Dislocation Transport

This chapter explores dislocation motion modeling for the representation of dislocation ensembles by smooth dislocation densities. Experimental studies suggest that the propagation of plastic strain waves is ubiquitous in the plasticity of metals and metallic alloys, provided that the observation length and time scales are appropriately chosen. Although the prediction of such waves has been a goal of plasticity theories for a long time, it has usually been hampered by the elliptic structure of these theories. It is only in the presence of spatial variations in the mechanical properties, as in polycrystals, for instance, or of peculiarities of the boundary conditions that they allow such predictions. One of the main mechanisms for the increase in dislocation density is dislocation multiplication through loop expansion. The chapter describes plasticity by means of dislocation transport.