Ultrawide band gaps in beams with double-leaf acoustic black hole indentations.
Ultrawide band gaps in beams with double-leaf acoustic black hole indentations.
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DOI：
10.1121/1.5009582
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发表时间：
2017-11
期刊：
影响因子：
--
通讯作者：
Liling Tang;Li Cheng
中科院分区：
文献类型：
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作者：
Liling Tang;Li Cheng
传统声子晶体(PC)中的带隙在振动控制、波操纵和吸声等方面具有广泛的应用前景。然而，它们的实际实现受到几个因素的阻碍，其中所需的大量小区以及确保在合理低频下的阻带的不切实际的大小是首要的。本文报道了一种内部雕刻有两个双叶声学黑洞凹口的波束。通过引入局域共振效应和由连接压痕两个分支的加固螺柱产生的布拉格散射效应，实现了超宽带隙。增加螺柱的长度或减小压痕的剩余厚度允许调谐带隙以显著扩大带隙，这可以超过整个感兴趣的频率范围的90%。实验结果表明，这种梁只需要三个单元，就可以在包括低频在内的超宽频率范围内实现相当大的振动能量衰减，这是传统PC很难达到的。同时，该结构还提高了结构的完整性，从而在振动控制和高性能滤波器设计中具有广阔的应用前景。
Band gaps in conventional phononic crystals (PCs) are attractive for applications such as vibration control, wave manipulation, and sound absorption. Their practical implementations, however, are hampered by several factors, among which the large number of cells required and their impractically large size to ensure the stopbands at reasonably low frequencies are on the top of the list. This paper reports a type of beam carved inside with two double-leaf acoustic black hole indentations. By incorporating the local resonance effect and the Bragg scattering effect generated by a strengthening stud connecting the two branches of the indentations, ultrawide band gaps are achieved. Increasing the length of the stud or reducing the residual thickness of the indentation allows the tuning of the band gaps to significantly enlarge the band gaps, which can exceed 90% of the entire frequency range of interest. Experimental results show that with only three cells, the proposed beam allows considerable vibration energy attenuation within an ultra-broad frequency range including the low frequency range, which conventional PCs can hardly reach. Meanwhile, the proposed configuration also enhances the structural integrity, thus pointing at promising applications in vibration control and a high performance wave filter design.