Non-linear response analysis of jacket supported offshore wind turbine under seismic loads using Hilbert-Huang transform
Kashyap, S.; Saha, N.; Abhinav, K.A. (2021). Non-linear response analysis of jacket supported offshore wind turbine under seismic loads using Hilbert-Huang transform, in: ASME 2021 40th International Conference on Ocean, Offshore and Arctic Engineering - Volume 9: Ocean Renewable Energy. pp. V009T09A037. https://dx.doi.org/10.1115/OMAE2021-67597 In: (2021). ASME 2021 40th International Conference on Ocean, Offshore and Arctic Engineering - Volume 9: Ocean Renewable Energy. ASME: [s.l.]. ISBN 978-0-7918-8519-2. , more |
| Keyword | | | Author keywords | NREL 5MW OC4 Jacket; Earthquake Loading; Coupled Analysis; 1P and 3P loading; Hilbert-Huang Transform (HHT); Soil-Structure Interaction |
| Authors | | Top | - Kashyap, S.
- Saha, N.
- Abhinav, K.A., more
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| Abstract | The present work studies the performance of an offshore wind turbine system in an earthquake coupled with wave and wind loading. The NREL 5MW offshore wind turbine, supported on the OC4 jacket [14] has been analysed within a finite element framework. A coupled model of hydrodynamics and soil-structure interaction has been implemented. The structure-foundation system is analysed under earthquakes recorded close to offshore waters and at sites with shear-wave velocities, classified under Site-Class D or Site-Class E as per API RP: 2EQ [8]. The soil conditions emulate characteristics of a prospective offshore wind turbine site along the west coast of India, which falls within the Site-Class D classification mentioned above. The geotechnical modelling is done as per the soil curves prescribed by the non-linear Winkler springs along the pile's length. The complete analysis has been processed in a finite-element framework through the commercial program USFOS [16]. The Hilbert-Huang transform [29] of the tower-responses suggests the increased vulnerability to the resonance phenomenon with 1P and 3P loading. It also suggests an involvement of higher modes in the tower-response. The change in the frequency of the structure foundation system during and post-earthquake has also been studied. |
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