Flexural Vibration Band Gaps in Periodic Sandwich Beams With Auxetic Core

2007 ◽  
Author(s):  
Jihong Wen ◽  
Xisen Wen ◽  
Dianlong Yu
Keyword(s):  
Flexural Vibration ◽  
Expansion Method ◽  
Phononic Crystals ◽  
Band Gaps ◽  
Vibration Band ◽  
Sandwich Beams ◽  
Plane Wave Expansion ◽  
Plane Wave Expansion Method ◽  
One Dimensional ◽  
Material Parameters

The flexural vibration band gaps in one-dimensional periodic sandwich beams with auxetic core are studied basing on the theory of Phononic crystals. The band structures of one-dimensional periodic sandwich beams with auxetic core are presented with the plane wave expansion method, the regular calculation method in phononic crystals. Further, the effects of material parameters and structure parameters on the gaps are analyzed. The vibration band gaps in the sandwich beams provide a new idea for the vibration controlling of the structure.

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.

Triply Coupled Vibration Band Gaps in Periodic Thin-Walled Open Cross Section Beams

2005 ◽  
Author(s):  
Dianlong Yu ◽  
Yaozong Liu ◽  
Jing Qiu ◽  
Gang Wang ◽  
Jihong Wen
Keyword(s):  
Cross Section ◽  
Expansion Method ◽  
Band Gaps ◽  
Vibration Band ◽  
Coupled Vibration ◽  
Plane Wave Expansion Method ◽  
Filling Fraction ◽  
Thin Walled ◽  
Gap Width ◽  
Open Cross Section

Triply coupled vibration through periodic thin-walled open cross section nonsymmetrical beams composed of two kinds of material is studied in this paper. Based on the triply coupled vibration equation, plane wave expansion method for the thin-walled beams is provided. If the filling fraction keeps constant, the lattice is one of the factors that affect the normalized gap width. If the lattice and filling fraction keep constant, the Young’s modulus contrast plays a fundamental role for the band gap width, but not density contrast. Finally, the frequency response of a finite periodic binary beam is simulated with finite element method, which provides an attenuation of over 20dB in the frequency range of the band gaps. The findings will be significant in the application of phononic crystals.

scholarly journals Complete photonic band gaps in Sn2P2X6 (X = S, Se) supercell photonic crystals

2020 ◽  
Vol 557 (1) ◽  
pp. 92-97
Author(s):  
Sevket Simsek ◽  
Selami Palaz ◽  
Husnu Koc ◽  
Amirullah M. Mamedov ◽  
Ekmel Ozbay
Keyword(s):  
Optical Properties ◽  
Finite Difference ◽  
Maxwell Equations ◽  
Expansion Method ◽  
Band Gaps ◽  
Plane Wave Expansion ◽  
Photonic Band Gaps ◽  
Plane Wave Expansion Method ◽  
Difference Time ◽  
Photonic Band

In this work, we present an investigation of the optical properties and band structures for the photonic crystal structures (PCs) based on Sn2P2X6: X = S, Se) with Fibonacci superlattices. The optical properties of PCs can be tuned by varying structure parameters such as the lengths of poled domains, filling factor, and dispersion relation. In our simulation, we employed the finite-difference time domain technique and the plane wave expansion method, which implies the solution of Maxwell equations with centered finite-difference expressions for the space and time derivatives.

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.

PHOTONIC GAPS IN PERIODIC DIELECTRIC STRUCTURES

1992 ◽  
Vol 06 (03) ◽  
pp. 139-144 ◽  
Author(s):  
C.T. CHAN ◽  
K.M. HO ◽  
C.M. SOUKOULIS
Keyword(s):  
Plane Wave ◽  
Electromagnetic Waves ◽  
Expansion Method ◽  
Dielectric Materials ◽  
Band Gaps ◽  
Plane Wave Expansion ◽  
Photonic Band Gaps ◽  
Plane Wave Expansion Method ◽  
Dielectric Structures ◽  
Photonic Band

Using a plane wave expansion method, we solved the Maxwell’s equations for the propagation of electromagnetic waves inside periodic dielectric materials, and found the existence of photonic band gaps in several classes of periodic dielectric structures.

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.

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