Shear band dynamics from a mesoscopic modeling of plasticity

Abstract

The ubiquitous appearance of regions of localized deformation (shear bands) in different kinds of disordered materials under shear is studied in the context of a mesoscopic model of plasticity. The model may or may not include relaxational (aging) effects. In the absence of relaxational effects the model displays a monotonously increasing dependence of stress on strain-rate, and stationary shear bands do not occur. However, in start up experiments transient (although long lived) shear bands occur, that widen without bound in time. I investigate this transient effect in detail, reproducing and explaining a t^1/2 law for the thickness increase of the shear band that has been obtained in atomistic numerical simulations. Relaxation produces a negative sloped region in the stress vs. strain-rate curve that stabilizes the formation of shear bands of a well defined width, which is a function of strain-rate. Simulations at very low strain-rates reveal a non-trivial stick-slip dynamics of very thin shear bands that has relevance in the study of seismic phenomena. In addition, other non-stationary processes, such as stop-and-go, or strain-rate inversion situations display a phenomenology that matches very well the results of recent experimental studies.

10 pages, 10 figures

References in corpus (5)

• Phenomenology and physical origin of shear-localization and shear-banding in complex fluids
• Shear-transformation-zone theory of plastic deformation near the glass transition
• Strain localization in a shear transformation zone model for amorphous solids
• Evaluation of the "disorder temperature" and "free volume" formalisms via simulations of shear banding in amorphous solids
• Strain localization and anisotropic correlations in a mesoscopic model of amorphous plasticity

Cited by in corpus (14)

• Stress overshoot in a simple yield stress fluid: an extensive study combining rheology and velocimetry
• Criteria for shear banding in time-dependent flows of complex fluids
• Spontaneous formation of permanent shear bands in a mesoscopic model of flowing disordered matter
• Strain localisation above the yielding point in cyclically deformed glasses
• Triggers and signatures of shear banding in steady and time-dependent flows
• Heterogeneous dynamics during yielding of glasses: effect of aging
• Shear banding in large amplitude oscillatory shear (LAOStrain and LAOStress) of soft glassy materials
• Yielding, shear banding and brittle failure of amorphous materials
• Shear Band Broadening in Simulated Glasses
• The yielding of amorphous solids at finite temperatures
• Shear banding in large amplitude oscillatory shear (LAOStrain and LAOStress) of polymers and wormlike micelles
• Elastoviscoplastic rheology and ageing in a simplified soft glassy constitutive model
• The Fate of Shear-Oscillated Amorphous Solids
• Volume-shear coupling in a mesoscopic model of amorphous materials