Thin-Walled Structures 67 (2013) 144–154

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Thin-Walled Structures
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Structural efficiency of a wind turbine blade
Neil Buckney n, Alberto Pirrera, Steven D. Green, Paul M. Weaver
Advanced Composite Centre for Innovation and Science (ACCIS), Department of Aerospace Engineering, University Walk, Bristol BS8 1TR, UK

a r t i c l e i n f o
Article history: Received 6 August 2012 Received in revised form 12 December 2012 Accepted 8 February 2013 Available online 28 March 2013 Keywords: Wind turbine blade Topology optimization Structural efficiency Shape factors

a b s t r a c t
Alternative structural layouts for wind turbine blades are investigated with the aim of improving their design, minimizing weight and reducing the cost of wind energy. New concepts were identified using topology optimization techniques on a 45 m wind turbine blade. Additionally, non-dimensional structural shape factors were developed for non-symmetric sections under biaxial bending to evaluate structural concepts in terms of ability to maximize stiffness and minimize stress. The topology optimization evolves a structure which transforms along the length of the blade, changing from a design with spar caps at the maximum thickness and a trailing edge mass, to a design with offset spar caps toward the tip. The shape factors indicate that the trailing edge reinforcement and the offset spar cap topology are both more efficient at maximizing stiffness and minimizing stress. In summary, an alternative structural layout for a wind turbine blade has been found and structural shape factors have been developed, which can quantitatively assess the structural efficiency under asymmetric bending. & 2013 Elsevier Ltd. All rights reserved.

1. Introduction 1.1. Wind energy In order for wind energy to be competitive in the market, it is important that its cost is minimized. One way to achieve this is to...