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Shock and Vibration
Volume 2018, Article ID 1369858, 12 pages
https://doi.org/10.1155/2018/1369858
Research Article

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

1Key Laboratory of Microgravity, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China
2University of Chinese Academy of Sciences, Beijing 100049, China

Correspondence should be addressed to Heng Jiang; nc.ca.hcemi@gnaijgneh and Yuren Wang; nc.ca.hcemi@gnawneruy

Received 20 July 2017; Revised 4 December 2017; Accepted 24 December 2017; Published 24 January 2018

Academic Editor: Marcello Vanali

Copyright © 2018 Meng Chen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

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.