Thursday, December 22, 20112:00 PM - 3:00 PMCNLS Conference Room (TA-3, Bldg 1690)|
Dislocation Mediated Plasticity with Configurational Entropy Effects
Ido RegevT-4 and CNLS
A reformulated theory of plastic deformation is presented which builds upon models that describe plasticity as a combination of dislocation accumulation and thermal activation processes. The theory includes an entropic equation of state which accounts for the disordering and entanglement of dislocations that is typical of strain-hardening in metals. The theory was shown to describe strain hardening effects such as the transition from stage II to stage III hardening, including the observation that this transition occurs at smaller strains for higher temperatures using a relatively small number of free parameters. We modify the theory in such a way as to allow us to describe even a larger variety of experimental results. Specifically, we include the effects of dislocation drag, in order to account for high strain-rate plasticity, strain-rate sensitivity and stress-overshoot. We also show how the theory can be used to explain features that were not mentioned in the initial work.
Host: Kipton Barros, T-4 and CNLS