Analysis of Irradiation Swelling and Irradiation Creep Models with the Stress Effect Account in the Problems of Inelastic Strain Mechanics. Part 3. Taking into Account Accumulated Irreversible Strain in the Irradiation Swelling Model

The paper presents the results of an analysis of the correctness of constitutive equations of irradiation creep, which describe non-isothermal processes of inelastic deformation, taking into account the irradiation swelling and irradiation creep of material under the conditions of neutron irradiation, high temperatures, and damaging dose. Current models of irradiation swelling and irradiation creep, which take into account the damaging dose, irradiation temperature, and the effect of stress state and accumulated irreversible strain on the processes of swelling and creep of material, are considered. The conditions under which dissipation power and the power developed by additional stresses on additional deformations do not decrease during loading under neutron irradiation conditions have been studied. On the basis of the obtained energy inequalities, which generalize Drucker’s postulate for the irradiated material, the conditions that ensure the correctness of the formulated creep equations have been determined. The results of an analysis of the correctness conditions for irradiation creep equations showed that taking into account accumulated irreversible strain in the confined swelling model contributes to the relaxation of restrictions on the possible swelling of the material and initial data, which ensure the correctness of the constitutive equations of irradiation creep.