Experiment-informed finite element modeling and design optimization of a non-pneumatic tire featuring an auxetic anti-tetrachiral metamaterial

Non-pneumatic tires have received wide interest in the latest years due to their puncture-proof capability and low environmental footprint. Apart from common spoke-type designs, lattice structures are employed as a way to enhance the tire’s structural response and stiffness characteristics. The current paper sheds light upon the use of an auxetic anti-tetrachiral metamaterial in a non-pneumatic tire (NPT), based on previous foundational research. A detailed finite element model is developed, capturing material, contact and geometrical non-linearity. The initial anti-tetrachiral NPT undergoes multiobjective optimization, achieving 2.3 times higher vertical stiffness with 7% lower mass and 28.5% lower inertia compared to the baseline design. Furthermore, experimental characterization of the metamaterial’s representative volume element (RVE) takes place through uniaxial tensile and compression testing and exploited in a hyperelastic metamaterial model construction, contributing to the fidelity and realism of the FEA model. Last, the optimized non-pneumatic tire is compared against conventional pneumatic tires of the same dimensions, proving the tunability and adequacy that such a structure can offer in airless tire design.