Experiment and numerical investigation on beetle elytra inspired lattice structure: Enhanced mechanical properties and customizable responses

•The novel beetle elytra inspired lattice configuration is proposed.•The IBCC exhibits superior stiffness and energy absorption than BCC and OCT under the same relative density.•The bio-inspired topological design and interaction effects of curved rods contributes to the enhanced mechanical performance.•The structure of IBCC with “target” mechanical properties can be inversely designed using genetic algorithm. The elytra of the ironclad beetles possess very strong and toughness performance, to protect the body from catastrophic physical damage, owing to its unique curved geometry and layered microstructure. In this paper, inspired by the elytra of ironclad beetles, a novel configuration of lattice structure (IBCC) was developed. The digital light processing (DLP) with hard-tough resin was used to fabricate the lattice structures. The compression experiment and simulation were performed to investigate the mechanical response and deformation mechanism. The response surface model (RSM) was adopted to build a forward relationship between structure parameters and mechanical properties. A numerical method was developed to inversely design structure parameters of IBCC with “target” mechanical properties using genetic algorithm. The novel lattice structure exhibits superior stiffness and energy absorption than conventional BCC (body-centered cubic) and OCT (Octet) structures, under the same relative density. For example, IBCC shows a maximum 59% improvement (at ρ¯=9.60%) of stiffness, and a maximum 25% improvement (at ρ¯=7.40%) of SEA, with respect to OCT. Besides, the stress plateau of IBCC is more stable than OCT, even at relatively large compression strain. The superior mechanical response of the IBCC lattice structure is mainly ascribed to bio-inspired topological design and interaction effects of curved rods in the “V-shaped” region. Besides, the effectiveness of the proposed inverse design method is verified by three numerical cases. The proposed bio-inspired design strategy, mechanical enhancement mechanism, and customizable method will be helpful in expanding the prospects of lattice structures in future multifunctional application fields.