Damgaard, Mads3; Andersen, Lars Vabbersgaard3; Ibsen, Lars Bo3
1 Division for Structures, Materials and Geotechnics, The Faculty of Engineering and Science, Aalborg University, VBN2 Department of Civil Engineering, The Faculty of Engineering and Science, Aalborg University, VBN3 The Faculty of Engineering and Science, Aalborg University, VBN4 Geotechnical Engineering, The Faculty of Engineering and Science, Aalborg University, VBN
Dynamic vibration response of a wind turbine structure is examined. Emphasis is put on the dynamic interaction between the foundation and the subsoil, since stiffness and energy dissipation of the substructure affect the dynamic response of the wind turbine. Based on a standard lumped-parameter model fitted to the frequency response of the ground, a surface foundation is implemented into the aeroelastic code FLEX5. In case of a horizontal stratum overlaying a homogeneous half-space and within the low frequency range, analyses show that a standard lumped-parametermodel provides an accurate prediction of the frequency dependent foundation stiffness. The generalized stiffness matrix of the substructure is found to be in a reasonable agreement with the corresponding values based on a Guyan reduction scheme. In addition, experimental findings based on traditional and operational modal techniques on a Vestas V112-3.3MWwind turbine installed on drained soil clearly indicate that the energy dissipation related to the lowest eigenmode is described accurately in the aeroelastic simulation.