Quasi-static Crush of Additively Manufactured Tubulane Structures

Abstract

This study investigates the quasi-static compressive behavior of additively manufactured tubulane structures fabricated using stereolithography (SLA), an additive manufacturing technique. The samples were manufactured such that the number of unit cells (N = 2–5) were systematically varied, while maintaining constant material volume. The effects of varying unit cell density on crashworthiness were examined across two material systems: a hard plastic and an elastomeric resin. Mechanical performance and crashworthiness were evaluated by using the stress-strain curve to identify the crush efficiency (CE), and energy absorption efficiency (EAE). Hard plastic samples with N = 2–4 exhibited brittle, global fracture, while N = 5 samples demonstrated localized failure and retained load-bearing capacity beyond 60% strain. Remarkably, the N = 5 samples also rebounded to over 90% of their original height after testing. In contrast, all elastomeric samples were fully compressible to densification and recovered without permanent deformation. CE and EAE metrics revealed that while elastomeric samples outperformed rigid ones in efficiency, the N = 5 hard plastic configuration uniquely combined ductile-like energy absorption with structural recovery. These results emphasize the potential of geometry-driven design to create scalable, lightweight energy-absorbing structures.