Successful fatigue testing of blade torsion box in Reliable2-NL
Within the Reliable2-NL project, a major milestone has been achieved: the successful fatigue testing of a 4-metre torsion box, representing the primary internal structure of a wind turbine blade.
Bridging the gap in structural testing The torsion box, manufactured by Suzlon, was tested under fatigue loading at TU Delft using its 350-tonne fatigue testing machine. These tests provide critical insights at the structural component level, effectively bridging the gap between coupon-scale and full-scale testing.
This intermediate level of testing plays a key role in improving the accuracy of damage prediction models for wind turbine blades, contributing to more reliable and cost-effective designs.
Advanced monitoring techniques During the tests, continuous strain measurements were captured using strain gauges and advanced fibre optic measurement systems supplied by Fibersail. These systems not only measured strains, but also identified loads, deflections, and local hotspots within the structure.
In addition, Digital Image Correlation (DIC), visual imaging, and thermal imaging were deployed to monitor the behaviour of the torsion box. These systems were triggered every thousand cycles, as well as by significant acoustic events, enabling detailed observation of damage initiation and growth.
The combination of trigger mechanisms and pre-trigger recordings allows researchers to effectively “capture” structural damage as it develops in real time.
This project is a collaboration of the following partners: Shell, TNO, Delft University of Technology, Fibersail, Suzlon Group, and Tarucca, and strong international alignment with the wider ReliaBlade2 programme.
Curious to find out more about this project have a look at and listen to this episode of GROW to GO about Reliable2-NL.
