Wind Turbine Gearbox Dynamic Characterization Using Operational Modal Analysis

2014 ◽  
pp. 41-52 ◽  
Author(s):  
E. Di Lorenzo ◽  
S. Manzato ◽  
J. Houben ◽  
F. Vanhollebeke ◽  
S. Goris ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Modal Analysis ◽  
Operational Modal Analysis ◽  
Dynamic Characterization ◽  
Wind Turbine Gearbox

Monitoring Changes in the Soil and Foundation Characteristics of an Offshore Wind Turbine Using Automated Operational Modal Analysis

2013 ◽  
Vol 569-570 ◽  
pp. 652-659 ◽  
Author(s):  
Gert de Sitter ◽  
Wout Weitjens ◽  
Mahmoud El-Kafafy ◽  
Christof Devriendt
Keyword(s):  
Wind Turbine ◽  
Modal Analysis ◽  
Continuous Monitoring ◽  
Low Frequency ◽  
Operational Modal Analysis ◽  
Human Interaction ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Support Structure ◽  
Lower Natural Frequency

This paper will show the first results of a long term monitoring campaign on an offshore wind turbine in the Belgian North Sea. It will focus on the vibration levels and resonant frequencies of the fundamental modes of the support structure. These parameters will be crucial to minimize O&M costs and to extend the lifetime of offshore wind turbine structures. For monopile foundations for example, scouring and reduction in foundation integrity over time are especially problematic because they reduce the fundamental structural resonance of the support structure, aligning that resonance frequency more closely to the lower frequencies. Since both the broadband wave energy and the rotating frequency of the turbine are contained in this low frequency band, the lower natural frequency can create resonant behavior increasing fatigue damage. Continuous monitoring of the effect of scour on the dynamics of the wind turbine will help to optimize the maintenance activities on the scour protection system. To allow a proper continuous monitoring during operation, reliable state-of-the-art operational modal analysis techniques should be used and these are presented in this paper. The methods are also automated, so that no human-interaction is required and the system can track the natural frequencies and damping ratios in a reliable manner.

Operational Modal Analysis for Dynamic Characterization of a Ro-Lo Ship

2014 ◽  
Vol 58 (04) ◽  
pp. 216-224 ◽  
Author(s):  
Esben Orlowitz ◽  
Anders Brandt
Keyword(s):  
Modal Analysis ◽  
Natural Frequencies ◽  
Operating Conditions ◽  
Operational Modal Analysis ◽  
Mode Shapes ◽  
Dynamic Characterization ◽  
Sea Trial ◽  
Global Modes ◽  
Bending Modes

The dynamic characteristics of ship structures are becoming more important as the flexibility of modern ships increases, for example, to predict reliable design life. This requires an accurate dynamic model of the structure, which, because of complex vibration environment and complex boundary conditions, can only be validated by measurements. In the present paper the use of operational modal analysis (OMA) for dynamic characterization of a ship structure based on experimental data, from a full-scale measurement of a 210-m long Ro-Lo ship during sea trial, is presented. The measurements contain three different data sets obtained under different operating conditions of the ship: 10 knots cruising speed, 18 knots cruising speed, and at anchor. Natural frequencies, modal damping ratios, and mode shapes have been successfully estimated for the first 10 global modes. Damping ratios for the current ship were found within the range 0.9%–1.9% and natural frequencies were found to range from 0.8 to 4.1 Hz for the first 10 global modes of the ship at design speed (18 knots). The three different operating conditions showed, in addition, a speed dependency of the natural frequencies and damping ratios. The natural frequencies were found to be lower for the 18-knots condition compared with the two other conditions, most significantly for the vertical bending modes. Also, for the vertical bending modes, the damping ratios increased by 28%–288% when the speed increased from 10 to 18 knots. Other modes were not found to have the same strong speed dependency.

Dynamic Research with Drivetrain Simulation and Modal Analysis of Wind Turbine Gearbox

2014 ◽  
Vol 952 ◽  
pp. 161-164 ◽  
Author(s):  
Zheng Li ◽  
Yang Chen
Keyword(s):  
Wind Turbine ◽  
Modal Analysis ◽  
Dynamic Theory ◽  
Dynamic Performance ◽  
Modal Parameters ◽  
Analysis Software ◽  
Wind Turbine Gearbox ◽  
System Vibration ◽  
Multi Body ◽  
Body Dynamic

