Khelif A, Aoubiza B, Mohammadi S, Adibi A, Laude V
Institut FEMTO-ST, CNRS UMR 6174, Université de Franche-Comté, Besançon, France.
Phys Rev E Stat Nonlin Soft Matter Phys. 2006 Oct;74(4 Pt 2):046610. doi: 10.1103/PhysRevE.74.046610. Epub 2006 Oct 17.
The propagation of acoustic waves in a phononic crystal slab consisting of piezoelectric inclusions placed periodically in an isotropic host material is analyzed. Numerical examples are obtained for a square lattice of quartz cylinders embedded in an epoxy matrix. It is found that several complete band gaps with a variable bandwidth exist for elastic waves of any polarization and incidence. In addition to the filling fraction, it is found that a key parameter for the existence and the width of these complete band gaps is the ratio of the slab thickness, d, to the lattice period, a. Especially, we have explored how these absolute band gaps close up as the parameter d/a increases. Significantly, it is observed that the band gaps of a phononic crystal slab are distinct from those of bulk acoustic waves propagating in the plane of an infinite two-dimensional phononic crystal with the same composition. The band gaps of the slab are strongly affected by the presence of cutoff frequency modes that cannot be excited in infinite media.
分析了声波在由周期性放置在各向同性基体材料中的压电夹杂组成的声子晶体平板中的传播。给出了嵌入环氧树脂基体中的石英圆柱正方形晶格的数值示例。研究发现，对于任意极化和入射角的弹性波，存在几个带宽可变的完全带隙。除了填充率外，还发现这些完全带隙的存在和宽度的一个关键参数是平板厚度d与晶格周期a的比值。特别地，我们研究了随着参数d/a的增加，这些绝对带隙如何闭合。值得注意的是，观察到声子晶体平板的带隙与在具有相同组成的无限二维声子晶体平面中传播的体声波的带隙不同。平板的带隙受到在无限介质中无法激发的截止频率模式的强烈影响。
