High-temperature embrittlement and long-term strength of metallic materials

N. Hoff, L. M. Kachanov, and Yu. N. Rabotnov derived coupled high-temperature creep and damage equations on the basis of several assumptions; in particular, they used the incompressibility condition, which contradicts the notion of damage. To eliminate this contradiction, one should consider the mass conservation law and take the irreversible change of density for the damage parameter. The coupled damage and creep equations and the long-term strength criterion for a compressible medium are stated in the present paper with these concepts taken into account.