Modal Analysis for Crack Detection in Small Wind Turbine Blades

Abstract

The aim of the present paper is to evaluate structural health monitoring (SHM) techniques based on modal analysis for crack detection in small wind turbine blades. A finite element (FE) model calibrated to measured modal parameters will be introduced to cracks with different sizes along one edge of the blade. Changes in modal parameters from the FE model are compared with data obtained from experimental tests. These comparisons will be used to validate the FE model and subsequently discuss the usability of SHM techniques based on modal parameters for condition monitoring of wind turbine blades.

Optimal Design and Operational Monitoring of Wind Turbine Blades

“…divergence between the centre of geometry and centre of mass) [4]. Of the unbalanced parameters, [5][6][7] note that natural frequencies may comparatively be less prone to error than others unbalanced parameters like mode shapes and modal damping. They thus provide a ready application in using it for structural health monitoring (SHM) of the WT blades [8] both during design and operation.…”

Numerical and experimental analysis of a segmented wind turbine blade under assembling load effects

“…The most common method to measure vibration is to attach accelerometers to the blade and tap it with a hammer or excite it with a mechanical shaker. Experimental modal analysis of a 19.1 meter wind turbine blade was established by Larsen et al (2002) to determine the blade natural frequencies, damping and mode shapes. It was also stated that there was a good agreement between the obtained results from the experimental work and those obtained by the FEM analysis.…”

Modal analysis of micro wind turbine blade using COSMOSWorks

“…Micro wind turbines are usually referring to the ones that the rated power is less than 1 kW and the rated voltage range is between 12 V and 48 V [6]. They have low requirements for wind energy resources and owning the advantages of compact structure and convenient installation.…”