Research On Structural Main Scale Parameter Design And Stability Of Suction Bucket Jacket Of Offshore Wind Turbine

With the further increase in global temperature,the development of clean energy has become the common expectation of people all over the world.Offshore wind turbine is a kind of clean energy with great potential.Countries all over the world are sparing no effort to develop marine wind energy resources.Due to the high cost of marine geological surveys and complex changes in marine environmental loads,the construction and installation costs of offshore wind power foundations are high and the construction period is long.Reducing construction costs and improving construction efficiency have become a hot topic in the design and study of offshore wind turbine infrastructure.The suction bucket jacket foundation is a new type of offshore wind turbine foundation form.It has many advantages such as high construction efficiency,reusability,no need for rock inlay,and has great development prospects.This paper first introduces the development significance of offshore wind turbine and the structural characteristics of common basic types,summarizes the current research status of suction bucket foundation at home and abroad,puts forward several problems in the research of suction bucket foundation,and elaborates the research content and technical route of this paper.Next,this paper discusses the theoretical basis involved in the design of the main dimensions of the suction bucket jacket foundation and the finite element modeling analysis,including the calculation theory of wind,wave and current load,the theory of modal analysis,and the theory of penalty function for the contact problem between the bucket and soil,the principle of viscoelastic artificial boundary and its realization method in finite element software.On this basis,based on the ultimate equilibrium equations of the suction bucket foundation under different failure modes,relevant literature and engineering example experience,and based on the hydrological observation data,engineering geological survey data and wind turbine data of a certain sea area in the South China Sea,the main scale parameter of the suction bucket jacket is designed.Then,this paper establishes a full three-dimensional finite element model of blade + nacelle + hub + tower + suction bucket jacket + foundation + viscoelastic boundary in the finite element software ANSYS Mechanical APDL,and applies the wind,wave and current load through ANSYS parametric programming on the structure,and research the strength,stiffness,stability,installation direction and foundation bearing capacity of the foundation under extreme conditions once in50 years.Finally,this paper carried out a resonance check on the turbine,studied the influence of different boundary conditions on the vibration characteristics of the whole structure,and carried out a sensitivity analysis on the elastic modulus of the foundation soil,the friction coefficient between the bucket and soil,and the spring stiffness of the viscoelastic artificial boundary.The research in this paper shows that the suction bucket jacket foundation can meet the load-bearing requirements of high-power offshore wind turbines,and can provide sufficient load-bearing capacity,structural strength and rigidity under the condition of shallow soil entry.Using viscoelastic artificial boundary as the boundary condition of finite element analysis can more accurately grasp the vibration characteristics of the structure than using traditional boundary conditions,so that the turbine impeller speed can more accurately avoid the natural frequency of the whole structure and avoid resonance.The research in this paper has practical application value and can provide reference for the design and calculation of similar projects in the future.