| Popis: |
Metasurfaces exhibit an extraordinary ability in modulating flexural waves. Most of the existing studies on them focus on infinite structures, which are difficult to apply to engineering. In this paper, we design a single-phase circular meta-slab with subunits of different thicknesses to realize total reflection of flexural waves, and then we embed the designed meta-slab into a finite and boundary-free plate to isolate omnidirectional vibration. We theoretically indicate that the total reflection is attributed to multiple reflections of the 0th order diffraction wave and determined by two factors: the central angle of the supercell and the ratio of the wavelength to the sum of the inner and outer radii. To verify the correctness of the theoretical analyses, we design a circular meta-slab and numerically demonstrate its total reflection performances for a wave source individually imposed on the central point of the circular meta-slab, an eccentric point within the circular meta-slab, and a point outside the circular meta-slab. In addition, the simulations and experiments of vibration isolation for a finite and boundary-free plate embedded with the designed circular meta-slab are conducted, and the results show that the designed circular meta-slab omnidirectionally isolates vibrations in broadband. Our design provides a method for vibration isolation and may facilitate the application of metasurfaces in practical engineering. |
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