Considerations Concerning the Mechanical Strength of Wind Turbine Blades made of Fiberglass Reinforced Polyester

The paper shows and analyzes the results of some researches on a plastic composite material as fiberglass reinforced polyester (FGRP) that is considered for being used for manufacturing the blades of small power wind turbines, such is the 5 kW wind turbine from Ciugud site in Alba County, Romania. During their operation the wind turbine blades are continuously subject to variable loadings developed by the stochastic and uncontrollable wind flow. Consequently has been performed mechanical strength researches done on a real blade, as well as, by lab testing on test specimens sampled from the original material of one blade tested at SC CLAGI Srl Company. The results of this research work came to confirm the quality of the FGRP used for blade fabrication, as well as, its capacity to bear well the loads and implicitly the structural stresses produced by the wind upon the wind turbine blades, although a metallic reinforcement included within the inner part enhances the whole mechanical strength of the blade structure.