Research On Wind Turbine Foundation Quality Inspection And Operation Risk Assessment

The stability of concrete foundations for wind turbines is crucial for their safe operation.In this thesis,a combination of theoretical analysis,indoor experiments,and numerical simulation was adopted to conduct static and dynamic simulation calculation analysis on the fan foundation structure,and the safety of the fan foundation in combination with concrete quality inspection was evaluated.(1)Based on elastic wave CT technology,geological radar method,acoustic transmission method,and indoor mechanical testing methods,the quality of the concrete material for a certain wind turbine foundation in the Toudaoling Wind Farm project was determined.The results show that the strength grade of the foundation concrete of the fan meets the design strength specification requirements,and the concrete appearance is complete,compacted,and meets the engineering requirements.(2)ANSYS software was used to simulate and analyze the stability of the fan foundation under operating conditions.The results show that under normal operating load conditions and extreme load conditions,the anisotropic displacement and overall deformation of the fan foundation structure meet the design requirements.With the increase of external load,the anisotropic displacement and overall deformation of the fan foundation increase,and the position of the maximum deformation also changes.The influence of stress concentration occurs at the flange connection between the tower and anchor plate.(3)Modal analysis and seismic analysis were conducted on the fan foundation structure,and the results showed that the vibration mode of the fan foundation structure was mainly caused by the deformation of the tower tube.The first natural vibration period of the tower drum is 0.072 s,and the vibration direction is inclined deformation;Starting from the third order,a vertical vibration state occurs;Starting from the fifth order,it exhibits a rotating vibration state,and the fifth mode shape better reflects the torque effect of the vibration.The displacement vibration amplitude of the fan foundation structure in the y-direction under the action of the standard earthquake response spectrum is 8.7 mm,which is the most destructive to the structure.It is necessary to increase the anchoring and protection measures in the vertical direction of the fan foundation.(4)Analytic Hierarchy Process and Fuzzy Comprehensive Evaluation Method were used to construct quality evaluation indicators and evaluation system for wind turbine foundation concrete materials,the obtained evaluation model consists of 4first level indicators,14 second level indicators,and 34 third level indicators.The results indicate that the risk of instability and failure of the concrete foundation of the wind farm project is relatively low.In addition,special attention should be paid to the control of concrete construction quality in key parts of the wind turbine foundation structure.The thesis systematically analyzes the development of wind turbine foundation structural forms and related research progress,and elaborates on the research status and latest progress of wind turbine foundation structural forms and calculation analysis methods.Based on the finite element method,the fan load and environmental load,statics and dynamics calculation of the fan foundation structure system and other related issues are simulated and studied,and the safety of the fan foundation is evaluated.The research results can provide guidance for the accident prevention and safe operation and maintenance of the fan unit.