Effect of nonuniform size on internal stresses in a rapid, simple shear flow of granular materials. 2. Multiple grain sizes

Résumé du livre

In the past all theoretical analyses for rapidly sheared granular flows assumed that the granular solids are either disks or spheres and are uniform in size. However, natural materials that create these granular flows are in general irregular in shape and have various spectra of sizes. The stress and rate of energy dissipation levels in granular flows are significantly influenced by the size distribution. In part 1 of this report series (AD-A154 045), the formulation of the constitutive equations considering a two-size granular mixture is presented, where the ratio of the two sizes is nearly one. In part 2, the constitutive equations for a two-size mixture are extended to include a general size ratio. In addition, a complete spectrum of size distribution is incorporated, which allows the quantification of the size distribution effect in the most general way. In analyzing the stresses, intergranular collision is assumed to be the major dynamic activity at the microscopic level. Because of the present limited knowledge of testing shape effects, the analysis is confined to the flow of either disks or spheres. The result of this work provides necessary information for a more realistic analysis of natural and industrial granular flow. Keywords: Granular flow, and Particle size distribution.