Diffusion potential and well-posedness in non-associative plasticity

The problem of ill-posedness of the boundary value problem in non-associative plasticity is addressed. Well-posedness is achieved through the introduction of a potential q) that plays the dual role of a hardening function and a diffusion potential. Simultaneous constitutive equations in the form of partial differential equations for the velocity field ai and ~ are established. The problem of simple shearing is solved as an example and patterned deformation is shown to occur in the presence of softening. The work is confined to small deformation. © 1998 Elsevier Science Ltd. All rights reserved