Investigation on structural design and grounding characteristics of two dimensional double-U honeycomb non-pneumatic tires

Non-pneumatic tires (NPTs) are subjected to cyclic tension-compression loads during rolling. To address the issues of poor auxetic characteristics and short service life in traditional NPTs, this paper proposes a two dimensional double-U honeycomb (2D DUH) NPT with negative Poisson's ratio (NPR) support structure. Firstly, the support structure for NPT is designed based on the NPR structure of two dimensional double-U unit cells. Then, two typical tire grounding conditions, bottom grounding and top grounding of U-shaped unit cells, are selected according to the structure of the NPT's support part and the grounding characteristics of the tire is investigated. Finally, the influences of height ratio and density of 2D DUH unit cells on tire grounding characteristics are investigated. The results show that the support structure of the grounding part of the 2D DUH NPT has a tendency to shrink inward when compressed by the radial load, increasing the radial stiffness. In addition, the lower ground stress of 2D DUH NPTs increases their service life. The support structure composed of low height ratio and high unit cell density can effectively improve the load-bearing performance and driving stability of 2D DUH NPTs. The results provide a theoretical basis and reference for the structural design of NPTs.