Bio-inspired vertex modified lattice with enhanced mechanical properties

Abstract

Conventional lattices usually exhibit tradeoff relations between their strength, deformation stability and energy absorption capacity. Here, inspired by the local structure characters of the skeletal system of deep-sea glass sponge, a new structure called vertex modified body-centered cubic (VM-BCC) lattice was proposed. The mechanical properties of the proposed lattices were compared with those of the conventional BCC, Octet and face-centered cubic (FCC) lattices. The results revealed that the BCC, Octet, and FCC lattices correspond to the highest deformation stability, the largest energy absorption and the highest strength among the three conventional lattices investigated, respectively, while the proposed VM-BCC lattice outperforms them all in each of the three properties. Remarkably, the proposed lattice made of stainless-steel possesses strength and energy-absorbing capacity close to that of lattices and foams made of titanium alloy. Moreover, a parametric numerical simulation study was carried out to ascertain the effect of the deviation coefficient, a geometric parameter of VM-BCC lattice on the mechanical properties and the deformation pattern. It indicates that the VM-BCC lattice with an appropriate deviation coefficient can effectively suppress the expansion of shear bands, resulting in high and stable stress response. This work proposes a novel bio-inspired lattice and enriches the design space for lightweight energy absorbers, which have prospective application potential in the fields of national defense, aerospace, navigation, and medical implants.