Fatigue Testing of the Small Wind Turbine Blade

Abstract

Blades are the elements of a wind turbine which are the most vulnerable to destruction. Facing the unstable wind (one that changes its speed and direction), they are subjected to cyclic and fluctuating loads. This problem is particularly pronounced in case of small wind turbine (SWT) blades or blades for wind tunnel tests in scale, which are oftentimes made of anisotropic materials or manufactured in a way leading to anisotropy, like 3D-printing. SWT blades have to be designed in a way which will allow them to operate for a long time without any fracture. Hence, the fatigue strength is a key parameter, which determines their operation time and should be tested before putting a wind turbine into operation. The aim of this paper is to describe the methodology of fatigue tests of the small wind turbine blades. Next, the construction of the fatigue test stand and results of the experiment will be examined.