深海浮式平台Laplace域动力分析方法研究及系统构建

The deep-sea floating platform (DSFP) has been well recognized as one kind of the most critical marine structures in maritime power strategy of China. One of the key challenges in DSFP research is how to analyze the DSFP coupling dynamics considering the interaction between DSFP, wind and wave. Up to date, most of existing popular techniques investigating the DSFP coupling dynamics in the time or/and frequency domains. Although the state-of-the-art methodology, namely the Laplace domain-based methodology, is able to address the computation and accuracy issue in time or/and frequency domain-based methodologies, to our best knowledge, the researches using Laplace domain-based techniques for DSFP coupling dynamics analysis have not been found in dynamic analysis of marine structures, because of difficulties in dealing with random wave loadings, singularity of transfer functions, etc. This project aims at developing fundamental methods and tools for DSFP dynamic analysis in Laplace domain, which will be comparative to the existing analysis theories in time or/and frequency domains, based on potential improvements in response estimation of floating body, mooring system and so on. It is expected that, owing to excellent computational efficiency and analysis accuracy of the proposed theory in Laplace domain, it can be used to significantly reduce the accumulation error of the response prediction caused by employed numerical approximations, improve the motion transfer accuracy in the system dynamics, and solve the time-consuming computation of the DSFP coupling dynamics caused by the loop nested iteration in modelling the time-varying deep sea flexible system. The research outcomes disseminated in this project will enable the solution to the technical bottlenecks in DSFP coupling dynamics analysis, and will provide a new Laplace domain-based dynamic analysis theory for effective analysis, design and optimization of DSFP dynamics. The success of this project will produce independent intellectual property and proprietary technology analysis tools, benefiting the analysis and design of DFSPs in natural resources exploitation.

深海浮式平台是国家加快建设海洋强国战略的重要工程装备，科学高效的动力分析方法构成其结构设计的技术核心。目前，主流技术主要集中于时域或频域，计算精度与效率往往难以兼具；而Laplace域方法在理论上还存在无法处理波浪等任意荷载、传递函数奇异等一系列问题，难以直接应用于海工结构分析设计。本项目拟开展大型浮体、系泊等子系统Laplace域动力响应及整体耦合分析方法研究，构建平行于现有时域与频域的Laplace域动力分析技术体系。解决大型浮体运动方程因数值近似而导致的响应预报误差累积、传递难题，克服深海柔性系统因循环嵌套而带来的计算效率较低的问题，攻克浮式平台面临的更为严峻的动边界协同及同步流固耦合分析技术瓶颈，充分发挥Laplace域方法兼具良好计算精度与效率的技术优势，实现复杂庞大的深海浮式平台科学高效的分析设计。研发具有自主知识产权的软件系统，为我国深远海资源开发装备的安全设计提供技术支撑。

作为国家实施海洋开发战略的重要深海工程装备，浮式平台其环境条件更加恶劣，结构也更加庞大复杂，是风、浪、流等荷载作用下的非线性、多尺度、多场多体耦合的庞大系统，科学的分析方法其相关技术也构成深海平台结构设计的技术核心。本项目基于分离式耦合的思想，首先在解决传统Laplace域分析方法无法处理波浪等任意荷载的理论难题方面取得了突破，发展了基于复指数的任意荷载极值留数统一表征技术，解决了波浪、系泊力、推进力等任意荷载的极值留数统一求解问题；在大型水面自由浮体运动响应求解方法和系泊缆动力分析技术方面也实现了理论进展，通过引入状态空间模型，实现传统大型浮体的卷积项参数的近似表征，在技术上避免了时域方程中的卷积求解过程，大幅提升了计算效率；通过构造高阶全局形函数，实现了考虑系泊系统大变形的全局刚度理论近似解，解决了系泊系统求解中局部刚度矩阵向整体刚度矩阵转换的问题。基于上述进展，进一步发展了大型浮体与柔性结构的动边界分析技术，形成了深海浮式平台-柔性结构分离式耦合分析方法。理论验证层面上，相关成果已完成数值模型的理论验证以及与商业软件的对比验证工作；物理实验层面，在中国海洋大学山东省海洋工程重点实验室完成了半潜式平台的测试与验证工作，理论与实验数据吻合较好。目前，相关研究成果已在国内外学术期刊发表学术论文40篇，其中SCI论文25篇，EI论文16篇，JCR一区论文17篇，ESI高被引论文1篇；授权国家发明专利7件，授权软件著作权2项，申请美国专利1项，国家发明专利3项。研究成果纳入国家能源局标准1部。指导博士后5人，硕士研究生21人，博士研究生10人，其中已毕业硕士12人，博士2人，出站博士后3人。获电力工程科技进步奖、获电力建设科技进步奖等省部级奖励3项。研究成果得到中电建华东院等企业关注，正进一步在漂浮式风电领域转化应用。