Numerical Simulation Analysis Of Onshore Wind Turbine Foundation And Reinforcement Body

Over the past four decades,China's wind power industry has developed rapidly.From onshore wind power to offshore wind power,wind farms have been built to generate electricity.Basic safety is an important guarantee for stable power generation in wind farms.Since June 2007,the design of onshore wind turbine foundation mainly refers to the standards and experience of high-rise buildings,power energy and other related industries,resulting in a large difference in different aspects of the design,experience is preferred.It is very necessary to combine the finite element simulation to provide important reference basis for the review of the built projects.The wind turbine foundation is an important part of the wind generator.It not only bears the dead weight of the fan,but also bears the dynamic load generated during the operation of the fan.Therefore,the wind turbine foundation must have sufficient strength and stability.In a certain period of operation,many wind farms in China have experienced extreme loads,and the reliability of the foundation has been reduced,so they can no longer meet the safety operation standards.Therefore,they must be strengthened to recover and improve the bearing capacity.Moreover,the damage and damage of the foundation cannot be accurately verified.Therefore,using ABAQUS plastic damage theory to simulate the stress state and damage situation of wind turbine foundation before and after reinforcement will have important theoretical value and practical engineering significance.The wind turbine foundation and solid belong to a special mass reinforced concrete structure,so it is necessary to develop a hydration simulation subroutine for wind turbine foundation and solid based on ABAQUS secondary development platform.The complete thermodynamic coupling simulation analysis of the temperature field and the temperature stress field of hydration heat in the whole period of foundation and its solid casting is realized,which provides reference for the temperature control and shrinkage crack control of hydration heat and solid in the concrete structure of overland wind turbine foundation,and has important guiding significance for the optimization of reinforcement design and reinforcement construction.The main contents of this paper are as follows:(1)In this paper,the parameter conversion method of the plastic constitutive model of concrete damage is studied,and the general calculation method of the compression and tensile damage factors is introduced.The plastic strain value is used to judge whether the damage plastic parameters are wrong.(2)The study summarizes the law between the compression damage factor and the maximum tensile stress of the fan foundation,and establishes the safety assessment grade of the wind turbine foundation based on ABAQUS plastic damage theory,which is of great significance for guiding the reinforcement and predicting the safety of the wind turbine foundation.The numerical simulation results show that the stress peaks of the concrete and steel bars in the main parts of the original foundation can be reduced by the method of fixed plate ring beam reinforcement,and the tensile stress in the main parts of the tensile zone is less than the designed value of the tensile strength of the concrete,and the damage is no longer aggravated.(3)Based on the ABAQUS concrete damage plastic model theory,the interaction between the wind turbine foundation and the concrete and the concrete and the solid is studied,and the state of the concrete and the foundation with or without initial crack is compared and simulated,which verifies the necessity of the foundation surface to keep the concrete intact.(4)On the secondary development platform of ABAQUS,written by using FORTRAN language allows tensile stress,the adiabatic temperature rise,the volume contraction deformation,creep,the material such as modulus of elasticity,control parameters of a subroutine,through UMATHT interface docking,realize fully coupled thermo-mechanical analysis and the integrated solution of each characteristic parameters of stiffness matrix,obtained wind turbine base hydration heat simulation subroutine,judge the basis and the total area of solid temperature stress cracks frequently occur.