The Influence of Non-Pneumatic Tyre Structure on its Operational Properties

Abstract

A non-pneumatic tyre (NPT) is a novel type of safety tyre that is designed to provide similar elastic properties to those offered by conventional pneumatic tyres. The main advantage of NPT is the lack of compressed air (like in a pneumatic tire) to ensure adequate traction forces and directional control. Suitable materials and the appropriate geometry of the supporting structure allows to achieve properties provides by pneumatic tires. Flexible spokes and closed structure like honeycomb are the most common solutions of supporting structure. Appropriate geometry, thickness and materials of this part affect the NPT properties; radial stiffness, unit pressure in the contact patch and the parameters of an area in contact with a non-deformable surface. The paper presents the FEM NPT model (NPT_0), which was validated with the results of experimental research of NPT. The NPT_0 model is subject to further modifications (layout and shape of the radial spokes) was used in the study. Seven new geometries of NPT supporting structure were selected for simulation tests. During the numerical tests the radial stiffness, unit pressure in the contact patch and the parameters of an area in contact with a non-deformable surface were determined. It has been observed that an increase in the curvature of the spokes reduced radial stiffness and increased the length of the contact path.