Strain localization and internal stress fields in persistent slip bands

Long-range internal stresses arising from the heterogeneity of plastic strain in persistent slip bands (PSBs) are investigated. The PSB stress profile known from experimental measurements is calculated making use of a two-dimensional model which takes into account the periodicity of the dislocation arrangement within a PSB. Similarities and differences with respect to previous models are discussed. A rather inhomogeneous distribution of stresses within the channels and especially within the walls has been found already without taking into account the stress scatter caused by single dislocations and dislocation dipoles. The proposed model is compatible with observations indicating that a spectrum of strain distributions in PSBs exists and that local strains can exceed the constant PSB strain amplitude predicted by Winter's two-phase model.