Open AccessOrthotropic Laminated Open-cell Frameworks Retaining Strong Auxeticity under Large Uniaxial Loading
Author(s) -
Hiro Tanaka,
Kaito Suga,
Naoki Iwata,
Yoji Shibutani
Publication year - 2017
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/srep39816
Subject(s) - orthotropic material , materials science , auxetics , anisotropy , ultimate tensile strength , composite material , lamination , finite element method , microstructure , structural engineering , layer (electronics) , physics , optics , engineering
Anisotropic materials form inside living tissue and are widely applied in engineered structures, where sophisticated structural and functional design principles are essential to employing these materials. This paper presents a candidate laminated open-cell framework, which is an anisotropic material that shows remarkable mechanical performance. Using additive manufacturing, artificial frameworks are fabricated by lamination of in-plane orthotropic microstructures made of elbowed beam and column members; this fabricated structure features orthogonal anisotropy in three-dimensional space. Uniaxial loading tests reveal strong auxeticity (high negative Poisson’s ratios) in the out-of-plane direction, which is retained reproducibly up to the nonlinear elastic region, and is equal under tensile and compressive loading. Finite element simulations support the observed auxetic behaviors for a unit cell in the periodic framework, which preserve the theoretical elastic properties of an orthogonal solid. These findings open the possibility of conceptual materials design based on geometry.