DAMAGE DETECTING METHOD FOR WINDMILL BLADE, AND WINDMILL

摘要

PROBLEM TO BE SOLVED: To provide a damage detecting method for windmill blades that keeps high accuracy even in an environment of fluctuating temperature.SOLUTION: A damage detecting method for windmill blades for a windmill rotor equipped with at least one windmill blade comprises a light incidence step at which light is brought to incidence on an optical fiber sensor fitted to each of the windmill blades and having a diffraction grating part whose refraction index periodically varies in the lengthwise direction, a light detection step at which reflected light from the diffraction grating part is detected, an acquisition step at which a wavelength variation indicator indicating the extent of variation of the wavelength of the reflected light detected at the light detection step is acquired from the wavelength variation over time, and a detection step at which the presence or absence of any damage to the windmill blade or blades is detected on the basis of the wavelength variation indicator calculated at the acquisition step.SELECTED DRAWING: Figure 1