Author(s)

J.C. Radon and K. Nikben

Abstract

Fitness for purpose methodology in fatigue crack growth is dependent on validation and experimental evaluation. This investigation covers fatigue crack propagation in BS4360-50D Steel used in large structures, such as offshore oil platforms. The tests were conducted on surface crack bend specimens (SCB) in air under random loading. Three types of random load signals were applied: broad band, double peak and triple peak. SCB specimens, 1m long, were tested in servo-hydraulic machine. The results showed a considerable effect of mean stress, the fatigue crack growth (FCG) being much faster than under constant amplitude (CA) loading reported previously. The effect of thickness, limited only to 25 and 34mm, was not very prominent. The triple peaked spectrum signal produced a larger growth rate effect when compared to the other two signals. The larger bandwidth signa

Keywords