A study of crashworthiness performance in thin-walled multi-cell tubes 3D-printed from different polymers

Multicellular, thin-walled impact tubes have been intensely studied and used in various engineering fields in recent years due to their lightweight, high performance, ease of application, superior energy absorption, and stable deformation characteristics. In this study, energy absorption, crashworthiness performances, and deformation properties of thin-walled structures manufactured from polylactic acid (PLA+) and acrylonitrile butadiene styrene (ABS) using fused deposition modeling (FDM) technology were compared under quasi-static axial compression. Thin-walled structures consist of multicellular tubes connected by concentric corner-edge connections with square and hexagonal cross-sections. Experimental testing outcomes indicate that the energy absorption capacity increases with increasing the number of corners in multicellular structures. The tubes with square wall-to-wall (S-WW) and hexagonal wall-to-wall (H-WW) cross-sections exhibit superior crashworthiness performance compared to other cross-sections. Based on the experimental results, the absorbed energy by WW patterned PLA+ square tubes are 19%, 7%, and 46% more than that of wall-to-corner (WC), corner-to-wall (CW), and corner-to-corner (CC) patterned tubes, respectively, while it is 11%, 19%, and 80% more in hexagonal cross-section tubes, respectively. This study provides an informative reference for easier applicability of multicellular energy-absorbing structures with 3D-print and the design of corner-edge connections of internal connections in multicellular structures.