A model, based upon a representation of dislocation cell microstructures by a non-local 2-phase material with an evolving microstructures, was proposed for the elastic–plastic behavior of metals under monotonic and sequential loading. The first phase represented the cell interior and the second one represented the cell walls. The evolution of the microstructure was taken into account by considering the cell-wall interfaces to be free boundaries. The accumulation, within walls, of dislocations crossing the cells defined a non-local hardening process. The free energy of the system was calculated by assuming a piecewise uniform plastic strain field and ellipsoidal cells. The driving and critical forces which were associated with the plastic flow of the 2 phases, and the morphology of the cells, were established. Numerical results were presented for monotonic and sequential loading. The results revealed an overall softening that was related to destabilization of the dislocation microstructures which occurred in sequential as well as monotonic paths.

Overall Softening and Anisotropy Related with the Formation and Evolution of Dislocation Cell Structures. L.Langlois, M.Berveiller: International Journal of Plasticity, 2003, 19[5], 599-624