Using Modal Analysis for Detecting Cracks in Wind Turbine Blades

The structural integrity of blades is critical to the continued operation of a wind turbine. Resonant or modal properties of a mechanical structure are directly influenced by its physical properties. So any change in the physical properties of a structure should cause a change in its modal parameters. In this article, we present test results from a wind turbine blade with different induced cracks. Each result shows that some of the modes of the blade are significantly affected by a crack and that the modal parameters change more significantly with a more severe crack.