School of Electronic and Information Engineering, Beijing Jiaotong University, Beijing 100044, China.
Ultrasonics. 2012 Feb;52(2):255-65. doi: 10.1016/j.ultras.2011.08.010. Epub 2011 Sep 3.
The effects of the Poisson's ratio of the solid host on the band gaps and point defect states of the mixed elastic wave modes in two-dimensional vacuum/solid porous PNCs are studied by numerical simulations. Four typical systems are considered. The four systems are, respectively, (I) the system with a square lattice and circular pores, (II) the system with a hexagonal lattice and circular pores, (III) the system with a square lattice and square pores and (IV) the system with a hexagonal lattice and regular-hexagonal pores. In the latter two systems, with respect to the outer boundaries of the Wigner-Seitz unit cell, the pores rotate 45° and 30°, respectively. Some observable effects of the Poisson's ratio are found in the numerical results. Especially, the variations of the band gap boundaries with the Poisson's ratio exhibit relatively consistent behaviors. With the increase of the Poisson's ratio, the normalized frequency of a band gap boundary generally increases, except that in system (III) the normalized frequency of the upper boundary of the first band gap remains almost unchanged. Detailed interpretations on this phenomenon are given.
通过数值模拟研究了固体基质泊松比对二维真空/固体多孔 PNC 中混合弹性波模式带隙和点缺陷态的影响。考虑了四个典型系统。这四个系统分别为：（I）具有正方形晶格和圆形孔的系统，（II）具有六方晶格和圆形孔的系统，（III）具有正方形晶格和正方形孔的系统，以及（IV）具有六方晶格和正六边形孔的系统。在后两个系统中，相对于威格纳-塞茨晶胞的外边界，孔分别旋转 45°和 30°。在数值结果中发现了泊松比的一些可观测效应。特别是，带隙边界随泊松比的变化表现出相对一致的行为。随着泊松比的增加，带隙边界的归一化频率通常会增加，除了在系统（III）中第一带隙的上边界的归一化频率几乎保持不变。对此现象给出了详细的解释。
