Design and energy-absorption characteristics of a novel asymmetric rotatable reentrant honeycomb with circular ring

Negative Poisson’s ratio (NPR) architectures, as one of the representatives of advanced lightweight honeycomb materials, have good application prospects in aerospace, transportation, biomedical and other fields due to their unique deformation mechanisms and excellent energy absorption capabilities. This study introduces a novel two-dimensional asymmetric rotatable reentrant honeycomb with a circular ring (RARH-CR) that manifests the NPR effect. The compressive response of RARH-CR is systematically characterized through quasi-static axial compression experiments and validated finite element (FE) simulations. The experimental results confirm the robustness and predictive accuracy of the FE model and reveal that the integration of the central ring and reinforcing ribs effectively mitigates stress concentrations, thereby enabling RARH-CR to achieve substantially greater energy absorption than conventional asymmetric reentrant hexagonal (AR-RH) counterparts, manifested as an increase of about 70.2% in SEA, an increase of over 220% in plateau stress, and a more uniform and stable deformation mode. Orthogonal simulation analysis further elucidates the influence of key geometric parameters—including the height and width of the reentrant points and the radius of the circular ring—on its quasi-static compressive performance. These findings provide a new structural paradigm for NPR-based mechanical metamaterials, offering both theoretical insights and practical guidance for designing lightweight, high-performance energy-absorbing systems.