Numerical validation of a finite element thin‐walled beam model of a composite wind turbine blade

Abstract

This paper presents a numerical validation of a thin‐walled beam (TWB) finite element (FE) model of a realistic wind turbine rotor blade. Based on the theory originally developed by Librescu et al. and later extended to suit FE modelling by Phuong, Lee and others, this computationally efficient yet accurate numerical model is capable of capturing most of the features found in large blades including thin‐walled hollow cross section with variable thickness along the section's contour, inner reinforcements, arbitrary material layup and non‐linear anisotropic fibre‐reinforced composites; the present application is, for the time being, restricted to linearity. This one‐dimensional (1D) FE model allows retaining information of different regions of the blade's shell and therefore approximates the behaviour of more complex three‐dimensional (3D) shell or solid FE models more accurately than typical 1D FE beam models. A 9.2 m rotor blade, previously reported in specialized literature, was chosen as a case study to validate the static and dynamic behaviour predicted by a TWB model against an industry‐standard 3D shell model built in a commercial software tool. Given the geometric and material complexities involved, an excellent agreement was found for static deformation curves, as well as a good prediction of the lowest frequency modes in terms of resonance frequencies, mode shapes and frequency response functions; the highest (sixth) frequency mode shows only a fair agreement as expected for an FE model. It is concluded that despite its simplicity, a TWB FE model is sufficiently accurate to serve as a design tool for the recursive analyses required during design and optimization stages of wind turbines using only readily available computational tools. Copyright © 2011 John Wiley & Sons, Ltd.

A model for the structural dynamic response of the CX‐100 wind turbine blade

“…To the authors’ knowledge, this paper presents the first structural dynamic model of the CX‐100 blade that employs cross‐sectional modeling in a geometrically exact framework. In fact, there are currently few examples of applying the VAM/GEBT approach to wind turbine blade modeling (with the noted exception of the work carried out by Cárdenas et al . and Hodges and Yu).…”

“…Yu and Blair introduced a geometrically nonlinear beam analysis tool (named GEBT ) to be used in combination with the two‐dimensional (2‐D) cross‐sectional analysis presented by Hodges. A similar blade modeling approach was used by Cárdenas et al . to analyze a conceptual 9 m wind turbine blade and compare static response and modal characteristics to a 3‐D FE model of the same blade.…”

Structural Optimization Design of Large Wind Turbine Blade considering Aeroelastic Effect

“…Theoretical analysis and numerical calculation modes of the blade in the different rotation speeds and material paving methods were carried out by Yin et al [4]. Cárdenas et al [5] presented a numerical validation of a thin-walled beam finite element model of a realistic wind turbine blade. Harte et al [6] established the coupling model of the wind turbine; then the modal was analyzed under different loads.…”

Aeroelastic validation and Bayesian updating of a downwind wind turbine

“…In the academic community, three‐dimensional (3‐D) Navier‐Stokes aerodynamic/aeroelastic simulations for wind turbines with structural details of the wind turbine such as tower and nacelle have been considered in only a few studies . Multiple investigations have been performed considering only the aerodynamics, while structural analysis of rotor blades with complex geometry and material compositions has also been considered . The aerodynamic computations have generally been performed with some limitations, for example, with a simplified structural representation.…”