Influence of Relative Density and Material on the Compressive Response of 3D-Printed Honeycomb Structures for Crashworthiness

The present study investigates how the relative density of 3D-printed hexagonal honeycombs made from ABS and PET-G polymers affects their ability to withstand compression. The honeycombs were tested by quasi-static compression testing and analyzed for energy absorption performance. The goal is to evaluate suitable relative density levels for these structures when used as cores in hybrid energy absorbers. The results show that the type of material and its density are critical factors. Denser and moderate-density structures (STD, 15%, and 25%) absorbed more energy because they formed plastic hinges, then cell walls collapsed into the honeycomb core. On the other hand, lower-density structures (40% and 50%) were less effective at absorbing energy as they were more likely to flexural buckling and delaminate. PET-G performed better than ABS in energy absorption due to its higher flexibility and strain-hardening behavior. The study also identifies experimental trends describing how structural effectiveness and energy absorption vary with the relative density for both materials within the investigated range. These findings can support the selection of suitable density levels and materials for 3D-printed honeycomb structures intended for crashworthiness-related applications.