Micromechanically consistent calculation of rotational stiffness of radial tire

The rotational stiffness of a radial tire is one of the most important structural properties of the sidewall, and it has been evaluated conventionally by using a simplified model. However, in this paper, it is found that the conventional shear modulus used for the calculation of the stiffness is not micromechanically consistent. We examine the conventional shear modulus of the sidewall from the viewpoint of micromechanics, and present a new micromechanically consistent shear modulus for evaluating the rotational stiffness attributed to the shear deformation of sidewall. The developed method is discussed and rationalized through an approximate quantitative analysis. The calculation based on the micromechanically consistent shear modulus is validated by comparing it with experimental stiffness and the conventionally-calculated stiffness.