Meng H, Bailey N, Chen Y, Wang L, Ciampa F, Fabro A, Chronopoulos D, Elmadih W
Institute for Aerospace Technology & The Composites Group, The University of Nottingham, Nottingham, NG7 2RD, UK.
Department of Mechanical Engineering, University of Louisville, Louisville, KY, 40208, USA.
Sci Rep. 2020 Nov 4;10(1):18989. doi: 10.1038/s41598-020-75977-8.
We hereby report for the first time on the design, manufacturing and testing of a three-dimensional (3D) nearly-periodic, locally resonant phononic crystal (PnC). Most of the research effort on PnCs and metamaterials has been focused on the enhanced dynamic properties arising from their periodic design. Lately, additive manufacturing techniques have made a number of designs with intrinsically complex geometries feasible to produce. These recent developments have led to innovative solutions for broadband vibration attenuation, with a multitude of potential engineering applications. The recently introduced concept of rainbow metamaterials and PnCs has shown a significant potential for further expanding the spectrum of vibration attenuation in such structures by introducing a gradient profile for the considered unit cells. Given the above, it is expected that designing non-periodic PnCs will attract significant attention from scientists and engineers in the years to come. The proposed nearly-periodic design is based on cuboid blocks connected by curved beams, with internal voids in the blocks being implemented to adjust the local masses and generate a 3D rainbow PnC. Results show that the proposed approach can produce lightweight PnCs of a simple, manufacturable design exhibiting attenuation bandwidths more than two times larger than the equivalent periodic designs of equal mass.
我们在此首次报告一种三维（3D）近周期、局部共振声子晶体（PnC）的设计、制造和测试情况。关于声子晶体和超材料的大部分研究工作都集中在其周期性设计所带来的增强动态特性上。最近，增材制造技术使许多具有内在复杂几何形状的设计得以生产。这些最新进展为宽带振动衰减带来了创新解决方案，具有众多潜在的工程应用。最近引入的彩虹超材料和声子晶体概念通过为所考虑的单元引入梯度分布，在进一步扩展此类结构的振动衰减频谱方面显示出巨大潜力。鉴于上述情况，预计在未来几年，设计非周期声子晶体将引起科学家和工程师的极大关注。所提出的近周期设计基于由弯曲梁连接的长方体块，通过在块中设置内部空隙来调整局部质量并生成三维彩虹声子晶体。结果表明，所提出的方法能够生产出设计简单、可制造的轻质声子晶体，其衰减带宽比同等质量的等效周期设计大两倍以上。
