Experimental and Numerical Seismic Response of a 65 kW Wind Turbine

A full-scale shake table test is conducted to assess the seismic response characteristics of a 23 m high wind turbine. Details of the experimental setup and the recorded dynamic response are presented. Based on the test results, two calibrated beam-column finite element models are developed and their characteristics compared. The first model consists of a vertical column of elements with a lumped mass at the top that accounts for the nacelle and the rotor. Additional beam-column elements are included in the second model to explicitly represent the geometric configuration of the nacelle and the rotor. For the tested turbine, the experimental and numerical results show that the beam-column models provide useful insights. Using this approach, the effect of first-mode viscous damping on seismic response is studied, with observed experimental values in the range of 0.5–1.0% and widely varying literature counterparts of 0.5–5.0%. Depending on the employed base seismic excitation, damping may have a significant influence, reinforcing the importance of more accurate assessments of this parameter in future studies. The experimental and modeling results also support earlier observations related to the significance of higher modes, particularly for the current generation of taller turbines. Finally, based on the outcomes of this study, a number of additional experimental research directions are discussed.