Structural Analysis of Wind-Turbine Blades by a Generalized Timoshenko Beam Model

Abstract

An important aspect in wind-turbine technology nowadays is to reduce the uncertainties related to blade dynamics by the improvement of the quality of numerical simulations of the fluid-structure interaction process. A fundamental step in that direction is the implementation of structural models capable of capturing the complex features of innovative prototype blades, so that they can be tested at realistic full-scale conditions with a reasonable computational cost. To this end, we developed a code based on a modified implementation of the variational-asymptotic beam sectional (VABS) technique proposed by Hodges et al. VABS has the capacity of reducing the geometrical complexity of the blade section into a stiffness matrix for an equivalent beam, allowing accurate modeling of the 3D structure of the blade as a 1D finite-element problem. In this paper, we report some recent results we have obtained by applying our code to full-scale composite laminate wind-turbine blades, analyzing the fundamental vibrational modes and the stress load in normal operational conditions.