Static And Dynamic Finite Element Analysis Of Large Wind Turbine Tower

Tower is the main support equipment of wind turbine, which connects generator and ground, and makes rotor obtain enough height. For many years, china have not possessed unified design standard of wind turbine tower, and just refered to foreign design experience. But as the wind turbine tower have been large increasingly, it is necessary for us to make more careful research on its structure, thus lay the foundation for our own procedure and standard of design.3 MW large wind turbine tower was taken as the object of study, using finite element analysis software ANSYS to make static strength and stability analysis, dynamic analysis, and seismic analysis. Through the analysis of static strength, we make sure that the stress and displacement of tower in the rated wind speed condition, cut out wind condition,and maximum wind condition. The maximum stress and displacement are obtained in cut out wind condition, and the maximum stress appeares at the bottom of tower. We study the first kind of steady state of tower structure, and separately make analysis of buckling in gravity condition and three wind conditions, and get buckling mode and vibration of tower. The tower meets stability requirement in above conditions. In the dynamic analysis, we get the inherent frequencies and modal shapes of tower, and the results meet the frequency design principles of wind turbine.In addition,we analyse the influence on inherent frequency that changing tower top quality and changing tower wall thickness.Using the time-history method, we separately make analysis of tower in many earthquake conditions and the coupling effects of earthquakes and wind conditions, then determine the stress and displacement distribution of tower which is in corresponding conditions in earthquakes.The thesis bases on dynamic theory and finite element with reference to the current specification and technical standards, and makes static and dynamic analysis for 3 MW large wind turbine tower in many conditions, and provides beneficial reference for independent design of our large wind turbine tower.