基于柔性杆理论的脐带缆涡激振动数值模拟系统

针对目前海洋脐带缆分析软件缺乏的状况,本文基于MATLAB开发了脐带缆涡激振动数值模拟系统UCVIV-1.0.由于脐带缆的大变形和大转角会产生显著的几何非线性,脐带缆的静态平衡位形和整体力学响应计算采用了细长柔性杆模型,采用尾流振子模型模拟海流作用下的涡激力.该系统界面清晰友好,操作简单,适用于悬链线型脐带缆.选取了一组脐带缆参数,使用该系统进行了静力计算以及涡激振动计算;并将静力结果与采用国外商业软件OrcaFlex计算的结果进行了比对,发现结果吻合程度较高,在一定程度上验证了系统的可行性和准确性.本系统有望为脐带缆设计软件的开发提供借鉴.     

开放式脐带缆结构集成辅助设计分析软件平台的开发

基于开放式设计思想开发了一套集成脐带缆截面设计与整体线型设计的软件平台。创建各功能模块的交互端口,提供了良好的信息交互功能,实现了设计流程的自动化。该软件集成了脐带缆设计中建模、分析、评估和输出的完整流程,交互性好,功能丰富。设计师可以根据软件提供的CAD模块与脐带缆结构设计的基本理论完成初始设计,然后通过专业结构设计软件的数据接口进行截面设计与整体设计,完成工程图纸与计算报告的输出。该软件填补了国内脐带缆辅助设计分析软件的空白,具有较为完善和高效的脐带缆设计分析能力。     

脐带缆深水安装的参数影响分析(英文)

随着水深的增加引起外部压力的增大和脐带缆的重量相应增加,且由于海洋环境载荷和浮体的运动引起复杂的动力特性使得脐带缆的受力复杂,其安全性受到很大的挑战,故深水安装是脐带缆的关键问题之一。文章详细分析了安装过程中不同浮力块的布置方式(不同尺寸,长度和布置位置)和波浪与流的方向对脐带缆的影响。利用悬链线方程构建自由悬挂的脐带缆的模型,然后施加浮力与环境载荷得到动态脐带缆的安装模型。通过对比分析表明,浮力块的布置方案和波浪与流的方向对脐带缆的安装都有很大的影响,上述这些参数在安装中需要给予重视。     

流花19-5气田脐带缆截面分析优化设计

流花19-5气田使用水下生产系统进行生产,采用了钢制水下脐带缆的设计。脐带缆截面设计和分析是脐带缆系统设计中最关键的部分,其决定了脐带缆的截面形式、脐带缆的重量、尺寸等重要参数。本文从脐带缆的截面分析出发,应用了蒙特卡洛模拟分析方法,优化和验证了脐带缆承压能力分析,之后进行了安装和操作分析,并提出相对于流花19-5气田所采取的一些设计优化。该技术的研究和应用可为其他深水油气田的开发提供很好的参考与借鉴效果。     

基于Vega Prime的ROV柔性脐带缆动态模拟

模拟柔性脐带缆在深海作业环境中的动态形态变化是构建遥控潜器（ROV）作业视景仿真系统的重点和难点之一。由于柔性脐带缆在海流作用下受力情况复杂、运动形态多变,利用现有成熟的视景仿真软件难以做到逼真模拟。采用凝聚参数法建立柔性脐带缆的模型、运动方程及变长度算法并进行仿真求解,结合所得数值解,利用OpenGL语言和纹理映射技术动态绘制柔性脐带缆三维模型,并将柔性脐带缆动态模型与在Vega Prime平台建立的ROV主体进行衔接,获得了逼真的柔性脐带缆跟随ROV运动的动态模拟效果。     

静态脐带缆安装工况参数分析

结合工程实例对静态脐带缆安装工况下的基本力学问题进行了归纳分析,依据海洋管线设计规范计算了脐带缆简化模型关键力学参数,对脐带缆安装工况下的水动力性能进行了分析。通过等效刚度替代原则建立了钢管脐带缆有限元简化模型,重点对比分析了摩擦力对脐带缆应力分布的影响,当缆体承受较大弯曲载荷时可忽略摩擦对脐带缆应力计算的影响。不同拉弯组合载荷作用下脐带缆最大应力均出现在0.025 4 m钢管受拉面,依据计算结果提出了钢管脐带缆的简化设计意见。     

