Numerical evaluation on fatigue crack growth and life predictions of an FPSO mooring system. (1st December 2022)

• Record Type: Journal Article
• Authors: He, Wentao; Cao, Shihui; Hu, Zhiqiang; Xie, De; Zhang, Zhengyi; Wang, Changzi
• Is Part Of: Ocean engineering. Volume 265(2022)
• Publication Date: 2022-12-01
• Subjects: Crack growth -- Fatigue life prediction -- Fracture mechanics-based approach -- Crack morphology -- Mooring chain; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2022.112501
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: This study aims to systematically study the fatigue crack propagation characteristics of the mooring system for a floating production storage and offloading vessel (FPSO) through the fracture mechanics-based approach. The remaining fatigue life of the mooring lines is predicted by a self-integrated program through the simulation of the crack growth behavior. Additionally, parametric studies are performed to investigate the influence of initial crack status (location/size/shape) on mooring crack propagation characteristics. Results illustrate that the remaining fatigue life at the uppermost position of mooring lines at the wave-ward side is similar, which is approximately 178 years longer than that of mooring lines at the wave-back side. Fatigue issues are the severest in the crown region, where the critical fatigue life is about 49% of that in the bend region and 19.9% of that in the straight region. With the increase of the initial crack size and aspect ratio, the remaining fatigue life experiences a remarkable decrease with amplitudes up to 47.8% and 30.1% respectively. The integrated evaluation program is a promising tool for the damage tolerance design of mooring system due to the excellent capability in predicting the remaining fatigue life and charactering the crack growth behavior. Graphical abstract: Image 1 Highlights: FCG characteristics of the mooring system is investigated through fracture mechanics-based approach. Remaining fatigue lives of different mooring lines are predicted through the simulation of crack propagation. The influence of initial crack status is explored through the parametric studies of initial crack location/size/shape. The self-integrated evaluation program is a promising tool for the damage tolerance design of mooring system.