Wind farms are typically constructed in offshore areas using floating structures. However, such structures are difficult to maintain, sufficient fatigue life must be ensured during the design process. Therefore, techniques for determining the fatigue load on a floating structure in a marine environment and predicting its lifespan are required. This paper proposes a deterministic fatigue damage analysis method of semi-submersible platform for wind turbines using a hydrodynamic-structure interaction analysis. The process for calculating the fatigue load cycle consists of generating the waves in the time series using the JONSWAP spectrum from probabilistic wave scatter diagrams and decomposes them repeatedly into a number of individual regular waves. This process can simplify calculation of the fatigue load cycle by converting irregular dynamic wave load into a combination of static wave loads. The stress range for fatigue analysis is calculated through hydrodynamic structure interaction analysis. The stress ranges are applied to the S–N curves specified in the DNV-RP-C203 and cumulative fatigue damage is predicted using Miner’s rule. To detailed describe the proposed method, fatigue damage analysis was performed on the DeepCwind semi-submersible developed by the National Renewable Energy Laboratory based on the state of the western sea of Jeju Island, South Korea.

风电场通常使用浮动结构在近海区域建造。但此类结构维护难度大，在设计过程中必须保证足够的疲劳寿命。因此，需要确定海洋环境中浮动结构的疲劳载荷并预测其寿命的技术。本文提出了一种基于水动力-结构相互作用分析的风电机组半潜式平台确定性疲劳损伤分析方法。计算疲劳载荷周期的过程包括使用来自概率波散点图的 JONSWAP 谱在时间序列中生成波，并将它们反复分解为许多单独的规则波。该过程可以通过将不规则的动态波浪载荷转换为静态波浪载荷的组合来简化疲劳载荷循环的计算。疲劳分析的应力范围通过水动力结构相互作用分析计算。应力范围应用于 DNV-RP-C203 中指定的 S-N 曲线，并使用 Miner 规则预测累积疲劳损伤。为了详细描述所提出的方法，基于韩国济州岛西部海域的状况，对国家可再生能源实验室开发的 DeepCwind 半潜式潜艇进行了疲劳损伤分析。应力范围应用于 DNV-RP-C203 中指定的 S-N 曲线，并使用 Miner 规则预测累积疲劳损伤。为了详细描述所提出的方法，基于韩国济州岛西部海域的状况，对国家可再生能源实验室开发的 DeepCwind 半潜式潜艇进行了疲劳损伤分析。应力范围应用于 DNV-RP-C203 中指定的 S-N 曲线，并使用 Miner 规则预测累积疲劳损伤。为了详细描述所提出的方法，基于韩国济州岛西部海域的状况，对国家可再生能源实验室开发的 DeepCwind 半潜式潜艇进行了疲劳损伤分析。