The Ultra-low Frequency and Broad Band Gaps Characteristics of Multilayer Composite Cylindrical Three-dimensional pentamode metamaterials

Abstract For three-dimensional pentamode metamaterials, it is of great significance to realize underwater ultra-low frequency acoustic wave control. Therefore, two types multilayer composite cylindrical three-dimensional pentamode metamaterials with ultra-low frequency and broad band gaps are proposed in this paper. By using pentamode metamaterials with lattice constants on the order of centimeters, the phononic band gaps below 60 Hz and the single-mode area below 30Hz can be obtained. Compared with asymmetrical double-cone locally resonant pentamode metamaterials, the lower edge frequency, relative bandwidth and figure of merit of the first phononic band gap can be reduced by up to 61.4%, 10.3% and 40.6%, respectively. It will provide reference and guidance for the engineering application of pentamode metamaterials in controlling the ultra-low frequency broadband acoustic waves, vibration and noise reduction.

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Multi-cavity locally resonant structure with the low frequency and broad band-gaps

AIP Advances ◽

10.1063/1.4968830 ◽

2016 ◽

Vol 6 (11) ◽

pp. 115024 ◽

Cited By ~ 6

Author(s):

Jiulong Jiang ◽

Hong Yao ◽

Jun Du ◽

Jinbo Zhao

Keyword(s):

Broad Band ◽

Low Frequency ◽

Band Gaps ◽

Resonant Structure

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Active Control of Low Frequency Modes in an Aircraft Fuselage Using Spatially Weighted Arrays

Journal of Vibration and Acoustics ◽

10.1115/1.1303848 ◽

2000 ◽

Vol 122 (3) ◽

pp. 227-234 ◽

Cited By ~ 13

Author(s):

Steven A. Lane ◽

Robert L. Clark ◽

Steve C. Southward

Keyword(s):

Three Dimensional ◽

Pressure Sensors ◽

Low Frequency ◽

Single Mode ◽

Open Loop ◽

H2 Control ◽

Low Frequencies ◽

Control Approach ◽

Aircraft Fuselage ◽

Transducer Arrays

Acoustic enclosures such as aircraft cabins often display lightly damped modal behavior at low frequencies where passive treatments are impractical due to mass and volume constraints. This work presents a feedback control approach using dynamic H2 controllers implemented with spatially weighted arrays of collocated pressure sensors and constant volume-velocity actuators. The open-loop system is shaped using spatially weighted transducer arrays to yield increased pole-zero separation, which results in better closed-loop performance. The transducer arrays are weighted to emphasize coupling to a particular acoustic mode or modes, which facilitates global control of the targeted dynamics. This work presents a method to determine the spatial weighting vectors for the transducer arrays from frequency response measurements. The development and implementation of low-order, dynamic H2 control laws is also discussed. Experimental results are presented for a single-mode and a multiple-mode controller implemented on an aircraft fuselage section, and demonstrate significant reduction of the targeted acoustic modes. To the best of the authors’ knowledge, this is the first experimental implementation of a feedback controller of this type capable of achieving such levels of global reduction in a three-dimensional acoustic system. [S0739-3717(00)02303-5]

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Multi-cavity coupling acoustic metamaterials with low-frequency broad band gaps based on negative mass density

Modern Physics Letters B ◽

10.1142/s0217984916503176 ◽

2016 ◽

Vol 30 (23) ◽

pp. 1650317

Author(s):

Chuanhui Yang ◽

Jiu Hui Wu ◽

Songhua Cao ◽

Li Jing

Keyword(s):

Band Gap ◽

Mass Density ◽

Resonant Cavity ◽

Broad Band ◽

Low Frequency ◽

Band Gaps ◽

Acoustic Metamaterials ◽

Negative Mass ◽

Closed Cavity ◽

Cavity Coupling

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.

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Low-frequency penetration of acoustic waves through a periodic arbitrary-shaped grating: the three-dimensional problem

Wave Motion ◽

10.1016/0165-2125(95)00027-g ◽

1995 ◽

Vol 22 (2) ◽

pp. 133-144 ◽

Cited By ~ 9

Author(s):

M.A. Sumbatyan

Keyword(s):

Acoustic Waves ◽

Three Dimensional ◽

Low Frequency ◽

Dimensional Problem

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Multiple low-frequency broad band gaps generated by a phononic crystal of periodic circular cavity sandwich plates

Composite Structures ◽

10.1016/j.compstruct.2017.05.048 ◽

2017 ◽

Vol 176 ◽

pp. 294-303 ◽

Cited By ~ 11

Author(s):

Shan Jiang ◽

Hao Chen ◽

Longxiang Dai ◽

Hongping Hu ◽

Vincent Laude

Keyword(s):

Phononic Crystal ◽

Broad Band ◽

Low Frequency ◽

Band Gaps ◽

Sandwich Plates ◽

Circular Cavity

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Identification of broad-band waves above the auroral acceleration region: Cluster observations

Annales Geophysicae ◽

10.5194/angeo-22-4203-2004 ◽

2004 ◽

Vol 22 (12) ◽

pp. 4203-4216 ◽

Cited By ~ 3

Author(s):

M. Backrud ◽

M. André ◽

A. Balogh ◽

S. Buchert ◽

N. Cornilleau-Wehrlin ◽

...

