FPSO多点系泊掣链器基座结构分析

Structural analysis of chain stopper and fairlead base at spread moored FPSO

多点系泊超大型FPSO作业于有主控波浪等环境荷载方向、环境条件较温和的特定海域。掣链器将系泊荷载传递至船体结构上。以一艘深水超大型FPSO多点系泊掣链器及基座为研究对象,介绍了多点系泊的总体方案和基本设计、详细设计成果,分析了采用企业标准、船级社规范等对多点系泊系统设计和分析工况的要求。运用时域耦合水动力分析方法,计算了系泊缆准动态最大拉力和掣链器与船体结构界面处的荷载。运用有限元分析方法,分析了掣链器、基座及船体的结构强度,确定了系泊荷载对FPSO船体结构的影响范围,预测了掣链器基座和FPSO船体结构的疲劳寿命。

The spread moored super large FPSO is operated in the special sea area of mild environmental conditions with main control directional wave.The chain stopper and fairlead transmits the mooring line load to the hull structure.Taking the spread mooring chain stopper and fairlead base at a deepwater super large FPSO as the research object,this paper introduces the general scheme,basic design and detailed design of the mooring system,and analyzes the requirements of the enterprise specifications,Classification Society Rules for the design and analysis of the spread mooring system,and so on.By applying the time-domain coupled hydrodynamic analysis method,the maximum quasi-dynamic axial tensions in the mooring lines and the loads at the interface between the chain stopper and fairlead and the hull are calculated.The finite element analysis(FEA)method is applied to analyze the structural strengths of the chain stopper and fairlead,the base and the FPSO hull.The influence scope of the mooring loads on the FPSO hull is determined.The fatigue life of the chain stopper and fairlead base and the FPSO hull structure is predicted.