New investigation of mechanical properties of a horizontal axis wind turbine blade based on a hybrid composites with kenaf fibers

Abstract

The present work aims to assess the benefit of introducing simultaneously kenaf and carbon fibers in a composite wind turbine blade made initially of epoxy glass fiber. After an in-depth analysis of the optimal design of the blade using the Blade Element Momentum theory, an algorithm is generated in order to, firstly, establish the foundation of the blade geometry and secondly, to make a conservative static loading estimation representing a 50-years extreme gust. After performing the blade geometry on the 3D-modeler CATIA® V5, it was imported to PATRAN® software in order to create the mesh of the turbine blade. By modifying the way of stacking layups at each zone of the blade and by taking into account the plies properties, seven models were created. A further comparison was made between these models with a view of finding the best combination of fibers to satisfy the allowable thresholds. After several attempts of fibers combinations, it was finally revealed that the best way to combine the three fibers consists of replacing all unidirectional glass fibers of the blade skin with kenaf fibers and substituting those of the spar cap with carbon fibers while maintaining intact the remaining blade layups.