Relating gradient plasticity with Discrete Dislocation Dynamics


Konstantinos Michos
Aristotle University of Thessaloniki

13. March 2013, 17.00
WW8, Room 2.018, Dr.-Mack-Str. 77, Fürth

During the last decade it has become increasingly evident that plastic deformation of crystalline solids is not a smooth flow-like process, but rather exhibits intermittent fluctuations spanning several orders of magnitude in size. This is particularly clear in micropillar compression experiments, where these fluctuations, or dislocation avalanches, are visible as steps in the stress-strain curves. In larger systems the stress-strain curves appear smooth, but bursty dislocation activity is still observable as a broad distribution of the amplitudes or energies of acoustic emission events. Such observations have obviously raised the question of their origin, and pictures related to an underlying non-equilibrium yielding phase transition have been proposed.

In this talk I will review some of the recent developments in the field of statistical physics of plastic deformation of crystalline solids, and discuss some related open questions.