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基于亥姆霍兹共振腔单元设计并制作了一种一维局域共振型声子晶体,针对结构中存在点缺陷的情况,进行了实验研究.实验结果表明,由于点缺陷的存在,局域共振型声禁带中出现了缺陷模式,并且在缺陷单元周围引起了能量的局域现象,与理论结果符合较好.缺陷单元从两个不同的方向趋近于完美单元时,缺陷模式分别按照不同的规律变化,但是越靠近禁带边缘,所局域的能量就越多.另外,当缺陷单元共振频率小于完美单元共振频率时,局域能量主要集中在声波导内;反之,局域能量则主要集中在共振腔内.本研究对设计新型低频声滤波装置及高声强集中装置具有一定意义.
A one-dimensional local resonance phononic crystal is designed and fabricated based on the Helmholtz resonator unit. Experimental studies are conducted on the existence of point defects in the structure. The experimental results show that due to the existence of point defects, Resonance type sound forbidden band appeared in the defect mode, and in the defect around the unit caused by the energy of the local phenomenon, in line with the theoretical results in good. Defective unit from two different directions approaching the perfect unit, the defect mode in accordance with the However, the closer to the band edge, the more energy in the local area.In addition, when the resonant frequency of the flaw element is less than the perfect element’s resonant frequency, the local energy mainly concentrates in the acoustic waveguide; on the contrary, the local energy It is mainly concentrated in the resonant cavity.This study is of great significance to the design of new low-frequency acoustic filtering devices and high-intensity strong concentration devices.