Wind turbine blade pitch fault is easy to cause unstable ultra-high load

which can lead to structural failure and damage. Firstly

the aerodynamic characteristics of NREL 5 MW wind turbine blades with pitch fault/success were analyzed based on the computational fluid dynamics method. Then

the two-way strong fluid-structure coupling and bending analysis were used to study the state of blades with pitch fault under typical azimuths. The results show that average flapwise torque of the blade with pitch fault under the cut-out wind speed is 13. 8 times that of the blade with successful pitch

and the flow field wake of the former is more obvious. The fluctuation range of blade flapwise torque under two-way strong fluid-structure coupling is significantly wider than that without fluid-structure coupling

and the maximum tip displacement of the blade with pitch fault is 14. 1 times that of the blade with successful pitch. For the four typical azimuth angles of 0°

60°

120°

and 180°

the bending moment

tip displacement

bending degree

end effect

wake range and strength of the blade with pitch fault gradually decrease with the increase of the angle. Buckling analysis reveals that the buckling factor increases with the enlargement of azimuth angle

and the first-order buckling factor of 180°azimuth is 20.2% higher than that of 0° azimuth.