Last updated: 5 November 2023

Methodologies planned for the characterisation of the novel material solutions developed in the NEMMO project were presented, including testing for the study of the fatigue and impact resistance of nano-enhanced materials, the anti-fouling performance and cavitation resistance of anti-fouling materials and the fatigue testing of composite blade elements and the full blades.

The behaviour of bonded joints was characterised using the single lap shear test to identify the best performing resin from the candidate formulations. Fracture and fatigue testing of the best performing material is addressed focussing on the two major failure modes: delamination of composites and debonding of adhesive joints. A characterisation of the loading modes was covered for both failure modes relying on statistical approach. The best performing candidate material will be integrated into the final design. A full-scale blade prototype will be built and tested to compare the new blade behaviour against test results with the current blade.

From the ageing point of view, the three materials tested presented outstanding behaviour, such good that it wasn’t possible to characterise properly the effect of possible damages due to the interaction with water, nor define an acceleration factor for the accelerated ageing test. In addition, the fouling removal appeared to be a real challenge that couldn’t be solved in the frame of the NEMMO project. Overall, the material s076 seemed to have the best behaviour, followed by the material s096 and the s025. From the fouling evolution in quasi-static conditions after a long time of immersion in real seawater, all the surface finishing seemed to present similar behaviour without significant difference. Nevertheless, this condition is not representative of most of the part and operational conditions of the tidal turbine.

(Deliverable D4.5 is not available for public download. )