Micromechanical formulation of the mobilized stress ratio under principal stress rotation in granular materials

Abstract

In this paper the mobilized stress ratio is investigated by using the static equilibrium at the micro scale level analysis. The mobilized stress ratio is obtained in the distribution of the contact normal, E(β), and the inter-particle mobilized friction angle, ϕμ . The second invariant of the fabric tensor, α is used to account for fabric and its evolution. There is a difference between the theoretical rotation of principal stress axes that is obtained by the classical equations of the mechanics of materials and the experimental rotation of principal stress axes. The experimental rotation is related to the anisotropic parameter, α. The noncoincidence between the theoretical and experimental is related to the relative direction of the mobilized plane and the bedding plane. A comparison with experimental tests demonstrates the validity of this formulation