基于超材料的声聚焦效应在医学、声学、信号检测等领域具有广泛的应用前景。本文设计了一种用于声学聚焦效应的声学超材料柱体,它是一个特殊的圆柱形声学超材料,其结构由三层复合材料(硅溶胶、软木和流体橡胶)形成。当声波在空气中传播遇到这个超材料时,就会在超材料中产生特殊的聚焦现象。通过对这些奇怪的现象进行理论分析和研究,结果表明,当人射声波的频率增加时,聚焦极点外侧的外围带的数量会周期性地增加。此外,有大量的多极聚焦现象会在高频声波中人射时出现。理论分析和实验模拟表明,这种声学超材料的设计是成功的,可用于声学通信和测试等领域。
The acoustic focusing effect of metamaterial has a wide range of applications in medicine,acoustic imaging,signal detection,etc.This paper presents an acoustic metamaterial applied to the acoustic focusing effect.The formation of acousticmetamaterial is designed into a cylindrical structure with three layers of ludox,cork and fluid rubber,which can produce a focusingphenomenon when acoustic waves propagate in air.For these strange phenomena,a scientific description is given theorietically.It can also be concluded that when the frequency of the incident acoustic wave increases?the number of peripheral bandsoutside the focusing poles will increase periodically.Besides,there are numerous groups of multipolar focusing phenomena inhigh frequency.The design of this acoustic metamaterial is successful through theorietical and experimental verification,therefore,it can be applied to acoustic communication and test.