Numerical Prediction of the Yield Surface of a Chiral Auxetic Structure

Abstract

For today’s requirements, the material itself is often not sufficient anymore. This leads to structural cellular materials and metamaterials, which allow for more degrees of freedom by a strong structure‐property‐relationship. Auxetic structures investigated in this contribution belong to metamaterials. Auxetic metamaterials show huge advantages in their properties, e.g. an enhanced specific energy absorption capacity as well as a negative Poisson’s ratio, combined with a very high stiffness‐to‐weight ratio. Experimental probing of these structures is very challenging, hence, up to now, auxetic materials are only investigated in uniaxial, bending or shear loading. But for an industrial application, the knowledge of the multiaxial yield behaviour is inevitable. For the first time, the present study deals with the numerical probing of the yield surface for a chiral auxetic structure applying multiaxial loading. The changes in Poisson’s ratio, specific energy absorption capacity and the resulting non‐convex yield surface are studied numerically. It showed, that the highest specific energy absorption capacities are reached under compression load cases while higher stiffnesses and yield stresses are achieved under tensile loading. There is a strong‐structure‐property relationship and load case dependency for the Poisson’s ratio as well as for the specific energy absorption capacity.This article is protected by copyright. All rights reserved.