Optimized hexagonal perforated honeycomb–chiral metamaterial for multidirectional energy absorption

This paper introduces a novel hexagonal perforated honeycomb-chiral (HPH-C) structure, achieved by integrating curved perforated rib elements into a hexagonal perforated framework. The incorporation of curved ribs forms rotating chiral units, imparting distinctive deformation characteristics under radial compression, including rotational and winding bending behaviors. This innovative structural design substantially enhances the energy absorption capacity in the radial direction. Under axial compression, the structure demonstrates pronounced negative Poisson's ratio behavior by contracting and deforming toward regions of reduced stiffness near the perforations, further augmenting its energy absorption capacity. Quantitative comparisons with the original structure indicate that while the innovative design increases weight by 107%, the specific energy absorption (SEA) under radial compression is improved by 200% and under axial compression by 111%. The proposed design approach introduces innovative strategies for achieving multidimensional impact protection in metamaterials. Leveraging the advantages of additive manufacturing, this study highlights the significant potential of perforated negative Poisson's ratio metamaterials to advance the development and application of multi-dimensional, multi-scale energy-absorbing structures in engineering fields.