Study on the mechanical properties of cylindrical mechanical metamaterials with biomimetic honeycomb units of the diabolical ironclad beetle

Abstract

In the long process of evolution in nature, the elytra of the diabolical ironclad beetle are connected in a jigsaw way, so that the overall structure of the beetle has strong pressure resistance. The study of the geometric features and interlocking effect of elytra junctions provides new ideas for the development of new bionic applications. The honeycomb structure is a new type of material structure with excellent mechanical properties, and has broad application prospects in building structure, aerospace and other aspects. Through the reasonable design and modification of the honeycomb structure, the honeycomb structure has different characteristics. Based on the concave hexagonal honeycomb structure, combined with the geometric characteristics of the diabolical ironclad beetle jigsaw connection, the concave hexagonal honeycomb structure is redesigned, and a new type of bionic honeycomb structure is proposed. Through the combination of experiments and simulations, the mechanical response of the bionic honeycomb structure of diabolical ironclad beetles was studied. Research has shown that as the connection angle increases, the curvature on both sides of the unit also increases, making the units more compact. The overall structure exhibits two types of mechanical responses under compression: "U" and "Γ". The structure with connection angle of 25° can rely on the support and buckling on both sides of the unit, thus having the best energy absorption characteristics. As the axial ratio of the ellipse (a:b) increases, the degree of concavity in the structural unit continues to deepen, resulting in three forms of deformation of the structural unit. The structural unit changes from being supported on both sides to being bent on both sides, resulting in a stacking phenomenon in structures with ratios of 2.2:1 and 2.4:1, and the overall structure has better deformation resistance.