scholarly journals STRUCTURAL ANALYSIS OF SLEWING BEARINGS FOR WIND TURBINES

2020 ◽  
Vol 11 (11) ◽  
Author(s):  
J. H. Kang ◽  
S. J. Heo ◽  
J. H. Yu ◽  
H. W. Lee
Keyword(s):  
Structural Analysis ◽  
Wind Turbines ◽  
Slewing Bearings

Structural Analysis of a Hybrid Substructure With Multi-Cylinder for 5MW Offshore Wind Turbines

2014 ◽  
Author(s):  
Min-Su Park ◽  
Youn-Ju Jeong ◽  
Young-Jun You
Keyword(s):  
Free Surface ◽  
Structural Analysis ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Expansion Method ◽  
Wave Force ◽  
Offshore Wind ◽  
Wave Forces ◽  
Offshore Wind Turbines ◽  
Scattering Wave

The substructure for offshore wind turbines is strongly influenced by the effect of wave forces as the size of substructure increases. Therefore, it is very important to reduce the wave force acting on substructures. In the present study the hybrid substructure, which is composed of a multi-cylinder having different radius near free surface and a gravity substructure at the bottom of multi-cylinder, is suggested to reduce the wave forces. The fluid domain is divided into two regions to calculate the wave forces acting on the hybrid substructure with multi-cylinder and the scattering wave in each fluid region is expressed by an Eigen-function expansion method. The comparison between the mono pile and the hybrid substructure is made for wave forces. Using the wave forces obtained from this study, the structural analysis of hybrid substructure is carried out through ANSYS mechanical. In order to investigate the resonance between the wind turbine and the hybrid substructure, the modal analysis is also carried out.

A life test method and result analysis for slewing bearings in wind turbines

2015 ◽  
Vol 229 (18) ◽  
pp. 3499-3514 ◽  
Author(s):  
Haiyong Zong ◽  
Hua Wang ◽  
Shuhua Tian ◽  
Xuehai Gao
Keyword(s):  
Fatigue Life ◽  
Service Life ◽  
Wind Turbines ◽  
Test Method ◽  
Test Equipment ◽  
Life Test ◽  
Complex Load ◽  
Slewing Bearing ◽  
Remaining Service Life ◽  
Slewing Bearings

Slewing bearings generally consist of the rotational connection between two substructures and are usually used for complex load at very low speeds. If the slewing bearing has some faults during the working lifecycle, the machine will have to be stopped and the slewing bearing will be disassembled for checking the internal surface damage of the rings or rolling elements to prevent serious accidents. However, this is a very difficult process and will cost a lot of manpower, time, and money. Although there is a large number of traditional or modern techniques used widely in general bearings, they may not be able to predict the remaining service life of slewing bearings precisely due to the huge difference between the general bearings and the slewing bearings, thus, the experiments are the most effective and reliable methods. In this paper, a special test table for slewing bearings applied in wind turbine generators is presented and an accelerating fatigue life test method based on the test equipment is proposed to study the fatigue properties and predict the remaining service life of the slewing bearings used in wind turbines. It is shown that the presented test equipment can realistically reflect the state of slewing bearings under the actual working conditions. What’s more, the experimental results show that the proposed method is conservative and provides a more accurate prediction of the fatigue life for the slewing bearings and also can meet the high reliability requirements of the slewing bearings in wind turbines.

Structural analysis and optimisation of transverse flux permanent magnet machines for 5 and 10 MW direct drive wind turbines

Wind Energy ◽  
2012 ◽  
Vol 15 (1) ◽  
pp. 19-43 ◽  
Author(s):  
A. Zavvos ◽  
D. Bang ◽  
A.S. McDonald ◽  
H. Polinder ◽  
M. Mueller
Keyword(s):  
Structural Analysis ◽  
Permanent Magnet ◽  
Wind Turbines ◽  
Permanent Magnet Machines ◽  
Direct Drive ◽  
Transverse Flux

Validation of a Novel Floating Wind Turbine Simulation Tool via Benchmarking: Case Study of a Semi-Submersible Platform

2021 ◽  
Author(s):  
Aengus John Connolly ◽  
Gerard O'Mahony
Keyword(s):  
Finite Element ◽  
Structural Analysis ◽  
Numerical Modelling ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Offshore Wind ◽  
Simulation Tool ◽  
Offshore Wind Turbines ◽  
Structural Simulation ◽  
Fully Coupled

