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.

Effects of rotated square inserts on the longitudinal vibration band gaps in thin phononic crystal plates

2015 ◽  
Vol 29 (20) ◽  
pp. 1550105
Author(s):  
Haojiang Zhao ◽  
Rongqiang Liu ◽  
Chuang Shi ◽  
Hongwei Guo ◽  
Zongquan Deng
Keyword(s):  
Plane Wave ◽  
Longitudinal Vibration ◽  
Phononic Crystal ◽  
Expansion Method ◽  
Band Gaps ◽  
Vibration Band ◽  
Plane Wave Expansion ◽  
Plane Wave Expansion Method ◽  
Filling Fraction ◽  
Gap Width

Longitudinal vibration of thin phononic crystal plates with a hybrid square-like array of square inserts is investigated. The plane wave expansion method is used to calculate the vibration band structure of the plate. Numerical results show that rotated square inserts can open several vibration gaps, and the band structures are twisted because of the rotation of inserts. Filling fraction and material of the insert affect the change law of the gap width versus the rotation angles of square inserts.

ONE-DIMENSIONAL PHONONIC CRYSTAL SLABS BORDERED WITH ASYMMETRIC UNIFORM LAYERS

2012 ◽  
Vol 26 (23) ◽  
pp. 1250133 ◽  
Author(s):  
HONG-BO ZHANG ◽  
JIU-JIU CHEN ◽  
XU HAN
Keyword(s):  
Band Gap ◽  
Lamb Waves ◽  
Phononic Crystal ◽  
Comsol Multiphysics ◽  
Total Thickness ◽  
Plane Wave Expansion ◽  
Fe Method ◽  
One Dimensional ◽  
Gap Width ◽  
Band Gap Width

We investigate theoretically the propagation of Lamb waves in a one-dimensional phononic crystal (PC) slabs bordered with asymmetric uniform layers based on the supercell plane wave expansion (SC-PWE) method. The validity is proved by using the finite-element (FE) method with Comsol Multiphysics 3.5a. The effect of changing the thickness of substrate and superstrate on the variation of the band gap width and frequency are studied when the total thickness of the loading layers is fixed. We also investigate the property of band gap maps by changing the total thickness or the material of the loading layers. The results show that the band structure can be tuned by changing the material or the thickness of the substrate or the superstrate. These structures may be used as filters and acoustic sensors.

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.

Flexural Vibration Band Gaps in a Ternary Phononic Crystal Thin Plate

2011 ◽  
Vol 675-677 ◽  
pp. 1085-1088
Author(s):  
Zong Jian Yao ◽  
Gui Lan Yu ◽  
Jian Bao Li
Keyword(s):  
Band Gap ◽  
Thin Plate ◽  
Mass Density ◽  
Phononic Crystal ◽  
Flexural Vibration ◽  
Expansion Method ◽  
Band Gaps ◽  
Physical Parameters ◽  
Vibration Band ◽  
Filling Fraction

The band structures of flexural waves in a ternary locally resonant phononic crystal thin plate are studied using the improved plane wave expansion method. And the thin concrete plate composed of a square array of steel cylinders hemmed around by rubber is considered here. Absolute band gaps of flexural vibration with low frequency are shown. The calculation results show that the band gap width is strongly dependent on the filling fraction, the radius ratio, the mass density and the Young’s modulus contrasts between the core and the coating. So by changing these physical parameters, the required band gap could be obtained.

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.

Thermal Tuning of Vibration Band Gaps in Thin Phononic Crystal Plates with Nitinol

2014 ◽  
Vol 597 ◽  
pp. 78-83 ◽  
Author(s):  
Hao Jiang Zhao ◽  
Rong Qiang Liu ◽  
Hong Wei Guo
Keyword(s):  
Plane Wave ◽  
Phononic Crystal ◽  
Band Gaps ◽  
Vibration Band ◽  
Plane Wave Expansion ◽  
Band Structures ◽  
Filling Fraction ◽  
Wave Expansion ◽  
Square Array ◽  
Thermal Tuning

Vibration band structures of thin phononic crystal plates (PCPs) with square array and graphite array of nitinol inserts are calculated by the plane wave expansion (PWE) method. The influences of filling fraction are considered when investigating the effects of the varying temperature on the band gaps. Vibration band gaps of these PCPs can be tuned by changing temperature. This study will be useful in designing PCPs with tunable gaps.

scholarly journals Tunable Low Frequency Band Gap and Waveguide of Phononic Crystal Plates with Different Filling Ratio

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 828
Author(s):  
Shaobo Zhang ◽  
Jiang Liu ◽  
Hongbo Zhang ◽  
Shuliang Wang
Keyword(s):  
Band Gap ◽  
Composite Structure ◽  
Structural Parameters ◽  
Phononic Crystal ◽  
Low Frequency ◽  
Filling Ratio ◽  
Height Ratio ◽  
Road Vehicles ◽  
Aluminum Base ◽  
Gap Width

Aiming at solving the NVH problem in vehicles, a novel composite structure is proposed. The new structure uses a hollow-stub phononic-crystal with filled cylinders (HPFC) plate. Any unit in the plate consists of a lead head, a silicon rubber body, an aluminum base as outer column and an opposite arranged inner pole. The dispersion curves are investigated by numerical simulations and the influences of structural parameters are discussed, including traditional hollow radius, thickness, height ratio, and the new proposed filling ratio. Three new arrays are created and their spectrum maps are calculated. In the dispersion simulation results, new branches are observed. The new branches would move towards lower frequency zone and the band gap width enlarges as the filling ratio decreases. The transmission spectrum results show that the new design can realize three different multiplexing arrays for waveguides and also extend the locally resonant sonic band gap. In summary, the proposed HPFC structure could meet the requirement for noise guiding and filtering. Compared to a traditional phononic crystal plate, this new composite structure may be more suitable for noise reduction in rail or road vehicles.

Wave propagation in acoustic metamaterials with resonantly shunted cross-shape piezos

2018 ◽  
Vol 29 (13) ◽  
pp. 2744-2753 ◽  
Author(s):  
Shengbing Chen
Keyword(s):  
Wave Propagation ◽  
Band Gap ◽  
Vibration Isolation ◽  
Band Gaps ◽  
Acoustic Metamaterials ◽  
Resonant Frequencies ◽  
Piezoelectric Patch ◽  
Transmission Properties ◽  
Gap Width ◽  
Band Gap Width

Cross-shape piezoelectric patches were originally proposed to improve the band-gap properties of acoustic metamaterials with shunting circuits. The dispersion curves are characterized through the application of finite element method. Also, the theoretical band-gap predictions are verified by simulation results obtained from COMSOL. The investigation results show that the proposed scheme distinguishes itself from the conventional square patches by broader band gaps, whose bandwidth is almost doubled. The inherent capacitance of the piezoelectric patch is strongly related to the boundary conditions, so the local resonant band gap is strongly affected by the shape of piezoelectric patches as well. As a result, the band-gap width and location of metamaterials with different shape patches are rather different, even with the same size patches. Also, negative modulus (NM) and Poisson’s ratio were observed around the resonant frequencies. The transmission properties of finite periods agree well with band-gap predictions. An obvious attenuation zone (AZ) is produced around the band-gap location, in which the wave propagation is decayed strongly. Similarly, the width of AZ of the proposed metamaterial is much larger than that of the conventional one. Hence, the proposed scheme demonstrates more advantages in the application to vibration isolation when compared with the conventional.

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