The physics of plastic deformation

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A simplified physical picture is extracted from the many complicated processes occuring during plastic deformation. It is based upon a set of continuously distributed straight edge dislocations, the carriers of plastic deformation, moving along their slip plane, interacting with each other and the lattice, multiplying and annihilating. The principles of continuum physics, that is the conservation laws of mass and momentum, and results from discrete dislocation modelling are then employed to analyze the situation and deduce a closed set of relations describing the evolution of deformation and the associated forces that bring it about. A simple method is suggested for extending these relations to macroscales. This way, current phenomenological models of plasticity are physically substantiated. Moreover, a framework is provided for rigorously constructing small and large deformation theories of plasticity. Finally, a new possibility is made available for capturing the salient features of the heteogeneity of plastic flow including the wavelength of persistent slip bands, the width of shear bands, and the velocity of Portevin-Le Chatelier bands. © 1987.

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International Journal of Plasticity