Bending modeling and analysis of hybrid auxetic honeycomb with multidirectional mechanical modifications

Advanced auxetic honeycombs have attracted extensive attention due to their counterintuitive mechanical behaviors, while research on improving and analyzing their bending performance is still limited. This work first designs three hybrid auxetic honeycombs called Re-entrant-arrow-snake, Re-entrant-arrow and Re-entrant-snake. Then the analytical models of their out-of-plane bending properties are established, in which different connection boundaries are specially considered. By comparison, the established analytical models exhibit good agreement with the numerical models. Further, the bending mechanical properties of the hybrid auxetic honeycombs, including the bending stiffness and bending modes, are systematically studied. Results show that the hybrid designs can effectively modify the multidirectional bending properties of the auxetic honeycomb and significantly improve their designability. Especially, due to different deformation mechanisms, adjusting the inclined angle can dominantly affect the y-direction stiffness, and adjusting the height of the snake-shaped structure can independently adjust x-direction bending behaviors, thereby enabling its excellent adaptability across various engineering applications. This work provides significant guidance for designing and studying the bending behaviors of advanced hybrid auxetic honeycombs with multidirectional mechanical modifications, further promoting the applications of auxetic honeycombs in related fields such as flexible robots, flexible wings and biomedical stents.