Dependence of the period of subcritical growth of a creep fatigue crack on the duration of loading cycles

We construct the kinetic equation for the period of growth of a creep fatigue crack. By using the experimental data, it is shown that this equation correctly describes the behavior of the crack. It follows from the solution of Sack’s problem that the larger the duration of the loading cycle T, the more pronounced the effect of creep and, hence, the smaller the residual service life of the structure.