浅水中OSV锚泊定位分析研究

本文采用数值计算方法对浅水中海洋平台支持船(OSV)的锚泊定位性能开展研究.首先,基于三维频域势流理论,对一艘OSV不同水深的水动力性能开展分析,计算了水动力系数、运动幅值响应算子、一阶波浪力和二阶波浪力.由于浅水中非线性效应显著,本文采用中场公式计算了该OSV全二阶波浪力传递函数(Full Quadratic Transfer Function,简称全QTF).然后,本文对不同水深下锚泊系统的水平刚度开展了分析,计算了不同水深下锚泊系统的水平刚度,研究了水深对锚泊系统水平刚度的影响.最后,采用准动态方法对不同水深下的OSV和锚泊系统开展时域分析,研究了水深对船体运动性能和锚索张力的影响.     

大型无动力船舶防台浮筒系泊力数学模型研究

本文提出大型无动力船舶防台浮筒系泊系统设计中,船舶的风、浪、流等自然环境载荷计算模型,求取在自然环境载荷以及船艏锚链作用下达到平衡状态时的锚链受力,并和物理模型,实测试验等研究结果进行比对验证,确定单点系泊数学模型的科学性和合理性。继而分析了防台浮筒系泊系统数学模型计算结果在防台浮筒工程设计中的应用。     

锚泊辅助动力定位研究与进展

  目的  为优化布锚夹角并满足锚泊线的强度要求,提出一种计算锚泊系统静回复力的方法。  方法  使用该方法,研究布锚夹角对平台静回复力、艏向变化及锚泊线受力均匀程度的影响。利用改进的遗传算法,优化布锚夹角,并从2个方面提高算法精度：一是通过对3种因素（静回复力大小、静回复力对扰动方向的敏感程度、锚泊线的受力均匀程度）的影响分析人为生成初始种群;二是结合自适应算法加强局部搜索能力。  结果  结果显示,改进后的遗传算法拥有更高的优化精度,把优化后的结果反馈给锚泊系统受力模型,可降低锚泊线对破坏强度的要求。  结论  所做研究可为锚泊系统布锚夹角及锚泊线材质的选择提供参考。     

基于AQWA的FPSO系泊系统响应数值模拟

针对墨西哥湾海域和西非海域,1 828.8 m水深转塔式FPSO系泊系统,利用水动力通用软件AQWA,建立风浪流作用下船体/锚链耦合系统模型,得到FPSO系泊系统频域与时域的动态响应.着重分析了浪向角180°和225°情况下的各自由度一、二阶响应.利用AQWA的缆索动力学模块,设计校核了系泊缆索受力情况.AQWA提供的...     

A simplified method for reliability- and integrity-based design of engineering systems and its application to offshore mooring systems

This paper presents a simplified method for the reliability- and the integrity-based optimal design of engineering systems and its application to offshore mooring systems. The design of structural systems is transitioning from the conventional methods, which are based on factors of safety, to more advanced methods, which require calculation of the failure probability of the designed system for each project. Using factors of safety to account for the uncertainties in the capacity (strength) or demands can lead to systems with different reliabilities. This is because the number and arrangement of components in each system and the correlation of their responses could be different, which could affect the system reliability. The generic factors of safety that are specified at the component level do not account for such differences. Still, using factors of safety, as a measure of system safety, is preferred by many engineers because of the simplicity in their application. The aim of this paper is to provide a simplified method for design of engineering systems that directly involves the system annual failure probability as a measure of system safety, concerning system strength limit state. In this method, using results of conventional deterministic analysis, the optimality factors for an integrity-based optimal design are used instead of generic safety factors to assure the system safety. The optimality factors, which estimate the necessary change in average component capacities, are computed especially for each component and a target system annual probability of system failure using regression models that estimate the effect of short and long term extreme events on structural response. Because in practice, it is convenient to use the return period as a measure to quantify the likelihood of extreme events, the regression model in this paper is a relationship between the component demands and the annual probability density function corresponding to every return period. This method accounts for the uncertainties in the environmental loads and structural capacities, and identifies the target mean capacity of each component for maximizing its integrity and meeting the reliability requirement. In addition, because various failure modes in a structural system can lead to different consequences (including damage costs), a method is introduced to compute optimality factors for designated failure modes. By calculating the probability of system failure, this method can be used for risk-based decision-making that considers the failure costs and consequences. The proposed method can also be used on existing structures to identify the riskiest components as part of inspection and improvement planning. The proposed method is discussed and illustrated considering offshore mooring systems. However, the method is general and applicable also to other engineering systems. In the case study of this paper, the method is first used to quantify the reliability of a mooring system, then this design is revised to meet the DNV recommended annual probability of failure and for maximizing system integrity as well as for a designated failure mode in which the anchor chains are the first components to fail in the system.     

深水半潜式生产储油平台系泊锚机电控系统设计及应用

系泊锚机是1500m深水半潜式生产储油平台的关键装备之一,其电控系统要求可靠性高、布置紧凑、智能化水平高.文章通过分析深水半潜式生产储油平台系泊系统组成、锚机的结构、电控系统所要求功能,划分出功能模块,选择可编程逻辑控制器(PLC)及现场总线的技术思路,进行设备布置、网络架构、硬软件的选择,设计出一套电控系统,实现了系...     

