Motivated by our previous study on the flexibility and low local stress of auxetic hexagonal honeycombs in uni-axial loading, we explore the dynamic characteristics of a flexible auxetic hexagonal lattice structure when it is used as the flexible spokes of a non-pneumatic tire. In this study, a modal analysis and the steady state vibration characteristics of NPTs with cellular spokes are investigated with a series of vertical loads and rolling speeds using a commercial finite element code, ABAQUS/Explicit. The angular velocity and the displacement at the hub center and the reaction force on the ground were investigated in the time and frequency domains for the steady state rolling condition for vehicle speeds of 60km/h and 80km/h. The orthotropic properties of the honeycomb spokes create different modal behaviors compared with those of pneumatic tires; e.g., the in-plane shear at the initial mode. The discrete spoke geometry induces a non-homogeneous mass (non-uniformity) distribution, which also causes local vibration effects.

With an increased interest in a non-pneumatic tire (NPT) and its possible performance on safety in driving and low rolling resistance, extensive research on mechanical properties including dynamic characteristics are required to explore for the commercialization of NPTs. In this study, we explore the dynamic characteristics of NPTs with flexible hexagonal lattice spokes. A steady state vibration characteristic of NPTs is investigated with a series of load carrying capability and rolling speed for two hexagonal spokes using a commercial finite element code, ABAQUS. The obtained vibration characteristics are compared with those of conventional pneumatic tires, which are available in the literature.