Additively manufactured auxetic arc-based architected metamaterial: Mechanical properties and their directional dependency

Additive manufacturing is widely used to fabricate metamaterials. The mechanical properties of these are tailored by modifying topological parameters to meet desired performance. Here, an auxetic metamaterial composed of arc-shape elements is presented. The directional dependency of the apparent stiffness was characterized through finite element analysis and tensile and compressive tests on additively manufactured samples with fused filament fabrication in thermoplastic polyurethane. Poisson's ratio was measured with computational vision. The effective Young's modulus resulted with a nonlinear relation to the wall thickness. The orientation sensibility exposed the relevance of rotational symmetry in a lattice architected metamaterial.