Modal testing of a simplified wind turbine blade

Date
2012-07
Authors
Tartibu, LK
Kilfoil, M
Van Der Merwe, AJ
Supervisor
Item type
Journal Article
Degree name
Journal Title
Journal ISSN
Volume Title
Publisher
International Journal of Advances in Engineering & Technology (IJAET)
Abstract

This paper examines the modal analysis techniques applied in experiments using a uniform and a stepped beam. These simplified shapes are representative of the a wind turbine blade. Natural frequencies have been identified, therefore designers can ensure those natural frequencies will not be close to the frequency of the main excitation forces (1P or NbP with Nb being the number of rotor blades) in order to avoid resonance. The turbine blade is approximated by a cantilever, therefore, it is fully constrained where attached to a turbine shaft/hub. Flap-wise, edge-wise and torsional natural frequencies are calculated. The results found have been compared to numerical results and the exact solution of an Euler-Bernoulli beam. Concurrence is found for the frequency range of interest. Although, some discrepancies exist at higher frequencies (above 500 Hz), finite element analysis proves to be reliable for calculating natural frequencies.

Description
Keywords
Modal testing , Wind turbine , Natural frequencies , Finite element analysis , Euler Bernoulli beam
Source
International Journal of Advances in Engineering & Technology, vol.4(1), pp.649 - 660 (12)
DOI
Rights statement
IJAET is an Open Access journal.