Learning from Nature
and leveraging 3D printing, mechanical testing,
and numerical modeling, this study aims to provide a deeper understanding
of the structure–property relationship of crystal-lattice-inspired
materials, starting from the study of single unit cells inspired by
the cubic Bravais crystal lattices. In particular, here we study the
simple cubic (SC), body-centered cubic (BCC), and face-centered cubic
(FCC) lattices. Mechanical testing of 3D-printed structures is used
to investigate the influence of different printing parameters. Numerical
models, validated based on experimental testing carried out on single
unit cells and embedding manufacturing-induced defects, are used to
derive the scaling laws for each studied topology, thus providing
guidelines for materials selection and design, and the basis for future
homogenization and optimization studies. We observe no clear effect
of the layer thickness on the mechanical properties of both bulk material
and lattice structures. Instead, the printing direction effect, negligible
in solid samples, becomes relevant in lattice structures, yielding
different stiffnesses of struts and nodes. This phenomenon is accounted
for in the proposed simulation framework. The numerical models of
large arrays, used to define the scaling laws, suggest that the chosen
topologies have a mainly stretching-dominated behavior—a hallmark
of structurally efficient structures—where the modulus scales
linearly with the relative density. By looking ahead, mimicking the
characteristic microscale structure of crystalline materials will
allow replicating the typical behavior of crystals at a larger scale,
combining the hardening traits of metallurgy with the characteristic
behavior of polymers and the advantage of lightweight architected
structures, leading to novel materials with multiple functions.