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The paper deals with experimental studies of inhomogeneous strain fields with regions of supercritical behavior of the material in the case of extension of plane specimens of steel 20 with concentrators of different geometry by using the method of digital image correlation. The use of a video system permits obtaining experimental data about the distribution of the fields of longitudinal, transverse, and shear components and the strain intensity. The previously considered criteria for the deformation process transition to the supercritical stage for different types of the stress–strain state were used to distinguish the regions of supercritical behavior and to analyze the evolution of the strain and temperature fields in their stable development.

The paper deals with experimental studies of inhomogeneous strain fields in the “neck” region in extension of plane and cylindrical specimens at the postcritical stage, which directly precedes the fracture, by using a video system and a digital image correlation method. We consider the problems of interpretation of extension diagrams obtained for specimens of various length with strain inhomogeneity in the working section of the specimen with a “neck.”We obtain experimental data about the distribution of longitudinal, transverse, and shear strain fields and the displacement fields in the region of the plane specimen localization by using the digital image correlation method.

The paper deals with experimental study of carbon steel plastic deformation laws at the stage of yield delay and yield plateau formation in uniaxial extension tests. The kinematics of formation and propagation of localized plastic flow bands of the material on the surface of solid cylindrical specimens of various length was analyzed by using the digital image correlation method. The influence of the rate of kinematic loading, unloading, and repeated loading on the processes of development of inhomogeneous elastoplastic deformation fields is estimated at the stage of formation of the yield plateau.