Monitoring of small wind turbine blade using FBG sensors

Dynamic behavior of a small wind turbine blade has been analyzed experimentally. Arrays of Fiber Bragg Grating (FBG) sensors and strain gauges were used to extract mode shapes of a small wind turbine blade made of fiber reinforced plastic (FRP). The root of the blade was fixed by a cantilever system developed for this study and dynamic strains from the sensors attached from the top and bottom surfaces of the blade were measured. The fundamental frequencies and higher modes of the blade cantilever system obtained from both sensors were almost identical. The mode shapes were also close but slightly different from each other. The differences are considered due to the fact that the top and bottom sections are non-symmetric.