Fatigue Life Analysis on The Local Construction Near the Chain Stopper Area of Papa Terminal Floating Storage Offloading (FSO) With 4X2 Chain Line Spread Mooring Configuration

Abstract This research aims to determine the fatigue life of the structure near the chain stopper of a storage tanker using the spectral fatigue analysis method. The wave spectrum is developed based on six significant wave height and period variations from the site wave scatter data using a modified spectrum of JONSWAP. The stress analysis is carried out using finite element analysis software. It can then be processed into Stress RAO from each loading direction. The response spectra are generated from the wave spectrum, multiplying with the square of the Stress RAO. These response spectra will determine the stochastic values of each stress range variation in obtaining the number of cycles that occur in each variation (nL). The accumulation of each ratio obtained from all existing variations will produce a fatigue index value (D). The American Bureau of Shipping’s S-N curve D-Class is used in this fatigue life analysis. The Gamkonora Aframax tanker operated as a temporary storage tanker at Papa’s field area is used as the case of this study.