Breaking the Tradeoffs between Different Mechanical Properties in Bioinspired Hierarchical Lattice Metamaterials

It is a long-standing challenge to break the tradeoffs between different mechanical property indicators such as the strength versus toughness in the design of lightweight lattice materials. To tackle this challenge, a hierarchical lattice metamaterial with modified face-centered cubic (FCC) cell configuration, inspired by the glass sponge skeletal system, is proposed. The proposed lattice metamaterial simultaneously possesses high strength, high energy absorption, considerable toughness, as well as controllable deformation patterns through integration of both bionic features of double diagonal reinforcement and hierarchical circular modification. The compressive strength and energy absorption can reach 69.13 MPa and 53.39 J cm(3), respectively. Furthermore, the proposed lattice also exhibits exceptionally high damage tolerance compared with existing lattice metamaterials with comparable strength by attenuating stress and deformation concentration that may cause catastrophic collapse. This design approach combines the advantages of tensile-dominated and bending-dominated lattices. Quantitatively, in terms of specific strength, specific energy absorption, and crushing force efficiency, the modified hierarchical circular FCC (MHCFCC) lattice metamaterial outperforms the Octet lattice by 14.85%, 53.28%, and 110.52%, respectively. This multibionic feature integration approach provides advanced design strategies for high-performance architected metamaterials with promising application potential.

Automated summary

It is a challenge to compromise between mechanical property indicators in the design of lightweight lattice materials. A hierarchical lattice metamaterial is proposed to overcome this challenge, inspired by the glass sponge skeletal system. This lattice metamaterial possesses high strength, energy absorption, toughness, and controllable deformation patterns, combining bionic features of reinforcement and modification. The proposed lattice demonstrates superior damage tolerance compared to existing lattice metamaterials and outperforms the Octet lattice in terms of specific strength, energy absorption, and crushing force efficiency.