Modal Analyses Based on Whole Gearbox FE Model in Wind Turbine

2016 ◽  
pp. 71-75
Author(s):  
Qingkai Han ◽  
Jing Wei ◽  
Qingpeng Han ◽  
Hao Zhang
Keyword(s):  
Wind Turbine ◽  
Fe Model

Research on the Door Buckling Strength of Turbine Tower of HAWTs

2012 ◽  
Vol 268-270 ◽  
pp. 1239-1243
Author(s):  
Kai Long ◽  
Ji Xiu Wu
Keyword(s):  
Wind Turbine ◽  
Large Scale ◽  
Horizontal Axis ◽  
Engineering Method ◽  
Fe Model ◽  
Horizontal Axis Wind Turbine ◽  
Buckling Modes ◽  
Buckling Strength ◽  
Design Structure ◽  
Wind Turbine Tower

In order to realize the buckling strength design for the opening door of the large-scale horizontal axis wind turbine tower, the method combined with the engineering method and the FEM was presented. The FE model of the door was established. The first-order buckling eigenvalues and buckling modes for three different structures were calculated and analyzed. Based on engineering method, the stress and buckling strength for the sections of tubular tower were obtained. Corrected by FEM results, the tower door with opening buckling strength were checked by engineering method. The results were compared with those by FEM. The safe design structure anti-buckling were presented. The method presented in this paper is feasible and effective for the opening door design in large-scale horizontal axis wind turbine tower.

scholarly journals Static analysis of wind turbine blade using 1D FE model

2021 ◽  
Vol 13 (1) ◽  
pp. 125-130
Author(s):  
Tushar Sharma ◽  
V. Murari ◽  
K.K. Shukla
Keyword(s):  
Wind Turbine ◽  
Beam Theory ◽  
Fe Model ◽  
Beam Model ◽  
Static Response ◽  
Order Polynomial ◽  
1D Model ◽  
Twisting Angle ◽  
Blade Model ◽  
Fourth Order Polynomial

The study presents a unique technique to determine the static response of wind turbine (WT) blade. A 1D Finite element (FE) beam model of WT blade is developed using thin-walled beam theory coupled with PreComp tool used to compute crosssectional stiffness with elastic coupling effects. A realistic 9.2 m long, WT blade is developed using different aerofoils with fourth order polynomial variation for twisting angle of blade span. Three different aerfoil sections NREL S818, NREL S825, and NACA 2412 are employed in the current study. For validation, the results of 1D model developed using MATLAB are compared with that of 3D WT blade model which is analyzed in ANSYS using NuMAD..

scholarly journals Reliability analysis of offshore wind turbine foundations under lateral cyclic loading

2020 ◽  
Vol 5 (4) ◽  
pp. 1521-1535
Author(s):  
Gianluca Zorzi ◽  
Amol Mankar ◽  
Joey Velarde ◽  
John D. Sørensen ◽  
Patrick Arnold ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Wind Turbine ◽  
Limit State ◽  
Large Diameter ◽  
Probabilistic Approach ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Fe Model ◽  
Foundation Design

Abstract. The design of foundations for offshore wind turbines (OWTs) requires the assessment of long-term performance of the soil–structure interaction (SSI), which is subjected to many cyclic loadings. In terms of serviceability limit state (SLS), it has to be ensured that the load on the foundation does not exceed the operational tolerance prescribed by the wind turbine manufacturer throughout its lifetime. This work aims at developing a probabilistic approach along with a reliability framework with emphasis on verifying the SLS criterion in terms of maximum allowable rotation during an extreme cyclic loading event. This reliability framework allows the quantification of uncertainties in soil properties and the constitutive soil model for cyclic loadings and extreme environmental conditions and verifies that the foundation design meets a specific target reliability level. A 3D finite-element (FE) model is used to predict the long-term response of the SSI, accounting for the accumulation of permanent cyclic strain experienced by the soil. The proposed framework was employed for the design of a large-diameter monopile supporting a 10 MW offshore wind turbine.

scholarly journals Analysis of Tightening Sequence Effects on Preload Behaviour of Offshore Wind Turbine M72 Bolted Connections

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4406 ◽  
Author(s):  
Braithwaite ◽  
Mehmanparast
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Fe Model ◽  
Bolted Connections ◽  
Minimum Requirement ◽  
Offshore Wind Turbines ◽  
Sequence Effects ◽  
Transition Piece

Offshore wind turbines in shallow waters are predominantly installed using a monopile foundation, onto which a transition piece and wind turbine are attached. Previously, the monopile to transition piece (MP-TP) connection was made using a grouted connection, however, cases of grout failure causing turbine slippage, among other issues, were reported. One solution is to use bolted ring flange connections, which involve using a large number of M72 bolts to provide a firm fixing between the MP-TP. It is in the interest of offshore wind operators to reduce the number of maintenance visits to these wind turbines by maintaining a preload (Fp) level above the minimum requirement for bolted MP-TP connections. The present study focuses on the effect of the tightening sequence on the Fp behaviour of M72 bolted connections. A detailed finite element (FE) model of a seven-bolt, representative segment of a monopile flange was developed with material properties obtained from the available literature. Three analyses were made to examine the effect on Fp after tightening, including the initial Fp level applied to the bolts, the tightening sequence and the effect of an additional tightening pass.

