Role of interparticle forces and interparticle friction on the bulk friction in charged granular media subjected to shearing

SJ Antony — 2008-06-11T22:25:54-00:00

Physical Review E (Statistical, Nonlinear, and Soft Matter Physics), Vol. 75, No. 3. (2007)

We study the consequences of the interplay between electrostatic forces, mechanical contact forces, and frictional properties of grains upon the bulk frictional properties of charged granular media subjected to quasistatic shearing. We show that, the variations in short-range electrostatic forces between the grains (which are often ignored in the existing studies) dominantly affect the bulk friction. Charging enhances the fabric anisotropy of heavily loaded contacts—this enhances the bulk friction, more significantly, in the case of low frictional granular systems.

Force, relative-displacement, and work networks in granular materials subjected to quasistatic deformation

NP Kruyt — 2008-04-26T22:31:19-00:00

Physical Review E (Statistical, Nonlinear, and Soft Matter Physics), Vol. 75, No. 5. (2007)

To describe the heterogeneous nature of stress transmission in granular materials, the concept of the “strong” network consisting of contacts with large normal forces has been proposed by Radjaï et al. [Phys. Rev. Lett. 80, 61 (1998)]. The shear stress is mainly determined by this strong network. The dual viewpoint is adopted here, by not only considering the forces at contacts, but also the deformation. It is shown that the strain increments are determined by the tangential component of the relative displacements at the contacts. A “mobile” network consisting of contacts with large tangential relative displacements is defined that primarily accounts for the strain increments. The investigation of the relation between the strong and the mobile networks shows that these networks are largely unrelated. An alternative network is defined that consists of contacts at which the contribution to the work input is large. It is found that this work input occurs primarily through the tangential forces and tangential relative displacements.

CiteULike: dchens Antony

Role of interparticle forces and interparticle friction on the bulk friction in charged granular media subjected to shearing

Force, relative-displacement, and work networks in granular materials subjected to quasistatic deformation