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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. [ABSTRACT FROM AUTHOR]

The elastic response of arc structures fabricated using curved-layered fused deposition modeling was studied using finite element method (FEM). The influence of structural parameters, such as subtending angle, overlap between layers and relative density on the mechanical response of such structures was studied. The results obtained showed high influence of the overlap between layers. The FEM model predicted a range in which the stiffness of such structures can lie. This was compared with experimental results, showing good agreement. The samples were further characterized microstructurally, revealing more defects for higher values of lattice porosity, affecting the structural properties. [ABSTRACT FROM AUTHOR]