The Application of Aeroelastic Analysis Output Load Distributions to Finite Element Models of Wind

2005 ◽  
Vol 29 (2) ◽  
pp. 153-168 ◽  
Author(s):  
Timothy J. Knill
Keyword(s):  
Finite Element ◽  
Wind Turbine ◽  
Turbine Blades ◽  
Fe Model ◽  
Wind Turbine Blades ◽  
Fe Modelling ◽  
Load Distributions ◽  
Aeroelastic Analysis ◽  
Extreme Load ◽  
Application Techniques

The structural design of wind turbine blades is a rapidly evolving technology. Finite element (FE) modelling is used extensively by structural designers to assess the behaviour of wind turbine blades under operational and extreme load conditions. This paper develops a method of transferring aerodynamic and inertial loads from the aeroelastic analysis output to the FE model. Once a procedure is developed and verified, case studies are undertaken using an FE model of a 34m blade. Loads are applied using the newly developed method and various FE analysis results compared to the same blade analysed under more traditional load application techniques. The case study clearly demonstrates that the method of applying loads can influence some types of analysis results significantly.

scholarly journals Structural Modeling and Failure Assessment of Spar-Type Substructure for 5 MW Floating Offshore Wind Turbine under Extreme Conditions in the East Sea

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6571
Author(s):  
Kwangtae Ha ◽  
Jun-Bae Kim ◽  
Youngjae Yu ◽  
Hyoung-Seock Seo
Keyword(s):  
Wind Energy ◽  
Wind Turbine ◽  
Three Dimensional ◽  
Offshore Wind ◽  
East Sea ◽  
Offshore Wind Turbine ◽  
Fe Model ◽  
Offshore Wind Energy ◽  
Floating Offshore Wind Turbine ◽  
Load Analysis

Not only the driving for offshore wind energy capacity of 12 GW by Korea’s Renewable Energy 2030 plan but also the need for the rejuvenation of existing world-class shipbuilders’ infrastructures is drawing much attention to offshore wind energy in Korea, especially to the diverse substructures. Considering the deep-sea environment in the East Sea, this paper presents detailed modeling and analysis of spar-type substructure for a 5 MW floating offshore wind turbine (FOWT). This process uses a fully coupled integrated load analysis, which was carried out using FAST, a widely used integrated load analysis software developed by NREL, coupled with an in-house hydrodynamic code (UOU code). The environmental design loads were calculated from data recorded over three years at the Ulsan Marine buoy point according to the ABS and DNVGL standards. The total 12 maximum cases from DLC 6.1 were selected to evaluate the structural integrity of the spar-type substructure under the three co-directional conditions (45°, 135°, and 315°) of wind and wave. A three-dimensional (3D) structural finite element (FE) model incorporating the wind turbine tower and floating structure bolted joint connection was constructed in FEGate (pre/post-structural analysis module based on MSC NASTRAN for ship and offshore structures). The FEM analysis applied the external loads such as the structural loads due to the inertial acceleration, buoyancy, and gravity, and the environmental loads due to the wind, wave, and current. The three-dimensional FE analysis results from the MSC Nastran software showed that the designed spar-type substructure had enough strength to endure the extreme limitation in the East Sea based on the von Mises criteria. The current process of this study would be applicable to the other substructures such as the submersible type.

Modal Analysis for Crack Detection in Small Wind Turbine Blades

2013 ◽  
Vol 569-570 ◽  
pp. 603-610 ◽  
Author(s):  
Martin Dalgaard Ulriksen ◽  
Jonas Falk Skov ◽  
Kristoffer Ahrens Dickow ◽  
Poul Henning Kirkegaard ◽  
Lars Damkilde
Keyword(s):  
Wind Turbine ◽  
Modal Analysis ◽  
Health Monitoring ◽  
Crack Detection ◽  
Turbine Blades ◽  
Experimental Tests ◽  
Modal Parameters ◽  
Fe Model ◽  
Wind Turbine Blades ◽  
Small Wind Turbine

The aim of the present paper is to evaluate structural health monitoring (SHM) techniques based on modal analysis for crack detection in small wind turbine blades. A finite element (FE) model calibrated to measured modal parameters will be introduced to cracks with different sizes along one edge of the blade. Changes in modal parameters from the FE model are compared with data obtained from experimental tests. These comparisons will be used to validate the FE model and subsequently discuss the usability of SHM techniques based on modal parameters for condition monitoring of wind turbine blades.

