Full scale testing of wind turbine blade to failure - flapwise loading

A 25m wind turbine blade was tested to failure when subjected to a flapwise load. With the test setup, it was possible to test the blade to failure at three different locations. The objective of these tests is to learn about how a wind turbine blade fails when exposed to a large flapwise load and how failures propagate. The report shows also results from ultra sonic scan of the surface of the blade and it is seen to be very useful for the detection of defects, especially in the layer between the skin laminate and the load carrying main spar. Acoustic emission was successfully used as sensor for the detection of damages in the blade during the test. The report contains measurements of the total deflection of the blade, the local deflection of the skin and the load carrying main spar and also measurement of strain all as a function of the applied load and up to failure of the blade. The “post mortem” analysis and description of how the damages propagate during the tests are reported in a separate report [2]. ISBN 87-550-3181-1 ISBN 87-550-3183-8(Internet) ISSN 0106-2840 Print: Pitney Bowes Management Services Denmark A/S