Paolo Cermelli, Math, Universita di Torino
"Work-hardening and dislocation pattern formation in rate-independent plasticity: a theoretical study"
Classically, the relation between the density of statistically stored dislocations and work-hardening is described by the so-called Kocks. law, which may be written as an ordinary differential equation governing the evolution of the dislocation densities. However, during plastic flow dislocations tend to form well-defined microscopic patterns (veins, walls or cells), which act as reservoirs of glide dislocations and dramatically affect hardening. In this study, we modify and generalize Kocks. law in the context of rate-independent plasticity, to obtain a system of reaction-diffusion PDEs which describe the formation of dislocations patterns. The results of numerical simulations are also discussed.
TUESDAY, February 11, 2003