Bio-Inspired Mechanical Metamaterial Architectures: Parametric Optimization of Novel 3D-Printed Structures for Sports Equipment

This study presents a novel bio-inspired round auxetic metamaterial whose unit-cell geometry is derived from the suture patterns observed in turtle shells. The design integrates natural inspiration with engineering optimization to achieve outstanding auxetic behavior, high energy dissipation, and superior mechanical resilience under compressive loading. The structure was fabricated using digital light processing (DLP) and analyzed through both experiments and finite element simulations in Abaqus. The experimental and numerical results show excellent agreement, with deviations below 5% in load–displacement response and buckling force, confirming the reliability of the simulation model. Parametric analyses reveal that increasing the unit-cell curvature radius enhances structural stiffness and raises the buckling force by up to 6%, while simultaneously reducing Poisson’s ratio by nearly 50%, thereby amplifying auxetic effects and radial contraction under load. Similarly, increasing the unit-cell thickness by 0.2[Formula: see text]mm significantly improves mechanical performance, raising the buckling force by approximately 70% and stiffness by around 45%. The findings underscore the novelty of this bio-inspired round metamaterial, demonstrating how geometric tuning enables tailored performance. The outcomes provide a framework for utilizing suture-inspired auxetic geometries in the creation of protective systems that combine low weight with structural robustness and enhanced energy dissipation.