Size effects in a slowly sheared granular media

In this paper we analyze the nature of stress distribution experienced by l arge particles in a dense granular media subjected to slow shearing, using the distinct element method. The particles were generated in a three-dimens ional cuboidal periodic cell in which a large solid spherical particle was submerged ("submerged particle") at the center of a bed of monodispersed sp herical particles. The granular systems with different size ratio (i.e., th e ratio of the diameter of submerged particle to that of the surrounding mo nodispersed particles) were subjected to quasi-static shearing tinder const ant mean stress condition. The evolution of stress distribution in the subm erged particle during shearing was carefully tracked down and presented her e. The nature of stress distribution is bifurcated into two components, viz ., (i) hydrostatic and (it) deviatoric Components. It has been shown that, for size ratio greater than c.a. 10, the nature of stress distribution in t he submerged particle is hydrostatically dominant (increases the 'fluidity' ). For smaller size ratios, the nature of stress distribution in the submer ged particle is dominantly deviatoric.