Thermal expansion regulation and bandgap analysis of a novel dual-constituent negative Poisson’s ratio lattice metamaterial

Abstract

Negative Poisson's ratio lattice metamaterials (NPR-LM) have broad application prospects in explosion-proof and impact resistance due to their excellent energy absorption and cushioning properties. The development of science and technology has put forward higher requirements for the versatility of materials, but the currently existing lattice metamaterials are often limited to a single function. In this paper, a novel dual-constituent re-entrant hexagonal lattice metamaterial (DRHLM) with tunable thermal expansion behavior, negative Poisson's ratio (NPR) effect, and outstanding band-gap characteristics are designed based on traditional re-entrant hexagonal metamaterial and bi-layer curved rib. The tunable thermal expansion characteristics and NPR effect of DRHLM are verified by analytic and finite element numerical simulation methods. Finally, the bandgap of DRHLM is studied by using the finite element method, and the influence of the bending angle of the ribs on the bandgap is analyzed for DRHLM configurations with different coefficients of thermal expansion (CTEs) and NPRs. The results show that the designed DRHLM can simultaneously achieve different positive/negative/zero CTE and NPR with outstanding band gap characteristics by reasonably selecting material parameters and geometric parameters. This paper provides a new idea for the design of mechanical metamaterials with various properties and functions.