二维正方排列圆柱状亥姆赫兹共振腔阵列局域共振声带隙的研究

通过对二维正方排列圆柱状亥姆赫兹共振腔阵列声性质的研究,指出局域共振型声子晶体中存在两类耦合作用, 即共振单元与基体的弱耦合作用及共振单元间的耦合作用.其中前一种耦合作用可以通过改变共振单元的品质因子而改变, 逐渐减小这种耦合作用可以实现从局域共振到布拉格共振的连续转变;后一种耦合是通过共振单元周围的近场耦合实现的, 通过减小共振单元的间距可以增大其耦合强度,因而增大带隙宽度,但带隙中波的衰减深度却是随这种耦合强度的增大而减小的.

Local resonant acoustic band gaps in two-dimensional square-arranged Helmholtz resonators array

In this paper, by taking the acoustic property of a two-dimensional squarely arranged Helmholtz resonator array for example, we point out that there exist two kinds of couplings in the local resonance phononic crystal, which are the coupling between the resonator and background and the coupling among the resonators, respectively. The first coupling effect can be changed by changing the quality factor of the resonator. A local-resonant type of band gap can be converted into a Bragg-scattering type continually when this kind of coupling becomes larger and larger. The second one, which is based on the overlapping of the near filed around the resonators, can be enhanced by reducing the distance between the nearest resonators. As a result, a wider band gap, but a smaller penetration depth of the wave, can be obtained.