The Optimization Design Research For The Foundation Of Offshore Wind Turbine's Transition Section

Offshore wind energy is a kind of clean and renewable engry with the most development prospectl. Development of large-scale offshore wind farm is important to adjust engry structure and improve the environment and it is also a crucial part of national sustainable development strategy. The support of offshore wind turbine is necessary to build a large-scale offshore wind farm. The offshore wind turbine structure is of a massive size and it is difficult to build it under the complex marine environment. Besides, it bears a high cost. Therefore, it is necessary for us to deal with the safety and economy of the structure.So it is of theoretical and practical significance to study the optimization design of the foundation of offshore wind turbine's transition section.In this thesis, the object of study is the transition of jacket offshore wind turbine. The optimization is based on the theory of orthogonal experiment and response surface methodology. In the prosess of optimization, the structural static strength and fatigue strength must be considered. What this thesis mainly researches include as follows:First of all, ANSYS is applied to analyze the structure from the aspects of static strength and fatigue strength. The analysis can confirm the optimation working condition of the static and factigue and the key areas of fatigue optimization.Next, there are many factors which can affect the structure stress of the foundation of offshore wind turbine's transition section. This thesis selects five variables as the orthogonal experiment's factors. They are brace angle?reinforcement ring's position?drum tower's thickness?the upper brace diameter?brace's thickness. The methods of range analysis and variance analysis can be used to determine the optimum combination level and compare the structure from the aspects of ecomoy and security before and after the optimization.Finally, based on the data of the orthogonal experiment and in the use of response surface methodology to separately fitting the function of weight and strength, this thesis builds the optimized mathematical model and realizes the optimation of the foundation of offshore wind turbine's transition section. After analyzing the optimization's result,the effect is proved to be better by utilizing response surface methodology. This method not only ensures the structure's security,but also reduces the cost.