海洋核动力平台定位系统多体动力学建模与分析

MULTIBODY DYNAMICAL MODELING AND ANALYSIS OF MARINE NUCLEAR POWER PLATFORM POSITIONING SYSTEM

海洋核动力平台可以为海上油气开发、偏远岛屿和海水淡化等提供稳定的能源供给,是具有潜力的重要海洋装备.定位系统作为核动力平台的核心部位,主要由单点转塔、YOKE刚臂、系泊腿和系泊支架组成,属于典型的多刚体动力学系统.对定位系统进行多体动力学分析可以提高核动力平台长期作业的可靠性.基于多刚体动力学理论,结合定位系统多铰连接的拓扑结构,建立了定位系统的多体动力仿真模型;进而考虑核动力平台作业海洋环境,通过谱分析与线性叠加原理得到核动力平台在多年重现期下的六自由度运动时程.以我国首座海洋核动力平台为例,利用多体动力学模型分别计算了一年一遇、十年一遇和百年一遇海况下定位系统的系泊回复力与连接结构受力行为.计算结果与准静力学模型、Kane动力学模型进行对比,给出了定位系统的系泊回复刚度曲线,并提出了系泊回复力动力放大系数.研究可为定位系统系泊能力评估和各连接结构受力分析提供参考和借鉴.

Marine nuclear power platform can provide a stable energy supply for oil and gas exploitation,remote islands and desalination of sea water.It is an important marine equipment with potential.As the core part of the nuclear power platform,the positioning system is mainly composed of a single-point turret,YOKE,mooring legs and mooring bracket,which is a typical multi-rigid body dynamic system.The multi-body dynamic analysis of the positioning system can improve the long-term operation reliability of nuclear power platform.Based on the theory of multi-body dynamics and the topology of multi-hinge connection of positioning system,a multi-body dynamic simulation model of positioning system is established.Then,considering the marine environment of nuclear power platform operation,the 6-DOF motion time history of nuclear power platform under multi-year return periods is obtained through spectral analysis and the theory of linear superposition.Taking the first marine nuclear power platform in China as an example,the mooring restoring force of the positioning system and the mechanical behavior of each hinge joint are calculated under the sea conditions of 1-year return period,10-year return period and 100-year return period by using multi-body dynamic model.Compared with the quasi-static mechanical model and Kane dynamic model,the mooring restoring stiffness curve of the positioning system is calculated,and the dynamic amplification factor of the mooring restoring force is proposed.The research can provide a reference for the evaluation of the mooring capacity of the positioning system and the mechanical analysis of each hinge structure.