Fatigue Life Evaluation of Wind Turbine Tower Based on Measured Data

Table 2

Stress concentration factor .

Extrapolation method	Normal operating condition		Extreme load condition
	(MPa)		(MPa)
Fixed-point method	78.42	1.25	168.25	1.21
Linear extrapolation method	70.52	1.12	150.65	1.08
Quadratic extrapolation method	69.75	1.11	149.07	1.07