Influence of lotus-inspired spoke design parameters on the static and dynamic performance of non-pneumatic tires

Non-pneumatic tires (NPTs), characterized by their non-pneumatic nature, offer high safety and high load-carrying capacity, effectively mitigate the risk of blowouts, and demonstrate broad application potential in various engineering fields. This paper applies the biomimetic structural model of the lotus flower to the design of NPTs. Firstly, based on the morphological characteristic equations of the lotus, spoke structures with and without gradient distributions were designed, and corresponding finite element models were established. Subsequently, under the condition of constant spoke thickness, the influence of the number of spokes on the load-bearing performance of tires was analyzed. Furthermore, through sensitivity analysis, the impact of spoke thickness on stiffness was investigated. Additionally, based on two typical grounding conditions, the impact of thickness variation on tire grounding characteristics, including grounding stress, tread stress, and spoke stress, was systematically studied for a fixed number of spokes. Finally, simulations of the dynamic mechanical performance of the tire were conducted. The findings demonstrate that both spoke count and the spoke thickness significantly affect the load-bearing ability of the tire, and the grounding stress distribution shows distinct variations with changes in thickness. During dynamic rolling, the NPT structure with moderate spoke thickness and gradient distribution demonstrates superior performance. This research provides theoretical foundation and practical guidance for the design of the structure and thickness refinement of non-pneumatic tires.