Methodology for total reliability evaluation of the mooring lines of floating offshore Structures

Abstract

Offshore structures, especially floating structures are subjected to various uncertainties, whereas the environmental factors are considered as the most important factors and must be considered as requirements of current codes and standards. In these standards, the offshore structures are carried out by two main limit states independently: Ultimate Limit State (ULS) and Fatigue Limit State (FLS). In this article, the two limit states are combined by a new approach based on probabilistic principle for total reliability assessment of floating structural mooring lines. Moreover, environmental extreme conditions will be taken into account in the process of cumulative fatigue damage of the mooring lines. The research results will make it possible to estimate more precisely the actual behavior of the systems. Finally, the new method has been applied to evaluate the mooring lines of a FSO at the White Tiger field in Vietnam sea conditions.