TY - CONF A1 - Rücker, Werner A1 - Said, Samir A1 - Rohrmann, Rolf A1 - Schmid, Wolfgang A1 - Hille, Falk A1 - Mehdianpour, Milad T1 - Aufgaben der Dauerüberwachung und baulichen Bewertung am Beispiel von Betonbrücken und Windenergieanlagen T2 - Fachtagung 2005 des Deutschen Ausschusses für Stahlbeton "Zerstörungsfreie Prüfverfahren und Bauwerksdiagnose im Betonbau" CY - Berlin, Deutschland DA - 2005-03-10 KW - Monitoring KW - Zustandsüberwachung KW - Verkehrslasten KW - Dynamik KW - Brücken KW - Windenergieanlagen KW - Bauliche Bewertung PY - 2005 SP - A39 EP - A46 PB - BAM CY - Berlin AN - OPUS4-7334 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hu, Wei-Hua A1 - Rohrmann, Rolf A1 - Said, Samir A1 - Rücker, Werner ED - Xu, Y. L. ED - Zhu, S. ED - Xia, Y. ED - Ni, Y.Q. ED - Law, S.S. ED - Yin, J. H. ED - Su, Z.Q. T1 - Development of a vibration-based structural health monitoring system for wind turbines N2 - In the context of national innovative project IMO-WIND, an integrated long term monitoring System was installed on a prototype of an offshore wind turbine System of 5 megawatt dass. The Federal Institute for Materials Research and Testing (BAM) was responsible for development of the SHM System. It consists of a signal acquisition System and a Signal processing and management System. The signal acquisition System is composed of 14 acceleration sensors, 110 strain gauges and 4 inclination sensors, installed at the tripod foundation and the tower. It began to work in August 2007. In order to investigate the structural dynamic properties, extract efficient damage index and manage huge amounts of Vibration Signals and analysis results, an automated signal processing and management Software System is developed in LabVIEW® environment. It includes functions such as automated Operational Modal Analysis (OMA) on the basis of Stochastic Subspace Identification (SSI) method and poly-reference Least-Squares Complex Frequency Domain (p-LSCF) approach, investigation of environmental/operational effects on structural dynamic properties under operational conditions, features extraction using Principal Component Regression (PCR) and Multiple Linear Regression (MLR) as well as data/result management and visualization. Besides, this paper also presents variations of structural modal parameters of a wind turbine system under complex environmental/operational conditions. Comparison of modal parameters automatically extracted by SSI method and poly-reference p-LSCF approach indicates that the latter method provides more stable modal identification results ffom the viewpoint of long term OMA. Subsequently, the influences of temperature, wind velocity, rotation speed and nacelle direction on modal parameters are generally discussed. Finally, variations of indentified modal parameters during two years are presented. T2 - SHMII-6 - 6th International conference on structural health monitoring of intelligent infrastructure CY - Hong Kong, China DA - 09.12.2013 KW - Wind turbine KW - Vibration-based structural health monitoring system KW - Automated operational modal analysis KW - Environmental and operational effects KW - Feature extraction KW - Damage detection PY - 2013 SN - 978-962-367-768-4 SP - 1 EP - 10 AN - OPUS4-32973 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hu, Wei-Hua A1 - Said, Samir A1 - Rohrmann, Rolf A1 - Rücker, Werner A1 - Cunha, A. T1 - Continuous dynamic monitoring of structures N2 - This paper presents the development of a continuous dynamic monitoring System and its applications to different structures, with the purpose of understanding structural real behaviours under operational conditions and detecting early structural modifications. The first part of paper introduces a complete continuous dynamic System, consists of signal acquisition and communication, automated signal processing and management, investigation