Finite element model of bolt looseness of wind turbine tower

Flange bolt looseness is one of the common problems of wind turbine tower, and is the main factor leading to the collapse of wind turbine tower. In this paper, based on ANSYS Based on the finite element analysis method of workbench, the local finite element vibration analysis model of tower drum is established and verified by experiments. Based on this model, the influence of bolt looseness number, wind strength and wind direction on the phase difference between the upper and lower flange plates is studied. The results show that the flange plate with certain bolt looseness ratio is at the top and bottom. The absolute value of the phase difference between the plates is obviously larger than that when the bolts are tightened. Therefore, the phase difference between the upper and lower flanges can be used as the basis for judging the looseness of the bolts in the tower flange.