Low frequency phononic band structures in two-dimensional arc-shaped phononic crystals

2012 ◽  
Vol 376 (33) ◽  
pp. 2256-2263 ◽  
Author(s):  
Zhenlong Xu ◽  
Fugen Wu ◽  
Zhongning Guo
Author(s):  
Zi-Gui Huang ◽  
Yunn-Lin Hwang ◽  
Pei-Yu Wang ◽  
Yen-Chieh Mao

The excellent applications and researches of so-called photonic crystals raise the exciting researches of phononic crystals. By the analogy between photon and phonon, repetitive composite structures that are made up of different elastic materials can also prevent elastic waves of some certain frequencies from passing by, i.e., the frequency band gap features also exist in acoustic waves. In this paper, we present the results of the tunable band gaps of acoustic waves in two-dimensional phononic crystals with reticular band structures using the finite element method. Band gaps variations of the bulk modes due to different thickness and angles of reticular band structures are calculated and discussed. The results show that the total elastic band gaps for mixed polarization modes can be enlarged or reduced by adjusting the orientation of the reticular band structures. The phenomena of band gaps of elastic or acoustic waves can potentially be utilized for vibration-free, high-precision mechanical systems, and sound insulation.


2019 ◽  
Vol 33 (32) ◽  
pp. 1950403
Author(s):  
Fengxiang Guo ◽  
Hui Guo ◽  
Pei Sun ◽  
Tao Yuan ◽  
Yansong Wang

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.


Crystals ◽  
2017 ◽  
Vol 7 (11) ◽  
pp. 328 ◽  
Author(s):  
Mao Liu ◽  
Jiawei Xiang ◽  
Yongteng Zhong

2014 ◽  
Vol 81 (9) ◽  
Author(s):  
Y. Huang ◽  
C. L. Zhang ◽  
W. Q. Chen

The control of band structures of 2D phononic crystals (PCs) composed of piezoelectric inclusions and elastic isotropic matrix with mechanical/electrical biasing fields is theoretically investigated. The theory for small fields superposed on biasing fields and the plane wave expansion (PWE) method is employed to compute the band structures of the PCs under different biasing fields, including the initial shear/normal stress and the initial electric field. We find that the initial shear stress breaks the symmetry of the material. In consequence, the two bands associated with the level repulsion effect are opened near the apparent crosspoint and form a local band gap. On the other hand, the normal initial stress and the biasing electric field change the effective stiffness and shift the positions of band gaps. The observed phenomena show that the biasing fields can be flexibly used to tune the PC devices.


2012 ◽  
Vol 26 (29) ◽  
pp. 1250189 ◽  
Author(s):  
ZHENLONG XU ◽  
FUGEN WU ◽  
ZHONGNING GUO

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.


2017 ◽  
Vol 31 (06) ◽  
pp. 1750038 ◽  
Author(s):  
Ailing Song ◽  
Xiaopeng Wang ◽  
Tianning Chen ◽  
Lele Wan

In this paper, the acoustic wave propagation in a two-dimensional phononic crystal composed of rotational multiple scatterers is investigated. The dispersion relationships, the transmission spectra and the acoustic modes are calculated by using finite element method. In contrast to the system composed of square tubes, there exist a low-frequency resonant bandgap and two wide Bragg bandgaps in the proposed structure, and the transmission spectra coincide with band structures. Specially, the first bandgap is based on locally resonant mechanism, and the simulation results agree well with the results of electrical circuit analogy. Additionally, increasing the rotation angle can remarkably influence the band structures due to the transfer of sound pressure between the internal and external cavities in low-order modes, and the redistribution of sound pressure in high-order modes. Wider bandgaps are obtained in arrays composed of finite unit cells with different rotation angles. The analysis results provide a good reference for tuning and obtaining wide bandgaps, and hence exploring the potential applications of the proposed phononic crystal in low-frequency noise insulation.


2016 ◽  
Vol 30 (07) ◽  
pp. 1650029 ◽  
Author(s):  
Ailing Song ◽  
Xiaopeng Wang ◽  
Tianning Chen ◽  
Ping Jiang ◽  
Kai Bao

In this paper, we theoretically investigate the propagation characteristics of Lamb wave in a two-dimensional (2D) asymmetric phononic crystal (PC) plate composed of cylinder stubs of different radius deposited on both sides of a thin homogeneous plate. The dispersion relations, transmission spectra and displacement fields of the eigenmodes are calculated by using the finite element method (FEM). Two complete bandgaps (BGs) can be found in low-frequency range and the transmission spectra coincide with the band structures. We investigate the evolution of dispersion relations with the decrease of the upper stub radius. The physical mechanism of the upper stub radius effect is also studied with the displacement fields of the unit cell. Numerical results show that the symmetry of the stub radius can remarkably influence the band structures and the asymmetric double-sided plate exhibits a new bandgap (BG) in lower frequency range due to the coupling between the lower stub’s resonant mode and the plate’s Lamb mode becomes weak and the adjacent bands separate. Moreover, we further investigate the effect of the stub height on the dispersion relations and find that the BGs shift to lower frequency regions with the increase of the stub height. In addition, the BGs’ sensitivity to the upper stub radius and the stub height is discussed. The low-frequency BGs in the proposed PC plate can potentially be used to control and insulate vibration in low frequency range.


2015 ◽  
Vol 34 (5) ◽  
pp. 335-342
Author(s):  
Yoon Mi Kim ◽  
Kang Il Lee ◽  
Hwi Suk Kang ◽  
Suk Wang Yoon

Sign in / Sign up

Export Citation Format

Share Document