Fatigue Life Evaluation of Wind Turbine Tower Based on Measured Data

Table 3

Damage matrix corresponding to 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	8.14	8.14	6.45	6.22	5.76	5.40	5.25	5.47	8.55	6.60
NNE	6.87	6.13	6.29	6.29	5.76	5.57	5.64	9.26	5.25	6.34
ENE	5.93	6.03	6.92	6.14	6.11	6.14	5.25	5.25	5.25	5.89
E	7.19	7.53	6.61	6.09	6.05	5.64	5.49	—	—	6.37
ESE	7.63	6.95	5.25	5.25	5.25	5.82	—	—	—	6.03
SSE	7.76	7.60	6.46	5.96	6.18	5.25	5.49	—	—	6.39
S	8.05	7.04	6.46	6.37	6.05	5.69	5.57	5.25	—	6.31
SSW	8.56	6.90	6.79	6.19	5.67	5.49	5.70	5.25	—	6.32
WSW	7.73	7.50	6.29	6.34	6.07	5.53	5.50	5.25	5.25	6.16
W	8.56	7.05	6.28	6.24	5.73	5.52	5.25	5.25	—	6.23
WNW	8.21	6.15	6.89	5.85	5.43	5.33	5.25	—	—	6.16
NNW	8.08	6.30	5.99	5.59	5.54	5.31	5.25	5.25	—	5.91
Dave	7.73	6.94	6.39	6.04	5.80	5.56	5.42	5.78	6.08