Analytical solution and experimental verification for the buckling failure of additively manufactured octagonal honeycombs

In this study, an analytical closed-form expression was developed based on the beam-column theory for the buckling strength of octagonal honeycombs without and with defects under additive manufacturing, and an analytical expression of the critical relative density of the octagonal honeycomb was also proposed. Plateau borders and wavy cell walls were considered in the studied structure. Finite element simulations and experiments on the buckling strengths of the octagonal honeycombs with and without defects were also performed, and the results were then compared with the theoretical results. Good agreement between the results validated the presented analytical solution for the buckling strength, and the critical relative density was used to accurately predict the failure modes of the honeycomb structures. The buckling resistance of the octagonal honeycomb structure was better than that of the traditional hexagonal honeycomb structure. For the octagonal honeycomb with defects, the analytical solution was consistently in good agreement with the experimental and simulation results. The buckling stress distribution, buckling mode, and buckling strength of the octagonal honeycomb were significantly affected by the presence of defects.