Size Effects in a Slowly Sheared Granular Media

In this paper, we analyze the nature of stress distribution experienced by large particles in a dense granular media subjected to slow shearing, using the distinct element method. The particles were generated in a three-dimensional cuboidal periodic cell in which a large solid spherical particle was submerged (“submerged particle”) at the center of a bed of monodispersed spherical particles. The granular systems with different size ratio (i.e., the ratio of the diameter of submerged particle to that of the surrounding monodispersed particles) were subjected to quasi-static shearing under constant mean stress condition. The evolution of stress distribution in the submerged particle during shearing was carefully tracked down and presented here. The nature of stress distribution is bifurcated into two components, viz., (i) hydrostatic and (ii) deviatoric components. It has been shown that, for size ratio greater than c.a. 10, the nature of stress distribution in the submerged particle is hydrostatically dominant (increases the ‘fluidity’). For smaller size ratios, the nature of stress distribution in the submerged particle is dominantly deviatoric.