The process of plastic deformation of many materials could be governed not only by shear sliding but also by developing of present and creation of new elements of media discontinuity, migration and damage of structural elements. The behavior of discontinuities under material deformation depends on the type of external forces, which appears in the dependence of plasticity characteristics and strength capability of various materials on the loading conditions. Based on the experimental analysis, a possible approach to the description of the dependence of plastic deformation characteristics on the stress state type realized under loading is performed. By means of flow theory associated with plasticity condition, represented in corresponding generalized form, constitutive equations for plastic deformation of media under consideration are obtained. Based on the rigid- plastic media model, a number of solutions of boundary value problems are obtained. The dependence of stress distribution in plastic areas and the values of limit loads on the parameter which characterizes material stress state sensitivity are investigated. Using numerical modeling, the influence of elastic deformation on the shape of plasticity areas and on the limit loads is studied. Theoretical and experimental investigations of plastic deformations of pore material based on steel wire were done; a good correlation between theoretical and experimental dependencies is obtained.
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