Zero-frequency Bragg gap by spin-harnessed metamaterial

Autor: Joo Hwan Oh, Seong Jae Choi, Jun Kyu Lee, Yoon Young Kim
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: New Journal of Physics, Vol 20, Iss 8, p 083035 (2018)
Druh dokumentu: article
ISSN: 1367-2630
DOI: 10.1088/1367-2630/aada38
Popis: The Bragg gap that stops wave propagation may not be formed from zero or a very low frequency unless the periodicity of a periodic system is unrealistically large. Accordingly, the Bragg gap has been considered to be inappropriate for low frequency applications despite its broad bandwidth. Here, we report a new mechanism that allows formation of the Bragg gap starting from a nearly zero frequency. The mechanism is based on the finding that if additional spin motion is coupled with the longitudinal motion of a mass of a diatomic mechanical periodic system, the Bragg gap starting from a nearly zero frequency can be formed. The theoretical analysis shows that the effective mass and stiffness at the band gap frequencies are all positive, confirming that the formed stop band is a Bragg gap. The periodic system is realized by a spin-harnessed metamaterial which incorporates unique linkage mechanisms. The numerical and experimental validation confirmed the formation of the low-frequency Bragg gap. The zero-frequency Bragg gap is expected to open a new way to control hard-to-shield low-frequency vibration and noise.
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