Calculation method for ultimate strength and fatigue strength of yaw bearing connecting bolt of wind turbine

The invention relates to a calculation method for ultimate strength and fatigue strength of a yaw bearing connecting bolt of a wind turbine. Mesh generation and assembling are separately performed on three-dimensional geometrical models of devices on a load transfer path related to the bolt by use of finite element software, so as to establish a finite element model, so that the load transfer path is completed and is consistent with the reality. The devices on the load transfer path at least comprise a gear box body, a main frame, a tower drum, a yaw bearing and a yaw bearing connecting bolt. Limit loads of different working conditions are applied to the models, and the models are submitted to finite element analysis software to be solved, so as to obtain the ultimate strength and fatigue strength of the yaw bearing connecting bolt of the wind turbine. Through adoption of the method, the complete load transfer path is realized, the accuracy of bolt security coefficient is improved, and the operation reliability of the wind turbine is improved.