Seismic performance of a wind turbine tower under near-field vertical earthquake excitation

For researching the influence of vertical component of near-field records on the seismic response of wind turbine towers, firstly, shaking table test of a 1/20 scaled 2.0 MW wind turbine is carried out. Second, the finite element (FE) model of the scaled tested model is established by ABAQUS. Finally, the dynamic stability is analysed based on the validated FE model. Moreover, the sensitivity of seismic response to different V/H ratios (peak vertical acceleration to horizontal acceleration) of near-field records is analysed through experimental and numerical studies. The results show that the near-field earthquakes have a greater effect on the acceleration and displacement response. The vertical acceleration, vertical displacement and the axial force of this tower are sensitive to the vertical ground motions and the V/H ratios. The larger contributions of vertical component of near-field ground motions lead to smaller safety factors, which is particularly more unfavourable for the dynamic stability of this tower. The middle and lower section of this tower is the dangerous position for local buckling. The influence of the near-field vertical ground motions and a reasonable value of V/H ratios should be better understood and studied, so as to provide guidance for structural seismic design.