Study on Hydrodynamic Forces and Safety of Huge Floating Body

为了充分利用海洋空间，浮式超大型海洋结构物正日益受到重视。例如，可以解决噪音、有限的陆地空间和生态问题的浮动机场。为了实现这种超大型海洋结构物，必须准确评估其在海洋环境中的安全性和可靠性，包括在波浪中的行为。为此，必须准确地知道风、波浪和水流等水动力外力，必须估计浮体的水弹性特性，并反馈到规划和设计中。本研究以巴西的石油相关浮式海洋结构物为基础，对超大型海洋结构物的外力、水弹性响应、安全性、可靠性和姿态控制进行评估。在本研究中，研究人员相互委托，海洋结构物的操作和实验的执行相互搜索。通过研究，可以了解柱间相互作用、姿态控制等水动力特性。在姿态控制方面，提出了气动执行机构。对于作动器布置不均匀的情况，用模态合成表示弹性变形进行数值仿真，可以得到较好的控制效果。通过7 m长的模型试验，验证了姿态控制的可行性和局限性。

For the utilization of ocean space, floating type very large offshore structures are taking into account today. A floating airport, which can resolve the problems of noise, limited land space and ecology, will be one example.In order to realize such kind of very large offshore structure, safety and reliability in ocean environment including behavior in waves must be evaluated accurately. For that purpose, hydrodynamic external forces like wind, waves and current must be known exactly and hydro elastic characteristics of the floating body must be estimated and feed backed to the planning and design. This research is aiming at the evaluation of die external forces, hydro elastic responses, safety, reliability and attitude control of very large offshore structure based on the oil related floating offshore structures operated in Brazil. For this research, researchers are delegated each other, and operation of offshore structures and execution of experiments are searched each other. From the research, we could know the characteristics of hydrodynamic forces like interaction between columns and attitude control. About attitude control, we proposed pneumatic actuator. For the case of non-uniform actuator arrangement, the optimal control could give relatively good results by carrying out numerical simulation expressing elastic deformation by modal composition. Furthermore, the possibility of attitude control and its limitation were examined by carrying out model test using 7m length model.