Dokument-ID Dokumenttyp Autoren/innen Persönliche Herausgeber/innen Haupttitel Abstract Auflage Verlagsort Verlag Herausgeber (Institution) Erscheinungsjahr Titel des übergeordneten Werkes Jahrgang/Band ISBN Veranstaltung Veranstaltungsort Beginndatum der Veranstaltung Enddatum der Veranstaltung Ausgabe/Heft Erste Seite Letzte Seite URN DOI Lizenz Datum der Freischaltung OPUS4-25076 Beitrag zu einem Tagungsband Grasse, Fabian; Trappe, Volker; Thöns, Sebastian; Said, Samir De Roeck, G.; Degrande, G.; Lombaert, G.; Müller, G. Structural health monitoring of wind turbine blades by strain measurement and vibration analysis Wind turbine blades have to withstand a high number of load cycles in mostly hard weather conditions over 20 years. In a research project BAM and several partners have designed, evaluated and tested a condition monitoring system for all parts of a wind turbine. At a rotorblade with a length of 58 m fibre bragg grating sensors were applied for in-service strain measurement. Additionally a complex test rig was designed to enable real biaxial loading conditions at a representative test rotor blade to simulate the mechanical loading conditions in the lab. In this test blade with a length of 8 m also fibre bragg grating sensors were implemented to determine their influences for the structure and the condition monitoring system. Vibration measurements were carried out at different test phases. The results were compared with finite element strain and modal analysis. Katholieke Universiteit Leuven 2011 EURODYN 2011 - 8th International conference on structural dynamics (Proceedings) 978-90-760-1931-4 EURODYN 2011 - 8th International conference on structural dynamics Leuven, Belgium 04.07.2011 06.07.2011 MS25 Tue 3490 3497 2016-02-19 OPUS4-29104 Beitrag zu einem Tagungsband Rücker, Werner; Thöns, Sebastian; Said, Samir; Schmid, Wolfgang Zingoni, A. SHM strategies, application and measurements on tripod offshore wind energy converters within the German offshore park Alpha Ventus Prototypes of wind turbines of the megawatt dass are to be built and tested until 2008 within a German offshore wind energy test field in the North Sea (ALPHA VENTUS). To ensure a high operational reliability of offshore wind turbines with economically acceptable repair and maintenance efforts, comprehensive diagnosis and supervision concepts are required. Automatic monitoring Systems will be an essential part of such concepts. Because of the fact, that during Operation there will be static and dynamic interaction between the components 'structure', 'machinery' and 'blades' it is necessary to develop the monitoring techniques in an overall concept. These monitoring Systems are supposed to be applied for the design and testing as well as for the Operation and maintenance phases. In the paper the developed approaches for the measurement of actions and the condition monitoring of all components of an offshore wind energy plant will be shown. CRC Press 2013 Research and applications in structural engineering, mechanics and computation - 5th International conference on structural engineering, mechanics and computation (Proceedings) 978-1-138-00061-2 Research and applications in structural engineering, mechanics and computation - 5th International conference on structural engineering, mechanics and computation Cape Town, South Africa 02.09.2013 04.09.2013 977 982 2016-02-20 OPUS4-19795 Beitrag zu einem Sammelband Rohrmann, Rolf; Rücker, Werner; Thöns, Sebastian; Said, Samir; Schmid, Wolfgang Ergebnisse der Dauerüberwachung an einem Prototypen von Offshore-Windenergieanlagen Düsseldorf VDI-Verl. 2009 VDI-Berichte - Baudynamik 2063 978-3-18-092063-4 3. VDI-Fachtagung - Baudynamik Kassel, Deutschland 2009-05-14 2009-05-15 455 466 2016-02-19 OPUS4-19872 Beitrag zu einem Tagungsband Rohrmann, Rolf; Rücker, Werner; Thöns, Sebastian; Said, Samir Design and operation of integrated monitoring systems for offshore wind turbines To ensure a high operational reliability of future generations of offshore wind conversion systems (OWEC) with economically acceptable repair and maintenance efforts, comprehensive diagnosis and supervision concepts are required. Automatic monitoring systems will be an essential part of such concepts. Because of the fact, that during operation there will be static and dynamic interaction between the components 