Author(s): Haoyang Yin; Bin Wang; Shan Gao; Yan Qu; Zhenju Chuang
Linked Author(s):
Keywords: Ice-induced vibration; Frequency lock-in; Ductile damage-collapse; Fixed offshore wind turbine; Ice-structure interactions; Wind turbine in ice regions
Abstract: Ice-induced vibration is a serious problem for offshore structures in ice-covered sea areas. Various monitoring efforts have identified three types of ice-structure vibrations. Similarly, wind turbine structures experience three main types of vibration. When ice moves slowly against structures, the coupling of ice crushing and structural vibration can cause a lock-in between ice loads and structural vibrations, leading to a dangerous loading condition known as frequency lock-in (FLI) vibration. This scenario must be considered during the design process because it can result in strong structural vibrations. Current practice involves either using approaches provided in design standards or applying pregenerated ice load time series in the wind turbine aeroelastic model. This paper proposes a new mechanism and analysis method. A 5MW fixed monopile wind turbine was used as a sample to compare the new analysis method with the ISO method. The study shows that the results of the ISO method are smaller than those of the new method proposed in this paper. The study also indicates that the probability of FLI occurrence on an offshore wind turbine is lower than that on oil platforms and lighthouses because the wind turbine has high-rise and low-frequency characteristics.
Year: 2024