L. Min et al., LARGE-SAMPLE SIZE EXPERIMENTAL INVESTIGATION ON THE STATISTICAL NATURE OF FATIGUE-CRACK INITIATION AND GROWTH, International journal of fatigue, 18(2), 1996, pp. 87-94
A statistical investigation of the fatigue crack initiation and growth
process is conducted in this paper. A total of 102 replicate constant
-amplitude crack initiation and growth tests were designed and carried
out on Ly12-CZ aluminium alloy. According to the post-mortem fractogr
aphic examination by scanning electron microscopy (SEM), some qualitat
ive observations of the spatial correlation between fatigue striations
are developed to reveal the statistical nature of the intrinsic mater
ial inhomogeneity during the crack growth process. From the experiment
al data, the distributions of crack initiation life Ni and growth life
N-g are found to be accepted as log-normal distributions, and the sta
tistical characteristics of crack growth rate da/dN are also investiga
ted. All of these results would be able to provide solid test foundati
on for the study of probabilistic fatigue, probabilistic fracture mech
anics, fatigue reliability and its engineering applications.