Structural design of carbon/epoxy bio-inspired wind turbine blade using fluid/structure simulation Mariana Correa-Álvarez, Valentina Villada-Quiceno, Julián Sierra-Pérez * ,† , Juan Guillermo García-Navarro and César Nieto-Londoño Grupo de Investigación en Ingeniería Aeroespacial, Universidad Pontificia Bolivariana, Campus de Laureles Circular 1 N 70-01, Medellín, Colombia SUMMARY The purpose of this paper is to present the structural design procedure of a low-speed, horizontal axis, bio-inspired wind turbine blade made of carbon/epoxy. The methodology initiates with the mechanical characterization of the carbon fiber composite material. An aerodynamic simulation using Computational Fluid Dynamics (CFD) method is performed in order to obtain the pressure distribution profile of the blade. This result is coupled with a Finite Element Analysis (FEA) to carry out an iterative design process through a Fluid-Structure Interaction (FSI) simulation. Different stacking sequences of laminates are evaluated to find a configuration which allows balance between aerody- namic and dynamic inertial loads, ensuring an almost undeformed geometry during wind turbine’s operation. The final structural design of the blade consists in six regions with different laminates. These are balanced and symmetric with dis- tinct thickness characteristics and stacking sequences, which vary in three different orientations: 0 ∘ , ± 45 ∘ and 90 ∘ , achieving a minimum deflection at the tip close to 3.11 cm, and a total weight of 3.6 kg of a 1.8 m radius blade, even with the restric- tions imposed by the non-conventional geometry. Copyright © 2016 John Wiley & Sons, Ltd. KEY WORDS aerodynamic loads; bio-inspired; composite materials; fluid–structure interaction; structural design; wind turbine blade Correspondence *Julián Sierra-Pérez, Grupo de Investigación en Ingeniería Aeroespacial, Universidad Pontificia Bolivariana, Campus de Laureles Circu- lar 1 N 70-01, Medellín, Colombia. † E-mail: julian.sierra@upb.edu.co Received 15 February 2016; Revised 23 April 2016; Accepted 25 April 2016 1. INTRODUCTION The development of renewable energies has acquired great importance across the world because of the interest of many agents in alternative ways of sustainable and clean energy’s generation. Eolic industry picks up the most at- tention from enterprises, accounting around the half of clean energy produced and expected to grow 25% each year [1,2]. Most of it is produced through wind turbines, which transforms the kinetic energy from the wind into electricity, avoiding polluting gases emissions to the envi- ronment produced by non-renewable resources [3]. With the enormous increase in energy requirements, wind turbine’s production has expanded too. By the end of 2014, nearly 268000 of these devices were running around the world, supplying 3% of global electricity [4]. A wind turbine can recover the energy spent in its production, operation and recycling in a period from three (3) to six (6) months, offering a 20 to 25-year lifetime [4,5]. Because of the facts exposed, wind turbines have been investigated in several research activities conductive to create and improve designs, aerodynamic and performance characteristics according to its operational conditions, toward efficiency’s and power output’s maximization. Bio-inspired designs help to innovate this area of study by improving energy production, storage or delivery, replicating nature designs, commonly from marine creatures, flowers and plants [6]. Composite materials are used in customized designs and applications where high strength to weight ratios and high modulus to weight ratios are needed [7]. Wind turbine’s struc- tural requirements can be successfully fulfilled with this kind of materials, making of composites a leading provider for this expanding industry at commercial costs [8]. Its anisotropic character provides both benefits and drawbacks that must be evaluated in order to make a proper selection. However, for a wind turbine blade, this decision cannot be made without having into account the operational loads (both aerodynamic and dynamic inertial) to which the component will be subjected, reason by which it is necessary to study the effects of wind and inertial forces on a composite structure. INTERNATIONAL JOURNAL OF ENERGY RESEARCH Int. J. Energy Res. (2016) Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/er.3564 Copyright © 2016 John Wiley & Sons, Ltd.