Flexible Cube Tilt Lattice with Anisotropic Cosserat Effects and Negative Poisson's Ratio

Abstract

A 3D lattice structure consisting of pivoting cubes with flexible links at the corners is presented. It exhibits anisotropic negative Poisson's ratio −0.54 and −0.75. Size effects occur in torsion and bending; these effects are consistent with Cosserat elasticity but not with classical elasticity. Cosserat elastic solids exhibit sensitivity to strain gradients; size effects occur in torsion and bending; also reduction in stress concentrations. The observed Cosserat effects also reveal anisotropy.