Interaction network analysis in shear thickening suspensions

Abstract

Dense, stabilized, frictional particulate suspensions in a viscous liquid undergo increasingly strong continuous shear thickening (CST) as the solid packing fraction, φ, increases above a critical volume fraction, and discontinuous shear thickening (DST) is observed for even higher packing fractions. Recent studies have related shear thickening to a transition from mostly lubricated to predominantly frictional contacts with the increase in stress. The rheology and networks of frictional forces from two and three dimensional simulations of shear-thickening suspensions are studied. These are analyzed using measures of the topology of the network, including tools of persistent homology. We observe that at low stress the frictional interaction networks are predominantly quasi-linear along the compression axis. With an increase in stress, the force networks become more isotropic, forming loops in addition to chain-like structures. The topological measures of Betti numbers and total persistence provide a compact means of describing the mean properties of the frictional force networks, and provide a key link between macroscopic rheology and the microscopic interactions. A total persistence measure describing the significance of loops in the force network structure, as a function of stress and packing fraction, shows behavior similar to that of relative viscosity, and displays a scaling law near the jamming fraction for both dimensionalities simulated. arXiv:1903.08493v1 [cond-mat.soft]

On intermittency in sheared granular systems

“…We call this quantity total persistence, TP0 or TP1 depending on whether it is extracted from PD 0 or PD 1 . In previous studies TP was found to be a very useful quantity e.g., in [47] TP1 was correlated with the viscosity of a shared suspension, showing directly the connection between force network properties and rheological properties of the considered system.…”

“…PH has been extensively used to describe complex patterns in a variety of settings [42][43][44][45]. There is also a growing body of literature that uses PH to study granular systems exposed to compression [30,33], vibrations [31,35,46], or shear [47]. In this section, we only provide a brief summary of PH and introduce the measures used in this paper.…”

Capillary flow of a suspension in the presence of discontinuous shear thickening

“…There is now a large consensus that, in order to experimentally observe a DST transition, the particles should initially be separated by a repulsive force and that this transition will occur when the shear forces dominate the repulsive ones allowing a frictional contact between the surfaces of the particles. It is the formation of a percolated network of particles in frictional contacts, as the ones observed in numerical simulations (Mari et al 2014;Gameiro et al 2020), able to support the stress through elastoplastic contacts, which explains the jump of viscosity (see for example reviews (Brown and Jaeger 2014;Denn et al 2018;Morris 2020)). The correlation between an increase of the normal force between particles and the one of the interparticle friction has been confirmed by AFM (Comtet et al 2017;Hsu et al 2018;Madraki et al 2020).…”

Correlating the force network evolution and dynamics in slider experiments

“…the present work, we will consider application of persistent homology (PH), which allows for formulating precise and objective measures of static and dynamic properties of the force networks. This approach has been used extensively in analysis of the data obtained via discrete element simulations in the context of dry granular matter [19,20] and suspensions [21], but its application to experimental data has so far been rather sparse [22,23]. We show that this method allows to develop clear correlations between the static and dynamic properties of the force networks on micro-and meso-scale and the macro-scale system dynamics.…”