Structural Analyses of Fixed Offshore Wind Turbine Jacket-Type Support Structure

Resumo

This work aims to study a steel jacket supporting a 10 MW offshore wind turbine (OWT) in a 40 m
water depth on the Northeastern Brazilian Coast. In order to do so, various structural analyses were carried out.
First, the system’s natural frequencies were evaluated, and stresses caused by local environmental loads of wind,
waves, and currents were assessed. GeniE was responsible for calculating the utilization ratio of the jacket’s
elements under extreme loads. The jacket foundations, composed of piles on sandy soil, were also analyzed in

GeniE, highlighting the representation of soil-foundation interaction and the soil load capacity according to API-
RP-2A-WSD. SIMA-RIFLEX performed fatigue analysis through the Rainflow Counting method associated with

an S-N curve to assess fatigue damage, which is pivotal for the project. Different wind turbulence intensities were
investigated as this factor proved to influence the structure’s lifetime greatly. A final adjustment was made to the
jacket cross-section, after the analyses, in order to guarantee its structural integrity.