The dynamic performance of wind turbine gearbox is very important for measuring the integrated vibration and noise of the whole drivetrain system of wind turbine. The stiffiness and modal parameters of the gearbox will influence the system vibration situation obviously. The wind turbine gearbox is a kind of complicated coupled mechanics; it means the modal analysis on gearbox should consider the coupling effects of the components and define logical damping factors. This paper presents a method to simulate wind turbine gearbox system with the multi-body drivetrain dynamic analysis software. The modal analysis of wind turbine gearbox can be carried out on the basis of the multi-body dynamic theory.

scholarly journals Structural health monitoring of offshore wind turbines using automated operational modal analysis

2014 ◽  
Vol 13 (6) ◽  
pp. 644-659 ◽  
Author(s):  
Christof Devriendt ◽  
Filipe Magalhães ◽  
Wout Weijtjens ◽  
Gert De Sitter ◽  
Álvaro Cunha ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Modal Analysis ◽  
Wind Turbines ◽  
Operational Modal Analysis ◽  
Offshore Wind ◽  
Dynamic Monitoring ◽  
Mode Shapes ◽  
Offshore Wind Turbine ◽  
Complex Frequency ◽  
Offshore Wind Turbines

This article will present and discuss the approach and the first results of a long-term dynamic monitoring campaign on an offshore wind turbine in the Belgian North Sea. It focuses on the vibration levels and modal parameters of the fundamental modes of the support structure. These parameters are crucial to minimize the operation and maintenance costs and to extend the lifetime of offshore wind turbine structure and mechanical systems. In order to perform a proper continuous monitoring during operation, a fast and reliable solution, applicable on an industrial scale, has been developed. It will be shown that the use of appropriate vibration measurement equipment together with state-of-the art operational modal analysis techniques can provide accurate estimates of natural frequencies, damping ratios, and mode shapes of offshore wind turbines. The identification methods have been automated and their reliability has been improved, so that the system can track small changes in the dynamic behavior of offshore wind turbines. The advanced modal analysis tools used in this application include the poly-reference least squares complex frequency-domain estimator, commercially known as PolyMAX, and the covariance-driven stochastic subspace identification method. The implemented processing strategy will be demonstrated on data continuously collected during 2 weeks, while the wind turbine was idling or parked.

scholarly journals Vibration Analysis and Dynamic Characterization of Structural Glass Elements with Different Restraints Based on Operational Modal Analysis

Buildings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 13 ◽  
Author(s):  
Chiara Bedon ◽  
Marco Fasan ◽  
Claudio Amadio
Keyword(s):  
Modal Analysis ◽  
Video Tracking ◽  
Operational Modal Analysis ◽  
Analytical Models ◽  
Design Stage ◽  
Damping Capacity ◽  
Structural Glass ◽  
Dynamic Characterization ◽  
Analysis And Design

Given a series of intrinsic features of structural glass systems (i.e., material properties, type of restraints, operational conditions, etc.), special care should be spent at the design stage, to ensure appropriate fail-safe requirements, but also in the service life of these innovative building components and assemblies. In this paper, the dynamic characterization of simple monolithic glass elements is presented, based on non-destructive laboratory experiments and Operational Modal Analysis (OMA) techniques, including Finite Element (FE) numerical simulations, classical analytical models, and video-tracking approaches. It is shown, in particular, how the actual restraint condition (i.e., flexibility of supports, with respect to ideal boundaries) can affect the vibration parameters of a given glass member (frequency and damping capacity). This turns out in possible variations of its overall structural performance, including stress-strain-related effects, hence suggesting the need for even further dedicated studies and methods for the reliable analysis and design of structural glass assemblies and complex systems under dynamic loads.

Modal Analysis and Experiment on 2.0 MW Wind Turbine Gearbox

2012 ◽  
Vol 542-543 ◽  
pp. 52-56 ◽  
Author(s):  
Guo Yang Wu ◽  
Cheng Rong Jiang ◽  
Yi Jian Liao
Keyword(s):  
Wind Turbine ◽  
Modal Analysis ◽  
Three Dimensional ◽  
Structure Design ◽  
Solid Model ◽  
Unit Operation ◽  
Wind Turbine Gearbox ◽  
Spring Element ◽  
Coupling Dynamic ◽  
Case Structure

By using Solidworks, a three-dimensional solid model of the wind turbine gearbox is established. Use Spring element in ANSYS joins transmission system and case structure system, the whole gearbox coupling dynamic model is built up and the first 20-order bound mode of the gearbox is calculated. Through modal analysis and experimental test show that the structure of wind turbine gearbox is reasonable, and resonance wouldn’t occur during the operational process, ensure the reliability of the unit operation and that for the wind turbine gearbox structure design to provide the theoretical basis.

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