Influence of Spoke Parameters on Load Capacity of Non-Pneumatic Tires Using Orthogonal Study and Analysis of Variance

This study aims to investigate the relationship between the static characteristics of non-pneumatic tires (NPTs) and spoke design parameters using the finite element (FE) method. A three-dimensional FE model of the NPT was established. The influence of different ranges of stress and strain on the calculation accuracy of the Neo-Hookean and Yeoh constitutive models was analyzed. Subsequently, the main design parameters—spoke thickness, spoke number, and arc curvature—were selected according to the geometric characteristics of the spokes. The effects of these three parameters on the vertical stiffness, maximum spoke stress, overall maximum stress, and maximum and average contact pressures were examined using univariate and multivariate analysis methods. The range and variance analysis results indicated that the spoke thickness, spoke number, and arc curvature had a significant effect on the vertical stiffness. Finally, the relationship between the vertical stiffness and product of the spoke thickness and number was obtained using a nonlinear fitting method. When the arc curvature of the spoke was less than 5 m⁻¹, the errors between the calculated and simulated vertical stiffness did not exceed 5%. This observation can be used to facilitate the rapid design of spoke parameters under different load capacity requirements.