AUTHOR=Zou Tao , Niu Xinbo , Ji Xingda , Li Mingxin , Tao Longbin 

TITLE=The impact of initial imperfections on the fatigue assessment of tower flange connections in floating wind turbines: A review

JOURNAL=Frontiers in Marine Science

VOLUME=Volume 9 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2022.1063120

DOI=10.3389/fmars.2022.1063120

ISSN=2296-7745

ABSTRACT=During the massive manufactures and installations of fixed offshore wind turbines in China, initial imperfections in the tower flange connections were often found during inspection. As more and more attention and effort of the wind energy sector has been devoted to deep waters with fixed and floating wind turbines (FWTs), the impact of such initial imperfections on fatigue assessment is paramount to the reliable design and safe operation, which warrant rigorous study. This paper presents a comprehensive review of three different initial imperfections and their impact on the fatigue lifetime of FWTs’ tower flange connections. A brief introduction on FWTs and flange connections is provided at first. This is followed by a detailed discussion of the environmental loadings and fatigue assessment on the flange bolted connections. Finally, a comprehensive review of the state-of-art research on three common initial imperfections, including flatness divergence, bolt loosening and tower inclination, are presented. Their impact on fatigue assessment is further discussed.