Fatigue Life Evaluation of Wind Turbine Tower Based on Measured Data

Table 5

Annual total damage matrix based on maximum hourly damage [−log(D)].

Wind direction	Wind speed (m/s)									Dave
	0–3	3–5	5–7	7–9	9–11	11–13	13–15	15–17	17–19
N	5.92	5.75	3.99	3.81	3.54	3.37	3.57	4.27	7.91	4.68
NNE	4.64	3.88	4.19	4.40	3.84	3.92	4.47	8.42	5.01	4.75
ENE	3.84	4.00	5.02	4.54	4.75	5.60	4.70	4.70	4.83	4.66
E	5.19	5.70	5.26	4.97	5.51	—	—	—	—	5.33
ESE	5.54	4.83	3.56	3.80	4.27	5.28	—	—	—	4.55
SSE	5.50	5.25	4.56	4.72	4.96	4.46	5.55	—	—	5.00
S	5.78	4.62	4.21	4.34	4.40	4.14	4.92	4.70	—	4.64
SSW	6.15	4.45	4.34	4.02	3.92	4.17	4.86	5.31	—	4.65
WSW	5.36	5.30	4.01	4.27	4.25	4.05	4.24	4.35	4.83	4.52
W	6.20	4.82	4.06	4.19	4.10	4.40	4.23	4.83	—	4.60
WNW	5.99	3.86	4.58	3.99	3.97	4.38	4.61	—	—	4.48
NNW	5.87	3.93	3.51	3.25	3.32	3.48	3.95	4.46	—	3.97
Dave	5.50	4.70	4.27	4.19	4.24	4.29	4.51	5.13	5.64