Special Session 120: 

The effect of forest dislocations on the evolution of a phase-field model for plastic slip

Matthias W Kurzke
University of Nottingham
England
Co-Author(s):    Patrick W. Dondl, Stefan Wojtowitsch
Abstract:
We consider dynamics of a phase-field model for crystal dislocations in the large body/small Burgers vector limit. In the one-dimensional Peierls-Nabarro setting without a forest dislocation background, the limit of the gradient flows of the energies is the gradient flow of the $\Gamma$-limit, similar to related problems in ferromagnetic materials. Forest dislocations introduce an extra strange term into the $\Gamma$-limit. Although this term may speed up the evolution of the $\Gamma$-limit, we show that it does not represent an additional driving force: instead, the presence of forest dislocations introduces a wiggliness into the system that actually slows down the observed evolution.