RELIABILITY AGAINST FATIGUE FRACTURE IN THE PRESENCE OF SETS OF CRACKS

An approach to the reliability analysis against fatigue failure is dis cussed with the emphasis on the reliability in the presence of sets of cracks. The solution is divided into two stages: the assessment of re liability indexes with respect to a single arbitrary chosen crack and the evaluation of the reliability index for a structure as a whole. Th e second stage is realized in the assumption that fatigue cracks are r andomly distributed in a structure and form a Poissonian set. Crack fa milies of various origins (initial, new-born, detected, undetected, et c.) are taken into account as well as their nonhomogeneous distributio n in a structure that generally consists of domains with different pro perties including different dimensions.