of the interaction between structures and its environmental/operational conditions, feature extraction and detection of structural modification. The rest of paper describes the applications of continuous dynamic monitoring System to different structures such as a wind turbine System and a highway bridge. T2 - 13th International symposium on structural engineering (ISSE'13) CY - Hefei, China DA - 24.10.2014 KW - Continuous dynamic monitoring KW - Automated system identification KW - Environmental/operational effects KW - Resonance KW - Feature extraction KW - Structural modification PY - 2014 SN - 978-7-09-042032-9 SP - 1922 EP - 1933 PB - Science Press AN - OPUS4-32971 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz A1 - Said, Samir A1 - Knothe, Esther A1 - Rücker, Werner ED - Cunha, A. ED - Caetano, E. ED - Ribeiro, P. ED - Müller, G. T1 - The dynamic behavior of railway tracks with under sleeper pads, finite-element boundary-element model calculations, laboratory tests and field measurements N2 - A variety of isolation measures exists to reduce the vibration in the neighbourhood of railway lines. They can be roughly classified as elastic or stiffening systems. There are the following elastic elements, rail pads or resilient fixation systems between rail and sleeper, under sleeper pads or sleeper shoes under the sleepers, and ballast mats under the ballast. Stiffening systems (plates) are used as slab tracks, floating slab tracks, or mass-spring systems. In the EU project “Railway induced vibration abatement solutions (RIVAS)”, elastic under sleeper pads have been investigated. The dynamic behaviour of the track and the surrounding soil has been calculated by the combined finite-element boundary-element method in a systematic parameter study. It has been shown that the mitigation effect can be improved by soft under sleeper pads or by heavy sleepers. Consequently, such track elements (soft under sleeper pads and heavy sleepers) have been thoroughly investigated in laboratory tests to establish the static and dynamic parameters as well as their serviceability. Finally, field tests at and near railway tracks with and without under sleeper pads have been performed. To determine the reduction effect of the isolated track, the ground vibrations excited by trains or artificial sources have been measured. The soil properties at the different sites have also been measured so that the comparison of the isolated and un-isolated track can take into account possible differences of the soil parameters. The contribution shows how the different (numerical, laboratory and field) methods and results can be combined to achieve an improved mitigation solution with soft under sleeper pads and heavy sleepers for ballasted and slab tracks. T2 - EURODYN 2014 - 9th International conference on structural dynamics CY - Porto, Portugal DA - 30.06.2014 KW - Railway track KW - Track-soil interaction KW - Mitigation KW - Under sleeper pads KW - Laboratory tests KW - Field tests KW - Ground vibration PY - 2014 SN - 978-972-752-165-4 SN - 2311-9020 SP - 805 EP - 812 AN - OPUS4-31164 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rücker, Werner A1 - Said, Samir A1 - Auersch, Lutz T1 - Verkehrserschütterungen - Entstehung, Ausbreitung und bautechnische Beurteilung T2 - 12. Dresdner Baustatik-Seminar "Schwingungen in der Baupraxis" CY - Dresden, Deutschland DA - 2008-10-17 KW - Verkehrserschütterungen KW - Prognoseverfahren KW - Bodendynamik KW - Eisenbahnschwingungen PY - 2008 SN - 1615-9705 SP - 133 EP - 155 CY - Dresden AN - OPUS4-18803 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Rücker, Werner A1 - Said, Samir A1 - Schmid, Wolfgang A1 - Rohrmann, Rolf T1 - Zustandsüberwachung der Gärtnerplatzbrücke in Kassel unter Verwendung gemessener Einflusslinien T2 - 3. VDI-Fachtagung - Baudynamik CY - Kassel, Deutschland DA - 2009-05-14 KW - Schadensanalyse KW - Neigungseinflusslinie KW - Fußgängerbrücke KW - Ultrahochfester Beton PY - 2009 SN - 978-3-18-092063-4 SN - 0083-5560 VL - 2063 SP - 81 EP - 91 PB - VDI-Verl. CY - Düsseldorf AN - OPUS4-19861 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rücker, Werner A1 - Rohrmann, Rolf A1 - Said, Samir T1 - IMO-WIND: Ein integrales Monitoring-System für Offshore-Windenergieanlagen T2 - Workshop "Windkraftanlagen - Sicherheit und Zuverlässigkeit" CY - Darmstadt, Deutschland DA - 2004-11-04 KW - Wind Energy KW - Offshore Structures KW - Damage Detection KW - Health Monitoring KW - Modal analysis KW - Design Improvement KW - Embedded Sensors KW - Offshore KW - Windenergieanlagen KW - Dynamische Untersuchungen KW - Dauerüberwachung KW - Schadensfrüherkennung KW - Sensorik PY - 2004 SP - 13 Seiten PB - VDI-Verl. CY - Düsseldorf AN - OPUS4-4713 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Rücker, Werner A1 - Rohrmann, Rolf A1 - Said, Samir A1 - Schmidt, Wolfgang ED - Feltrin, G. ED - Wenk, T. T1 - Dynamische Verfahren zur Sicherheitsüberwachung von Brückenbauwerken N2 - Referat: Nach dem gegenwärtigen Stand der Prognosen wird in den nächsten 10 bis 15 Jahren eine Zunahme des Güterverkehrs in Deutschland um 50 % angenommen. Im Jahre 2001 wurden 85 % aller transportierten Güter auf der Straße bewegt. Dies bedeutet, daß die vorhandenen Ingenieurbauwerke innerhalb der Verkehrsinfrastruktur mit zunehmendem Alter immer höhere Belastungen ertragen müssen. Zum anderen werden die zur Verfügung stehenden Mittel zum Ersatz dieser Infrastrukturbauwerke immer geringer. Eine aktuelle Bewertung dieser Bauwerke bezüglich ihrer Sicherheit und Gebrauchsfähigkeit erfordert deshalb zusätzliche Informationen hinsichtlich Art und Umfang eventuell vorhandener Schäden, deren Auswirkung auf die aktuelle Tragwirkung und Tragfähigkeit sowie Information über die vergangenen, gegenwärtigen und zukünftigen Lasteinwirkungen. T2 - D-A-CH-Tagung 2003 CY - Zürich, Schweiz DA - 2003-09-18 KW - Tragfähigkeit von Brücken KW - Dynamische Untersuchungen KW - Dauerüberwachung KW - Verkehrslasten KW - baulicher Zustand PY - 2003 UR - http://www.baufachinformation.de/aufsatz.jsp?ul=05029003231 SN - 3-908483-74-3 SP - 35 EP - 42 PB - SIA CY - Zürich AN - OPUS4-2850 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rücker, Werner A1 - Rohrmann, Rolf A1 - Said, Samir T1 - Monitoring and assessment of structures under changed loading conditions T2 - SAMCO Summer Academy 2005 on Structural Assessment, Monitoring and control CY - Zell am See, Austria DA - 2005-09-05 KW - Monitoring KW - Assessment KW - Vibration PY - 2005 SP - 10 pages PB - Samco Network CY - Zell am See AN - OPUS4-11869 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rücker, Werner A1 - Rohrmann, Rolf A1 - Said, Samir T1 - Monitoring, Schadensfrüherkennung und Sensorik für Offshore-Windenergieanlagen T2 - 4. Symposium Offshore-Windenergie Bau- und umwelttechnische Aspekte CY - Hannover, Deutschland DA - 2005-09-27 KW - Monitoring KW - Zustandüberwachung KW - Schadensanalyse KW - Windlasten KW - Dynamik KW - Windenergieanlagen KW - Offshore KW - Bauliche Bewertung PY - 2005 VL - 4 IS - Beitrag 5 SP - 1(?) EP - 12(?) CY - Hannover AN - OPUS4-11871 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rücker, Werner A1 - Rohrmann, Rolf A1 - Said, Samir T1 - Offshore wind energy plants- a challenge for integrated structural health monitoring systems T2 - International Workshop on Lifetime Engineering of Civil Infrastructure CY - Ube Yamaguchi, Japan DA - 2005-11-09 KW - Offshore wind energy turbines KW - Structural health monitoring KW - Early damage detection KW - Control of dynamic behavior KW - Structural assessment PY - 2005 SP - 219 EP - 229 PB - Yamaguchi University CY - Ube Yamaguchi AN - OPUS4-12257 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz A1 - Said, Samir A1 - Schmid, Wolfgang