Abstract:

To deeply investigate dynamic and static mechanical properties of non-pneumatic tires under the condition of unstructured road， double-arrow cellular structure （DACS） with negative Poisson's ratio （NPR） with excellent mechanical properties is embedded into non-pneumatic tires as a novel support structure and double-arrow non-pneumatic tire （DANT） is selected as research object herein. Firstly， finite element models （FEM） of DACS with various gradient densities are developed， and quasi-static compression tests are conducted on DACS samples to verify the accuracy of FEM. Then， FEMs of DANT are established to obtain effect of layer number of double-arrow support structure on static properties of DANT， and influence of structural parameters of support structure on modal and ground properties of DANT are investigated. Finally， dynamic mechanical properties of DANT on unstructured road surfaces are investigated， including steady-state rolling， obstacle traversing， ditch crossing， and soil contact. The results show that the rolling resistance of DANT increases from 11.51 to 241.66 N with increment of radial load from 1 000 to 5 000 N. Meanwhile， a partial detachment of tread and ground come up with the increase of water velocity， and the stress distribution of support structure and the magnitude of contact stresses can be affected by the height and width of the obstacles. The spread and plastic deformation of soil occurs from contact location as soil is subjected to forces of DANT.

Key words: non-pneumatic tires, unstructured road, cellular structure with negative Poisson’s ratio, mechanical properties