation ◽  
Filling Fraction ◽  
Numerical Result ◽  
Index Contrast ◽  
Analytical Expressions ◽  
Approximate Expressions ◽  
Gap Width ◽  
Good Agreement

A derivation of approximate analytical expressions for band edges ω± of the first band gap of a multilayer periodic structure is presented for both TE and TM waves at arbitrary angles of incidence. It is found that the approximate expressions give an excellent agreement with the numerical results as verified by the band edge variation with respect to the filling fraction [Formula: see text] and refractive index contrast Δn. The analytical expressions for the band edges are further employed to derive a semi numerical optimization of the relative gap width [Formula: see text] with respect to the filling fraction ν. The result is again shown to be in good agreement with the numerical result.

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