A1 - Rücker, Werner T1 - Erschütterungen im Bauwesen: Messergebnisse an verschiedenen Gebäuden und eine einfache Berechnung von Fundament-, Wand- und Deckenschwingungen (Teil 1) PY - 2004 SN - 0005-6650 SN - 1436-4867 IS - 79 SP - 185 EP - 192 PB - Springer-VDI-Verl. CY - Düsseldorf AN - OPUS4-11507 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz A1 - Said, Samir A1 - Schmid, Wolfgang A1 - Rücker, Werner T1 - Erschütterungen im Bauwesen: Messergebnisse an verschiedenen Gebäuden und eine einfache Berechnung von Fundament-, Wand- und Deckenschwingungen (Teil 2) PY - 2004 SN - 0005-6650 SN - 1436-4867 SP - 291 EP - 299 PB - Springer-VDI-Verl. CY - Düsseldorf AN - OPUS4-11508 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Auersch, Lutz A1 - Rohrmann, Rolf A1 - Rücker, Werner A1 - Said, Samir T1 - Fahrzeug-Fahrweg-Untergrund-Umgebung: theoretische, rechnen- und meßtechnische Untersuchungen T2 - VDI-Tagung CY - Würzburg, Deutschland DA - 1987-06-01 PY - 1987 SN - 3-18-090635-9 SN - 0083-5560 N1 - Serientitel: VDI-Berichte – Series title: VDI-Berichte IS - 635 SP - 59 EP - 87 PB - VDI-Verl. CY - Düsseldorf AN - OPUS4-11511 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rücker, Werner A1 - Auersch, Lutz A1 - Said, Samir T1 - Reduzierung von Schienenverkehrserschütterungen T2 - D-A-CH-Tagung CY - Zürich, Schweiz DA - 1997-09-25 PY - 1997 IS - D 145 SP - 1(?) EP - 6(?) PB - SIA CY - Zürich AN - OPUS4-11581 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Auersch, Lutz A1 - Said, Samir A1 - Rücker, Werner T1 - Schwingungsminderung zwischen Quelle und Empfänger - FEM-Berechnung der Wellenausbreitung im Boden T2 - Messunsicherheit praxisgerecht bestimmen CY - Kassel, Germany DA - 17.05.2006 PY - 2006 SN - 3-18-091947-7 N1 - Serientitel: VDI-Berichte – Series title: VDI-Berichte IS - 1941 SP - 425 EP - 434 PB - VDI-Verl. CY - Düsseldorf AN - OPUS4-14052 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Auersch, Lutz A1 - Said, Samir A1 - Rücker, Werner ED - Sarsby, R. T1 - Prospecting soft deposits by wave propagation analysis in theory and experiment T2 - 3rd International Symposium on Geotechnics Related to the European Environment ; 3rd GREEN CY - Berlin, Germany DA - 2000-06-21 PY - 2001 SN - 0-7277-3004-5 SP - 65 EP - 73 PB - Telford CY - London AN - OPUS4-1594 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Auersch, Lutz A1 - Semrau, Norbert A1 - Schmid, Wolfgang A1 - Said, Samir A1 - Rücker, Werner ED - Grundmann, H. ED - Schuëller, G. I. T1 - Theory and experiments on wave propagation, on track-soil and on soil-building interaction related to railway induced vibration T2 - 5th International Conference on Structural Dynamics ; 4th International Conference on Structural Dynamics ; EURODYN 2002 CY - Munich, Germany DA - 2002-09-02 PY - 2002 SN - 90-5809-512-6 VL - 2 SP - 1137 EP - 1142 PB - Balkema CY - Lisse AN - OPUS4-1595 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hu, Wei-Hua A1 - Said, Samir A1 - Rohrmann, Rolf A1 - Rücker, Werner A1 - Cunha, A. A1 - Rogge, Andreas ED - De Stefano, A. T1 - Vibration-based structural health monitoring of a highway bridge based on continuous dynamic measurements during 14 years N2 - This paper presents the continuous dynamic measurements of an aging prestressed box-beam bridge during the period from 2000 to 2013, which consists of dynamic properties and environmental/operational factors, as well as the Variation of the extracted health features after removing the environmental/operational effects. Firstly, the variations of frequency estimates, temperatures and traffic loads from 2000 to 2013 are described. Subsequently, correlation analysis between them indicates the nonlinear influences of the temperature on the frequency estimates. The Multiple Linear Regression (MLR) method is used to remove the environmental/operational effects and the health index