LAUSR

Abstract In the China Bohai bay area, a Single anchor leg yoke mooring system (SYS) was mainly used for FPSO's permanent mooring due to the shallow water. This paper investigates the SYS failure and focus on the excessive wear that occurred to underwater turret bearings. The wear mechanism of bearing is researched by using morphology analysis and energy spectrum analysis. Nonlinear finite element analysis is performed to study the contact status between turret table and axial bearings considering the operational and extreme load condition. The comparison wear-test is carried out to clarify the contributions of eccentric load on the wear performance of axial bearing. Wear-test results indicate that eccentric load has a significant impact on wear of turret bearings. Eccentric wear also produce more abrasive particles to accelerate wear rate. A step-like is formed on bearing plate surface due to excessive wear. The failed bolts are attributed to stress corrosion crack under long-term shear fore caused by vessel surge motion.