Strain-softening of materials in the plane stress state conditions

Questions of experimental investigation of the mechanical behavior of materials on the postcritical deformation stage (strain-softening) are considered in the article. Taking into account of this deformation stage is important for construction survivability estimation. Deformation curves of structural steels under uniaxial tension, torsion and proportional tension with torsion of thin-walled tubular specimens are presented. The tests carried-out on universal biaxial servohydraulic test system Instron 8850.