Modulating lamb wave band gaps using an elastic metamaterial plate
| Autor: | Tianning Chen, Suobin Li, Xiaopeng Wang, Yanhui Xi |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Materials science
Acoustics and Ultrasonics business.industry Band gap Acoustics Composite number Bandwidth (signal processing) Binary number Metamaterial 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Finite element method Optics Lamb waves 0103 physical sciences Acoustic metamaterials 010306 general physics 0210 nano-technology business |
| Zdroj: | Acoustical Physics. 63:508-516 |
| ISSN: | 1562-6865 1063-7710 |
| DOI: | 10.1134/s1063771017050116 |
| Popis: | Modulating band gaps (extending the bandwidths or shifting into a lower frequency range) is a challenging task in phononic crystals. In this paper, elastic metamaterial plates composed of a square array of “hard” stubs or “soft” stubs on both sides of a 2D binary locally resonant plate are proposed, and their band structures are studied. The dispersion relationships and the displacement fields of the eigenmodes are calculated using finite element methods. Numerical results show that the band gaps are shifted to lower frequencies and the bandwidths are enlarged compared to classic elastic metamaterial plates. A conceptual “analogousrigid mode” that includes an “out-of-plane analogous-rigid mode” and an “in-plane analogous-rigid mode” is developed to explain these phenomena. The “out-of-plane analogous-rigid mode” mainly adjusts the band gaps into the lower frequency range, and the “in-plane analogous-rigid mode” mainly enlarges the bandwidth. Furthermore, the band gap effects of composite “hard” stubs and “soft” stubs are investigated. The results show that the location of the band gaps can be modulated into a relatively lower frequency and the bandwidth can be extended by the use of different composite stubs. These elastic wave properties in the proposed structure can be used to optimize band gaps and possibly produce low-frequency filters and waveguides. |
| Databáze: | OpenAIRE |
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