%0 Journal Article %T The Phenomenological Description of Plastic Flow in Solids %A O. V. Yushchenko %A D. S. Trotskaya %J Journal of Solid State Physics %D 2013 %R 10.1155/2013/604714 %X In the framework of the phenomenological scheme a self-consistent description of the transition from the solid state to the plastic flow was presented taking into account the point defects such as interstitials and vacancies. On the basis of the system of synergistic equations the dependencies of the internal stresses and curvature of the velocity profile of the shear displacement on the order parameter as well as the stationary distribution of the concentration of vacancies were found. 1. Introduction The processes occurring during the deformation of solids have attracted attention for a long time [1]. Moreover it is well known that the elastic deformation vanishes after the removal of the applied stress, and plastic deformation is retained even after removal of all external influences. Exception is the viscous flow of the material, which can continue indefinitely even when exposed to an arbitrarily small external stress (and the flow rate increases with stress). According to [2] it turns that some properties (elasticity and viscosity) are not unique to solids, but they are inherent in continuous media (e.g., granular materials, supercooled liquid polymers, suspensions, some gels, emulsions, etc.). In this regard, the science of the deformation and flow of continuous media (rheology) has received a great development recently [2, 3]. Particularly the plastic deformation should be noted: on the one hand, it is typical for many natural and technological processes and, on the other hand, it is difficult in terms of the theoretical description. Usually the plastic deformation of crystals is associated with the emergence and movement of the dislocations within the grains and can be implemented by slipping and twinning [1]. Although many methods are applied to the numerical simulation of the dynamics of dislocation lines [4¨C8], the description of the plastic deformation of crystals remains a difficult task. In the case of amorphous materials and continuous media the analytical description of the plastic flow is possible only within the framework of the phenomenological theories, where the material is considered as homogeneous. The purpose of this paper is to construct a self-consistent phenomenological scheme, which allows describing the transition of solids to the plastic flow state. Since the plastic flow always arises at the microscopic level, that is, at the level of elementary point defects of different physical nature, the influence of point defects on the behavior of solids under the action of the given stress will be an actual task. And although at %U http://www.hindawi.com/journals/jssp/2013/604714/