In order to get a deeper understanding of the blade-to-blade variations and to determine the statistical distribution of the fatigue strength of rotor blades, 37 small rotor blades have been tested in static and fatigue loading. The blades are 3.4 m commercially available blades adapted to the needs of the project. In addition to these blade tests, coupons of the blade material have been tested. The tests have encompassed static flapwise bending tests, flapwise fatigue tests at two different sections of the blade, and edgewise fatigue tests. Since some blades could be re-used after a first test, a total number of 42 blade tests has been carried out in three different testing laboratories. The blades showed large deformation, development of creep and stiffness reduction. After correction for these phenomena, the fatigue strength of the blades was predicted very well by the classical Goodman relation using the well-known slope parameter of 10.

Technical Specifications IEC61400-23 Wind turbine generator systems, Part 23 Full-scale structural testing of rotor blades, Reference number IEC/TS 61400-23:2001(E).
Lindenburg, C., 1999, STABLAD, StaBility Analysis for Anisotropic rotor BLADe panels, ECN-CX-99-031, Petten, The Netherlands.
FOCUS4, 2001, The Integrated Wind Turbine Design Tool, Version 4.1E, TUDelft/WMC-Group, Delft, The Netherlands.
De Smet, B. J., and Bach, P. W., 1994, DATABASE FACT, FAtigue of Composites for Wind Turbines, ECN-C-94-045, Petten, The Netherlands.
Verbruggen, T. W., 1999, Analysis of fatigue data from FACT-database for materials relevant for PROFAR,, TEC99-03, Petten, The Netherlands.
Germanischer Lloyd, Rules and Regulations, Edition 1999, IV-Part 1, Non-Marine Technology, Regulation for the Certification of Wind Energy Conversion Systems.
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