Operational Modal Analysis and Wavelet Transformation for Damage Identification in Wind Turbine Blades

Martin Dalgaard Ulriksen, Dmitri Tcherniak, Poul Henning Kirkegaard, Lars Damkilde

Research output: Contribution to journalConference article in JournalResearchpeer-review


This study demonstrates an application of a previously proposed modal and wavelet analysis-based damage identification method to a wind turbine blade. A trailing edge debonding was introduced to an SSP 34-m blade mounted on a test rig. Operational modal analysis was conducted to obtain mode shapes for undamaged and damaged states of the blade. Subsequently, the mode shapes were analyzed with one-dimensional continuous wavelet transformations for damage identification. The basic idea of the method is that structural damage will introduce local mode shape irregularities which are captured in the continuous wavelet transformation by significantly magnified transform coefficients, thus providing combined damage detection, localization, and size assessment. It was found that due to the nature of the proposed method, the value of the identification results highly depends on the number of employed measurement points. Since a limited number of measurement points were utilized in the experiments, only certain damage-sensitive modes, in which pronounced damage-induced mode shape changes occur, are applicable for valid identification of the damage.
Original languageEnglish
Article number1475921715586623
JournalStructural Health Monitoring
Issue number4, Special Issue
Pages (from-to)381-388
Number of pages8
Publication statusPublished - 2016
Event7th European Workshop on Structural Health Monitoring - Nantes, France
Duration: 8 Jul 201411 Jul 2014
Conference number: 7


Conference7th European Workshop on Structural Health Monitoring



  • Wind turbine blades
  • Structural health monitoring
  • Debonding
  • Wavelet transformation
  • Operational modal analysis

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