Influence of Random Disorders on Anti-Plane Waveguiding Modes in a Two-Dimensional Phononic Crystal

2011 ◽  
Vol 197-198 ◽  
pp. 352-357
Author(s):  
A Li Chen ◽  
Yue Sheng Wang ◽  
Chuan Zeng Zhang
Keyword(s):  
Phononic Crystal ◽  
Expansion Method ◽  
Guided Wave ◽  
Phononic Crystals ◽  
Two Dimensional ◽  
Wave Localization ◽  
Plane Wave Expansion Method ◽  
Band Structures ◽  
Line Defects ◽  
Random Disorder

In this paper, combined with the supercell technique, the plane wave expansion method is used to calculate the band structures of the two-dimensional phononic crystals with line defects and the random disorders in either radius or location of the scatterers. Phononic systems with plumbum scatterers embedded in an epoxy matrix are calculated in detail. The influences of the random disorder on the band structures of anti-plane waveguiding modes will be discussed. The displacement distributions are calculated to show the wave localization phenomenon. Propagation of the guided wave in the phononic crystals with different disordered degree is studied. The analysis is relevant to the assessment of the influences of manufacture errors on wave behaviors in waveguiding phononic crystals as well as the possible control of wave propagation by intentionally introducing disorders into the systems.

Localization of In-Plane Guided Elastic Waves in a Two-Dimensional Solid Waveguiding Phononic Crystal

2011 ◽  
Vol 52-54 ◽  
pp. 1233-1236 ◽  
Author(s):  
A Li Chen ◽  
Yue Sheng Wang ◽  
Chuan Zeng Zhang
Keyword(s):  
Plane Wave ◽  
Guided Waves ◽  
Phononic Crystal ◽  
Expansion Method ◽  
Phononic Crystals ◽  
Two Dimensional ◽  
Plane Wave Expansion Method ◽  
Band Structures ◽  
Disorder Degree ◽  
Line Defects

Combined with the supercell technique, the plane wave expansion method is used to calculate the band structures for the in-plane wave of the two-dimensional solid-solid phononic crystals with line defects and the random disorders in either radius or location of the scatterers. The influences of the random disorders on the band structures and guided waves will be discussed. Propagation of the wave with one certain frequency in the waveguiding phononic crystals with different disorder degree is studied.

Studies on Band Structures and Wave Localization Phenomenon of the Randomly Disordered Two-Dimensional Solid-Fluid Phononic Crystals

2011 ◽  
Vol 675-677 ◽  
pp. 639-642
Author(s):  
A Li Chen ◽  
Yue Sheng Wang ◽  
Chuan Zeng Zhang
Keyword(s):  
Phononic Crystal ◽  
Expansion Method ◽  
Two Dimensional ◽  
Wave Localization ◽  
Plane Wave Expansion Method ◽  
Displacement Fields ◽  
Band Structures ◽  
Water Matrix ◽  
Localization Phenomenon ◽  
Disorder Degree

The supercell based plane wave expansion method is used to study the effects of random disorders on the band structures of a two-dimensional (2D) solid-fluid phononic crystal. Phononic systems with steel scatterers embedded in a water matrix are calculated in detail. The radius disorder and location disorder are concerned. The influences of the disorder degree on the first band gap are investigated. The localization phenomenon is discussed by computing the displacement fields in the supercell.

Study on band gap properties of two-dimensional phononic crystals based on generalized viscoelastic modeling

2019 ◽  
Vol 33 (32) ◽  
pp. 1950403
Author(s):  
Fengxiang Guo ◽  
Hui Guo ◽  
Pei Sun ◽  
Tao Yuan ◽  
Yansong Wang
Keyword(s):  
Plane Waves ◽  
Single Mode ◽  
Expansion Method ◽  
Maxwell Model ◽  
Phononic Crystals ◽  
Band Gaps ◽  
Two Dimensional ◽  
Band Structures ◽  
Material Parameters ◽  
Multi Mode

Viscoelastic materials can dissipate energy and hinder propagation for plane waves, which can adjust the band structures of phononic crystals (PCs). In this study, the wave propagation in a two-dimensional PC with a viscoelastic matrix is investigated. The Maxwell model is utilized to analyze the effect of material parameters on the frequency dependence of viscoelasticity. Material parameters include the relaxation time, the initial value and the final value of the shear modulus. Band structures of viscoelastic phononic crystals (VPCs) are solved by combining the plane wave expansion method and iterative algorithm based on Bloch theory. The effects of the viscoelasticity on the band structures are studied using the single-mode and multi-mode Maxwell models. Results reveal that the viscoelasticity of the materials not only extends the band gaps but also shifts the band gaps to lower frequencies. Furthermore, the viscoelasticity simulated by the multi-mode model can precisely adjust anyone of the band gaps of VPCs separately. Results provide insights into the design and applications of VPCs.

