STRUCTURAL FATIGUE ASSESSMENT OF F(P)SO UNITS CONVERTED FROM AN OIL TANKERS

Abstract

The paper presents essential practical approaches concerning structural fatigue of floating (production) storage and offloading (F(P)SO) units converted from oil tankers. For this units it is very important to use an accurate service history to the correct evaluation of the accumulated fatigue damage, because they are much smaller than the values based on unlimited navigation conditions. All fatigue assessments are based on the Palmgren-Miner assumption and experimentally derived S-N curves. Simplified Method based on the widely accepted assumption that the long-term distribution of fatigue stress ranges fits a two-parameter Weibull cumulative distribution is used. Are discussed fatigue assessments in Initial Scantlings Evaluations (ISE) stage and further are performed fatigue FE Analysis for exclusive hull ship areas critical details and also for F(P)SO facilities and equipment (interface areas).