Self-organization approach to cyclic microplasticity: A model of a persistent slip band

The evolution of a persistent slip band is treated as a consequence of instability transitions accompanied by a process of self-organization of dislocations stored in the deformed metal crystal. The proposed qualitative model is analysed by the perturbation method. The first order perturbation analysis of the model at the state of zero hardening which simulates the disintegrating dislocation vein structure predicts an appearance of shear bands of localized slip. The second order perturbation analysis indicates that within the lamella of localized slip a new dislocation structure of the ladder type is formed. The thickness of the PSB lamella is controlled by the internal stresses caused by the ladder structure in the band. (C) 1998 Elsevier Science Ltd. All rights reserved.