NUMERICAL SIMULATION OF NATURAL FREQUENCY OF OFFSHORE WIND TURBINES AND ITS INFLUENCING FACTOR STUDY

Jiang Linfeng; Wu Teng; Wu Yong

doi:10.19912/j.0254-0096.tynxb.2024-0961

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Acta Energiae Solaris Sinica ›› 2025, Vol. 46 ›› Issue (10) : 596-604. DOI: 10.19912/j.0254-0096.tynxb.2024-0961

NUMERICAL SIMULATION OF NATURAL FREQUENCY OF OFFSHORE WIND TURBINES AND ITS INFLUENCING FACTOR STUDY

Jiang Linfeng^1,2, Wu Teng^1,3, Wu Yong⁴

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Abstract

Field data monitoring and analysis were carried out for a 4 MW offshore wind turbine at a nearshore wind farm in Jiangsu Province. An integrated model of the wind turbine-tower-foundation was established by finite element software and compared with the base-tower model. The models’ reliability was verified based on long-term monitoring data for the project. The effects of structural dimensions, foundation conditions, and wind turbine operating states on the natural frequency of the structure were analyzed based on the integrated model. The results show that the natural frequency of the wind turbine obtained from the integrated model is closer to the actual monitoring values compared to a simplified model, and simplifying the upper wind turbine structure leads to an overestimation of the natural frequency. The monitoring results of the natural frequency of the structure are not significantly affected by the monitoring elevation and can be used to assess the wind turbine's operational status based on the consistency of natural frequencies at different elevations. As the foundation embedment depth, pile diameter, soil elastic modulus, and internal friction angle increase, the natural frequency of the structure also increases. With an increase in the tower height, the natural frequency of the structure linearly decreases, and an increase in the tower wall thickness leads to a parabolic increase in the natural frequency of the structure. Changes in the friction coefficient between piles and soil have minimal impact on the natural frequency of the structure. Wind turbine operation increases the low-order natural frequencies of the structure, with the most significant impact on the first two natural frequencies.

Key words

offshore wind turbines / pile foundation / natural frequencies / integrated model / influence factors analysis

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Jiang Linfeng, Wu Teng, Wu Yong. NUMERICAL SIMULATION OF NATURAL FREQUENCY OF OFFSHORE WIND TURBINES AND ITS INFLUENCING FACTOR STUDY[J]. Acta Energiae Solaris Sinica. 2025, 46(10): 596-604 https://doi.org/10.19912/j.0254-0096.tynxb.2024-0961

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