Improving energy absorption in cellular 3D-Printed fiber–reinforced structures with radially reinforced composite shells

This study investigates the energy absorption capabilities of cellular structures combined with carbon fiber–reinforced polymer shells. The cellular core was produced by material extrusion 3D printing, while the shells were manufactured by the hand layup of carbon fiber-epoxy prepreg. Various material and reinforcement configurations were analyzed in a combined configuration and separately on a component level. The energy absorption properties of the printed specimens were evaluated after quasi-dynamic compression tests, demonstrating that the introduced radially reinforced hoop layers significantly improved compressive load-bearing capacity by resisting delamination and, consequently, local buckling in the 3D-printed cellular structures. This led to stable failure modes and higher specific energy absorption (SEA). The hybrid structures, which combined external shells with a cellular framework, exhibited a synergistic effect, resulting in up to a 200 % improvement in SEA.