Abstract The Powell's method was developed to determine the optimal stiffness and damping of multi-tuned mass dampers (MTMD) in offshore wind turbine (OWT) support structures under fatigue loads. Numerical examples indicated that the Powell's method results are always better than those using MTMD formulations. With the exception of the blade passing (3P) frequency, it was found in this work that a positive integer (n) multiple of the 3P frequency will also result in a large wind-induced vibration, which can be excited by the frequency of the first structural vertical rotation mode and will cause significant fatigue damage. The first translation mode TMD installed at the tower top is efficient to increase fatigue life at the tower and brace connections, but it cannot reduce fatigue damage at the column and brace connections below the platform. The second translation mode TMD can reduce fatigue damage resulting from large wave loads and thus increase the fatigue life of the braces and columns. The mode-3 TMD with a reduction in the 3(3P) vertical rotation can effectively increase the fatigue life of the braces and columns. Thus, the appropriate use of these TMDs can be effective for the fatigue problem of OWT support structures.

中文翻译：

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MTMD 使用鲍威尔方法增加 OWT 导管架结构的疲劳寿命

摘要 鲍威尔方法被开发用于确定疲劳载荷下海上风力涡轮机 (OWT) 支撑结构中多调谐质量阻尼器 (MTMD) 的最佳刚度和阻尼。数值例子表明，鲍威尔方法的结果总是优于使用 MTMD 公式的结果。除了叶片通过（3P）频率外，在这项工作中发现，3P频率的正整数（n）倍也会产生很大的风致振动，这种振动可以由频率的频率激发第一种结构垂直旋转模式，会造成显着的疲劳损伤。安装在塔顶的第一种平移模式 TMD 可有效增加塔和支撑连接处的疲劳寿命，但它不能减少平台下方立柱和支撑连接处的疲劳损坏。第二种平移模式TMD可以减少大波浪载荷引起的疲劳损伤，从而提高支撑和柱的疲劳寿命。减少3(3P)垂直旋转的mode-3 TMD可有效提高支撑柱的疲劳寿命。因此，适当使用这些 TMD 可以有效解决 OWT 支撑结构的疲劳问题。