LOCALIZED MODES OF A COMPRESSION WAVE IN TWO-DIMENSIONAL SOLID–SOLID PHONONIC CRYSTALS

2012 ◽  
Vol 26 (29) ◽  
pp. 1250189 ◽  
Author(s):  
ZHENLONG XU ◽  
FUGEN WU ◽  
ZHONGNING GUO
Keyword(s):  
Low Frequency ◽  
Expansion Method ◽  
Phononic Crystals ◽  
P Wave ◽  
Wave Band ◽  
Two Dimensional ◽  
Plane Wave Expansion Method ◽  
Localized Modes ◽  
Potential Applications ◽  
Localization Of Vibration

We have studied the compression (P) wave band structures at a low frequency in two-dimensional solid–solid phononic crystals. The plane-wave expansion method based on the decomposition of elastic waves was used. The pressure field distribution of P-wave localized modes at Γ points in the lowest bands, including multiple flat bands of systems comprising different configurations, were analyzed. The results show that a lower symmetry of the scatterer are an effective method to enhance the localization of vibration modes. The property has potential applications in the design of waveguides.

Wavelet-Based FDTD and High Resolution Spectral Estimation for Calculation of Band Structures in Two-Dimensional Phononic Crystals

2014 ◽  
Vol 575 ◽  
pp. 108-114
Author(s):  
Zhi Zhong Yan
Keyword(s):  
High Resolution ◽  
Spectral Estimation ◽  
Phononic Crystal ◽  
Fdtd Method ◽  
Phononic Crystals ◽  
Two Dimensional ◽  
Band Structures ◽  
Time Stepping ◽  
Long Time ◽  
Difference Time

This paper discusses the wavelet-based Finite Difference Time Domain (FDTD) method and high resolution spectral estimation with a specific problem of sound wave propagation through phononic crystals. If the band structures of a phononic crystal are calculated by the traditional FDTD method combined with the fast Fourier transform (FFT), good estimation of the eigenfrequencies can only be ensured by the postprocessing of sufficiently long time series generated by a large number of FDTD iterations. In this paper, a postprocessing method based on the high-resolution spectral estimation via the Yule-Walker method is proposed to overcome the difficulty. Numerical simulation results for two-dimensional phononic crystal show that, the wavelet-based FDTD method improves the efficiency of the time stepping algorithm, and high resolution spectral estimation shows the advantages over the classic FFT-based postprocessing.

TUNABLE BAND STRUCTURES OF 2D MULTI-ATOM ARCHIMEDEAN-LIKE PHONONIC CRYSTALS

2012 ◽  
Vol 01 (02) ◽  
pp. 1250016 ◽  
Author(s):  
Y. L. XU ◽  
C. Q. CHEN ◽  
X. G. TIAN
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Phononic Crystal ◽  
Phononic Crystals ◽  
Band Gaps ◽  
Two Dimensional ◽  
Primitive Cell ◽  
The Finite Element Method ◽  
Band Structures ◽  
Solid System

Two dimensional multi-atom Archimedean-like phononic crystals (MAPCs) can be obtained by adding "atoms" at suitable positions in primitive cells of traditional simple lattices. Band structures of solid-solid and solid-air MAPCs are computed by the finite element method in conjunction with the Bloch theory. For the solid-solid system, our results show that the MAPCs can be suitably designed to split and shift band gaps of the corresponding traditional simple phononic crystal (i.e., with only one scatterer inside a primitive cell). For the solid-air system, the MAPCs have more and wider band gaps than the corresponding traditional simple phononic crystal. Numerical calculations for both solid-solid and solid-air MAPCs show that the band gap of traditional simple phononic crystal can be tuned by appropriately adding "atoms" into its primitive cell.

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