Mode-Coupling Theory for the Pasty Rheology of Soft Glassy Materials

We introduce a simple mode-coupling model for concentrated suspensions under flow. This model exhibits a jamming transition and stress vs shear rate relations which are very similar to experimental results. Namely, a Newtonian regime or yield stress are followed by a slow variation of the stress for higher shear rates, and by an apparent Newtonian regime for very large shear rates. Another striking result is that under oscillating strain, even in the jammed state, the system exhibits a relaxation time which depends on the strain amplitude.