Systematic design of Cauchy symmetric structures through Bayesian optimization
Systematic design of Cauchy symmetric structures through Bayesian optimization
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DOI：
10.1016/j.ijmecsci.2022.107741
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发表时间：
2022-09
影响因子：
7.3
通讯作者：
Haris Moazam Sheikh;Timon Meier;Brian W Blankenship;Z. Vangelatos;Naicheng Zhao;P. Marcus;C. Grigoropoulos
中科院分区：
文献类型：
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作者：
Haris Moazam Sheikh;Timon Meier;Brian W Blankenship;Z. Vangelatos;Naicheng Zhao;P. Marcus;C. Grigoropoulos
摘要利用一种新的贝叶斯优化算法来指导机械超材料的设计，我们设计了具有柯西对称性的非均匀三维结构，该对称性决定了连续体和原子变形之间的关系。最近将优化技术与机械超材料设计相结合的努力导致了对其弹性和后弹性属性的集中调整。尽管可以使用多物理求解器和成熟的优化方案来模拟单个单胞或均匀连续介质的这些性质，但它们通常计算昂贵，需要多次设计迭代，使得验证阶段成为新超材料设计的一个重大障碍。这项研究旨在为如何利用最小的计算成本来控制超材料的弹性性质，从而实现特定的对称性提供一个框架。以柯西对称性为设计目标，我们通过在5×5×5立方对称微晶格结构中5个不同的单胞的策略排列来设计结构。这种网格设计虽然构成了一个具有5个10个3D网格构型的设计空间，但由于新的贝叶斯优化方案的效率，只需69次函数调用就可以收敛到有效解。为了验证设计的力学行为，采用多光子光刻技术制作了晶格结构，并对其进行了力学测试，结果表明，在弹性区域，实验结果与模拟结果具有很好的相关性。最终，类似的方法可以用来设计具有其他材料属性的超材料，渴望控制不同长度尺度的属性，这一努力需要过高的计算成本。
Abstract Using a new Bayesian Optimization algorithm to guide the design of mechanical metamaterials, we design nonhomogeneous 3D structures possessing the Cauchy symmetry, which dictates the relationship between continuum and atomic deformations. Recent efforts to merge optimization techniques with the design of mechanical metamaterials has resulted in a concentrated effort to tailor their elastic and post elastic properties. Even though these properties of either individual unit cells or homogenized continua can be simulated using multi-physics solvers and well established optimization schemes, they are often computationally expensive and require many design iterations, rendering the validation stage a significant obstacle in the design of new metamaterial designs. This study aims to provide a framework on how to utilize miniscule computational cost to control the elastic properties of metamaterials such that specific symmetries can be accomplished. Using the Cauchy symmetry as a design objective, we engineer structures through the strategic arrangement of 5 different unit cells in a 5× 5× 5 cubic symmetric microlattice structure. This lattice design, despite constituting a design space with 5 10 3D lattice configurations, can converge to an effective solution in only 69 function calls as a result of the efficiency of the new Bayesian optimization scheme. To validate the mechanical behavior of the design, the lattice structures were fabricated using multiphoton lithography and mechanically tested, revealing a close correlation between experiments and simulated results in the elastic regime. Ultimately, a similar methodology can be utilized to design metamaterials with other material properties, aspiring to control properties at different length scales, an endeavor that requires inordinate computation cost.