Tailorable Energy Absorption During Quasi-Static Crush via Additively Manufactured Honeycomb

Honeycomb materials are being used for energy absorption applications in aerospace and automotive industries due to their high strength-to-weight ratio. In this work, additively manufactured honeycombs with different inscribed diameters were tested in quasi-static compression on a servo-hydraulic material test system to determine how the geometry affects the energy absorption properties. Samples were made from acrylonitrile butadiene styrene in order to study the performance of brittle honeycomb structures in energy absorption applications. Samples were manufactured with buckling initiators, or small triangle cutouts, located at varying distances from the bottom of the sample, while others had no modifications. These buckling initiators create preferential stress concentrations, thus encouraging a controlled folding of the structure. As this study shows, the crush efficiency and energy absorbed efficiency increase as the inscribed diameter decreases. When the inscribed diameter is 20 mm, the crush efficiency is 20.29%, while it is three times larger when the inscribed diameter decreases to 10 mm (62%). The energy absorbed efficiency is 45% for the 10 mm sample while it decreases to 16.70% when the diameter is 20 mm (a 36% decrease). Similarly, the presence of buckling initiators increases crush efficiency and energy absorbed efficiency when compared to samples of similar geometry but no buckling initiators, regardless of the size of the honeycomb.