Park Jun-Hyoung, Lee Jae-Chul
Department of Materials Science and Engineering, Korea University, Seoul, 02841, South Korea.
Sci Rep. 2019 Feb 27;9(1):2941. doi: 10.1038/s41598-019-38660-1.
Molecular dynamics simulations were performed on nanostructured metamaterials (NMs) with gyroid, diamond, and primitive structures to evaluate their mechanical behavior, especially elastic properties. Unlike the constant nature of Young's (E) and shear (μ) moduli of bulk materials, the values of both E and μ of NMs change with relative density and cell size but at different rates depending on the morphologies of the structure. This is particularly the case for μ; for a given relative density and cell size of NMs, the μ values differ greatly, depending on the types of structure, causing the NMs to display differing μ/E values and thus resistance to shear deformation. The mechanistic origin of this observation was analyzed by resolving the morphologies of the NMs in terms of the numbers and orientations of the fundamental structural motifs for constructing metamaterials.
对具有类螺旋体、金刚石和原始结构的纳米结构超材料（NMs）进行了分子动力学模拟，以评估其力学行为，特别是弹性性能。与块状材料杨氏模量（E）和剪切模量（μ）的恒定性质不同，NMs的E和μ值会随相对密度和单元尺寸而变化，但根据结构形态，变化速率不同。对于μ来说尤其如此；对于给定相对密度和单元尺寸的NMs，μ值因结构类型而异，导致NMs表现出不同的μ/E值，从而具有不同的抗剪切变形能力。通过根据构建超材料的基本结构单元的数量和取向解析NMs的形态，分析了这一观察结果的机理起源。
