Mathematical models of plasticity and creep for the case of small deformations were proposed on the basis of the gauge theory of defects with allowance for energy dissipation. It was assumed that plasticity was related to the motion of dislocations, which occurred without changes in volume. In the creep model, the motion of dislocations could proceed with changes in volume, and the so-called extra volume was entrained (brought) by point defects. With the help of Godunov's generalized thermodynamic approach, it was shown that the proposed plasticity model was hyperbolic according to Friedrichs.

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