scholarly journals Bridging-Coupling Band Gaps in Nonlinear Acoustic Metamaterials

2018 ◽  
Vol 10 (5) ◽  
Author(s):  
Xin Fang ◽  
Jihong Wen ◽  
Dianlong Yu ◽  
Jianfei Yin
2018 ◽  
Vol 29 (13) ◽  
pp. 2744-2753 ◽  
Author(s):  
Shengbing Chen

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.


2021 ◽  
pp. 1-34
Author(s):  
Shaowu Ning ◽  
Dongyang Chu ◽  
Fengyuan Yang ◽  
Heng Jiang ◽  
Zhanli Liu ◽  
...  

Abstract The characteristics of passive responses and fixed band gaps of phononic crystals (PnCs) limit their possible applications. For overcoming this shortcoming, a class of tunable PnCs comprised of multiple scatterers and soft periodic porous elastomeric matrices are designed to manipulate the band structures and directionality of wave propagation through the applied deformation. During deformation, some tunable factors such as the coupling effect of scatterer and hole in the matrix, geometric and material nonlinearities, and the rearrangement of scatterer are activated by deformation to tune the dynamic responses of PnCs. The roles of these tunable factors in the manipulation of dynamic responses of PnCs are investigated in detail. The numerical results indicate that the tunability of the dynamic characteristic of PnCs is the result of the comprehensive function of these tunable factors mentioned above. The strong coupling effect between the hole in the matrix and the scatterer contributes to the formation of band gaps. The geometric nonlinearity of matrix and rearrangement of scatterer induced by deformation can simultaneously tune the band gaps and the directionality of wave propagation. However, the matrix's material nonlinearity only adjusts the band gaps of PnCs and does not affect the directionality of wave propagation in them. The research extends our understanding of the formation mechanism of band gaps of PnCs and provides an excellent opportunity for the design of the optimized tunable PnCs and acoustic metamaterials.


2020 ◽  
Vol 35 ◽  
pp. 100623 ◽  
Author(s):  
Shaowu Ning ◽  
Fengyuan Yang ◽  
Chengcheng Luo ◽  
Zhanli Liu ◽  
Zhuo Zhuang

2021 ◽  
Author(s):  
Joseph Mora ◽  
Justin Mibaile ◽  
Vroumsia David ◽  
Sylvere Azakine ◽  
Gambo Betchewe

Abstract In this paper, by means of the expanded Taylor series and Lindstedt-Poincar ́e perturbation methods, the coupled nonlinear Schrödinger equations (CNLSE) modeling the propagation of acoustic waves in acoustic metamaterial is obtained. Using these equations, the Modulational Instability (MI) phenomenon is observed in disturbance mode. Manakov integrable system is derived with suitable parameters and we shown that the Rogue Waves (RWs) can propagate diatomic acoustic metamaterials.


2021 ◽  
Vol 35 (06) ◽  
pp. 2150089
Author(s):  
Hongzhu Li ◽  
Qian Ding ◽  
Zhisai Ma ◽  
Qingquan Ren ◽  
Xiaofei Lyu ◽  
...  

In this paper, we introduce a linear waveguide implemented by cascading acoustic black holes (ABHs). The asymmetric wave propagation, up to 46 dB, is observed and verified in simulation and experiment. It is shown that, in comparison with the previous nonlinear acoustic diodes, our waveguide can rectify the sound without shifting the impinging sound frequency. The device is simple and easy-to-fabricate without using complex nonlinear materials and space–time modulation. This feature could open a new route for designing acoustic waveguide devices that preserve the key information.


Crystals ◽  
2016 ◽  
Vol 6 (8) ◽  
pp. 86 ◽  
Author(s):  
Jiangyi Zhang ◽  
Vicente Romero-García ◽  
Georgios Theocharis ◽  
Olivier Richoux ◽  
Vassos Achilleos ◽  
...  

2016 ◽  
Vol 30 (23) ◽  
pp. 1650317
Author(s):  
Chuanhui Yang ◽  
Jiu Hui Wu ◽  
Songhua Cao ◽  
Li Jing

This paper studies a novel kind of low-frequency broadband acoustic metamaterials with small size based on the mechanisms of negative mass density and multi-cavity coupling. The structure consists of a closed resonant cavity and an open resonant cavity, which can be equivalent to a homogeneous medium with effective negative mass density in a certain frequency range by using the parameter inversion method. The negative mass density makes the anti-resonance area increased, which results in broadened band gaps greatly. Owing to the multi-cavity coupling mechanism, the local resonances of the lower frequency mainly occur in the closed cavity, while the local resonances of the higher frequency mainly in the open cavity. Upon the interaction between the negative mass density and the multi-cavity coupling, there exists two broad band gaps in the range of 0–1800 Hz, i.e. the first-order band gap from 195 Hz to 660 Hz with the bandwidth of 465 Hz and the second-order band gap from 1157 Hz to 1663 Hz with the bandwidth of 506 Hz. The acoustic metamaterials with small size presented in this paper could provide a new approach to reduce the low-frequency broadband noises.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Meng Chen ◽  
Dan Meng ◽  
Heng Jiang ◽  
Yuren Wang

The acoustic characteristics of 2D single-oscillator, dual-oscillator, and triple-oscillator acoustic metamaterials were investigated based on concentric ring structures using the finite element method. For the single-oscillator, dual-oscillator, and triple-oscillator models investigated here, the dipolar resonances of the scatterer always induce negative effective mass density, preventing waves from propagating in the structure, thus forming the band gap. As the number of oscillators increases, relative movements between the oscillators generate coupling effect; this increases the number of dipolar resonance modes, causes negative effective mass density in more frequency ranges, and increases the number of band gaps. It can be seen that the number of oscillators in the cell is closely related to the number of band gaps due to the coupling effect, when the filling rate is of a certain value.


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