'structure', 'machinery' and 'blades' it is necessary to develop the monitoring techniques in an overall concept. These monitoring systems are supposed to be applied for the design and testing as well as for the operation and maintenance phases. The used methods are focused on the design requirements for the structure, which are stated in the respective standards and certification guidelines. For the validation of the design, methods are specified which would be also applicable for SHM in the operating condition, e.g. for the evaluation of the structural conditon possibly after the occurrence of damages or changes. The further task consists in the realization of condition monitoring for all components, aiming at early damage detection and the observation of the damage development and its evaluation. Here the task consists of determining with assessment procedures the optimum time for maintenance actions to be carried out. BARD Engineering GmbH 2008 DEWEK 2008 - 9th German wind energy conference (Proceedings) DEWEK 2008 - 9th German wind energy conference Bremen, Germany 2008-11-26 2008-11-27 1 4(?) 2016-02-19 OPUS4-23712 Beitrag zu einem Tagungsband Rohrmann, Rolf; Thöns, Sebastian; Rücker, Werner; Bicker, S.; Said, Samir; Schmid, Wolfgang Structural investigations and monitoring results on a prototype of offshore wind turbines of multibrid M5000 series The concept and technical details of the implementation of the developed integrated monitoring system within the IMO-WIND project are presented. The tasks of the components of the system and its requirements are described. Selected results from the continuous monitoring during operation of the plant M5000_2 regarding the task design verification and dynamic structural analysis are given. DEWI GmbH 2011 DEWEK 2010 - 10th German wind energy conference (Proceedings) DEWEK 2010 - 10th German wind energy conference Bremen, Germany 2010-11-17 2010-11-18 S03 1 5 2016-02-19 OPUS4-24293 Beitrag zu einem Tagungsband Rohrmann, Rolf; Said, Samir; Schmid, Wolfgang; Thöns, Sebastian; Bicker, S.; Rücker, Werner De Roeck, G.; Degrande, G.; Lombaert, G.; Müller, G. Results from monitoring and assessment of offshore wind turbines To ensure a high operational reliability of offshore wind turbines (OWEC) with economically acceptable repair and maintenance efforts, comprehensive diagnosis and supervision concepts are required. Automatic monitoring Systems will be an essential part of such concepts. Because of the fact, that during Operation there will be static and dynamic interaction between the components 'structure', 'machinery' and 'blades' it is necessary to develop the monitoring techniques in an overall concept. These monitoring Systems are supposed to be applied for the design and testing as well as for the Operation and maintenance phases. The knowledge of the dynamic behavior of wind turbines is important both for the design and for a safe Operation. The available monitoring data from a period of three years, allow first conclusions on the long-term Operation of such Systems in terms of quality requirements to the instrumentation to the structure and the rotor blades Katholieke Universiteit Leuven 2011 EURODYN 2011 - 8th International conference on structural dynamics (Proceedings) 978-90-760-1931-4 EURODYN 2011 - 8th International conference on structural dynamics Leuven, Belgium 04.07.2011 06.07.2011 MS25 3450 3456 2016-02-19 OPUS4-32878 Zeitschriftenartikel Hu, Wei-Hua; Thöns, Sebastian; Rohrmann, Rolf; Said, Samir; Rücker, Werner Vibration-based structural health monitoring of a wind turbine system. Part I: Resonance phenomenon This paper is focused on a resonance phenomenon of a wind turbine system in 5 MW class, on the basis of dynamic signals acquired continuously from the tubular tower under normal operational conditions during two years. Firstly, technique specifications of the wind turbine system are introduced and a finite element model is developed to characterize the structural dynamic properties. The following part describes the continuous dynamic monitoring system integrated with an automated operational modal analysis procedure using the poly-reference Least Squares Complex Frequency domain (p-LSCF) method. Subsequently, variations and mutual relationships of environmental/operational factors such as vibration amplitude, temperature, wind