Session: 01-06-03: Impact, Fatigue, Damage and Fracture of Composite Structures 3
Paper Number: 162052
162052 - Increased Damage Tolerance and Fatigue Resistance of Hierarchical Re-Entrant Honeycombs
Composite materials are increasingly used in current aerostructures, due to their superior specific strength which is comparable to that of metals. Under repeated loading cycles, the damage tolerance and fatigue resistance of composite materials is critical for the safety and service life of the aerostructures. The damage tolerance and fatigue resistance of materials are largely determined by both the strength and ductility of the materials. However, the strength and ductility are two competing constituent material properties. To address this challenge, a structural design approach is proposed in this study. The hierarchical re-entrant honeycomb (H-ReH) structure has been designed and manufactured by additive manufacturing with relative densities of 0.25, 0.35 and 0.45. Regular re-entrant honeycombs (R-ReH) with same relative densities have been manufactured by using the same polyjet printing technology and material. The mechanical properties of the ReHs have been characterized by quasi-static compression tests. The strength of the R-ReH and H-ReH has been improved by 370% and 411%, respectively by tuning the relative density of the structure from 0.25 to 0.45. While the total deformability of the R-ReH has been decreased by 75%, the total deformability of the H-ReH has been maintained at 52% as a constant. These findings demonstrate that the hierarchical design of the re-entrant honeycomb has improved the strength without sacrificing the total deformability. This structural design approach is a promising strategy to improve the damage tolerance and fatigue resistance of future composite structures.
Presenting Author: Zachary Ahmed Michigan State University
Presenting Author Biography: I am in my first year of PhD studies at Michigan State University in the Department of Civil & Environmental Engineering. My work in research began during undergraduate studies also at MSU focusing on asphalt characterization and fracture mechanics and then developed into Structures & Materials through the rest of undergrad and M.S. I am interested in the optimization of material and structural combined effects for future development in relevant applications.
Increased Damage Tolerance and Fatigue Resistance of Hierarchical Re-Entrant Honeycombs
Paper Type
Technical Presentation Only