This research reports on the design, fabrication, and multiscale mechanical characterization of flexible, planar mechanical metamaterials with tailorable mechanical properties. The tunable mechanical behavior of the structures is realized through the introduction of orthogonal perforations with different geometric features. Various configurations of the perforations lead to a wide range of Poisson’s ratios (from −0.8 to 0.4), load-bearing properties, and energy absorption capacities. The correlations between the configuration of the perforations and the auxetic response of the structures are highlighted through computational and experimental characterizations performed at multiple length scales. It is demonstrated that the local in-plane rotation of the solid ligaments in a uniaxially loaded structure is the primary factor that contributes to its strain-dependent auxetic behavior at macroscopic scales. Confinement of these local rotations is then used as a practical strategy to activate a self-strengthening mechanism in the auxetic structures. It is further shown that the fabrication of planar flexible structures with controllable Poisson’s ratios is feasible through spatial adjustment of perforations in the structure. Finally, discussions are provided regarding the practical applications of these structures for a new generation of highly energy-absorbing protective equipment.
Article
Flexible planar metamaterials with tunable Poisson’s ratios
Materials and Design
Document Type
Article
Version Deposited
Published Version
Publication Date
2-4-2022
DOI
10.1016/j.matdes.2022.110446
Disciplines
Abstract
Creative Commons License
Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International
Citation Information
Nicholas Pagliocca, Kazi Zahir Uddin, Ibnaj Anamika Anni, Chen Shen, George Youssef, & Behrad Koohbor. Flexible planar metamaterials with tunable Poisson’s ratios. Materials & Design,
Volume 215, March 2022, 110446.
Open Access under a Creative Commons license.