Investigation of the Measurability of Selected Damage to Supporting Structures of Wind Turbines

The present work deals with a measurability study of damage to supporting structures of wind turbines. The examined hybrid tower consists of a prestressed concrete part with an attached steel section on top. Principal focus is on developing a data preprocessing and analysis concept aiming to investigate the measurability of the two selected failure cases missing pretension of tendons and fatigue based change of Young's modulus in reinforcement concrete. A simulation deduced out of real world mass and thrust forces provides a comparison with measured data based tower displacements, natural frequencies and mode shapes. The measurability of given deviations is investigated by means of virtual sensors, derived from the measurement setup of a test facility measuring acceleration, velocity, displacement and strain on different positions of the wind turbine tower, aiming the development of detection methods of such cases of damage for condition monitoring systems. The simulation input can be given by strain-based external forces or vibration-based displacements.