Abstract:
To quantify the impact of near-field earthquakes (NFE) with velocity pulses and vertical acceleration effects on the seismic response of wind turbine tower (WTT), a finite element model (FEM) of a 2MW WTT is established firstly, and the accuracy of the calculation results obtained by using the model was verified through a comparison with experimental data from shaking table tests. Then, the effects of velocity pulses with different formation mechanisms on the acceleration response, on the displacement response, and on the foundation internal forces of WTT were studied under 30 typical measured NFE (near field earthquake), and the spectral analysis of NFE was conducted. Finally, the influence of vertical component on structural dynamic response was analyzed through 7 NFE with significant V/H ratios, and 10 sets of V/H ratios (V/H ratios of 0.0, 0.2, 0.4, 0.6, 0.8, 1.2, 1.4, 1.6, 1.8, 2.0) were selected to further study the sensitivity of WTT to V/H ratios. The research result has shown that NFE has unique spectral characteristics, leading to a significant impact on WTT. The average value of structural dynamic responses under NFE with velocity pulses is more than 1.5 times than that under NFE without pulses. The vertical component of NFE has a significant amplification effect on both the vertical response and axial force, and the vertical dynamic response approximately increases linearly with the increase of V/H ratio. Therefore, when conducting aseismic design of WTT in areas near fault zones, the influence of NFE should be considered.