脐带缆轻量化设计及其力学性能

脐带缆内部结构是由众多功能单元集成的复合结构,随着油气资源开发向深海推进,常用铠装钢丝脐带缆的有效抗拉能力急剧下降,有必要对其进行轻量化改进。因此,通过对碳纤维脐带缆的截面和芳纶增强脐带缆的增强层进行设计,从脐带缆的理论求解和数值仿真两方面分析碳纤维脐带缆和芳纶增强脐带缆相较于钢管脐带缆和铠装钢丝脐带缆的力学性能和轻量化程度。通过数值仿真分析缆长对3种脐带缆刚度的影响。研究发现,碳纤维脐带缆的轻量化程度最高,可达26.1%。     

基于一体化平台的海洋脐带缆设计

针对深海脐带缆工程设计过程,使用一体化的海洋工程设计平台进行脐带缆的截面选型、线形设计、强度分析、规范校核。并使用一体化平台实现脐带缆的建模,计算工况设置,生成计算模型,导入商业软件分析和结果处理过程。在设计阶段对多种截面在多种工况条件下进行模拟,得到各截面脐带缆关键性能参数,通过脐带缆方案比选,确定脐带缆设计方案。     

安装载荷下脐带缆的抗压抵抗力参数研究

脐带缆作为水下生产系统进行油气资源开发的关键结构之一,在安装过程中的脐带缆受到动态的拉伸载荷和张紧器挤压载荷,保障脐带缆的安装下放过程的结构安全有着重要的工程应用意义。本文应用ABAQUS建立脐带缆有限元模型,充分考虑脐带缆内部各构件之间的相互作用,研究不同张紧器角度与不同摩擦系数下脐带缆的抗压抵抗力性能。结果表明,张紧器与脐带缆之间的摩擦力随着摩擦系数、和张紧器夹角增加而增加,基于此提出可通过优化张紧器夹角及张紧器与脐带缆间的摩擦系数来降低深水对于脐带缆安装的限制。     

海洋缆体系统凝集参数法在水下管道维修干式舱设计中的应用

本文采用凝集参数法模拟缆-体结构系统,用时域法对海洋缆体系统的三维动态性能进行了分析,并给出了计算机程序。将此程序应用在水下管道干式压力维修作业舱系统的初步设计中,对其脐带缆在定常流干扰下的动力响应进行分析,计算结果为设计方案的拟定提供了可靠依据。     

Time series prediction based on LSTM neural network for top tension response of umbilical cables

The umbilical cable is an essential component of offshore oil and gas extraction systems. The severe marine environment poses a high challenge to the safety of the umbilical cable structure during operation. The analysis of an umbilical cable requires complex and resource-demanding finite element time-domain simulations to obtain their nonlinear dynamic response. Therefore, in order to solve the problem of structural safety monitoring and real-time assessment of remaining life of umbilical cables under extreme sea states, there is a great need to predict the dynamic response of umbilical cables quickly and accurately during operation, for ease of making fast decisions for system operation and maintenance before the arrival of extreme sea states. Given the strong nonlinear function-approximation ability of the neural network, this study proposes an efficient method for the prediction of the time series of umbilical cable top tension response based on LSTM (long short-term memory) neural network. We use LSTM neural network and ARIMA (autoregressive integrated moving average) model in a real engineering case for time series prediction of the top tension response of the umbilical cable, and the results of the two models are analyzed and compared, and the efficiency and accuracy of the LSTM neural network model are verified. Furthermore, the hyperparameter, dataset and generalization ability of LSTM model are discussed. The results indicate that feasibility of the tension response prediction of umbilical cables under dynamic load in complex marine environments.     

Development of study on the dynamic characteristics of deep water mooring system

To meet the needs of those exploiting deepwater resources, TLP and SPAR platforms are used in some areas and are considered excellent platforms in deep water. However, many problems remain to be resolved. The design of mooring systems is a key issue for deep water platforms. Environmental loads in deep water effect the physical characteristics of mooring line materials. The configuration and analysis of mooring systems involve nonlinearity due to this fluid-solid coupling, nonlinear hydrodynamic forces, and their effects on stability of motion. In this paper, some pivotal theories and technical questions are presented, including modeling of mooring lines, the theory and method of coupled dynamics analysis on the mooring system, and the development of methodologies for the study of nonlinear dynamics of mooring systems. Further study on mooring systems in deep water are recommended based on current knowledge, particularly dynamic parameters of different materials and cable configuration, interactions between seabed and cable, mechanisms of mooring system response induced by taut/slack mooring cables, discontinuous stiffness due to system materials, mooring construction, and motion instability, etc.     

