Cheng Yong, Zhou Xiaoming, Hu Gengkai
Key Laboratory of Dynamics and Control of Flight Vehicle, Ministry of Education and School of Aerospace Engineering, Beijing Institute of Technology, Beijing, 100081, China.
Sci Rep. 2017 Oct 16;7(1):13197. doi: 10.1038/s41598-017-13322-2.
We have proposed solid elastic metamaterials with anisotropic stiffness and inertial mass simultaneously, denoted as the dual anisotropy, for the potential use of elastic wave controlling. The dual anisotropy has been designed weakly dispersive in a broad frequency range, wherein broadband anisotropic mass is achieved by employing the sliding-interface concept in fluid-solid composites. Results have been validated through the band-structure, effective-medium, and modal-field analyses. We have further found that the proposed solid metamaterial, when its shear stiffness is diminished until neglected, would reduce to the pentamode-inertial material model. This reduced model is the general form of mediums following transformation acoustic theory, which has been proved vital for acoustic wave controlling. Our studies are expected to pave a new route toward broadband acoustic and elastic wave controlling using dual-anisotropic solid metamaterials.
我们提出了同时具有各向异性刚度和惯性质量的固体弹性超材料，称为双各向异性，以用于弹性波控制。双各向异性被设计为在很宽的频率范围内具有弱色散，其中宽带各向异性质量是通过在流固复合材料中采用滑动界面概念来实现的。结果已通过能带结构、有效介质和模态场分析得到验证。我们进一步发现，所提出的固体超材料，当其剪切刚度减小到可忽略不计时，将简化为五模惯性材料模型。这种简化模型是遵循变换声学理论的介质的一般形式，已被证明对声波控制至关重要。我们的研究有望为使用双各向异性固体超材料进行宽带声学和弹性波控制开辟一条新途径。
