(388d) Rigid Structures in Frictional Dense Suspensions | AIChE

(388d) Rigid Structures in Frictional Dense Suspensions

Authors 

van der Naald, M., University of Chicago
de Pablo, J. J., University of Chicago
Jaeger, H. M., The University of Chicago
In concentrated suspensions of neutrally buoyant particles, the apparent viscosity is often found to undergo an abrupt increase making a transition from a low-viscosity to a high-viscosity state, termed discontinuous shear thickening (DST)1. The observed behavior has recently been linked to a transition from an unconstrained "lubricated" rheology, where close interactions between suspended particles take place through a thin liquid film, to a constrained "frictional" rheology, where particles make unlubricated frictional contacts2,3. Particle simulations that led to this concept have been successful in quantitatively reproducing the non-Newtonian behavior of thickening suspensions3–5. However, none of these studies have moved beyond the mean-field description and analyzed the rigidity of the underlying evolving frictional force network. Here, we use the pebble-game algorithm to decompose the simulated frictional contact networks into so-called “rigid clusters” which are the minimally rigid portions of the contact network. In dry granular literature, the emergence of rigidity is often associated with the onset of jamming6. However, we find the emergence of system-spanning rigid clusters at volume fractions below the frictional jamming point. These results move beyond the current mean-field description and provide a new way to understand the onset of rigidity in shear thickening suspensions.

References:

  1. Morris, J. F. Shear Thickening of Concentrated Suspensions: Recent Developments and Relation to Other Phenomena. Annu. Rev. Fluid Mech. 52, 121–144 (2020).
  2. Seto, R., Mari, R., Morris, J. F. & Denn, M. M. Discontinuous Shear Thickening of Frictional Hard-Sphere Suspensions. Phys. Rev. Lett. 111, 218301 (2013).
  3. Singh A., Mari R., Denn M.M., Morris J.F. A constitutive model for simple shear of dense frictional suspensions. J. Rheol. 62, 457–468 (2018).
  4. Singh, A., Jackson, G. L., van der Naald, M., de Pablo, J. J. & Jaeger, H. M. Stress-activated Constraints in Dense Suspension Rheology. ArXiv210809860 Cond-Mat (2021).
  5. Singh, A., Ness, C., Seto, R., de Pablo, J. J. & Jaeger, H. M. Shear Thickening and Jamming of Dense Suspensions: The “Roll” of Friction. Phys. Rev. Lett. 124, 248005 (2020).
  6. Henkes, S., Quint, D. A., Fily, Y. & Schwarz, J. M. Rigid Cluster Decomposition Reveals Criticality in Frictional Jamming. Phys. Rev. Lett. 116, 028301 (2016).