Yield Stress Discontinuity in a Simple Glass

Abstract

Large scale molecular dynamics simulations are performed to study the steady state yielding dynamics of a well established simple glass. In contrast to the supercooled state, where the shear stress, $\sigma$, tends to zero at vanishing shear rate, $\gammadot$, a stress plateau forms in the glass which extends over about two decades in shear rate. This strongly suggests the existence of a finite dynamic yield stress in the glass, $σ^+ (T) \equiv σ(T; \gammadot \to 0) >0$. Furthermore, the temperature dependence of ${\sigma }^{+}$ suggests a yield stress discontinuity at the glass transition in agreement with recent theoretical predictions. We scrutinize and support this observation by testing explicitly for the assumptions (affine flow, absence of flow induced ordering) inherent in the theory. Also, a qualitative change of the flow curves enables us to bracket the glass transition temperature $T_c$ of the theory from above and (for the first time in simulations) {\it from below}. Furthermore, the structural relaxation time in the steady state behaves quite similar to the system viscosity at all studied shear rates and temperatures.

4 pages, 5 figures

References in corpus (18)

• Testing Mode-Coupling Theory for a Supercooled Binary Lennard-Jones Mixture I: The van Hove Correlation Function
• Rheology of Soft Glassy Materials
• Rheological constitutive equation for model of soft glassy materials
• Scaling behavior in the $\beta$-relaxation regime of a supercooled Lennard-Jones mixture
• Testing Mode-Coupling Theory for a Supercooled Binary Lennard-Jones Mixture II: Intermediate Scattering Function and Dynamic Susceptibility
• Theory of nonlinear rheology and yielding of dense colloidal suspensions
• Nonequilibrium dynamics and fluctuation-dissipation relation in a sheared fluid
• Two-time scales, two-temperature scenario for nonlinear rheology
• Shear localization in a model glass
• How does the relaxation of a supercooled liquid depend on its microscopic dynamics?
• A study of the static yield stress in a binary Lennard-Jones glass
• Schematic models for dynamic yielding of sheared colloidal glasses
• Relaxation in a glassy binary mixture: Mode-coupling-like power laws, dynamic heterogeneity and a new non-Gaussian parameter
• Supercooled Liquids Under Shear: Theory and Simulation
• A Molecular Hydrodynamic Theory of Supercooled Liquids and Colloidal Suspensions under Shear
• Flow curves of dense colloidal dispersions: schematic model analysis of the shear-dependent viscosity near the colloidal glass transition
• Integration through transients for Brownian particles under steady shear
• Yield stress, heterogeneities and activated processes in soft glassy materials

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• From Equilibrium to Steady State: The Transient Dynamics of Colloidal Liquids under Shear
• Shear stresses of colloidal dispersions at the glass transition in equilibrium and in flow
• Long-lived neighbors determine the rheological response of glasses
• Non-linear rheology of a nanoconfined simple fluid
• Structural relaxation and rheological response of a driven amorphous system
• Shear-induced anisotropic decay of correlations in hard-sphere colloidal glasses
• Fluctuation dissipation relations in stationary states of interacting Brownian particles under shear
• Shear Induced Structural Ordering of a Model Metallic Glass
• Heterogeneous shear in hard sphere glasses
• Flow curves of colloidal dispersions close to the glass transition: Asymptotic scaling laws in a schematic model of mode coupling theory
• Long-range strain correlations in 3D quiescent glass forming liquids
• Nonequilibrium mode-coupling theory for uniformly sheared systems
• Yield stress in amorphous solids: A mode-coupling theory analysis
• Nonequilibrium fluctuation dissipation relations of interacting Brownian particles driven by shear
• An order parameter equation for the dynamic yield stress in dense colloidal suspensions
• From Equilibrium to Steady-State Dynamics after Switch-On of Shear
• The rheology of confined colloidal hard discs
• Integration through transients for inelastic hard sphere fluids
• Profile blunting and flow blockage in a yield stress fluid: A molecular dynamics study
• Wall effects on spatial correlations of non-affine strain in a 3D model glass
• Maintaining the equipartition theorem in small heterogeneous molecular dynamics ensembles
• A crossover in spatio-temporal correlations of strain fluctuations in glass forming liquids
• Composition effect in the thermo-mechanical behavior of glasses, and its modelization