Probability distribution of fatigue life controlled by defects

An equation is derived for determining the cumulative probability distribution of fatigue life controlled by the defects in the material, and a method is proposed to determine the most deleterious to the fatigue life group of defects. The equation avoids some serious drawbacks of the classical approach to determine the fatigue life distribution, which are revealed on the basis of counter-examples. The theoretical relationships derived have been verified by Monte Carlo simulations.