TY  - EJOU
AU  - Liu, Shengya 
AU  - Bian, Wei 
AU  - Li, nan 
AU  - Xue, Yang 
AU  - Yin, Jingxun 

TI  - Dynamic Behavior of Offshore Wind Turbines Considering Monopile Flexibility under Combined Wind, Wave and Soil
T2  - Energy Engineering

PY  - 2026
VL  - 123
IS  - 9
SN  - 1546-0118

AB  - 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 <mml:math id="mml-ieqn-1"><mml:mi>p</mml:mi><mml:mrow><mml:mtext>-</mml:mtext></mml:mrow><mml:mi>y</mml:mi></mml:math> and <mml:math id="mml-ieqn-2"><mml:mi>Q</mml:mi><mml:mrow><mml:mtext>-</mml:mtext></mml:mrow><mml:mi>z</mml:mi></mml:math> 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.
KW  - Offshore wind turbine; soil-structure interactions; dynamic behavior; pile flexibility

DO  - 10.32604/ee.2025.074804