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

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.