mpeti . One w arger w ost per rated uare o creases ws tha increa nd tur
decreasing the mass can have a signiﬁcant effect by reducing the
sites wich have
Contents lists available at SciVerse ScienceDirect
Thin-Walled Structures 67 (2013) 144-154
aim of this study is to investigate alternative structuralE-mail address: email@example.com (N. Buckney).
material demands, and thereby cost of the nacelle, tower, and 1.3. Aims and objectives
For all of the aforementioned reasons, there is a clear need to improve the structural efﬁciency of wind turbine blades, so the
0263-8231/$ - see front matter & 2013 Elsevier Ltd. All rights reserved.
n Corresponding author. Tel.: þ44 117 33 15514.
ﬁt the entire wind turbine through decreased mass-induced loads. Indeed, the cost of the rotor may represent 20% of the total, but
become widely used for their ability to provide high bending stiffness, strength and buckling resistance (per unit weight) .
remained largely unchanged. Larger blades are also more efﬁcient from manufacturing and
ﬁnancial viewpoints. Furthermore, lightweight designs can bene-
buckling phenomena. The caps are often thick hybrid compo of carbon and glass ﬁber, whereas the webs are often sand panels which typically carry shear forces. Sandwich panels
through improved design methodology, the blade mass of current turbines has been found to be growing at an average exponent of 2.3 as opposed to 3 . Despite this limited efﬁciency gain, as wind turbines have grown in size, the loads due to self-weight have become increasingly inﬂuential. Yet, the basic topology has
beam . The skins form the aerodynamic proﬁle of the blade. Typically, they are constructed from sandwich panels to resist buckling and are bonded at the leading and trailing edges. The spar provides the stiffness and strength requirements of the blade, performing as a beam while simultaneously resisting
1.1. Wind energy
In order for wind energy to be co important that its cost is minimized continue the present trend toward l as their rated power increases, the c happens because the power gene theoretically proportional to the sq the other hand, the blade mass in length . This square-cube law sho faster than the energy output as size speculation of a size limit for wi
tive in the market, it is ay to achieve this is to ind turbines, because, kW decreases . This by a wind turbine is f the blade length. On with the cube of the
t the blade mass grows ses, and is the basis for bines [2,3]. In reality,
becomes more important to increase structural efﬁciency. It is thought that the current blade topology may have reached
maturity and that without major changes there will be no signiﬁcant weight and cost reduction . By improving the structural efﬁciency of the...