The Dislocations Gallery
Aim of this page:
The elementary properties of dislocations (the linear defects that carry
plastic deformation in crystalline solids) are illustrated by snapshots
realized from a 3-D dislocation dynamics (DD) simulation developed at the
LEM (CNRS/ONERA) by Benoit Devincre, Ronan Madec
and Ladislas Kubin.
This page was first created in January 1997 by Benoit Devincre as a tutorial
tool for illustrating the theory of dislocations and plasticy in metals
and alloys. New movies and illustrative results are periodically added to
"the dislocation Gallery". You are welcome to use it for teaching
purposes. Remarks and/or comments are welcomed and can be e-mailed to devincre@zig.onera.fr
Dislocation properties:
--> The Frank-Read source.
--> Dislocation spiral (single-ended) source
--> Dynamics of two interacting Frank-Read
sources.
--> Dislocation dipole.
--> Dislocations annihilation by cross-slip.
--> The double cross-slip.
--> The dislocation reaction.
--> The "forest" hardening.
--> Formation of dislocation debris.
--> Complete 3-D dislocation dynamics.
--> Model simulations of slip-systems interactions.
3D simulation of dislocation dynamics at the mesoscopic scale:
Dislocations are the elementary carriers of plastic flow. The ultimate aim
of dislocation theory is the prediction of the mechanical properties of
crystalline materials. Because of the complexity of dislocation dynamics
and interactions, and because plasticity is inherently a dissipative process
far from equilibrium, this objective has still not yet been fully reached.
To provide an alternative approach to existing theoretical attempts, a mesoscopic
simulation of dislocation dynamics and interactions has been developed,
which can be applied to various crystalline structures.
The method used combines features deriving from molecular dynamics and cellular
automata techniques. It is based on a discretisation of space and time and
incorporates all the basic properties of dislocations, viz. their core and
elastic properties. Starting from an elementary length scale in the nanometer
range and a time scale in the nanosecond range, this simulation yields outputs
for simulated crystals of typical sizes between a few tens and a few hundreds
of micrometers and for maximum strains in the range of one percent.
This simulation method provides potential means for checking the existing
models as well as elaborating new models, for the investigation of the properties
of self-organized dislocations configurations and for the connection between
the microscopic and macroscopic approaches of plasticity.
Related scientific articles