The use of strain sensors for modal identification of aeroelastic structures

Kurzfassung

Acceleration measurements are most commonly employed to determine mode shapes by modal identification. There are two simple reasons for this: an acceleration sensor is easy to apply and deflection mode shapes can directly be estimated from acceleration signals by experimental or operational modal analysis techniques. In the past strain gauges have played a minor role in modal identification because they were of single use and more difficult to apply. Another drawback is that strain modes need to be converted into deflection modes. Nevertheless there are applications where strain measurements show better performance than acceleration measurements if rotating structures are considered. Recent progress in strain measurement technology with fiber optical strain sensors offering spatially nearly continuous measurements up to more than 100Hz of sampling rate raise the interest for aeroelastic applications. This study will analyze the use of strain sensors for aeroelastic applications.