Application of double cantilever beam model to the analysis of creep crack growth under neutron irradiation

The effect of neutron irradiation on creep crack growth in an infinite plate is analyzed by use of a double cantilever shear beam model. The model is assumed to consist of a stripe of creep damage zone which includes the crack plane and is in a state of uniaxial tension perpendicular to the crack plane, combined with the shear dominant elastic zone outside the creep damage zone. The creep crack growth in the creep damage zone is modeled by the constitutive equations of irradiation creep and irradiation creep damage proposed by the present authors. By solving differential equations of an elastic shear beam combined with the constitutive equations of irradiation creep and irradiation creep damage, the velocity of creep crack growth, the stress, strain and damage distribution in front of the crack tip, and the effects of neutron irradiation are elucidated. (author). 14 refs., 9 figs