Modal analysis of a wind turbine tower by digital image correlation

Abstract

Operational Modal Analysis is a method widely used in the wind industry to characterize structures and perform structural health monitoring or numerical model calibration. To reach this goal, optical techniques are becoming appealing because of their non-intrusiveness and their full-field feature in contrast to sensor-based methods. An innovative method is proposed herein for modal measurement with a single camera via Digital Image Correlation. The first resonance frequency of the tower is well captured from images of a shut down turbine.