Quasi-static in-plane compression of zig-zag folded metamaterials at large plastic strains

The work aims to study the large, plastic deformation and energy absorption characteristics of zig-zag folded metamaterials, BCH_n, under quasi-static in-plane compression, using an analytical method and numerical analysis. In analytical modelling, the zig-zag folded materials are assumed as rigid origami in the y direction. The BCH_n materials are considered as cellular materials with various topologies defined by the characteristic geometric parameters (a,b,h;α,γ₀;n) when the strength at large plastic strains and densification strain are defined. The obtained analytical relationships between material topology and material strength provide an easy way to assess the energy absorption of BCH_n materials with various geometric parameters. Particular attention is paid to the compression response of BCH₂ and BCH₃ materials, and comparisons are made with Miura-ori based materials having the same parameters (a,b,h;α,γ₀). It is found that the zig-zag folded materials outperform the Miura-ori based material in terms of energy absorption. Besides, tunable geometric parameters of the BCH_n zig-zag folded materials allow better tailoring of their mechanical properties. Comparisons of the energy absorption efficiency between zig-zag folded materials and hexagonal honeycomb materials show that the parameters of the BCH_n materials can be selected to obtain metamaterials with superior energy absorption characteristics. Finite element models of zig-zag folded materials are built using ABAQUS/Explicit and numerical simulations of quasi-static compression are carried out to verify the analytical results. The observed agreement in terms of force and deformation confirmed that the analytical models are valid, and the analytical predictions are reliable.