Mathematical models of plasticity and creep, for the case of small deformations, were developed on the basis of the gauge theory of defects; with allowance being made for energy dissipation. It was assumed that plasticity was related to the motion of dislocations; which occurred without changes in volume. In the case of creep, the motion of dislocations could proceed with changes in volume and the so-called extra volume was supplied by point defects.

Model of Elastoplastic Deformation of Materials, Based on the Gauge Theory of Defects with Allowance for Energy Dissipation. S.P.Kiselev: Journal of Applied Mechanics and Technical Physics, 2004, 45[2], 292-300