Experimental and numerical analysis of a novel three-dimensional auxetic metamaterial

An innovative three-dimensional (3D) auxetic structure based on 2D re-entrant honeycombs was developed in this article. A sample of the proposed structure made of acrylonitrile-butadiene-styrene (ABS) was fabricated through 3D printing technology, and a compression test was performed on it. Meanwhile, the unit cell required for the finite-element (FE) analysis was determined to simulate the auxetic behavior of the proposed structure. Both experimental and numerical results showed that the 3D structure can achieve a negative Poisson's ratio (NPR) in two principal orthogonal coordinate directions when it was compressed along the other principal axis. A systematic numerical simulation was performed through the experimentally validated finite element models to analyze the effects of structural parameters (i.e., top-view reentrant angle and lateral-view re-entrant angle) and deformation on the auxetic behavior. Numerical results revealed that this structure can achieve a negative Poisson's ratio (NPR) under large deformation and the structural parameters and compression strain have significant effects on the auxetic behavior. Our structure, with large flexibility in design, is based on very simple initial geometric shapes. This analysis can provide useful information for the design, fabrication of this kind of 3D auxetic structure, which is promising in some technical applications. (C) 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim