Extensible beam-like metastructures at the microscale: Theoretical and modified Hencky bar-chain modeling
Extensible beam-like metastructures at the microscale: Theoretical and modified Hencky bar-chain modeling
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DOI：
10.1016/j.ijmecsci.2020.105636
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发表时间：
2020-08
影响因子：
7.3
通讯作者：
H. Zhang;Xiaoyun Xie;Yiwei Xie;C. Wang;P. Jiao
中科院分区：
文献类型：
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作者：
H. Zhang;Xiaoyun Xie;Yiwei Xie;C. Wang;P. Jiao
具有梁状形状配置的建筑超结构由于其波纹诱导的几何非线性而表现出有前途的机械性能。由微扰引起的变形梁的可拓性在几何非线性中起作用，然而，在文献中被忽略了。出于研究拉伸（或收缩）对力学特性的影响，本研究分析和数值研究了设计有不同的拉伸模式的元梁。通过对Hencky条链法（HBM）的改进，提出了一种新的离散化模型来考虑亚结构的可扩展性。一个尺寸相关的（即，长度比例因子l）的分析模型开发使用修改后的偶应力理论和封闭形式的结果。HBM和理论结果之间观察到良好的协议。通过参数研究，探讨了延伸率和长度比例因子对菱形、圆柱形、六边形和网篮形波纹变形梁力学行为的影响。最佳图案比（即图案直径与图案间隙比D pat W pat）和几何比（即宽度与厚度比W t）通过最小化图案板的自重来获得。HBM准确预测了可伸展变形梁的力学行为，可用于设计板状先进结构，满足刚性和良好变形恢复的要求。
Architected metastructures with beam-like shape configurations have demonstrated promising mechanical performance due to their corrugation-induced geometric nonlinearity. Extensibility of the metabeams caused by corrugation plays a role in the geometric nonlinearity, which, however, has been omitted in the literature. Motivated by investigating the influence of stretching (or shrinking) on the mechanical characteristics, this study analytically and numerically investigates the metabeams designed with different corrugation patterns. A new discretized model is developed to considers the extensibility of the metastructures by modifying the Hencky bar-chain method (HBM). A size-dependent (ie, length scale factor l) analytical model is developed using the modified couple-stress theory and closed-form results are obtained. Good agreements are observed between the HBM and theoretical results. Parametric studies are conducted to investigate the influence of extensibility and length scale factor on the mechanical behavior the metabeams with the rhombille, cylindrical, hexagonal and basketweave corrugations. Optimal pattern ratio (ie, pattern diameter-to-pattern gap ratio D pat W pat) and geometric ratio (ie, width-to-thickness ratio W t) are obtained by minimizing the self-weight of the patterned plates. The reported HBM accurately predict the mechanical behavior of extensible metabeams, which can be used to design plate-shaped advanced structures for applications requiring rigidity and well deformation recovery.