Strain and work-hardening in a coulomb-type granular medium

Equations are given for the elastoplastic strain of a granular medium together with experimental relationships for sands. Equations for the characteristics are drawn up in general form for the two-dimensional case. It is shown that experimental data on the dilatancy rate as a function of the angle of internal friction reflect the condition for orthogonality of the characteristics of the velocity distribution to the direction of the dry-friction forces in the sliding areas. The flow in a shear tester is discussed. The calculation from the universal relationships agrees with experiment.