Novel Bézier-based metamaterials: synthesis, mechanics and additive manufacturing

Abstract

The design of mechanical metamaterials often uses lattice arrangements being benefited from the increase in Additive Manufacturing technologies available. Such design freedom allows the fabrication of lattice arrangements with complex curved geometries. Here we propose a whole family of novel lattice matematerials parametrized using cubic Bézier curves. The methodology presented permits the generation of unit cells with different degrees of curvature based on the location of the Bézier control points along a spiral. The apparent stiffness of these structures was characterized using finite element analysis (FEA) and compression tests on additively manufactured samples using stereolithography (SLA). The mechanical properties of spiral based cubic Bézier (SBCB) metamaterials were related to the location of the control points. The methodology was expanded to generate metamaterials with porosity in the three orthogonal planes, and the apparent stiffness of these structures was obtained by FEA. The procedure presented for the synthesis of metamaterials enables the generation of structures with customized mechanical properties by adjusting the geometry of the unit cells. The apparent stiffness of both 2D and 3D SBCB metamaterials from simulation was compared to existing metamaterials,defining a design region that is limited by manufacturing and geometry conditions.