Negative Effective Mass Density of One-Dimensional Hierarchical Metacomposite

2015 ◽  
Vol 82 (3) ◽  
Author(s):  
Xiyue An ◽  
Fangfang Sun ◽  
Peishi Yu ◽  
Hualin Fan ◽  
Shiping He ◽  
...  
Keyword(s):  
Effective Mass ◽  
Mass Density ◽  
Rigid Bodies ◽  
Band Gaps ◽  
Mass Ratio ◽  
One Dimensional ◽  
Negative Effective Mass ◽  
Specific Frequency ◽  
The Relationship ◽  
Internal Resonators

A theoretical model of one-dimensional (1D) hierarchical metacomposite with internal resonators was proposed to generate negative effective mass over specific frequency ranges. Different from the single-resonator microstructure, the current hierarchical metamaterial with multilevel resonators was constructed by a series of springs and rigid bodies. The general formula of the current hierarchical metamaterial model was induced to reveal the relationship between the effective mass and the forcing frequency. It is found that the hierarchical metamaterial with multilevel resonators generates multifrequency band gaps with negative effective masses. The number of the band gaps equals to the order of the hierarchy. The total bandwidth for the negative effective mass increases with the hierarchy, meanwhile increasing the mass ratio can also obviously increase the bandwidth generating negative effective mass.

scholarly journals Investigation on the Band Gap and Negative Properties of Concentric Ring Acoustic Metamaterial

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Meng Chen ◽  
Dan Meng ◽  
Heng Jiang ◽  
Yuren Wang
Keyword(s):  
Band Gap ◽  
Effective Mass ◽  
Coupling Effect ◽  
Mass Density ◽  
Band Gaps ◽  
Acoustic Metamaterials ◽  
Concentric Ring ◽  
Resonance Modes ◽  
Negative Effective Mass ◽  
Single Oscillator

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.

Using the Mass Ratio to Induce Band Gaps in a 1D Array of Nonlinearly Coupled Oscillators

2012 ◽  
Author(s):  
Brian P. Bernard ◽  
Jeffrey W. Peyser ◽  
Brian P. Mann ◽  
David P. Arnold
Keyword(s):  
Coupled Oscillators ◽  
Stable Equilibrium ◽  
Equations Of Motion ◽  
Band Gaps ◽  
Dimensional System ◽  
Mass Ratio ◽  
Frequency Range ◽  
One Dimensional ◽  
Propagation Zone ◽  
The Masses

A one dimensional system of nonlinearly coupled magnetic oscillators has been studied. After deriving the equations of motion for each oscillator, the system is linearized about a stable equilibrium and studied using an assumed solution form for a traveling wave. Wave propagation and attenuation regions are predicted by reducing the system of equations to a standard eigenvalue problem. Through evaluating these equations across the entire irreducible Brillouin zone, it is determined that when the masses of each oscillator are identical, the entire frequency range of the system is a propagation zone. By varying the masses comprising a unit cell, band gaps are observed. It is shown that the mass ratio can be used to guide both the size and location of these band gaps. Numerical simulations are performed to support our analytical findings.

Elastic superlattices with simultaneously negative effective mass density and shear modulus

2013 ◽  
Vol 113 (9) ◽  
pp. 093508 ◽  
Author(s):  
I. S. Solís-Mora ◽  
M. A. Palomino-Ovando ◽  
F. Pérez-Rodríguez
Keyword(s):  
Shear Modulus ◽  
Effective Mass ◽  
Mass Density ◽  
Negative Effective Mass

scholarly journals Radiation phenomenon for large meteoroids

2020 ◽  
Vol 633 ◽  
pp. A25
Author(s):  
C. Park
Keyword(s):  
Mass Density ◽  
Computer Code ◽  
Inviscid Flow ◽  
Light Curves ◽  
Intrinsic Properties ◽  
Dimensional Approach ◽  
One Dimensional ◽  
Thermochemical Equilibrium ◽  
Transfer Problems ◽  
The Relationship

Aims. The relationship between the intrinsic properties of a large meteoroid, that is, mass, density, chemical composition, and flight velocity, and its spectrum are identified. Methods. Assuming thermochemical equilibrium and inviscid flow and using a quasi-one-dimensional approach, the flow-field and radiative transfer problems are solved from the ablating wall of a meteoroid to the observer on the ground. Results. The study discovers that the precursor region immediately ahead of the shock layer absorbs nitrogen and oxygen lines, and thereby modifies the spectrum received by the ground observer. The study leads to a computer code with which the observed spectra and light-curves for Benesov and Sumava meteoroids are numerically and approximately reproduced with the help of a meteoroid fragmentation theory. Luminous efficiency value is obtained as a byproduct.

Negative effective mass density of acoustic metamaterial plate decorated with low frequency resonant pillars

2014 ◽  
Vol 116 (18) ◽  
pp. 184504 ◽  
Author(s):  
Mourad Oudich ◽  
Bahram Djafari-Rouhani ◽  
Yan Pennec ◽  
M. Badreddine Assouar ◽  
Bernard Bonello
Keyword(s):  
Effective Mass ◽  
Mass Density ◽  
Low Frequency ◽  
Acoustic Metamaterial ◽  
Negative Effective Mass

Meta-atom cluster acoustic metamaterial with broadband negative effective mass density

2014 ◽  
Vol 115 (5) ◽  
pp. 054905 ◽  
Author(s):  
Huaijun Chen ◽  
Shilong Zhai ◽  
Changlin Ding ◽  
Song Liu ◽  
Chunrong Luo ◽  
...  
Keyword(s):  
Effective Mass ◽  
Mass Density ◽  
Acoustic Metamaterial ◽  
Atom Cluster ◽  
Negative Effective Mass ◽  
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