An integrated methodology for the design of mooring systems and risers

Traditionally, the design of mooring lines and risers of floating production systems (FPS) has been performed separately, by different teams, employing uncoupled analysis tools that do not consider the nonlinear interaction between the platform hull and the mooring lines and risers. Design processes have been focused on fulfilling the design criteria of the respective component (mooring/riser) alone, with few or no consideration to the other component, and little interaction between the design teams. Nowadays the importance of employing analysis tools based on coupled formulations is widely recognized, and analysis strategies have been proposed to consider feedback between mooring lines and risers within their respective design processes.In this context, this work details a proposal of one single and fully integrated design methodology for mooring systems and risers for deep-water FPS. In this methodology, the design stages of both risers and mooring lines are incorporated in a single spiral, allowing the full interaction of different teams; mooring design implicitly considers the riser integrity, and vice-versa, leading to gains in efficiency and cost reduction.Different analysis strategies are employed, taking advantage of uncoupled and coupled numerical models. The models generated at the initial/intermediate design stages can be reused in subsequent stages: simpler models are used in the initial stages, and more refined models are gradually introduced, to reach an ideal balance between computational cost and accuracy of results. In the advanced stages, the exchange of information between mooring/riser also allows the definition of criteria for the selection of governing/critical loading cases to be revised and verified in detail. This leads to the reduction of the original loading case matrix, allowing a feasible use of time-consuming fully coupled analysis.Results of a case study illustrating the application of some of the main processes of the methodology are included.     

系泊系统的稳定性、分岔与混沌研究

概述了近年来在系泊系统的稳定性、分岔与混沌研究方面的进展.从系泊系统的数学模型、非线性动力学特性的研究方法等角度分析了以后的发展趋势.     

波浪与系缆方式对系泊船舶响应的影响研究

系泊船舶响应的影响因素很多,且十分复杂。针对影响系泊船舶响应的主要因素（波浪和系缆方式）开展研究,通过船舶系泊物理模型试验,研究波浪条件及系缆方式对系泊船舶响应的影响规律,其中波浪条件包括不同的波向及波浪周期,系缆方式包括不同缆绳配置（有无缆尾索）和不同系缆布置方案。研究结果表明,45°斜向浪作用下系泊船舶的运动量和系缆力均明显小于横浪作用下的结果;试验波浪周期范围（T=3.5~6.0 s）内,系泊船舶的运动量和系缆力均随着波浪周期的增大而变大;从船舶系泊安全角度看,设置缆尾索是有利的;码头前后沿共同系缆布置可明显提高船舶系泊（非装卸作业时）的抗风浪流能力。     

系泊系统对波能发电装置动力响应的影响

[目的]为了设计造价合理、性能高效的系泊系统,研究不同系泊系统对波能发电装置(WEC)的能量摄取(PTO)能力和定位性能的影响.[方法]选择一典型的两刚体点吸式WEC装置为研究对象,采用WEC-Sim和MoorDyn开源代码设计两类系泊系统,一类采用锚链,另一类采用锚链和聚酯缆绳所组成的混合缆.通过对这两类系泊系统进行...     

位置随动控制系统设计与实现

计算机控制系统是保证位置随动系统功能和性能的重要部分,文中结合船用仿真转台阐述了多机集散控制结构形式的位置随动转台的计算机控制系统方案,并以某位置随动转台为背景,对系统工程实现中的接口电路设计、电机、伺服放大器以及采样频率选取、程序设计等一系列问题进行了讨论,设计结果在位置随动试验样机中应用取得了良好效果.     

系泊系统的时域仿真及其非线性动力学特性分析

应用时域仿真的方法研究了系泊系统的非线性动力学特性。以三阶操纵运动方程为基础,引入定常的风力、潮流作用力和二阶波浪力,建立了系泊系统三自由度的运动微分方程。在此数学模型的基础上,建立了系泊系统的多自由度的计算机仿真模型。在风浪流联合作用的情形下,对一艘单点系泊油轮的动力学行为进行了仿真研究。以潮流速度和系缆程度为分岔控制参数,在参数平面上给出了局部分岔集。研究表明,系泊系统的动力学行为具有强烈的非线性特征。在仿真过程中观察到了吸引子的共存和Hopf分岔。局部分岔集将参数平面分为3个系统动力学行为本质不同的区域。极值系泊力水平与系泊系统的动力学行为有着密切的关系。对于单点系泊船舶而言,顶风顶浪顶流的状态并不一定是最为危险的工况。局部分岔集的确定为系泊系统参数的选择提供了决策依据。     

船舶操控及锚泊过程的运动数学建模研究

船舶结构的锚泊过程大多采用经验公式进行计算,计算过程较为复杂,且其计算精度往往较差。为提高船舶锚泊力计算精度,本文根据多体系统动力学对船舶锚泊过程进行动力学建模,研究锚泊链张力对船舶运动稳定性的影响,获得锚泊预张力与张力峰值之间的规律。计算结果表明,锚泊系统预张力越大,则船舶的摇晃幅值越小,船舶的平稳性也越好。船舶锚泊过程中,锚泊预张力越大,则对应的锚泊力峰值也越大,对锚泊链的强度要求也越高。     

