基于框架式板型声学超材料低频隔声模型设计

Design of Low-Frequency Sound Insulation Model Based on Framed Plate Acoustic Metamaterials

与传统隔声材料相比,声学超材料具有更好的低频隔音性能,因此广受欢迎。针对低频声波的控制,本文提出了一种圆形孔洞的框架式板状声学超材料。该结构由周期性方形超材料单元的大型板式声超材料和带有相同圆孔的双面框架组成。根据有限元法研究了框架型板状声超材料的声传输损失,计算了其等效质量密度和振动位移,并结合其在隔声峰和隔声谷处的振动模态进一步验证了所设计的超材料结构的局域共振特性。所设计的超材料结构能够在100~500 Hz频率范围内有效隔离低频噪声,最大可得到43 dB的声衰减,从而达到良好的低频隔声效果。随后,讨论了单一几何参数和材料参数对传声损耗的影响。所提出的框架型板声超材料结构可能有助于声超材料的工程应用。

Acoustic metamaterials are popular because they have better low-frequency sound insulation properties than conventional sound insulation materials. For the control of low-frequency sound waves, a framed plate acoustic metamaterial with circular holes is proposed in this paper. The structure consists of a large plate-type acoustic metamaterial with periodic square metamaterial cells and a double-sided frame with identical circular holes. The acoustic transmission loss of the frame-type plate acoustic metamaterial is investigated based on the finite element method, and its equivalent mass density and vibration displacement are calculated, which are combined with its vibration modes at the peak and valley values of acoustic isolation to further verify the local resonance characteristics of the designed metamaterial structure. The designed metamaterial structure can effectively isolate low-frequency noise in the frequency range of 100~500 Hz with a maximum sound attenuation of 43 dB, thus achieving good low-frequency sound insulation. Subsequently, the effects of single geometrical and material parameters on the sound transmission loss are discussed. The proposed frame-type plate acoustic metamaterial structure may be useful for engineering applications of acoustic metamaterials.