Supporting the Engineering Analysis of Offshore Wind Turbines Through Advanced Soil-Structure 3D Modelling

2017 ◽  
Author(s):  
Simone Corciulo ◽  
Omar Zanoli ◽  
Federico Pisanò
Keyword(s):  
Dynamic Analysis ◽  
Wind Turbines ◽  
Soil Structure ◽  
Current Trend ◽  
Offshore Wind ◽  
Fe Modelling ◽  
Offshore Wind Turbines ◽  
Geotechnical Design ◽  
Foundation Type ◽  
Increasing Load

Monopiles are at present the most widespread foundation type for offshore wind turbines (OWTs), due to their simplicity and economic convenience. The current trend towards increasingly powerful OWTs in deeper waters is challenging the existing procedures for geotechnical design, requiring accurate assessment of transient soil-monopile interaction and, specifically, of the associated modal frequencies. In this work, advanced 3D finite element (FE) modelling is applied to the dynamic analysis of soil-monopile-OWT systems under environmental service loads. Numerical results are presented to point out the interplay of soil non-linearity and cyclic hydro-mechanical (HM) coupling, and its impact on transient response of the system at increasing load magnitude. It is shown how the lesson learned from advanced modelling may directly inspire simplified, yet effective, spring models for the engineering dynamic analysis of OWTs.

scholarly journals Comparative Modal Analysis of Monopile and Jacket Supported Offshore Wind Turbines including Soil-Structure Interaction

2020 ◽  
Vol 20 (10) ◽  
pp. 2042016
Author(s):  
A. Abdullahi ◽  
Y. Wang ◽  
S. Bhattacharya
Keyword(s):  
Wind Turbines ◽  
Soil Structure ◽  
Natural Frequencies ◽  
Model Updating ◽  
Offshore Wind ◽  
Fe Model ◽  
Analysis And Design ◽  
Offshore Wind Turbines ◽  
Future Design ◽  
Wide Range

Offshore wind turbines (OWTs) have emerged as a reliable source of renewable energy, witnessing massive deployment across the world. While there is a wide range of support foundations for these structures, the monopile and jacket are most utilized so far; their deployment is largely informed by water depths and turbine ratings. However, the recommended water depth ranges are often violated, leading to cross-deployment of the two foundation types. This study first investigates the dynamic implication of this practice to incorporate the findings into future analysis and design of these structures. Detailed finite element (FE) models of Monopile and Jacket supported OWTs are developed in the commercial software, ANSYS. Nonlinear soil springs are used to simulate the soil-structure interactions (SSI) and the group effects of the jacket piles are considered by using the relevant modification factors. Modal analyzes of the fixed and flexible-base cases are carried out, and natural frequencies are chosen as the comparison parameters throughout the study. Second, this study constructs a few-parameters SSI model for the two FE models developed above, which aims to use fewer variables in the FE model updating process without compromising its simulation quality. Maximum lateral soil resistance and soil depths are related using polynomial equations, this replaces the standard nonlinear soil spring model. The numerical results show that for the same turbine rating and total height, jacket supported OWTs generally have higher first-order natural frequencies than the monopile supported OWTs, while the reverse is true for the second-order vibration modes, for both fixed and flexible foundations. This contributes to future design considerations of OWTs. On the other hand, with only two parameters, the proposed SSI model has achieved the same accuracy as that using the standard model with seven parameters. It has the potential to become a new SSI model, especially for the identification of soil properties through the model updating process.

scholarly journals Dynamic Analysis of Mooring Cables with Application to Floating Offshore Wind Turbines

2016 ◽  
Vol 142 (3) ◽  
pp. 04015101 ◽  
Author(s):  
Crescenzo Petrone ◽  
Nicholas D. Oliveto ◽  
Mettupalayam V. Sivaselvan
Keyword(s):  
Dynamic Analysis ◽  
Wind Turbines ◽  
Offshore Wind ◽  
Offshore Wind Turbines ◽  
Floating Offshore Wind Turbines

scholarly journals Soil–Structure Interactions for Offshore Wind Turbines

2012 ◽  
Vol 1 (1) ◽  
Author(s):  
Subhamoy Bhattacharya ◽  
Georgios Nikitas ◽  
Laszlo Arany ◽  
Nikolaos Nikitas
Keyword(s):  
Wind Turbines ◽  
Soil Structure ◽  
Offshore Wind ◽  
Offshore Wind Turbines
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