Structural Design and Finite Element Analysis of Composite Wind Turbine Blade

Abstract

This paper presents structural studies of a medium scale composite wind turbine blade construction made of epoxy glass fiber for a 750kW rated power stall regulated horizontal axis wind turbine system. The complex geometry of the blade with a skin-spar foam sandwich structure was generated by utilizing commercial code ANSYS finite element package. Dimensions of twist, chord and thickness were developed by computer program. NREL S-series airfoils with different chord thickness are used along current blade cross-sections. The current design method uses blade element momentum (BEM) theory to complete satisfactory blade design and can be carried out using a spreadsheet, lift and drag curves for the chosen aerofoil. According to composite laminate theory and finite element method, optimal blade design was obtained. The focus is on the structural static strength of wind turbine blades loaded in flap-wise direction and methods for optimizing the blade cross-section to improve structural reliability. Moreover, the natural frequencies and modal shapes of the rotor blade were calculated for defining dynamic characteristics. Structural analysis was performed by using the finite element method in order to evaluate and confirm the blade to be sound and stable under various load conditions.

Computational analysis and material selection in cross-section of a composite wind turbine blade

“…A future research with 3D brick elements and dynamic loads has to be considered in order to analyze further the behavior of the blade box girder under flap-wise loading and to compare the results for the stress and stain fields with competing approaches. 26–30 On the other hand, a very interesting topic would be the use of sandwich materials in the spar caps of the box girder.…”

“…The subject of materials selection and computational analysis for a WTB is a currently developed research area, [3][4][5][6][7][8]16,17,29 emphasizing on finite element analysis (FEA) modeling and simulation 12,[26][27][28][29][30] with the intention to investigate the behavior of WTB due to different possible loadings. In addition, some investigations deal with the very interesting subject of fatigue life and failure prediction of the blade 4,19 combined with the numerical simulation 12,19,20,26,27 and the guidelines for design.…”

“…In addition, some investigations deal with the very interesting subject of fatigue life and failure prediction of the blade 4,19 combined with the numerical simulation 12,19,20,26,27 and the guidelines for design. [22][23][24]29 Remarkable results also come from studies concerning experimental full-scale tests. 19,23,24 The main objective of this study is to further advance the use of computer-aided engineering methods and tools (e.g.…”