Elastic Signature of Flow Events in Supercooled Liquids Under Shear

Joyjit Chattoraj (1) , Anael Lemaitre (1)

1 Rhéophysique

Using numerical simulation of a 2D Lennard-Jones system, we study the crossover from shear thinning to Newtonian flow. We find that the short-time elastic response of our system essentially does not change through this crossover, and show that, in the Newtonian regime, thermal activation triggers shear transformations, i.e., local irreversible shear events that produce Eshelby (long-ranged, anisotropic) deformation fields as previously seen in low-T glasses. Quite surprisingly, these Eshelby fields are found to persist much beyond the α-relaxation time, and shear thinning to coincide with the emergence of correlations between shear relaxation centers.

Mots clés: Kinematics of deformation and flow; Deformation and plasticity; Steady shear flows viscometric flow

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Joyjit Chattoraj, Anael Lemaitre. Elastic Signature of Flow Events in Supercooled Liquids Under Shear. Physical Review Letters, 2013, 111 (6), pp.066001-066001-5. ⟨10.1103/PHYSREVLETT.111.066001⟩. ⟨hal-00969131⟩