Fatigue life prediction and structural optimization design of the bionic petal non-pneumatic tire with spokes

Fatigue durability of the non-pneumatic tire (NPT) has a decisive influence on vehicle safety and transport economy. This paper aims at the research on the fatigue life prediction method suitable for the flexible spokes of the NPT, and explores the influence of structural parameters on fatigue performance. By simultaneously taking consideration of fatigue performance, bearing capacity, and weight of the NPT, the optimal model parameters are obtained by the proposed structural optimization method. Firstly, based on the Thomas crack model, the fatigue life of the bionic petal non-pneumatic (BP-NPT) is predicted. Then, the influential mechanism of key structural parameters including the curvature, array period, and spoke thickness on tire fatigue durability is investigated by numerical simulation methods. Finally, an optimization method based on the Kriging model and modified NSGA-II is proposed to optimize the structure characteristics of the BP-NPT for better fatigue life and bearing capacity while ensuring lightweight. The results show that the predicted fatigue failure mileage of the BP-NPT is 2.54 × 10 4 km. By properly increasing the curvature and thickness of the spoke, the maximum strain energy density of the BP-NPT will be reduced, thus improving its fatigue durability. The performance of the optimized structure is significantly improved by the proposed optimization method. The total mass is reduced by 7.44%. The fatigue life and bearing capacity are improved by 9.75% and 4.16%, respectively. It is indicated that a more durable and safer tire configuration is provided for tire safety applications.