Mechanics and band gaps in hierarchical auxetic rectangular perforated composite metamaterials
Mechanics and band gaps in hierarchical auxetic rectangular perforated composite metamaterials
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DOI：
10.1016/j.compstruct.2016.10.121
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发表时间：
2017-01-15
影响因子：
6.3
通讯作者：
Hetherington, Alistair
中科院分区：
文献类型：
--
作者：
Billon, Kevin;Zampetakis, Ioannis;Hetherington, Alistair
在这项工作中，我们描述了一种复合超材料的分层拓扑结构，通过镶嵌穿孔，表现出拉胀（负泊松比）的行为。我们执行的层次结构的分析，通过评估与多孔复合材料的拓扑结构的分形顺序。周期性的分层晶格配置显示负泊松比的特点，在更高层次的层次结构，即使当基线配置的拓扑结构不表现出拉胀行为。我们调查波的传播特性，这些特定的层次晶格，通过使用布洛赫波的方法应用到详细的有限元几何形状的单元格配置。我们表明，层次的水平创建新的带隙与大的相对宽度，它也向较低的频率转移相同的带隙。我们将多尺度拉胀穿孔超材料的机械性能、分形阶数和色散特性与定义晶格几何形状和层次结构的参数相关联，并以无量纲形式讨论结果，以提供机械和动态性能的性能图。(C)2016爱思唯尔有限公司版权所有
We describe in this work a composite metamaterial with a hierarchical topology made by tessellating perforations that exhibit an auxetic (negative Poisson's ratio) behaviour. We perform an analysis of the hierarchical structure by evaluating the fractal order of the topologies associated to the perforated composites. The periodic hierarchical lattice configuration shows negative Poisson's ratio characteristics at higher levels of hierarchy, even when the baseline configuration has a topology not exhibiting an auxetic behaviour. We investigate the wave propagation characteristics of these particular hierarchical lattices by using a Bloch wave approach applied to detailed Finite Element geometries of the unit cell configurations. We show that the level of hierarchy creates new band gaps with large relative widths, and it also shifts the same bandgaps towards lower frequencies. We correlate the mechanical properties, fractal order and the dispersion characteristics of the multiscale auxetic perforated metamaterial with the parameters defining the geometry of the lattice and the hierarchy levels, and discuss the results in a nondimensional form to provide a performance map of the mechanical and dynamic properties. (C) 2016 Elsevier Ltd. All rights reserved.