Hirsekorn M, Delsanto P P, Batra N K, Matic P
INFM, Dipartimento di Fisica, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy.
Ultrasonics. 2004 Apr;42(1-9):231-5. doi: 10.1016/j.ultras.2004.01.014.
Sonic crystals are artificial structures consisting of a periodic array of acoustic scatterers embedded in a homogeneous matrix material, with a usually large impedance mismatch between the two materials. They exhibit strong sound attenuation at selective frequency bands due to the interference of multiply reflected waves. However, sound attenuation bands in the audible range are only achieved by unfunctionally large sonic crystals. If local resonators are used instead of simple scatterers, the frequencies of the attenuation bands can be reduced by about two orders of magnitude. In the present paper we perform numerical simulations of acoustic wave propagation through sonic crystals consisting of local resonators using the local interaction simulation approach (LISA). Three strong attenuation bands are found at frequencies between 0.3 and 6.0 kHz, which do not depend on the periodicity of the crystal. The results are in good qualitative agreement with experimental data. We analyze the dependence of the resonance frequencies on the structural parameters of the local resonators in order to create a tool for design and optimization of any kind of sonic crystal.
声子晶体是由嵌入均匀基体材料中的声学散射体周期性阵列构成的人工结构，两种材料之间通常存在较大的阻抗失配。由于多次反射波的干涉，它们在特定频段表现出强烈的声衰减。然而，可听范围内的声衰减带仅通过尺寸大到失去功能的声子晶体才能实现。如果使用局部谐振器而非简单散射体，衰减带的频率可降低约两个数量级。在本文中，我们使用局部相互作用模拟方法（LISA）对声波通过由局部谐振器组成的声子晶体的传播进行了数值模拟。在0.3至6.0千赫兹的频率之间发现了三个强衰减带，它们不依赖于晶体的周期性。结果与实验数据在定性上吻合良好。我们分析了谐振频率对局部谐振器结构参数的依赖性，以便创建一种用于设计和优化任何类型声子晶体的工具。
