Blatigue 2 – Sebastiaan van Putten on wind turbine blade testing

Can wind turbine blade testing be sped up? Yes, says Sebastiaan van Putten, development engineer at DTU Wind’s Large Scale Facility at Campus Risø. Certifying a long blade means bending it up and down one million times, at roughly one cycle per second. That adds up to about a year of testing, so every possible speed-up matters. In one of the final test campaigns in Blatigue-2, the DTU team is trying “segmented tests”. They cut the tip off the blade and attach a carbon spring underneath it. Combined with other project results, this could cut testing time from a year, depending on blade length, to a matter of months. That gets blades to market faster, but certainty matters as much as speed. The team has also studied “cross-talk”, converting measured strain into bending moments. They tested different calibration methods to produce valid cross-talk matrices, which is of interest to both industry and science. To check that the approach scales, the work runs at two sizes. DTU is testing a 12.6-metre blade cut down to about 9.5 metres, while partner Blaest tests a much larger blade with a considerably bigger spring. If the results match, Sebastiaan is confident the method can speed up testing of wind turbine blades and of any other structure that vibrates.