The material-dependent variability of fatigue crack growth rates of aluminium alloys in the Paris regime

摘要

Constant amplitude fatigue crack growth rates of a number of heat-treatable thin-sheet wrought aluminium alloys are presented in terms of the Paris equation with the stress intensity factor range normalized by a characteristic value, in the present case 10 Mpa m~1/2. There is a considerable overall variability of the crack growth rates at any given value of △K. It turned out that there Are two markedly different groups of alloys. For the first group, the crack growth curves strongly focus at 10 Mpa m~1/2, whereas The Paris exponents vary considerably and are related to a material parameter obtained by dimensional analysis.