Beetle elytron plate and the synergistic mechanism of a trabecular-honeycomb core structure

For the development of lightweight biomimetic materials, the compressive properties of the beetle elytron plate (BEP, a type of biomimetic sandwich plate inspired from beetle elytra) and the underlying mechanism thereof were investigated. With the following results: (1) The shared mechanism of trabeculae was revealed by using structural analysis. It is further predicted that a BEP with hollow trabeculae should possess enhanced compressive properties. (2) When the trabecular number (N) in a hexagonal unit of the honeycomb is less than three, the compressive strength of the BEP is rapidly increased with the increment of N. When N is over four, the deformation capacity is significantly improved because of the arising of S-type buckling deformation in the core structure of the BEP. Furthermore, the definition of the BEP is proposed combined with the biological structure of the beetle elytra. (3) When N=6 and the external diameter of trabeculae is equal to the length of honeycomb walls, the synergistic mechanism between the trabeculae and the honeycomb walls in BEPs is fully exerted. Namely, the trabecula restricts the deformation of the honeycomb walls; in turn, the honeycomb walls provide lateral support for the trabecula. This mechanism leads the core in the BEP to generate an S-type global buckling deformation producing the best compressive properties. The results will greatly impact the biomimetic field of beetle elytra and many industries in which honeycomb structure also serves as a key component.