FATIGUE-CRACK PROPAGATION IN AEROSPACE ALUMINUM-ALLOYS

This article reviews fracture mechanics-based, damage tolerant characterizations and predictions of fatigue crack growth in aerospace aluminum alloys. The results of laboratory experimentation and micromechanical modeling are summarized in the areas of 1) the wide range crack growth rate response of conventional aluminum alloys, 2) fatigue crack closure, 3) the fatigue behavior of advanced monolithic aluminum alloys and metal matrix composites, 4) the short crack problem, 5) environmental fatigue, and 6) variable amplitude loading. Uncertainties and necessary research are identified. This work provides a foundation for the development of fatigue resistant alloys and life prediction codes for new structural designs and extreme environments, as well as to counter the problem of aging components.