is proposed by performing the Novelty Detection analysis of the residual errors. Finally, the variations of the health index may indicate clear structural modifications that can be also characterized by the long term monitoring of the dynamic strain in the prestressed cable. T2 - SHMII-7 - 7th International conference on structural health monitoring of intelligent infrastructure CY - Torino, Italy DA - 01.07.2015 KW - Westend bridge PY - 2015 SP - 1 EP - 12 AN - OPUS4-35124 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Rücker, Werner A1 - Said, Samir T1 - Erschütterungsübertragung zwischen U-Bahntunneln und dicht benachbarten Gebäuden N2 - Mit dieser Untersuchung sollen Grundlagen zur zuverlässigen Erschütterungsprognose von Nah-, Fern-, oder Hochgeschwindigkeitszügen geschaffen werden. Ein besonderes Problem stellen Fälle dar, in denen sich die Trasse dicht an oder unter Gebäuden befindet. T3 - BAM Forschungsberichtreihe - 199 PY - 1994 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-2510 SN - 978-3-89429-422-1 SN - 0938-5533 VL - 199 SP - 1 EP - 186 PB - Wirtschaftsverlag NW CY - Bremerhaven AN - OPUS4-251 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Auersch, Lutz A1 - Said, Samir A1 - Rücker, Werner T1 - Das Fahrzeug-Fahrweg-Verhalten und die Umgebungserschütterungen bei Eisenbahnen N2 - In dem Forschungsvorhaben „Das Fahrzeug-Fahrweg-Verhalten“ im Hinblick auf die Prognose von Zugerschütterungen und die Optimierung von Minderungsmaßnahmen – Förderkennzeichen BMBF 9346 - wurden sehr komplexe, vielfältig ineinander verzahnte und simultane Fahrzeug-, Fahrweg-, Brücken- und Zugmessungen durchgeführt. Mit diesem umfangreichen Arbeitsprogramm wurde die Relevanz verschiedener Anregungs- und Beanspruchungsanteile untersucht und eine Reihe von Messmethoden für diese Anteile herausgearbeitet, sowie Minderungsmöglichkeiten für die dynamischen Radlasten und für die Erschütterungen in der Umgebung von Bahnlinien zusammengestellt und bewertet. T3 - BAM Forschungsberichtreihe - 243 KW - Fahrzeugschwingungen KW - Fahrwegnachgiebigkeit KW - Dynamische Radlasten KW - Simultanmessungen KW - Bodenerschütterungen KW - Feste Fahrbahn KW - Brückengleis KW - Fahrgeschwindigkeit PY - 2001 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-2073 SN - 978-3-89701-565-X SN - 0938-5533 VL - 243 SP - 1 EP - 168 PB - Wirtschaftsverlag NW CY - Bremerhaven AN - OPUS4-207 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rohrmann, Rolf A1 - Thöns, Sebastian A1 - Rücker, Werner A1 - Bicker, S. A1 - Said, Samir A1 - Schmid, Wolfgang T1 - Structural investigations and monitoring results on a prototype of offshore wind turbines of multibrid M5000 series N2 - 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. T2 - DEWEK 2010 - 10th German wind energy conference CY - Bremen, Germany DA - 2010-11-17 KW - Integrated monitoring system KW - Offshore wind turbines KW - Design verification KW - Structural assessment KW - Limit values KW - Load transfer KW - Data management KW - Dynamic analysis KW - Rotor blades KW - Embedded sensors PY - 2011 IS - S03 SP - 1 EP - 5 PB - DEWI GmbH AN - OPUS4-23712 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Rohrmann, Rolf A1 - Rücker, Werner A1 - Thöns, Sebastian A1 - Said, Samir A1 - Schmid, Wolfgang T1 - Ergebnisse der Dauerüberwachung an einem Prototypen von Offshore-Windenergieanlagen T2 - 3. VDI-Fachtagung - Baudynamik CY - Kassel, Deutschland DA - 2009-05-14 KW - Integrated Monitoring System KW - Offshore wind turbines KW - Assessment KW - Damage identification KW - Load monitoring PY - 2009 SN - 978-3-18-092063-4 SN - 0083-5560 VL - 2063 SP - 455 EP - 466 PB - VDI-Verl. CY - Düsseldorf AN - OPUS4-19795 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rücker, Werner A1 - Thöns, Sebastian A1 - Said, Samir A1 - Schmid, Wolfgang ED - Zingoni, A. T1 - SHM strategies, application and measurements