Evaluation of a Hybrid Representation to Model the Wind Turbine, Platform and Mooring Lines in the Analysis of Floating Offshore Wind Turbines

2020 ◽  
Author(s):  
Elói Daniel de Araújo Neto ◽  
William Steven Mendez Rodriguez ◽  
Fabricio Nogueira Correa ◽  
Beatriz de Souza Leite Pires de Lima ◽  
Breno Pinheiro Jacob ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Nonlinear Dynamic ◽  
Offshore Wind ◽  
Elastic Behavior ◽  
Coupled Analysis ◽  
Fe Model ◽  
Mooring Lines ◽  
Floating Offshore Wind Turbines ◽  
Hybrid Methodology ◽  
Platform Motions

Abstract This work presents and evaluates a hybrid methodology for the analysis of FOWT, taking advantage of the SITUA-Prosim code developed by LAMCSO/COPPE/UFRJ, and the NREL FAST code. SITUA-Prosim has been originally developed for the coupled analysis of floating platforms for oil production. It fully couples a validated hydrodynamic model, which represents the hull motions, with a full nonlinear dynamic Finite-Element based structural model, which represents mooring lines and risers. The first step of the methodology is to employ the FAST code to generate time-series of forces on the bottom of the tower. These forces are then applied as input for an analysis with the SITUA-Prosim code where the platform and mooring lines are fully coupled, the latter being represented by a full nonlinear dynamic FE model. This may be considered as a “hybrid” methodology since it uncouples the platform motion response from the forces from the wind turbine, but couples the platform motions with the nonlinear dynamic structural response of the mooring lines. The methodology is applied to analyze the OC4 DeepCwind semisubmersible, taking different wind velocities, and evaluating the influence of the elastic behavior of the blades on the global motion and line tension responses. The results are compared with a standard procedure where the whole system is analyzed entirely by the FAST program. Due to its simplification, this hybrid methodology can be employed for preliminary or intermediate design stages. The main goal of the studies presented here is to comprise an initial step toward a full integration between the Prosim and FAST programs. In future works a full coupling between the wind turbine forces and the platform motions will be implemented.

Influence of Simplified Models on Seismic Response Analysis of Wind Turbine Towers

2011 ◽  
Vol 94-96 ◽  
pp. 369-374 ◽  
Author(s):  
Lai Wang ◽  
Ying Zhang
Keyword(s):  
Finite Element ◽  
Wind Turbine ◽  
Dominant Factor ◽  
Response Analysis ◽  
Fe Model ◽  
Seismic Action ◽  
Wind Turbine Tower ◽  
Mass Eccentricity ◽  
Wind Turbine Towers ◽  
The Impact

Abstract. The dynamic response of wind turbine tower under earthquake is analyzed by aid of the ANSYS program in this paper. To investigate the effects of simplification calculation models of blades and engines on calculation results, a blades-tower integrated finite element (FE) model and a mass-tower finite element (FE) model are established respectively. Then model analysis is discussed and the time history analysis of the system under the input of mean value earthquake record is carried out. The results show that seismic responses of a wind turbine tower are remarkable and seismic action may be the dominant factor in the design of wind turbine towers that located at a seismically active zone. Torsion effect of a tower is evident as a result of the impact of mass eccentricity. Bottom stress at the direction perpendicular to seismic waves is much bigger than that along it. It is also found that the blades-tower integrated finite element model can reflect more accurately the dynamic responses of the tower in the whole process of the earthquake and the “time-lag” effect by comparison, and these provide reliable reference to design and further research of towers.

scholarly journals Reliability analysis of offshore wind turbine foundations under lateral cyclic loading

2019 ◽  
Author(s):  
Gianluca Zorzi ◽  
Amol Mankar ◽  
Joey Velarde ◽  
John D. Sørensen ◽  
Patrick Arnold ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Wind Turbine ◽  
Limit State ◽  
Large Diameter ◽  
Probabilistic Approach ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Fe Model ◽  
Foundation Design

Abstract. The design of foundations for offshore wind turbines (OWT) requires the assessment of the long-term performance of the soil–structure-interaction (SSI) which is subjected to a large number of cyclic loadings. In terms of serviceability limit state (SLS), it has to be ensured that the foundation does not exceed the operational tolerance prescribed by the wind turbine manufacturer throughout its lifetime. This work aims at developing a probabilistic approach along with a reliability framework with emphasis on verifying the SLS criteria in terms of maximum allowable rotation during an extreme cyclic loading event. This reliability framework allows the quantification of uncertainties in soil properties, in the constitutive soil model for cyclic loadings and extreme environmental conditions and verifies that the foundation design meets a specific target reliability level. A 3D finite element (FE) model is used to predict the long-term response of the SSI accounting for the accumulation of permanent cyclic strain experienced by the soil. The proposed framework is employed for the design of a large diameter monopile supporting a 10 MW offshore wind turbine.

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