Open Access

ARTICLE

Dynamic Behavior of Offshore Wind Turbines Considering Monopile Flexibility under Combined Wind, Wave and Soil

Shengya Liu¹, Wei Bian^1,2, Linan Li^1,*, Yang Xue^1,2, Jingxun Yin³

1 The School of Mechanical Engineering, Tianjin University, Tianjin, China
2 China Electric Power Research Institute, Beijing, China
3 Dongfang Electric Wind Power Co., Ltd., Deyang, China

* Corresponding Author: Linan Li. Email:

Energy Engineering 2026, 123(9), 2 https://doi.org/10.32604/ee.2025.074804

Received 18 October 2025; Accepted 15 December 2025; Issue published 06 August 2026

Abstract

Offshore wind energy plays a critical role in achieving global decarbonization goals, while the dynamic response mechanisms of megawatt-scale turbines under complex environmental conditions remain insufficiently characterized. Current research often oversimplifies the effects of monopile flexibility and its interaction with soil dynamics, leading to gaps in dynamic predictions. To address this limitation, this study develops a comprehensive 15-degree-of-freedom dynamic model for a 22 MW monopile offshore wind turbine (OWT) that incorporates nonlinear pile flexibility and soil-structure interaction through p-y and Q-z curves. The integrated analytical framework, established using Euler-Lagrange equations, enables coupled analysis of aero-hydro-soil-structure interactions through systematic energy formulations. The simulation incorporates wind loads calculated via Blade Element Momentum theory and wave loads computed using Morison’s equation based on linear Airy wave theory. The dynamic responses of the OWT system, including displacements and natural frequencies, are then systematically evaluated under combined wind, wave and soil loadings. Comparative analysis of dynamic responses under rigid, semi-rigid and flexible pile configurations reveals distinct behavioral mechanisms, highlighting the crucial role of pile flexibility in soil-structure interaction. The proposed methodology establishes a scalable framework for integrating soil models and control strategies in future research. These findings offer valuable insights for optimizing foundation designs through site-specific stiffness and damping considerations in megawatt-scale OWT engineering applications.

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Keywords

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