Nonlinear seismic response and damage mechanism of jacket-supported offshore wind turbines considering soil-structure interaction

The quest for clean, renewable energy resources has given a global rise in offshore wind turbine (OWT) construction. As OWTs are more exposed to harsh environmental conditions, the dynamic behavior of OWTs with jacket support structures under critical loading scenarios is crucial yet least understood, which becomes more convoluted with the consideration of soil-structure interaction (SSI) effects. In addition, the seismic characteristics of such systems heavily depend on the excitation characteristics like frequency content, a feature that is still ambiguous. This research aims to examine the influence of seismic frequency contents on the dynamic characteristics and damage modes of jacket-supported OWT systems including SSI effects. The numerical model is established and validated based on a previous study, which ensures the accuracy of the numerical modeling framework. Upon validation, extensive numerical analyses are performed under earthquakes with varying frequency contents. Results reveal the relationship among the ground motion frequency, SSI, and the dynamic and damage behavior of jacket-supported OWTs, offering important insights for the improved seismic design and analysis of jacket-supported OWTs.