Mechanical Structure Design And Finite Element Analysis For Blade Of Tidal Current Turbine

With the rapid development of social economy and the consumption of traditional fossil energy,tidal current turbine(TCT)has gained extensive attention and achieved great progress in the past decades due to its development superiority.Blades of tidal current turbine are the core component of TCT,which convert the kinetic energy of tidal current to the mechanical energy of turbine.However,in addition to the hydrodynamic performance,such blades also experience complicated conditions of movements and loads.As a result,one of the key points for the commercialization and industrialization of TCT is the running stability and reliability of blades.In this paper,120kW horizontal axis tidal current turbine(HAMTCT)is regarded as the research object.And in order to find an effective analysis method of blades mechanical structure,this paper mainly consists of initial structure design,finite element analysis of ply structure and experimental verification based on the hydrodynamic structural design.The contents of each chapter are as follows:The first chapter describes the background of this paper and the development of tidal current turbine both at home and abroad.Then through the introduction of related aspects of blades,the research content and the significance of this paper are expounded.In chapter 2,blade element momentum(BEM)theory is used for load analysis of blade.Then the theory of composite fiber laminates and basic principles for laminating design are proposed for subsequent design and analysis.Also,some relevant failure criterias for the composite fiber blades are introduced.In chapter 3,hydrodynamic loads of blade's several sections are calculated by Tidal Bladed.Then preliminary design is conducted in terms of material selection,the section structure and the root connection of blade.Typically,the thickness of main spar cap,shear web and root reinforced layers are calculated.In chapter 4,the shell model of blade is established and then the finite element simulation of the composite laminated structure is completed.Based on this,static analysis of the blade under ultimate flap-wise bending is carried out and then the deflection and strength both are checked.Furthermore,modal analysis is performed to prevent fatigue due to resonance.In chapter 5,the modal test and the strain test under static load in flap-wise direction are described and conducted.The acquired data of experiment are compared with the results of FEA,along with error analysis,which prove the accuracy of FEA.The last chapter summarizes the work of the whole paper and points out aspects that deserve further research.