Compressive behaviors of fractal-like honeycombs with different array configurations under low velocity impact loading

Abstract Fractal-like structures have been found to offer excellent mechanical performance, showing remarkable potential in engineering applications. This study proposed the fractal-like honeycombs with different array configurations. Their intricate patterns were constructed based on a simple fractal cell inspired by Koch curve. Compressive behaviors of the proposed honeycombs were investigated theoretically and numerically. Compared with conventional honeycombs, the specific energy absorption (SEA) of the proposed honeycombs can be improved by 85%, 110% and 95% for triangular, square and hexagonal honeycombs, respectively. For every array configuration, the proposed structures all exhibit higher crushing force efficiency (CFE). Theoretical models of conventional honeycombs and the optimal fractal-like honeycombs were established. Folding mechanism was analyzed to reveal the mechanical improvement by comparing details of folding lobes in the forming process. Analytical solutions were compared in terms of the half-wave length, mean crushing force and SEA by a solution map, reflecting the ratios and trends of increment in each criterion. The influence of the cell number on the half-wave length was studied. The findings of this study provide new directions and guidelines for designing novel energy absorbers with enhanced crashworthiness.