speed, rotation speed of blades, pitch angle and nacelle direction are also presented. Finally, significant resonance is observed due to the fundamental frequency of the tower matching with the harmonic frequency induced by the rotation of three blades. As the rotation speed of rotor approaches to 8 rpm, the vibration amplitude of the tower increases significantly and the corresponding damping value decreases. With the further rising wind velocity, the rotation speed of blades stops increasing and the input energy just contribute to accumulate the vibration amplitude of tower. Such observation indicates the Sommerfeld effect that aggravates the resonance phenomenon. A vibration control device is necessary to minimize the excessive structural responses. A companion paper will further discuss the environmental/operational effects on dynamic properties of the wind turbine system under the operational conditions. Oxford Elsevier Ltd. 2015 Engineering structures 89 260 272 10.1016/j.engstruct.2014.12.034 2016-02-20 OPUS4-32879 Zeitschriftenartikel Hu, Wei-Hua; Thöns, Sebastian; Rohrmann, Rolf; Said, Samir; Rücker, Werner Vibration-based structural health monitoring of a wind turbine system. Part II: Environmental/operational effects on dynamic properties The second part of these companion papers mainly researches environmental/operational influences on structural dynamic properties under normal operational conditions during two years, in order to extract a statistical based damage-sensitive indicator for health monitoring of a wind turbine system. The correlation analyses between experimental identified frequencies, damping values as well as mode shapes and environmental/operational factors such as rotation speed of blades, wind speed, pitch angle, temperature and nacelle direction are presented. It is observed that the frequency estimates are influenced by the nacelle position, the activation of rotor, the rotation speed of blades and the wind speed as well as the temperature. Regarding to the damping estimates, they are mainly associated with variation of the aerodynamic damping due to the increasing wind speed. Besides, the resonance phenomenon is also observed in higher modes. The harmonic frequencies due to blades passing by tower are found and the corresponding damping value decreases. Moreover, the mode shapes in some modes are strongly affected by the position of the nacelle. Subsequently, two types of simulated damage including the reduction of stiffness in both the rotor blade and the tubular tower are successfully detected by applying the Principal Component Analysis (PCA) based methods to these temperature-sensitive frequency estimates. Comparison of change of the extracted health features indicates that they are more sensitive with the tower damage. Oxford Elsevier Ltd. 2015 Engineering structures 89 273 290 10.1016/j.engstruct.2014.12.035 2016-02-20 OPUS4-32970 Beitrag zu einem Tagungsband Hu, Wei-Hua; Thöns, Sebastian; Said, Samir; Rücker, Werner Cunha, A.; Caetano, E.; Ribeiro, P.; Müller, G. Resonance phenomenon in a wind turbine system under operational conditions A prototype of wind turbines in 5 megawatt dass was built and tested at the first German offshore wind energy test fteld in the North Sea. In order to investigate dynamic behaviors under a complex state of loads, a continuous dynamic monitoring System was implemented by Federal Institute for Material Research and Testing (BAM). It recorded structural responses and environmental/operational variables from November 2007 to October 2009. This paper presents significant resonance phenomenon due to the interaction in the tower-nacelle System under operational conditions. Modal parameters are automatically estimated by the poly reference Least Square Complex Frequency domain (p-LSCF) method. Campbell plot demonstrates that a three-blade passage frequency and its multiples f3n match with the natural frequencies of the wind turbine System in several modal Orders. The damping estimates decrease and the Vibration amplitude increase significantly. A control System is necessary to minimize the excessive vibrations. 2014 EURODYN 2014 - 9th International conference on structural dynamics (Proceedings) 978-972-752-165-4 EURODYN 2014 - 9th International conference on structural dynamics Porto, Portugal 30.06.2014 02.07.2014 3619 3626 2016-02-20