First-principle predictions for the rheology of soft jammed suspensions

Nicolas Cuny (1) , Éric Bertin (1) , Romain Mari (1)

1 LIPhy - Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères]

We explore the rheology predicted by a recently proposed constitutive model for jammed suspensions of soft elastic particles derived from microscopic dynamics [Cuny et al., arXiv:2102.05938]. Our model predicts that the orientation of the anisotropy of the microstructure, governed by an interplay between flow vorticity and contact elasticity, plays a key role at yielding and in flow. It generates normal stress differences contributing significantly to the yield criterion and Trouton ratio. It gives rise to non-trivial transients such as stress overshoots in step increases of shear rates, residual stresses after flow cessation and power law decay of the shear rate in creep. Finally, it explains the collapse of storage modulus as measured in parallel superposition for a yielded suspension.

Domaines: Matière Molle [cond-mat.soft]; Mécanique statistique [cond-mat.stat-mech]

Nicolas Cuny, Éric Bertin, Romain Mari. First-principle predictions for the rheology of soft jammed suspensions. Soft Matter, 2021. ⟨hal-03366961⟩