Dynamical correlations near dislocation jamming

Abstract

Dislocation assemblies exhibit a jamming or yielding transition at a critical external shear stress value $\sigma ={\sigma }_c$. Nevertheless the nature of this transition has not been ascertained. Here we study the heterogeneous and collective nature of dislocation dynamics within a crystal plasticity model close to ${\sigma }_c$, by considering the first-passage properties of the dislocation dynamics. As the transition is approached in the moving phase, the first passage time distribution exhibits scaling, and a related peak {\it dynamical} susceptibility ${\chi }_4^{\ast }$ diverges as ${\chi }_4^{\ast }\sim (\sigma -{\sigma }_c{)}^{-\alpha }$, with $\alpha \approx 1.1$. We relate this scaling to an avalanche description of the dynamics. While the static structural correlations are found to be independent of the external stress, we identify a diverging dynamical correlation length ${\xi }_y$ in the direction perpendicular to the dislocation glide motion.

4 pages, 5 figures

References in corpus (4)

• Direct experimental evidence of a growing length scale accompanying the glass transition
• Random Packings of Frictionless Particles
• Intermittent dislocation flow in viscoplastic deformation
• Topological persistence and dynamical heterogeneities near jamming

Cited by in corpus (15)

• Fluctuations and scaling in creep deformation
• Quenched pinning and collective dislocation dynamics
• The Universality Class of Nano-Crystal Plasticity: Self-Organization and Localization in Discrete Dislocation Dynamics
• Criticality of relaxation in dislocation systems
• Dynamic hysteresis in cyclic deformation of crystalline solids
• The Emergence and Role of Dipolar Dislocation Patterns in Discrete and Continuum Formulations of Plasticity
• Yielding and irreversible deformation below the microscale: Surface effects and non-mean-field plastic avalanches
• Plastic strain is a mixture of avalanches and quasi-reversible deformations: Study of various sizes
• Spatial fluctuations in transient creep deformation
• Machine learning depinning of dislocation pileups
• Dislocation avalanches from strain-controlled loading: A discrete dislocation dynamics study
• An efficient implicit method for discrete dislocation dynamics simulations
• Avalanches and rate effects in strain-controlled discrete dislocation plasticity of Al single crystals
• Avalanche correlations and stress-strain curves in discrete dislocation plasticity
• Planar 2-D Cracks And Inclusions In Elastic Media