In-plane crashworthiness of chiral honeycombs

In-plane dynamic crushing and energy-absorption capabilities of chiral honeycombs are studied numerically invoking Finite Element (FE) code ABAQUS®/Explicit. Chiral honeycombs are characterized by a non-intuitive negative in-plane Poisson's ratio Ï (auxeticity), for hexagonal chiral honeycombs, which exhibits a theoretic value of −1 (Prall and Lakes, 1997). The effects of topology parameters, stiffness ratio of ligament to node, impact velocity and impact mass on structural crashworthiness are studied based on a fixed-size model and a convergence study is also carried out to minimize the meshing induced result error. The numerical results show that increasing values of topology parameters give rise to better crashworthiness of chiral honeycombs which is dependent on boundary conditions. Specific energy absorption of chiral honeycomb is independent of relative stiffness after reaching a critical value. High velocity impact loading has dramatic effect on energy absorption of chiral honeycomb which is relatively independent of low velocity impact loading and impact mass.