Ding Changlin, Dong Yibao, Song Kun, Zhai Shilong, Wang Yuanbo, Zhao Xiaopeng
Department of Applied Physics, Northwestern Polytechnical University, Xi'an 710129, China.
Materials (Basel). 2019 May 13;12(9):1558. doi: 10.3390/ma12091558.
We present an acoustic metamaterial (AMM) consisting of a dumbbell-shaped split hollow sphere (DSSHS). Transmission results of experiments and simulations both presented a transmitted dip at the resonant frequency of AMM, which demonstrated its negative modulus property. As the two split holes in the DSSHS had strong coupling effects for the acoustic medium in the local region, the dip could be simply manipulated by tuning the distance between the split holes. When the distance was large enough, the mutual inductance tended to disappear, and a weak interaction existed in the structure. According to the property of weak interaction, a multiband AMM and a broadband AMM with a negative modulus could be achieved by arraying DSSHS clusters with different distances. Furthermore, mutual inductance and coupling in DSSHS reinforced the local resonance, and this kind of cell could be used to design the acoustic metasurface to abnormally control the refractive waves.
我们展示了一种由哑铃形分裂空心球（DSSHS）组成的声学超材料（AMM）。实验和模拟的传输结果均在AMM的共振频率处呈现出一个传输凹陷，这证明了其负模量特性。由于DSSHS中的两个分裂孔对局部区域的声学介质具有强耦合效应，通过调整分裂孔之间的距离可以简单地操控该凹陷。当距离足够大时，互感趋于消失，结构中存在弱相互作用。根据弱相互作用的特性，通过排列具有不同距离的DSSHS簇，可以实现具有负模量的多频段AMM和宽带AMM。此外，DSSHS中的互感和耦合增强了局部共振，这种单元可用于设计声学超表面以异常控制折射波。
