Development and Validation of a Modal Analysis Code for Wind Turbine Blades

ABSTRACT QBlade is an open source wind turbine design and simula-tion tool developed at the Berlin Institute of Technology. To en-able a coupling with the aeroelastic simulation tool FAST fromNREL an aditional module, called QFEM, was created and in-tegrated with QBlade. This module performs a modal analysison rotor blades designed in QBlade using isotropic tapered Eu-ler Beam elements. The newly developed module now providesstructural properties to the National Renewable Energy Labo-ratorys aeroelasticity simulation tool FAST. The 2D structuralproperties of the beam elements are created using integrationmethods. A number of test cases show that the 2D integrationmethods and beam element code work with adaquete accuracy.The integration of the modal analysis code greatly facilitates thestructural design and analysis of rotor blades and will be madeavailable to the public under an open source license. NOMENCLATURE [EA] Longitudinal Stiffness[ES xR ] Moment of Stiffness about the x Ref. Axis[ES