A novel analytical beam formulation and its application on composite wind turbine blades

This paper presents a novel analytical formulation for modelling the mechanics of non-uniform and asymmetrical straight beams made of functionally graded materials (FGMs) and composites. This approach addresses the complexities caused by the asymmetry of the cross-section and those arising from the variations in geometry and material properties along the beam's axis by approximating these variations as stepped changes. It is assumed that each segment of the beam has constant properties, which are determined through the averaging of functions representing the actual property variations. This method enables efficient and accurate modelling/representation of beam structures such as wind turbine blades. The accuracy and reliability of the analytical model are verified through a comparison with the Technical University of Denmark (DTU) 10 MW reference wind turbine blade, considering two representative load cases (bending, BLC1 and torsional, BLC2) and confirming its ability to accurately predict the structural response. Furthermore, the study assesses the computational performance of the model, demonstrating its efficiency. This study contributes to the literature by providing a robust and computationally efficient approach for the analysis of wind turbine blades.