3D printed hierarchical re-entrant honeycombs: Enhanced mechanical properties and the underlying deformation mechanisms. (15th June 2022)

• Record Type: Journal Article
• Authors: Zhan, Chi; Li, Mingzhe; McCoy, Robert; Zhao, Linda; Lu, Weiyi
• Is Part Of: Composite structures. Volume 290(2022)
• Publication Date: 2022-06-15
• Subjects: Re-entrant honeycomb -- Hierarchy -- Stretching-dominated -- Specific energy absorption -- 3D printing -- Digital image correlation; Composite construction -- Periodicals; Composites -- Périodiques; 624.18
• DOI: 10.1016/j.compstruct.2022.115550
• Languages: English
• ISSNs: 0263-8223

Abstract

Abstract: Re-entrant honeycombs are one type of lightweight cellular materials with superior energy absorption and impact resistance. Yet, the mechanical properties of re-entrant honeycombs need to be further improved due to its bending-dominated deformation mechanism. In this study, we designed a novel stretching-dominated re-entrant honeycomb by combining the structural hierarchy and auxetic cellular configurations. Such hierarchical re-entrant honeycomb (H-ReH) is manufactured through fine-resolution 3D printing technique. The mechanical behavior and deformation mechanism of the designed H-ReH has been investigated through combined digital image correlation and finite element simulation. The 3D-printed H-ReHs exhibit enhanced specific stiffness, specific initial-buckling strength, structural stability and specific energy absorption capacity due to the uniquely combined deformation mechanisms. A competition between the 1st order and the 2nd order hierarchy has been revealed, which governs the mechanical properties of the H-ReHs. These findings provide thorough understandings and facilitate future design of lightweight but robust cellular materials.