Customizable plateau in face-centered cubic hierarchical lattices achieved by self-similar embedded design

Customizable stress plateau of lattice structure is sought-after for various engineering applications. In this study, we present a new design strategy to achieve customizable plateau, by introducing the concept of embedding selfsimilar structure in a face-centered cubic (FCC) lattice, which thereby constitutes a novel FCC hierarchical lattice (FCCH). These FCCH specimens were experimentally validated through quasi-static compression tests, on samples 3D-printed through selective laser melting using SS316L. These deformation characteristics were clarified by finite element analysis. The experimental and numerical results consistently show the serrated, dual, and upward plateaus were experienced for the 0th-order FCC, 1st-order FCCH, and 2nd-order FCCH structures, respectively. The mechanical reinforcements are based on the stronger interactions between unit cells induced by the embedded sub-structures. The deformation mechanisms dominated by hierarchical order are determined by horizontal layer-by-layer interaction as well as longitudinal buckling and collapse. The effect of geometric configuration show that stress plateau can be customized via optimizing different slave-cell sizes, connecting face-centers of lattice components, and arranging row layered gradient strategies.

Automated summary

This study presents a new design strategy to achieve customizable stress plateau by introducing selfsimilar structure in an FCC lattice. Experimental and numerical results demonstrate that embedded sub-structures can enhance the mechanical properties of the lattice, and different hierarchical levels of FCCH structures experience different plateau characteristics. The geometric configuration also plays an important role in customizing the stress plateau.