A static grounding analysis model of non-pneumatic tire (NPT) was built and presented in this paper. The proposed NPT analysis model considers the non-linearity of the spoke stiffness and is suitable for the performance exploration of various structures of the NPT. First, the shear band, rigid rim, and spoke structure of the NPT were simplified, the main structural parameters and mechanical parameters were extracted, and an analysis model was established. The model can describe the deformation of the NPT when it is subjected to external forces. On this basis, the different stiffness of the spokes during tension and compression was considered, an iterative method was used to compensate for the difference in the deformation caused by the difference in radial stiffness of the spokes, and an analysis model of NPT with nonlinear spokes was established. Then, the contact between the tire and the road surface was introduced to iteratively compensate for the reaction force of the road surface, and the deformation of the NPT with nonlinear spokes on the road surface was obtained. Finally, the finite element software ABAQUS was used to verify the accuracy of the model. This model contains more comprehensive structural parameters and material parameters, which can more realistically simulate the structural characteristics and static grounding behavior of the NPT.

An analytical model of a non-pneumatic tire is proposed to study the static deformation responses of a non-pneumatic tire in contact with a rigid ground. The tire consists of a shear band which is formed by an annular beam, and elastic spokes that connect the shear band to the rigid hub of the tire. The shear band is modeled using a Timoshenko beam. The spokes are modeled by linear springs, which are distributed evenly in circumferential direction. Governing equations of the model were derived using a theoretical analysis. The shear band static deformation was obtained based on the discussion of the relationship between spoke stiffness and the parameters of the shear band. A finite element model was developed to verify the accuracy of the model. As a part of the results from this study, a parametric analysis of quantities of interest for the tire is presented, which can be used in improving the optimal design of non-pneumatic tires. This scheme offers a holonomic solution for the complicated differential equations and gives a computationally efficient tool for rapid analyzing and designing such systems.

Ground reaction force and impulse measurement is an established method for assessing the physical condition and efficacy of treatment for some animals. The primary aim of this study was to quantify the kinetic parameters of the limbs of healthy cats at different speeds. The second aim was to determine the explicit relationship between the kinetic parameters and speed. Peak vertical force (PVF), vertical impulse (VI), stance phase duration (SPD), and paw contact area (PCA) of each limb (forelimb, F; hindlimb, H) of seven clinically healthy, client-owned cats were recorded in the speed interval of 0.5–2.5 m/s. The cats were encouraged to pass by a pressure-sensitive walkway with different speeds. The results revealed that there were no significant differences in any of the tested parameters between the left and right forelimbs and the left and right hindlimbs. Means and regression formulas of the kinetic parameters with speed were obtained. It was evident that PVF-F and PVF-H increased linearly with speed, while VI-F and VI-H decreased exponentially. SPD-F was practically equal to SPD-H and exponentially decreased with speed. PCA-F increased linearly with speed, and PCA-H was almost invariable. Pressure-sensitive walkway is a suitable and convenient equipment for assessing the kinetic parameters of cats. Variation of these kinetic parameters with speed can be explained by the functional difference for forelimb-dominant and hindlimb-driven.