FATIGUE-CRACK PROPAGATION IN AEROSPACE ALUMINUM-ALLOYS

This article reviews fracture mechanics-based, damage tolerant charact erizations and predictions of fatigue crack growth in aerospace alumin um alloys. The results of laboratory experimentation and micromechanic al modeling are summarized in the areas of 1) the wide range crack gro wth rate response of conventional aluminum alloys, 2) fatigue crack cl osure, 3) the fatigue behavior of advanced monolithic aluminum alloys and metal matrix composites, 4) the short crack problem, 5) environmen tal fatigue, and 6) variable amplitude loading. Uncertainties and nece ssary 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 counte r the problem of aging components.