Optimal blades R & D project

In its quest to increase the durability of wind turbine blades, the University of Patras in Greece applied its expertise to defining a rigorous testing protocol for new WT models. In the framework of the 'Optimat blades'R & D project, which brings together more than 15 partners from both northern and southern Europe, new blade materials were created, but to determine how well they would hold up over time, it was necessary to repro duce the complex stresses and strains in the laboratory.

Mechanical engineers with the University of Patras employed finite element methods (FEM) to assess the new rotor blades. An extensive battery of tests, some based on ISO standards, provided insight into material properties. For instance, shear strength and elasticity were measured under different operating conditions, including both static and cyclic loading.

In this way, the Greek engineers identified which tests could be considered representative. With respect to the all important case of blade failure, they concluded that a simple one-dimensional computational approach could be applied as long as the effect of the different layers is accounted for. All test data were gathered into a central database. Extrapolating from the results, the University of Patras was able to provide specific design recommendations to the 'Optimat blades' consortium to extend blade life.

(Source Cordis Focus http://cordis.europa.eu/news/focus )

.