Performance Assessment of a Steel Wind Turbine Tower Subjected to Repeated Earthquakes

Abstract

As the wind market grows rapidly and wind power plants are installed in high seismicity areas, there is the increased need for researchers and practitioners to assess the dynamic performance of Wind Turbine (WT) structures under extreme events. The present work is a preliminary attempt to quantify the performance of conventional steel WT towers under repeated earthquakes and enhance the understanding of their dynamic response. The case study is a 22 m high, 65 kW WT tower, assembled from cylindrical and conical steel sections of varying diameter and thickness. A simplified numerical model of the WT is developed in RUAUMOKO software program and subjected to five sequences of seismic events, available in the PEER strong motion database. The paper focuses on the effect of the multiplicity of earthquakes on critical response parameters, such as interstorey drift ratios and residual displacements. Incremental dynamic analyses provide estimates of the structural demand and capacity under single and multiple earthquakes of recurring periods. The findings show that repeated earthquakes significantly influence the seismic response of WT towers. Therefore, the consideration of sequences of main events and aftershocks is essential for the enhancement of the seismic resilience of WT towers. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.