深水FPSO内转塔结构设计及分析

Finite Element Analysis for FPSO Turret Structural Design

内转塔系泊系统是船型FPSO运用最广泛的单点系泊方案。内转塔系统的核心是由集成在船体内、并可使船体自由转动的内转塔组成。有限元分析是内转塔结构设计的重要手段,目前工业界掌握内转塔分析和设计的公司较少,大部分技术和专利掌握在少数公司手中。该文提出了一种内转塔设计及分析方法,目标油田为南中国海深水海域,同时,较详细地描述了设计内转塔的方法和思路以及有限元计算的流程和特殊之处。分析流程和方法对于未来我国自主设计FPSO具有重要的意义,为我国未来完全自主设计FPSO积累了宝贵经验。

Turret mooring system is one of the most popular single point mooring （SPM） solutions to moor vessel-based FPSOs. The turret mooring system consists of a geostationary turret assembly that is integrated into the FPSO hull through a bearing system and attached to a mooring system. Finite element analysis （FEA） of turret structure is a key step in designing turret mooring system that is fit for purpose in harsh environment. However, industry standards of turret structural analysis technique, including loading condition and combination selection, boundary condition setup and structural analysis acceptance criterion, are not well documented. In this paper, an internal turret structure, which is designed for a FPSO operating in South China Sea, is used as a sample case to illustrate the detailed procedure of turret structural FEA. Emphases are given to aspects of practical importance to engineers conducting turret structure design, such as turret load derivation, boundary condition treatment at the bearing locations, and structural analysis software adoption, etc. It is concluded that the correct application of FEA is essential towards the safe design of a turret system.