In-Plane Crushing Behaviors of Hexagonal Honeycombs with Hollow-Circle Joint under Different Compressive Velocities

The in-plane crushing behaviors of hierarchical hexagonal honeycombs, structured by replacing every three-wall vertex of both the conventional and reentrant hexagonal honeycombs with a small hollow-circle, are investigated herein. The finite element (FE) models are first verified by an empirical formula from the literature and then further used to simulate the in-plane crushing behaviors of the honeycombs under different compressive velocities. The deformation mode, plateau stress, and specific energy absorption (SEA) are studied based on the FE simulations. With respect to the conventional hierarchical honeycombs, the reentrant hierarchical honeycombs, in most instances, are found to exhibit higher plateau stress but lower SEA. It is remarkable that the hierarchical hexagonal honeycombs exhibit higher plateau stress and SEA than the basic hexagonal ones, which indicates that the hierarchical design is effective in improving both the impact resistance and energy absorption capabilities of the honeycombs.