Quasi-Static, Rolling and Shear Behaviors of an Auxetic Non-Pneumatic Tire with TPMS-Based Spokes

This study investigates the quasi-static rolling behavior and shear response of a non-pneumatic tire incorporating a Triply Periodic Minimal Surface (TPMS)-based Rotated Primitive Auxetic Structure (RPAS).The RPAS spoke derives a negative Poisson's ratio from rotational transformations of Primitive TPMS unit cells, enabling load-adaptive variable stiffness through auxetic densification.Building upon validated static results, quasi-static rolling simulations over approximately 2.7 spoke-pitch cycles showed that position-dependent ground reaction force fluctuations were reduced to 0.78% for the RPAS, compared to 3.32% for a conventional honeycomb design at 2.5 mm compression.This reduction is attributed to a self-compensating mechanism where auxetic densification of the RPAS partially bridges the geometric gaps between discrete spokes.Shear analysis yielded a stiffness of 0.61 N/mm for the RPAS, comparable to the honeycomb tire (0.58 N/mm), indicating that the auxetic architecture does not compromise longitudinal stability.These numerical insights provide a foundation for future investigations involving multi-cycle loading and high-speed dynamics to further extend the scalability of the proposed RPAS design.The present findings should be interpreted as structural design tendencies obtained under quasi-static numerical conditions; extension to high-speed operation and full-scale rubber tires requires dedicated experimental and viscoelastic-dynamic validation.