Multiscale Strain Field Characterization in Flexible Planar Auxetic Metamaterials with Rotating Squares
Multiscale Strain Field Characterization in Flexible Planar Auxetic Metamaterials with Rotating Squares
复制标题
具有旋转正方形的柔性平面拉胀超材料的多尺度应变场表征
DOI：
10.1002/adem.202201248
复制
发表时间：
2022
影响因子：
3.6
通讯作者：
Koohbor, Behrad
中科院分区：
文献类型：
--
作者：
Uddin, Kazi Zahir;Pagliocca, Nicholas;Anni, Ibnaj Anamika;Youssef, George;Koohbor, Behrad
电磁机械超材料显示出巨大的潜力，影响许多工程领域，近年来一直是一个相当大的研究兴趣的主题。现有文献的主题往往旨在实现更大的负泊松比或可剪裁的响应精心设计和分布的单位细胞。本文旨在研究矩形中心对称穿孔平面结构中的全局和局部应变场之间的关系，从而突出局部形态对宏观材料响应的作用。具有超弹性本构行为的增材制造样品在张力下表征。该结构的设计和开发具有几个穿孔纵横比，导致不同程度的膨胀。使用多尺度数字图像相关测量方法，其特征在于全球和局部应变场。局部旋转和平面内的应变场内产生的固体部分的单位细胞与全局应变场和宏观泊松比为一系列的细胞几何形状。细胞旋转和应变之间的相互作用在细观（单位细胞）尺度被证明是在应变依赖的泊松比的结构演变的主导因素。
Auxetic mechanical metamaterials show significant potential to impact many engineering fields and have been a topic of considerable research interest in recent years. Existing literature on the topic often aims to achieve larger negative Poisson's ratios or tailorable responses by carefully designed and distributed unit cells. Herein, it is aimed to investigate the relationships between global and local strain fields in rectangular center‐symmetric perforated planar structures, thus highlighting the role of local morphology on the macroscopic material response. Additively manufactured samples with hyperelastic constitutive behavior are characterized under tension. The structures are designed and developed with several perforation aspect ratios, leading to various degrees of auxeticity. Global and local strain fields are characterized using a multiscale digital image correlation measurement approach. The local rotation and in‐plane strain fields generated within the solid portions of the unit cells are correlated with the global strain fields and macroscopic Poisson's ratios for a range of cell geometries. The interplay between cell rotation and strain at the meso (unit cell) scale is shown to be the dominant factor in the strain‐dependent evolution of the Poisson's ratio in the structures.