散射体固液形态下超材料带隙特性分析

Analysis of band gap characteristics of metamaterials in the solid-liquid state of scatterers

弹性超材料可以实现减振降噪、波导、隐身等弹性波操控功能,具有广阔的工程应用前景。本文引入固液相变材料作为散射体对比研究了散射体固液两种形态下的带隙特性和隔振性能,利用数值方法计算单胞的能带结构和动态有效质量,研究了影响超材料带隙特性的因素,并通过试验验证了两种形态超材料的隔振性能。结果表明:液态散射体超材料可产生局域共振带隙实现低频段隔振,固态散射体超材料可产生Bragg带隙实现宽频段隔振;同时,改变外界条件对两种设计形态的带隙均起到很好的调控作用。由此,超材料散射体两种设计状态的转变实现了带隙类型的转变和隔振频段的调节,可为适应热环境下的相变散射体超材料构型设计和隔振特性调控提供参考依据。

Elastic metamaterials can be used for vibration and noise reduction,waveguide,stealth and other special elastic wave control functions,which have broad engineering application prospects.In this paper,solid-liquid phase change materials are introduced as the scatterer to compare the band gap characteristics and vibration isolation performance of the scatterer under the two forms of solid and liquid.The numerical method is used to calculate the band structure and the dynamic effective mass of unit cells,the factors affecting the band gap characteristics of metamaterials are studied,and the vibration isolation performance of two forms of metamaterials is verified by experiments.The results show that the liquid scatterer metamaterial can generate local resonant band gap to achieve low frequency vibration isolation,and the solid scatterer metamaterial can generate Bragg band gap to achieve wide frequency vibration isolation.At the same time,the band gap of the two design forms can be well regulated by changing the external conditions.Therefore,the transformation of the two design states of the metamaterial scatterers realizes the transformation of the band gap type and the adjustment of the vibration isolation band,which can provide a reference for the configuration design and the regulation of the vibration isolation characteristics of the phase change scatterers metamaterial adapted to the thermal environment.