Dissipative materials as constitutive models for granular media (Q1082843)

We show that a recently proposed continuum theory for purely-dissipative simple materials [the author, J. Non-Newtonian Fluid Mech. 14, 141-160 (1984; Zbl 0555.76010)] provides a convenient rheological framework for the description of yielding and flow of granular materials. The isotropic version encompasses a number of the special models which emerge from experimental observation and from the kinetic theory of Savage and co- workers [\textit{C. K. K. Lun}, \textit{S. B. Savage}, \textit{D. J. Jeffrey} and \textit{N. Chepurniy}, J. Fluid Mech. 140, 223-256 (1984; Zbl 0553.73098)]. In the present work, grain-fluctuation energy is incorporated into the model, and we provide estimates for it, and for other important physical quantities, based on elementary microstructural considerations. With the picture of a system dominated by macroscopic deformation and microdissipation, we conclude that grain-energy estimates are insensitive to microstructural detail.