WISPER and WISPERX Final definition of two standardised fatigue loading sequences for wind turbine blades

WISPER and WISPERX are standardised variable-amplitude test loading histories for use in the fatigue design of horizontal axis wind turbine blades. They are based on flap load service measurements on 9 different horizontal axis wind turbines, covering a wide range of materials, rotor diameters and geographical locations. The present report is the third and final publication on the development work by the WISPER working group and is a compilation of all relevant information that was used to establish WISPER and WISPERX. It gives backgrounds, describes basic data and associated data handling procedures and presents quantitative data analysis results and statistical information on both standards. The information is this document will enable fatigue specialists to judge whether the standard will suit their test objectives and to check for correct application of the load sequences on their test equipment