Hybrid design of a multifunctional auxetic honeycomb for improved energy absorption and vibration isolation

Abstract Auxetic honeycombs have attracted considerable interest due to their distinctive properties, but their multifunctional potential has not been fully developed. This work introduces a hybrid chiral star-shaped honeycomb (CSH) created by combining the chiral honeycomb (CH) with the star-shaped honeycomb (SSH). Using the numerical model validated by experiments, the deformation mechanism and energy absorption capacity of the CSH are investigated, and theoretical models are subsequently developed to characterize its plateau stress and dynamic Poisson’s ratio. The CSH outperforms the individual SSH and CH at equal relative density, exhibiting two plateau stages and achieving a 140% and 15% higher specific energy absorption (SEA), respectively. Notably, this improvement in energy absorption is accompanied by a more pronounced negative Poisson’s ratio (NPR) effect, with the minimum Poisson’s ratio of the CSH being 148% and 18% lower than that of the SSH and CH, respectively. To extend functionality, local resonance units are incorporated into the CSH, resulting in a multifunctional honeycomb with improved vibration isolation performance. This is demonstrated by its broad bandgap characteristics, where the total width of the complete bandgaps occupies 27.9% of the studied frequency range. This work is expected to provide a new design strategy for multifunctional auxetic honeycombs and practical insights for their engineering application.