The glide motion of an assembly of interacting dislocations under the action of an external shear stress was simulated, and it was shown that the associated plastic creep relaxation obeyed Andrade’s law. The results indicated that Andrade creep in plastically deforming crystals involved the correlated motion of dislocation structures near to a dynamic transition that separated a flowing phase from a jammed phase. Simulations in the presence of dislocation multiplication and noise confirmed this, and highlighted the importance of metastable structure formation in relaxation.

Dislocation Jamming and Andrade Creep. M.C.Miguel, A.Vespignani, M.Zaiser, S.Zapperi: Physical Review Letters, 2002, 89[16], 165501 (4pp)