Consititutive modeling of time-dependent flows in frictional suspensions

This paper summarizes recent joint work towards a constitutive modelling framework for dense granular suspensions. The aim is to create time-dependent, tensorial theory that can implement the physics described in steady state by Wyart-Cates model. model of shear thickening suspensions supposes lubrication films break above characteristic normal force so frictional contact forces come into play: resulting non-sliding constraints be enough rigidify system would flow freely at lower stresses [1]. Implementing this idea time-dependent flows requires introduction new concepts including configuration-dependent ‘jamming coordinate’, alongside decomposition velocity gradient tensor compressive and extensional components which then enter evolution equation particle contacts distinct ways. approach [2, 3] qualitatively successful addressing (i) collapse stress during reversal flow, (ii) ability transverse oscillatory unjam system. However there much required refine quantitative accuracy, incorporating more under as determined close interrogation particle-based simulations.