on tripod offshore wind energy converters within the German offshore park Alpha Ventus N2 - 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. T2 - Research and applications in structural engineering, mechanics and computation - 5th International conference on structural engineering, mechanics and computation CY - Cape Town, South Africa DA - 02.09.2013 PY - 2013 SN - 978-1-138-00061-2 SN - 978-1-315-85078-8 SP - 977 EP - 982 PB - CRC Press AN - OPUS4-29104 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hu, Wei-Hua A1 - Thöns, Sebastian A1 - Rohrmann, Rolf A1 - Said, Samir A1 - Rücker, Werner T1 - Vibration-based structural health monitoring of a wind turbine system. Part II: Environmental/operational effects on dynamic properties N2 - 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. KW - Vibration KW - Structural health monitoring KW - Wind turbine KW - Environmental/operational effects KW - Modal properties KW - Principal Component Analysis KW - Novelty analysis KW - Damage detection KW - Sommerfeld effect KW - Automated operational modal analysis KW - Resonance PY - 2015 DO - https://doi.org/10.1016/j.engstruct.2014.12.035 SN - 0141-0296 VL - 89 SP - 273 EP - 290 PB - Elsevier Ltd. CY - Oxford AN - OPUS4-32879 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hu, Wei-Hua A1 - Thöns, Sebastian A1 - Rohrmann, Rolf A1 - Said, Samir A1 - Rücker, Werner T1 - Vibration-based structural health monitoring of a wind turbine system. Part I: Resonance phenomenon N2 - 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. KW - Vibration KW - Structural health monitoring KW - Wind turbine KW - Automated operational modal analysis KW - Resonance KW - Sommerfeld effect PY - 2015 DO - https://doi.org/10.1016/j.engstruct.2014.12.034 SN - 0141-0296 VL - 89 SP - 260 EP - 272 PB - Elsevier Ltd. CY - Oxford AN - OPUS4-32878 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rohrmann, Rolf A1 - Rücker, Werner A1 - Thöns, Sebastian A1 - Said, Samir T1 - Design and operation of integrated monitoring systems for offshore wind turbines N2 - 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. T2 - DEWEK 2008 - 9th German wind energy conference CY - Bremen, Germany DA - 2008-11-26 KW - Integrated monitoring system KW - Offshore wind turbines KW - Assessment KW - Damage identification KW - Load monitoring PY - 2008 SP - 1 EP - 4(?) AN - OPUS4-19872 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hu, Wei-Hua A1 - Thöns, Sebastian A1 - Said, Samir A1 - Rücker, Werner ED - Cunha, A. ED - Caetano, E. ED - Ribeiro, P. ED - Müller, G. T1 - Resonance phenomenon in a wind turbine system under operational conditions N2 - 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. T2 - EURODYN 2014 - 9th International conference on structural dynamics CY - Porto, Portugal DA - 30.06.2014 KW - Wind turbine KW - Tower-nacelle system KW - Resonance KW - Continuous dynamic monitoring KW - Automated operational modal analysis PY - 2014 SN - 978-972-752-165-4 SN - 2311-9020 SP - 3619 EP - 3626 AN - OPUS4-32970 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rohrmann, Rolf A1 - Said, Samir A1 - Schmid, Wolfgang A1 - Thöns, Sebastian A1 - Bicker, S. A1 - Rücker, Werner ED - De Roeck, G. ED - Degrande, G. ED - Lombaert, G. ED - Müller, G. T1 - Results from monitoring and assessment of offshore wind turbines N2 - 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 T2 - EURODYN 2011 - 8th International conference on structural dynamics CY - Leuven, Belgium DA - 04.07.2011 KW - Integrated monitoring system KW - Offshore wind turbines KW - Structural assessment KW - Limit values KW - Measurement hardware KW - Data management KW - Embedded FBG sensors KW - Data analysis KW - Damage detection KW - Rotor blades PY - 2011 SN - 978-90-760-1931-4 IS - MS25 SP - 3450 EP - 3456 AN - OPUS4-24293 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -