Design, local structural stress, and global dynamic response analysis of a steel semi-submersible hull for a 10-MW floating wind turbine

Abstract

Platforms for floating wind turbines cannot be designed using conventional procedures like other offshore constructions. The design of floating wind turbine platforms must consider the significant nonlinearity of the fully coupled aero-hydro-servo-elastic dynamics, which necessitates a time-domain load transfer for structural stress analysis. This article presents and verifies an effective yet practical design method for floating wind turbine platforms, which can provide reasonable internal stress for design checks. A robust design process is proposed. Following the proposed method and procedure of a 10-MW wind turbine, a steel semi-submersible platform is developed with the criterion for the steel platform’s design checks, intact stability analysis, natural period analysis, and buckling analysis executed. A tangible concept is established, along with fully coupled numerical models of the 10-MW wind turbines supported on the steel structure. The dynamic behavior of the steel platform is evaluated by accessing and comparing the dynamic performances of the concrete- and steel-support wind turbine numerical models. The key findings and conclusions from the steel platform’s design and numerical study are summarized below. In addition, future design and analysis ideas are proposed, expanding the engineering practice and research on floating wind turbine platforms.