Keyword(s):

Electric Fields ◽

Acoustic Waves ◽

Broad Band ◽

Low Frequency ◽

Ion Acoustic Waves ◽

Dispersion Surface ◽

Linear Waves ◽

Field Lines ◽

Auroral Phenomena ◽

Wave Modes

Abstract. We investigate broad-band emissions at frequencies above the ion gyrofrequency on auroral field lines at geocentric distances of about 4.5 Earth radii. Observations by the Cluster satellites are used to study the wave characteristics and to determine the wave modes involved. All events include some bursts of broad-band emissions with a substantial component of the electric field parallel to the geomagnetic field. Studying the polarization of the emissions we find that linear waves in a homogeneous plasma can be used to theoretically describe the observations. The broad-band emissions include short bursts of ion acoustic waves, and longer periods of ion Bernstein and Electrostatic Ion Cyclotron (EIC) waves. All waves occur during the same event within a few seconds, with EIC waves as the most common. Theoretically, there is no sharp limit between these wave modes and they can be described by the same dispersion surface. These emissions are closely associated with low-frequency Alfvén waves, indicating a possible generation mechanism. Key words. Magnetospheric physics (auroral phenomena; electric fields; plasma waves and instabilities)

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Ultrawide 3D Phononic Bandgap Metastructures as Broadband Low Frequency Filter

10.21203/rs.3.rs-114173/v1 ◽

2020 ◽

Author(s):

Muhammad ◽

C.W. Lim

Keyword(s):

Acoustic Waves ◽

Three Dimensional ◽

Low Frequency ◽

Mode Separation ◽

Gap Ratio ◽

Unique Material ◽

Structural Configurations ◽

Mass Spring ◽

Low Amplitude ◽

Global And Local

Abstract This present study reports a novel model for the study on three-dimensional phononic metastructures endued with ultrawide three-dimensional complete bandgaps. The phononic structure is made of a unique material without composite material composition. Based on the principal of mode separation and global and local modal masses participation, the well-engineered structural configurations give extremely wide bandgaps with the gap-to-mid gap ratio of 157.6% and 160.1% for two proposed prototypes that produce the widest three-dimensional bandgaps ever reported. The band structures are explained by a modal analysis and the findings are further corroborated by developing an analytical model based on monoatomic mass-spring chain and further verified with well-established FEM numerical simulations. Thanks to additive manufacturing, the prototypes are developed by using 3D printing technology and low amplitude vibration test is performed to access the real-time vibration mitigation characteristics. An excellent agreement is obtained between analytical, numerical and experimental results. The effects of material damping on transmission response is also taken into consideration that eventually merge the separated bandgaps to form a broadband vibration attenuation zone. The results reported are scale independent and the proposed strategy may pave the way for developing novel meta-devices to control the noise and vibration, and underwater acoustic waves at a wide frequency band in all directions.

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The effects of composite primitive cells on band gap property of locally resonant phononic crystal

Modern Physics Letters B ◽

10.1142/s0217984921503346 ◽

2021 ◽

pp. 2150334

Author(s):

Lijian Lei ◽

Linchang Miao ◽

Chao Li ◽

Xiaodong Liang ◽

Junjie Wang

Keyword(s):

Band Gap ◽

Formation Mechanism ◽

Phononic Crystal ◽

Engineering Application ◽

Low Frequency ◽

Structure Design ◽

Band Gaps ◽

Gap Formation ◽

Cell Spacing ◽

Low Frequency Vibration

Locally resonant phononic crystal (LRPC) has the extraordinary property to prohibit the wave propagation in specific low-frequency ranges, however it exists limitation in engineering application due to narrow band gap width. Extensive achievements have been obtained on the locally resonant band gap (LRBG) tunability, whereas existing investigations mainly concern the independent primitive cells structure, which have the limitation in obtaining low-frequency and broadband simultaneously. In this paper, the composited locally resonant phononic crystals (CLRPC) are proposed and the effects of primitive cells contact state on the LRBG properties are investigated. The dispersion curves are applied to obtain the LRBG, and the corresponding modal features are analyzed to explain the band gap formation mechanism. The band structure indicates the design of composite primitive cells is able to increase the band gap number and obtain lower band gap, which is verified by the frequency response function (FRF). For the band gap formation mechanism, the asymmetric vibration due to primitive cells contact leads to diverse and strong coupling response, which generates more band gaps and reduces the band gap starting frequency, therefore the band gaps can be tuned by designing carefully the geometry structure of CLRPC. Further researches on band gap optimization demonstrate that the smaller cell spacing, smaller lattice constant and larger damping of coating layer should be satisfied to obtain broader LRBG and considerable attenuation synchronously. This investigation can provide references for the locally resonant isolation structure design in the low-frequency vibration control field.

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Research on the Band Gap Characteristics of Two-Dimensional Phononic Crystals Microcavity with Local Resonant Structure

Shock and Vibration ◽

10.1155/2015/239832 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Mao Liu ◽

Pei Li ◽

Yongteng Zhong ◽

Jiawei Xiang

Keyword(s):

Band Gap ◽

Phononic Crystal ◽

Engineering Application ◽

Low Frequency ◽

Phononic Crystals ◽

Band Gaps ◽

Wave Band ◽

Two Dimensional ◽

Frequency Range ◽

Gap Characteristics

A new two-dimensional locally resonant phononic crystal with microcavity structure is proposed. The acoustic wave band gap characteristics of this new structure are studied using finite element method. At the same time, the corresponding displacement eigenmodes of the band edges of the lowest band gap and the transmission spectrum are calculated. The results proved that phononic crystals with microcavity structure exhibited complete band gaps in low-frequency range. The eigenfrequency of the lower edge of the first gap is lower than no microcavity structure. However, for no microcavity structure type of quadrilateral phononic crystal plate, the second band gap disappeared and the frequency range of the first band gap is relatively narrow. The main reason for appearing low-frequency band gaps is that the proposed phononic crystal introduced the local resonant microcavity structure. This study provides a good support for engineering application such as low-frequency vibration attenuation and noise control.

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