Abstract This paper describes the validation of a novel floating wind turbine simulation tool based on an existing finite element offshore structural analysis solver that recently has been extended to simulate offshore wind turbines. Given the growing importance of offshore wind in the decarbonization strategy of many countries, and particularly the predicted exponential future growth in floating offshore wind, the requirement for validated numerical modelling tools to support detailed engineering design is now greater than ever. The tool combines a unique structural analysis solver incorporating a 3D hybrid beam-column element featuring fully-coupled axial, torsional and bending deformation modes, with the open-source aerodynamic modelling software FAST, to enable it to perform fully coupled aero-hydro-structural simulation of offshore wind turbines. The validation process focuses on a floating semi-submersible platform hosting a 5MW turbine, which is the reference model used in the international research project Offshore Code Comparison Collaboration Continuation (OC4). This is a code-to-code verification project sponsored by the International Energy Agency (IEA) which benchmarks a range of simulation codes for offshore wind turbine modelling. Beginning with fundamental test cases, such as static equilibrium, eigen-analysis, and free-decay simulations, the scenarios advance in complexity to include current loading, regular and random wave excitation, in conjunction with both steady and turbulent wind inflow. The new tool generates results which exhibit a close correlation with the OC4 benchmark data, thereby validating the numerical modelling approach. Although primarily focused on the semi-submersible, the validation programme also considers the same 5MW turbine hosted by a jacket substructure in shallower water, illustrating the versatility of the modelling tool to simulate fixed support structures in addition to floating. Given the scope of the validation effort, this paper presents a representative sample of results only. A more comprehensive report covering the other load cases can be provided to interested readers by the authors. This paper complements the research work undertaken in OC4, further substantiating its insights into the dynamic responses of floating offshore wind turbines. The new tool offers advantages for non-linear structural simulation via its innovative finite element solution technique, and detailed hydrodynamic modelling via its established and proven numerical models. The combination underlines the benefits of exploiting synergies between offshore oil and gas and offshore wind.

scholarly journals Structural Analysis of Large-Scale Vertical Axis Wind Turbines Part II: Fatigue and Ultimate Strength Analyses

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2584 ◽  
Author(s):  
Jinghua Lin ◽  
You-lin Xu ◽  
Yong Xia
Keyword(s):  
Finite Element ◽  
Structural Analysis ◽  
Ultimate Strength ◽  
Wind Turbines ◽  
Large Scale ◽  
Vertical Axis ◽  
Strength Analysis ◽  
Fe Model ◽  
Composite Blade ◽  
Vertical Axis Wind Turbines

Vertical axis wind turbines (VAWTs) exhibit many advantages and great application prospect as compared with horizontal ones. However, large-scale VAWTs are rarely reported, and the codes and guidelines for designing large-scale VAWTs are lacking. Designing a large-scale composite blade requires precise finite element (FE) modeling and stress analysis at the lamina level, while precise modeling of an entire VAWT is computationally intensive. This study proposes a comprehensive fatigue and ultimate strength analysis framework for VAWTs. The framework includes load determination, finite element (FE) model establishment, and fatigue and ultimate strength analyses. Wind load determination has been presented in the companion paper. In this study, laminated shell elements are used to model blades, which are separately analyzed by ignoring the influence of the tower and arms. Meanwhile, beam elements are used to model an entire VAWT to conduct a structural analysis of other structural components. A straight-bladed VAWT in Yang Jiang, China, is used as a case study. The critical locations of fatigue and ultimate strength failure of the blade, shaft, arms, and tower are obtained.

Finite Element Methods for the Structural Analysis of Tension Leg Platforms for Floating Wind Turbines

2017 ◽  
Author(s):  
Markus S. Starr ◽  
Andreas Manjock ◽  
Christian Arjes ◽  
Ngoc-Do Nguyen ◽  
Torsten Faber
Keyword(s):  
Finite Element ◽  
Structural Analysis ◽  
Computational Methods ◽  
Wind Turbines ◽  
Special Focus ◽  
Simulation Methods ◽  
Analysis Model ◽  
Support Structure ◽  
Element Analysis ◽  
Study Results

This paper represents the condensed version of an original Master Thesis written in 2016 [1]. The main aim lays in the structural analysis of Tension Leg Platforms (TLP) as support structures for Floating Wind Turbines (FWT). Special focus is given to a methodology study of different static analysis methods for components of a FWT support structure by Finite Element Method (FEM). The analysis considers Ultimate Limit States (ULS) only. Based on a given open source TLP design [2], the support structure is fragmented in its components. Each component is categorized, based on whether it can be analyzed by parametric equations or by computational methods. For the components, verifiable by parametric equations, the relevant standards are examined. The analysis of the decomposed support structure shows that existing standards can be applied for many of the components. One specific tubular joint of the support structure is selected and analyzed by computational methods. Considering the complexity of Finite Element Analysis (FEA) for FWT, the performed methodology study compares and evaluates various simulation methods on how loads are applied onto the structure. The methodology study results show that for ULS consideration, all load driven simulation methods are generally applicable. In the prospect of fatigue analyses further developments and improvements are considered crucial. This especially includes a better coherence of the stiffness representation between global load simulation model and local structural analysis model.

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