Аннотация:Postcritical deformation stage of materials connected to the structural failure and
fracturing processes and reflected on the strain curve as a descending section. Realization
of the postcritical deformation stage allows using of the reserves of loadcarrying
ability, increase vitality and safety of the deformable systems. The work is
devoted to experimental investigation of the behavior of structural carbon steels on
the postcritical stage of deformation under different types of the stress-strain state.
The test results of uniaxial tension with various stiffness of the loading system with
using of special test tool are obtained. It is demonstrate, that the failure moment
of materials corresponds to a point on the descending section of strain curve and
depends on stiffness of the loading system. Got results of the behavior of different
structural steels on the postcritical stage of deformation under proportional and
non-proportional tension-torsion tests at room and high temperature.
The methodic of realization of the additional vibrations during quasi-static tension
with using of the biaxial test system is proposed. It is shown, that the additional
loadings could lead to equilibrium deformation of specimen on the postcritical deformation
stage.