Additively-manufactured anisotropic and isotropic 3D plate-lattice materials for enhanced mechanical performance: Simulations & experiments

Plate-lattices are an emerging category of mechanical metamaterials with exceptional mechanical performance. In this paper, a family of half-open-cell plate-lattices is innovated with exceptional mechanical properties and additive manufacturability. The elastoplastic properties and large strain response of the novel plate-lattices are investigated both numerically and experimentally. Design maps for tailoring the anisotropic index reveal that elastically isotropic plate-lattices can be obtained for a wide range of relative densities. Numerical results reveal that the isotropic plate-lattices exhibit significantly higher elastic properties than other competing topologies such as conventional truss-lattices and isotropic smooth shell-lattices, and their bulk modulus can attain the Hashin-Shtrikman upper bound for all relative densities. Large strain simulations demonstrate the remarkable energy absorption capacity of the novel platelattices. The numerical findings are confirmed through the compression experiments on the anisotropic and isotropic stainless steel 316 L specimens manufactured by selective laser melting. This work proposes a novel type of plate-lattices with both exceptional mechanical performance and good additive manufacturability, which opens a new channel for the design of lightweight mechanical metamaterials. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.