Experimental observation of crack propagation in 6063-T6 al-alloy under constant amplitude loading

Abstract Crack propagation experiments were performed on 6063-T6 Al-alloy for various load ranges and stress ratios. Experimental results show that for a constant load range, the life of specimens decreased as stress ratio increased. At constant maximum load, the life of the specimen increased as the load ratio increased. The crack growth data were analysed in terms of ΔK eff as a function of stress ratio R. The data covered R values from 0 to 0·5 and a good relationship was obtained for K eff K = 0·55 + 0·12 R 2 . A crack growth rate equation was developed.