带有弹性索的潮流能电站系泊系统的设计及特性

漂浮式电站潮流能发电机组依托于浮式载体,其系泊系统关系着潮流能电站的安全运行与生存。关于载体系泊系统的研究,目前主要集中在海洋钻井平台方面,而关于以潮流电站为代表的浅水系泊的开发研究相对较少。本文基于漂浮式潮流能电站,设计开发了一套带有弹性索的系泊系统,以悬链线理论为基础,分别分析了系泊系统中加入的弹性索长度及不同水深下对系泊系统的影响。研究发现,当工作水深小于60m的浅水海域时,对于系泊张力的作用显著,张力的最大值可以减少37%,具有极大的工程应用前景。     

Hinge joint damage identification method of soft yoke mooring system based on multibody dynamic modeling and structural monitoring data

Soft yoke mooring system (SYMs) is a single-point mooring system used in shallow water oil and gas development. In general, SYMs consists of mooring framework support, mooring legs, yoke, and single-point turret and it forms a multibody dynamic system with 13 hinge joint structures such as universal joints and thrust bearings. The hinge joint is one of the key components of SYMs; therefore, it is necessary to accurately evaluate the operating behavior of the hinge joints. In this study, real-time damage identification is conducted based on the multibody dynamic features of the SYMs. First, a long-term monitoring strategy for the prototype application is developed based on the multibody governing equations of the SYMs. The motion behaviors and stress state of the hinge joints and bodies are calculated using prototype monitoring data. A hinge joint damage identification based on the virtual moment is proposed by considering the changes in the friction coefficient in the damage state. The virtual moment method is used to transform the damage identification problem of the SYMs into a problem of seeking the optimal solution to the dynamics identification function. Genetic algorithm (GA) is implemented to seek the optimal solution of the friction coefficient of each hinge joint. A large-scale model testing system of the SYMs is established to perform the damage identification of the bottom hinge joints of the SYMs. The results show that the proposed method can effectively identify the damage degree and position of the hinge joints of the SYMs and provide a real-time warning system for the in-service operation of the SYMs.     

系泊系统非线性恢复力研究及其应用(英文)

Mooring system plays an important role in station keeping of floating offshore structures.Coupled analysis on mooring-buoy interactions has been increasingly studied in recent years.At present,chains and wire ropes are widely used in offshore engineering practice.On the basis of mooring line statics,an explicit formulation of single mooring chain/wire rope stiffness coefficients and mooring stiffness matrix of the mooring system were derived in this article,taking into account the horizontal restoring force,vertical restoring force and their coupling terms.The nonlinearity of mooring stiffness was analyzed,and the influences of various parameters,such as material,displacement,pre-tension and water depth,were investigated.Finally some application cases of the mooring stiffness in hydrodynamic calculation were presented.Data shows that this kind of stiffness can reckon in linear and nonlinear forces of mooring system.Also,the stiffness can be used in hydrodynamic analysis to get the eigenfrequency of slow drift motions.     

液压绞缆机控制阀的故障分析与排除

文章就某轮液压绞缆机出现的无法放缆及运转中出现的操纵阀芯敲击声的现象,对平衡阀的结构和工作原理进行分析,并提出了调整方法。     

风流作用下码头系泊船舶缆绳张力及运动量研究

基于力的平衡关系建立了系泊船舶在风和潮流作用下缆绳张力和运动的计算模型(Qmoor),其中根据船舶类型和吨位确定其水下的迎流面积和水上的迎风面积,由经验性公式计算风、流对码头前船舶的作用力,缆绳张力采用考虑缆绳非线性变形的Wilson公式计算,同时也考虑了护舷的变位与靠泊力之间的非线性关系。计算结果与物理模型试验结果较一致,且与Optimoor软件的计算结果进行了对比。     

多传感器融合技术在列车运行控制系统测速定位中的应用

准确可靠地获得列车速度和位置对列车运行控制系统是至关重要。提出了列车测速定位技术,引入了多传感器融合定位技术的概念,通过对多传感器融合技术的分析,说明多传感器融合测速定位技术能准确可靠地获得列车速度和位置,能使多传感器融合技术能够真正在列车测速定位中得到应用。     

基于VB.NET和AutoCAD平台的船舶锚系自动布置辅助系统

船舶锚系设计是船舶设计的重要内容,船舶艏部线型一旦发生变化,锚系布置就要反复的进行校核和修正,工作效率低,有必要使用新的设计工具来辅助工作。在参考有关规范和文献的基础上,对船舶锚系自动布置优化设计进行了研究,基于VB.NET和AutoCAD平台,开发了船舶锚系自动布置辅助系统。系统建立了锚参数数据库,为船舶锚系布置设计提供了方便快捷的数据库平台,并用二维自动作图比较的方法实现了锚系布置中锚链筒最优位置的确定。