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arXiv 1802.07214cond-mat.mtrl-scicond-mat.soft
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离散机械超材料的逆设计

Inverse Design of Discrete Mechanical Metamaterials

Henrik Ronellenfitsch, Norbert Stoop, Josephine Yu, Aden Forrow, Jörn Dunkel

摘要:

呈现负弹性模量、带隙振动光谱或拓扑保护模式的机械和声子超材料能够精确控制结构和声学功能。虽然在实验和理论表征方面取得了很大进展,但具有任意可编程光谱特性和模式局部化的机械超材料的逆设计仍然是一个未解决的问题。在这里,我们提出了一个灵活的计算逆设计框架,允许在离散声子超材料结构的频谱中的几乎任意位置的一个或多个间隙的有效调谐。底层算法直接优化弹性网络的线性响应,适用于有序和无序结构,在2D和3D中有效扩展,并可与各种数值优化方案相结合。我们通过设计机械带隙开关来说明这种方法的广泛实用潜力,该开关响应于外部施加的刺激(例如剪切或压缩)来打开和关闭预编程的光谱间隙。我们进一步表明,所设计的结构可以主机拓扑保护的边缘模式,并通过显式三维有限元模拟连续弹性实验相关的材料参数验证数值预测。一般来说,这种基于网络的逆向设计范式提供了一个直接的途径,制造声子超材料,DNA折纸结构和拓扑电路,可以实现广泛的静态和动态目标功能。

英文摘要:

Mechanical and phononic metamaterials exhibiting negative elastic moduli, gapped vibrational spectra, or topologically protected modes enable precise control of structural and acoustic functionalities. While much progress has been made in their experimental and theoretical characterization, the inverse design of mechanical metamaterials with arbitrarily programmable spectral properties and mode localization remains an unsolved problem. Here, we present a flexible computational inverse-design framework that allows the efficient tuning of one or more gaps at nearly arbitrary positions in the spectrum of discrete phononic metamaterial structures. The underlying algorithm optimizes the linear response of elastic networks directly, is applicable to ordered and disordered structures, scales efficiently in 2D and 3D, and can be combined with a wide range of numerical optimization schemes. We illustrate the broad practical potential of this approach by designing mechanical bandgap switches that open and close pre-programmed spectral gaps in response to an externally applied stimulus such as shear or compression. We further show that the designed structures can host topologically protected edge modes, and validate the numerical predictions through explicit 3D finite element simulations of continuum elastica with experimentally relevant material parameters. Generally, this network-based inverse design paradigm offers a direct pathway towards manufacturing phononic metamaterials, DNA origami structures and topolectric circuits that can realize a wide range of static and dynamic target functionalities.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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