Large irreversible local slips of a loose free–flowing material under hard sign–variable quasistationary loading

The theory of slip for the case of large strains is considered. Irreversible distortion by slippage is represented as a Truesdell transformation of simple shear and is specified with respect to the unstrained configuration. It is proved that a small local slip leads decreases tangential stresses on the slip area and changes the strained stress over the entire region. The calculated orientations of the local slip systems are compared to results of classical experiments on sign–variable quasistationary deformation of loose free–flowing materials.