This study aims to analyze the load-bearing characteristics of non-pneumatic tires with composite spokes using experimental and finite element simulation methods and to establish a mechanical analysis model based on the Timoshenko beam theory. Subsequently, experiments were conducted on carbon fiber-reinforced plastics and rubbers to establish the corresponding constitutive model. A finite element model of the non-pneumatic tires with composite spokes was also developed. The main structural and material parameters were selected, and their correlation with the vertical stiffness of the non-pneumatic tires with composite spokes was studied using response surface methodology. The stiffness characteristics of the composite spokes were simplified, and a load-bearing characteristic analysis model was established. The results indicated that among the parameters of the reinforcement plate structure and rubber, the constitutive parameter C₁₀ of the rubber in the spokes had the greatest impact, with a comprehensive influence value of 319.83 N/mm. Under a load of 5000 N, the load-bearing characteristic analysis model results were consistent with those of the finite element simulation, with a maximum relative error of 7.49%. The proposed load-bearing characteristic analysis model can assist in the rapid design and performance prediction of non-pneumatic tires with composite spokes.

This study aimed to investigate the relationship between the static stiffness of non-pneumatic tires (NPTs) and the design parameters of composites spokes and shear bands using the finite element (FE) method. The stress–strain curve of the rubber material was fitted using the neo-Hookean constitutive model. Subsequently, key design parameters, including the reinforcement plate thickness and constitutive parameters of the spoke and shear band materials, were selected based on the NPT structure. FE simulations were performed on multiple sets of different parameter design schemes for the NPTs, and polynomial models for the vertical, lateral, and longitudinal stiffnesses were established using response surface analysis. The sensitivity analysis results indicated that the thickness of the reinforcement plate significantly influenced the three-dimensional stiffness, whereas the constitutive parameters of the spoke and shear band materials had a relatively minor impact. Finally, multi-objective optimization was employed to determine a design scheme with maximum longitudinal stiffness while ensuring vertical load-bearing capacity. Under the premise of ensuring the vertical load-bearing capacity, the longitudinal stiffness increased by 39.1% and 32.9% in the forward and backward directions, respectively. This method can be used to predict the three-dimensional stiffness of NPTs under different design parameter schemes or to optimize the setting parameters of NPTs based on the desired target stiffness, facilitating the rapid design of the three-dimensional stiffness of NPTs.