Deterministic deterioration modeling of wind turbines toward the failure identification – a modal curvature approach

ABSTRACT The amount of built wind resource has greatly increased since wind turbines have started to get installed offshore in order to power much of the world. Topics relating to wind turbine have encouraged researchers to put in greater efforts towards developing modeling methodologies, analytical theories, assessment techniques. Through the establishment of certain models and new findings, potential ideas regarding structural health monitoring and non-destructive evaluations may be proposed and worthy of exploration. Based on the spectral formulation of a Timoshenko member with the consideration of soil–structure interaction, the simulated model of a wind turbine was investigated in this work in order to quantify the various effects due to defects as well as foundation stiffness on the dynamic responses of the tower. This paper focuses on the analysis of the tower structure using the modal curvature data of the first vibration mode. Preliminary results show that the curvature index defined in the proposed method is capable of indicating not only the damaged region of the tower, but also the degree of stiffness softening that the foundation system may have encountered. The presented methodology demonstrates potential as a feasible analysis method to be applied in a vibration-based assessment scheme for the wind turbine tower.