In-plane energy absorption characteristics and mechanical properties of 3D printed novel hybrid cellular structures

This paper developed and fabricated four novel hybrid metamaterial structures by combining honeycomb, re-entrant, and star-shaped unit-cells by additive manufacturing (AM) techniques and tested them to evaluate the enhanced mechanical properties. Then, the in-plane energy absorption capacity and uniaxial compressive response of novel structures were compared using finite element simulation and experimental techniques. In addition, all structures' failure modes and deformation mechanisms were explained in detail. A type one re-entrant-star-shaped (RS1) structure demonstrated higher compressive strength, plateau stress, and energy absorption than other structures, mainly due to the unique deformation mechanism. For comparing energy absorption and mechanical properties between the parent and hybrid cellular structures (HCS), the RS1 performed the best. A Poisson's ratio curve for HCS was also obtained, and the relevant results were analyzed. In addition, the results of this research should aid in determining the best unit-cell arrangement for HCS to improve their mechanical properties and energy absorption.