A Novel Design of Elliptical S-Chiral MetaComposite: The Finite Element/Experimental Data Approach

Abstract

This paper addresses a new concept of chiral metastructure the so-called elliptical S-shape chiral. All five groups of metamaterials studied exhibited large anisotropy. This the anisotropic behavior is controlled by the ellipses’ eccentricities. Moreover, the anisotropic response is also more evident when the loading axes are considered. For x-axis compressive loading conditions, the stiffness decreases as the ellipse eccentricity increases. The Poisson ratio's magnitude increases with the increase of a/b aspect ratio, showing a very high auxeticity when the ellipse is close to a flat configuration. In this case, the Poisson ratio was near to -18. For y-axis compressive loadings, the stiffness increases with the decrease of a/b aspect ratio leading to a flexible metastructure. The Poisson ratio's values decreases with the increasing of a/b aspect ratio, but all values were near zero (between -0.35 and -0.05). It seems that the transversal section practically does not change when the metastructure is compressed through y-direction.