The dynamics of wet granular matter

We present a numerical study of a shear-induced solid–fluid transition in wet granular matter in order to show the self-organized critical behavior close to the transition point. The continuous time simulation is based on a simple model considering both the cohesive forces induced by the adsorbed liquid amount and the repulsive forces due to the hard core interaction of the granules. Dissipation is assumed to be entirely due to the hysteretic character of the cohesive forces. The aim of our analysis concerns the crossover from a solid like behavior to a mobile ergodic state under the influence of an external force field F exceeding the critical force F_c. Diffusion coefficients, dissipation and kinetic order parameters can be expressed as characteristic scaling laws.