AN ENGINEERING ASSESSMENT OF FATIGUE-CRACK GROWTH OF IRREGULARLY ORIENTED MULTIPLE CRACKS

Knowledge of the behaviour of interacting and irregularly oriented mul tiple cracks is very limited. The recharacterisation rules for such cr acks are usually empirical. In order to provide more reasonable rules for an engineering assessment of fatigue growth of irregularly oriente d multiple cracks, this paper first studies the mechanics of fatigue g rowth of two-dimensional non-coplanar cracks. Uniaxial and biaxial fat igue testing on specimens with various multiple cracks are then carrie d out. Possible errors in the assessment of the cracks using the curre nt rules are discussed. An improved procedure for the fatigue life ass essment is developed.