A New Circular Honeycomb Made by Hemp/Epoxy Composite: Manufacturing and Mechanical Characterization

Abstract Composite materials, renowned for their versatile design and impressive mechanical properties coupled with lightweight attributes, are garnering increasing attention across industrial sectors. Among various emerging challenges, the exploration of their potential application for sandwich structure cores made of natural fibers represents an enticing prospect for both industry and academic researches. In line with the current imperative to investigate the utilization of sustainable materials, this study proposes a novel circular honeycomb structure reinforced with hemp fibers manufactured using an ad-hoc continuous manufacturing process capable of impregnating the hemp fabric with the desired resin content and forming it in a circular cell pattern. Three core samples, varying in elementary cell sizes with densities ranging from 0.144 g/cm 3 to 0.276 g/cm 3 , were produced. Out-of-plane compression and short beam shear tests were conducted on each sample family. The results were subsequently compared with those of a common foam utilized as a core in industrial applications. The compression and shear tests, along with the attained final density, revealed interesting specific properties, suggesting that this honeycomb structure reinforced with natural fibers, can be considered as a promising alternative to conventional core structures.