Primitive rotation mechanism of periodic stellated octahedron units with sharing edges
Primitive rotation mechanism of periodic stellated octahedron units with sharing edges
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DOI：
10.1016/j.ijsolstr.2019.09.013
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发表时间：
2020-03-01
影响因子：
3.6
通讯作者：
Shibutani, Y.
中科院分区：
文献类型：
--
作者：
Tanaka, H.;Suga, K.;Shibutani, Y.
给出了一类正交各向异性多面体结构独特的非线性力学性能，包括结构的互补性。这些结构是由组件的三维坐标旋转产生的。我们建立了一个由边缘共享的四面体组成的过约束周期框架。在初始构型中，晶胞是星形八面体，具有两种一致变换的构象机制。建立具有线性弹簧相互作用的四面体单元模型，分析了有效轴向泊松比和应力-应变曲线。在单轴张力作用下的单自由度受限单模模型中，面外泊松比是一个仅由初始高度比决定的负常数，而面内泊松比从-1开始，随着张力的增加而略有增加。具有附加几何参数的双模模型表现出丰富的弹性行为，例如，对于任何内部刚度，存在一个相同的点，通过平衡轨迹。双模模型也表现出与单模模型相似的增减特性。(C) 2019 Elsevier Ltd.版权所有。
The unique nonlinear mechanical properties including auxeticity of a class of orthotropic polyhedral structures are presented. These structures result from a three-dimensional coordinate rotation of the components. We establish an over-constrained periodic framework composed of edge-shared tetrahedra pivotally connected with each other. In the initial configuration, the unit cell is a stellated octahedron and has two conformational mechanisms both subject to uniform transformations. Modeling the tetrahedral unit with linear spring interactions, the effective on-axis Poisson's ratios and stress-strain curves are analyzed. In the restricted unimode model with a single degree of freedom under a uniaxial tension, the out-of-plane Poisson's ratio is a negative constant determined only by the initial height ratio, whereas the in-plane Poisson's ratio begins with -1 and slightly increases with increasing tension. The bimode model with additional geometric parameters exhibits a rich range of elastic behaviors, e.g., for any internal stiffness, an identical point exists through which pass the equilibrium trajectories. The bimode model also displays similar auxetic characteristics to the unimode model. (C) 2019 Elsevier Ltd. All rights reserved.