Integrated optimisation design of a dynamic umbilical based on an approximate model

An optimised design of a dynamic umbilical requires an extreme cross-sectional stress to be maintained within an allowable limit and a fatigue life to be guaranteed to be sufficient. It should be noted that a dynamic umbilical is a typical geometric bi-scale structural system. It consists of a local cross-sectional scale and a global configuration scale, which are significantly different in terms of geometric sizes. In this study, we established an approximate model to achieve an optimised design of the dynamic umbilical by considering the parameters of local cross-sections and global configurations simultaneously. The design variables of a dynamic umbilical are independently identified and defined at both local sectional and global configuration scales in the approximate model. Furthermore, we selected the maximum tension strain and the maximum bending moment, for covering local and global properties, as the objectives to be minimised. The approximate model was observed to be effective in integrating the local and global responses into one loop so that the computational efficiency could be significantly increased. We implemented the optimisation framework on a dynamic umbilical with a lazy-wave configuration, which is considered to be a basis for a case study. Furthermore, we verified the feasibility and effectiveness of the integrated optimisation strategy by numerical simulations. Moreover, we compared the optimised dynamic umbilical properties with those without optimisation. It was observed that the fatigue life of the optimised dynamic umbilical was improved significantly, thereby indicating that the integrated optimisation methodology provides a new model and algorithm for an efficient design of the dynamic umbilical.     

文昌脐带缆J型牵拉入位操作的水动力分析

参考863文昌脐带缆截面设计及具体工作环境参数,利用水动力分析软件Orcaflex建立了文昌缆J型管牵拉入位的水动力分析模型,计算了脐带缆在牵拉入位过程中的水动力响应。并结合有水动力分析结果,给出了该脐带缆的相关力学性能和在牵拉入位中应注意的事项,对实际工程实践有一定的指导意义。     

海底脐带缆铺设系统动力学仿真及张力补偿研究(英文)

For studying the dynamic performance of subsea umbilical cable laying system and achieving the goal of cable tension and laying speed control,the rigid finite element method is used to discrete and transform the system into a rigid-flexible coupling multi-body system which consists of rigid elements and spring-damping elements.The mathematical model of subsea umbilical cable laying system kinematic chain is presented with the second order Lagrange equation in the joint coordinate system,and dynamic modeling and simulation is performed with ADAMS.The dynamic analysis is conducted assuming the following three statuses:ideal laying,practical laying under wave disturbance,and practical laying with tension compensation.Results show that motion disturbances of the laying budge under sea waves,especially with heaving and pitching,will cause relatively serious fluctuations in cable tension and laying speed.Tension compensation,i.e.,active back tension torque control can restrict continuous tension increasing or decreasing effectively and rapidly,thus avoiding cable breach or buckling.     

流花4-1电缆和脐带缆安装技术及应用

介绍流花4-1油田电缆和脐带缆的形式、铺设过程及铺设施工中需要的主要设备、安装过程技术参数及限制条件,为国内其它项目的海缆安装及深水油田的开发提供借鉴。     

基于载人潜水器的深海敷缆运动仿真

提出了基于载人潜水器搭载海底敷缆装置的深海敷缆作业方式,建立了载人潜水器深海敷缆运动的二维稳态模型,仿真分析了余量敷缆时不同航行速度和放缆速度组合、潜水器相对海流速度、敷设余量、航行高度和海缆重量等参数对敷缆运动的影响。分析发现海缆张力随着敷设速度、潜水器相对海流速度、海缆重量的增大而增大,随着敷设余量的增大而减小;海缆水中位形曲线随着敷设速度、潜水器相对海流速度增大而趋于平缓,随着海缆重量的增大而更加陡峭,放缆速度的变化则对海缆位形曲线无影响;潜水器航行高度的变化对缆形和张力分布都没有影响,只是随着高度的增加,缆形和张力在原来的高度基础上有一定的延伸。