新型单相超材料的低频带隙和振动特性研究

Study of Low-frequency Band Gaps and Vibrational Properties in Novel Monophasic Metamaterials

低频振动和噪声的抑制一直是工程中的重要问题。本文提出了一种新型的单相超材料结构,有望应用于噪声控制。基于布洛赫(Bloch)定理和有限元方法(FEM),数值分析了这种新型结构的带隙特性和带隙形成机制,参数化分析了带隙与几何尺寸的依赖关系,用三维色散曲面、频率等值线、相速度和群速度等探究了波在结构中的传播特性,而且分析了有限尺寸晶格中的弹性波衰减,验证了带隙的存在对弹性波的有效抑制作用。结果表明,该新型结构具备优异的带隙特性,带隙对几何尺寸较敏感,可由此实现带隙的可调性,该新型结构能对1000Hz频率以内的弹性波起到很好的抑制。为低频超材料结构的设计开辟了一条思路。

Low frequency vibration and noise suppression has always been a problem that needs to be overcome.Therefore,a novel single-phase metamaterial structure is proposed in this paper.Based on Bloch's theorem and finite element method,the bandgap characteristics and formation mechanism of the proposed structure are numerically analyzed,and the dependence of the bandgap on geometric size is parameterized.The propagation characteristics of waves in the structure are explored using three-dimensional dispersion surfaces,frequency contours,phase velocity,and group velocity,Moreover,the attenuation of elastic waves in finite size lattices was analyzed,verifying the effective suppression effect on band gaps on elastic waves.The results indicate that the proposed structure has excellent bandgap characteristics,and the bandgap is sensitive to geometric dimensions,which can achieve tunable bandgap.The proposed structure can effectively suppress elastic waves within a frequency range of 1000Hz.It provides important clues and ideological guidance for the design of devices with low-frequency vibration isolation performance.