Yield And Fatigue Strength Analysis Of FPSO Bow Turret Structure

With the offshore petroleum explore continuously into deep water, fatigue and structuredamage become one of the important reasons in the marine structures.FPSO is the importantequipment of offshore oil. Only regular structure analysis and maintenance can ensure foroffshore reliable. Turret structure is an important part of FPSO, which is unable to avoidsevere environment, and subject to loading and unloading oil caused by alternating load.Therefore, FPSO bow turret structure is liable to strength failure and fatigue damage. It isextremely significant to make yield and fatigue strength analysis of the FPSO bow structure.An FPSO turret structure is taken for research, which is working at the South ChinaSea (SCS). FE model of FPSO Bow Turret structure is built. The direct finite elementcalculation is performed in accordance with the rules prescribed load and conditions. Thestress results are analyzed and the high-stress areas are obtained.The fundamental knowledge of fatigue is summarized. The basic principle and concretecomputational procedure of the simplified method and the spectrum analysis method offatigue assessment of shipping and marine structure are discussed.The fatigue assessment of FPSO Bow Turret structure is done using the simplifiedmethod. Additionally the load and motion responses of the FPSO Bow Turret in regularwaves are calculated by the linear wave loads calculation software Hytrostar. TheSpectral-based fatigue strength assessment of Bow Turret structure is made and the fatiguelife of all the hot spots is obtained.