ABSTRACT
This chapter aims to conduct both Palmgren–Miner’s rule and fracture mechanics based fatigue analyses for mooring lines of a semi-submersible installed in Offshore West Africa. It explores the wave, wind and swell effects are taken into account to examine the fatigue lives of mooring lines. The comparison of fatigue lives of mooring lines predicted by Palmgren–Miner’s rule and fracture mechanics based approaches shows that results calculated by these two types of methods are generally comparable. The narrow-banded spectral method is performed for estimating the combined mooring line tension ranges and the fatigue damage of mooring lines is predicted by Palmgren-Miner’s rule and fracture mechanics based approaches. J. Mathisen and K. Larsen, T. Lassen et al. and J. Lardier et al. applied the linear elastic fracture mechanics to estimate fatigue lives of mooring chains by assuming an initial surface to propagate at the surface of a chain link.
