Energy absorption of re-entrant honeycombs in tension and compression

Abstract

Energy absorption is essential for materials/structures in engineering application. It is related to their deformation mechanisms and force–displacement (stress–strain) relationships. Re-entrant honeycombs are expected to show better energy absorption performance in tension than in compression due to a longer stroke of plastic deformation. To examine this, the work aims to systematically examine the energy absorption performance of re-entrant honeycombs under both tensile and compressive loads in the two loading directions. Analytical models for re-entrant units are established based on an idealised deformation mechanism, which are validated using Finite element (FE) analysis and the experimental result in the reference. The results demonstrate that when loaded in the X2 direction, re-entrant honeycombs are more effective in tension rather than compression in terms of energy absorption, which means that one can take the full advantage of re-entrant honeycombs in tension-dominated energy dissipation applications. However, when loaded in the other direction, the performance depends on initial cell angles of the structures and θ0 = 45° is the divide.