Design and optimization of the dual-functional lattice-origami metamaterials

This study proposes a multi-scale composite lattice-origami metamaterial (MCLOM) to achieve excellent bandgap characteristics and energy absorption capacities. The MCLOMs are constructed by considering the high impedance mismatch of lattice structures, the spatial deformability of origami structures, and the tunability of the components in multi-scale composite materials. Firstly, elastic wave propagation characteristics are analyzed in the Bloch wave framework, revealing the realization of complete bandgaps and their generation mechanism by mode shape analysis and transmission spectrum. Subsequently, an optimization framework integrating the particle swarm optimization (PSO) algorithm is developed to maximize the first bandgap's bandwidth by adjusting various component parameters. Under optimal distribution, the proposed metamaterials achieve remarkable improvements of 289% and 271% in the design objectives of two lattice-origami metamaterials with 90 degrees dihedral angle compared to the initial distribution. It can be demonstrated that non-uniform distributions of multi-scale composite materials are dramatically effective for broadband wave attenuation. Additionally, while striving to widen the bandgap, the energy absorption capacities of structures are also crucial. The effect of the distribution of multi-scale composite materials with the optimal bandgap on the energy absorption performance is investigated. The results reveal that the optimal distribution of the lattice-origami metamaterials yields notable improvements of 48.26% and 34.86% under low-velocity impact, and 37.41% and 25.19% under medium-velocity impact. This work presents innovative concepts and approaches for devising and implementing novel dual-functional metamaterials, undoubtedly propelling the continual progress of material science and engineering technology in the times ahead.