Determining the structural response of composite horizontal axis wind turbine blades to wind loading is a challenging aeroelastic problem due to the coupling of unsteady aerodynamics and anisotropic structural dynamics. Methods such as Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) are readily available through respected commercial software such as ANSYS, but are found to be unsuitable for the preliminary design phase in which many simulations are to be run, due to high computational time. A more efficient algorithm has been developed using a panel method for determining the unsteady aerodynamic blade loading, an anisotropic beam dynamics solver based on the Variational Asymptotic Beam Section (VABS) analysis tool developed by Khouli (2009) and the Ritz method, and the Blade Element Momentum Theory (BEMT).The algorithm was implemented in MATLAB and validated by comparing the results with coupled two-way Fluid-Structure Interaction (FSI) simulations performed using ANSYS Workbench 14. Strong agreement was found between the algorithm results and the corresponding ANSYS simulations. Impressively, the algorithm achieved computational times of less than 2% of the ANSYS simulations. The algorithm is considered a success and has been found to be suitable for use in the preliminary design phase of horizontal axis wind turbines and other flexible, lightweight structures.ii Acknowledgments I would like to thank my thesis co-supervisors: Professors Robert (The Eagle) G.Langlois, master of peer-reviewing, and Fred. F. Afagh, the king of troubleshooting, for their excellent support during this project. I would also like to thank my colleague, Mohamed El Sherif, who always supplied motivating tunes and helped us retain our sanity during the CFD simulations.iii