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Modal-based damage identification for the nonlinear model of modern wind turbine blade

Rezaei, M. M ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1016/j.renene.2016.03.074
  3. Publisher: Elsevier Ltd
  4. Abstract:
  5. In this paper, the modal-based indices are used in damage identification of the wind turbine blade. In contrast of many of previous researches, the geometric nonlinearity due to the large structural deformation of the modern wind turbines blade is considered. In the first step, the finite element model (FEM) of the rotating blade is solved to obtain the modal features of the deformed structure under operational aerodynamic loading. Next, the accuracy and efficiency of the various modal-based damage indices including the frequency, mode shape, curvature of mode shape, modal assurance, modal strain energy (MSE) and the difference of indices (between the intact and damaged blades) are investigated. To adapt the MSE index calculation in nonlinear modeling, a new approach is introduced to include the effects of the structural nonlinearity. Furthermore, the effect of the damage length, its location and severity and also the effect of rotational speed and amplitude of loading are studied. The generic 5-MW NREL blade is used for the simulation study. The results show enough sensitivity of the mode shape curvature and MSE indices to the local damages. Moreover, the importance of geometric nonlinearity in the damage detection of the modern wind turbines is demonstrated
  6. Keywords:
  7. Operational loading ; Damage detection ; Finite element method ; Geometry ; Nonlinear systems ; Strain energy ; Turbine components ; Turbomachine blades ; Wind turbines ; Damage Identification ; Geometric non-linearity ; Modal strain energy ; Modal-based indices ; Wind turbine blades ; Loading
  8. Source: Renewable Energy ; Volume 94 , 2016 , Pages 391-409 ; 09601481 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0960148116302580