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 OPUS4-790 Beitrag zu einem Tagungsband Habel, Wolfgang; Hofmann, Detlef; Basedau, Frank Rückwirkungsarme faseroptische Dehnungssensoren für weiche Materialien und Verbundwerkstoffe Düsseldorf VDI-Verl. Gesellschaft Mess- und Regelungstechnik / Gemeinschaft Experimentelle Spannungsanalyse 1999 Anspruch und Tendenzen in der experimentellen Strukturmechanik 3-18-091463-7 GESA-Symposium 1999 Warnemünde, Deutschland 1999-05-06 1999-05-07 103 112 2016-02-19 OPUS4-1457 Beitrag zu einem Sammelband Habel, Wolfgang; Hofmann, Detlef; Basedau, Frank; Brandes, Klaus; Barner, Andreas; Crail, S.; Reichel, D.; Schreiner, U.; Ecke, W. Inaudi, D. Strain monitoring of a newly developed precast concrete track for high speed railway traffic using embedded fiber-optic sensors Bellingham, Wash. SPIE 2002 Smart structures and materials 2002 - Smart sensor technology and measurement systems 0-8194-4442-1 4694 259 264 2016-02-19 OPUS4-1458 Beitrag zu einem Sammelband Habel, Wolfgang; Hofmann, Detlef; Gutmann, Toivo; Basedau, Frank; Molter, M.; Hegger, J. Inaudi, D. Characterization of bond performance of textiles in cement matrices using fiber optic sensors Bellingham, Wash. SPIE 2002 Smart structures and materials 2002 - Smart sensor technology and measurement systems 0-8194-4442-1 Smart structures and materials 2002 - Smart sensor technology and measurement systems San Diego, CA, USA 2002-03-18 2002-03-19 4694 253 258 10.1117/12.472626 2016-02-19 OPUS4-1474 Zeitschriftenartikel Hofmann, Detlef; Habel, Wolfgang; Gutmann, Toivo; Basedau, Frank; Molter, M.; Hegger, J.; Will, N. Untersuchungen an textilbewehrtem Beton München Carl Hanser Verlag Bundesanstalt für Materialforschung und -prüfung 2002 Materialprüfung = Materials testing 44 5 194 198 2016-02-19 OPUS4-1725 Beitrag zu einem Sammelband Reichel, D.; Schreiner, U.; Lindner, E.; Habel, Wolfgang; Hofmann, Detlef; Basedau, Frank; Barner, Daniel Mencík, J. Strain Monitoring of a High Speed Railway Track Using Embedded Fibre-Optic Sensors Pardubice Univ. International Conference Reliability and Diagnostics of Transport Structures and Means 2002 Reliability and diagnostics of transport structures and means 2002 9788071944645 First International Conference Reliability and Diagnostics of Transport Structures and Means Pardubice, Czech Republic 2002-09-26 2002-09-27 2016-02-19 OPUS4-1755 Beitrag zu einem Sammelband Habel, Wolfgang; Hofmann, Detlef; Basedau, Frank; Barner, Andreas; Crail, S.; Reichel, D.; Schreiner, U.; Lindner, E. Static and dynamic measurements on a newly developed precast concrete track for high speed railway traffic using embedded fiber-optic sensors Düsseldorf VDI-Verl. Gesellschaft Mess- und Automatisierungstechnik 2002 Proceedings of the International Conference on Force, Mass, Torque, Hardness and Civil Engineering Metrology in the Age Globalization 3-18-091685-0 International Conference on Force, Mass, Torque, Hardness and Civil Engineering Metrology in the Age Globalization Celle, Germany 2002-09-24 2002-09-26 1685 147 152 2016-02-19 OPUS4-2374 Beitrag zu einem Sammelband Crail, S.; Reichel, D.; Schreiner, U.; Lindner, E.; Habel, Wolfgang; Hofmann, Detlef; Basedau, Frank; Barner, Andreas Casciati, F. Strain Monitoring of a High Speed Railway Track Using Embedded Fibre-Optic Sensors Chichester Wiley International Association for Structural Control 2003 Proceedings of the Third World Conference on Structural Control 2 0-471-48980-8 903 909 2016-02-19 OPUS4-3844 Beitrag zu einem Sammelband Hofmann, Detlef; Basedau, Frank; Habel, Wolfgang; Gloetzl, R. López-Higuera, J. M. Lightning-safe diaphragm pressure gauge for geotechnical applications using a long-term reliable absolute EFPI sensor Bellingham, Wash. SPIE Universidad de Cantabria, Santander / Grupo de Ingeniería Fotónica 2004 Second European Workshop on Optical Fibre Sensors 0-8194-5434-6 2nd European Workshop on Optical Fibre Sensors ; 2nd EWOFS '04 Santander, Spain 2004-06-09 2004-06-11 5502 128 131 10.1117/12.566543 2016-02-19 OPUS4-43371 Beitrag zu einem Sammelband Daum, Werner; Hofmann, Detlef; Basedau, Frank; Brandes, K.; Kubowitz, P. Curbach, M.; Opitz, H.; Scheerer, S.; Hampel, T. Erweiterte Strukturabbildung von Brücken mit adaptiven mathematischen Modellen zur Lösung aktueller noch ungelöster Probleme Health monitoring von größeren Strukturen erfordert die Betrachtung der gesamten Struktur, indem sowohl jener Bereich, der experimentell behandelt wird, als auch derjenige, der einer analytischen mechanischen Untersuchung unterzogen wird, in einem Gesamtzusammenhang erfasst wird. Die umfassende Behandlung des Problems gelingt dann in einer Gesamtmatrix, die im Beitrag vorgestellt wird. Auf eine Erweiterung der Methode zur Detektierung anwachsender Schädigungen wird hingewiesen. Dresden Institut für Massivbau, TU Dresden 2017 9. Symposium Experimentelle Untersuchungen von Baukonstruktionen Konstruktiver Ingenieurbau Dresden 43 183 188 urn:nbn:de:bsz:14-qucosa-201229 http://creativecommons.org/licenses/by/3.0/de/deed.de 2017-12-11 OPUS4-45892 Beitrag zu einem Tagungsband Eisermann, René; Basedau, Frank; Kadoke, Daniel; Gründer, Peter; Schoppa, André; Lehr, Christian; Szczepaniak, Mariusz; John, Sebastian; Schukar, Marcus; Munzke, Dorit; Mair, Georg W. Distributed strain sensing with sub-centimetre resolution for the characterisation of structural inhomogeneities and material degradation of industrial high-pressure composite cylinders Fibre-reinforced plastics (FRP) especially carbon-fibre-reinforced polymer (CFRP) and glass-fibre-reinforced polymer (GFRP) are commonly used materials in high pressure vessels and storage units for automotive and aerospace purposes. Optical fibres are suitable to be integrated or directly applied to the surface of FRP components. Using optical fibres it is possible to monitor the distributed strain profiles and changes within the fatigue life of a pressure vessel to ensure the operational safety. Within artificial ageing experiments we used swept wavelength interferometry (SWI) based distributed strain sensing for the monitoring of commercial high-pressure composite cylinder. This artificial ageing was performed using test conditions of 503bar pressure load (service pressure 300 bar) and 89 °C for 100 h. The polyimide coated optical fibres were glued to the surface externally in circumferential and axial direction. Using distributed strain sensing (DSS) material expansion of over 0.5% were monitored with sub-centimetre spatial resolution. Within the circumferential direction we observed up to 10 % local fluctuation compared to the median strain caused by inhomogeneous material expansion, which could cause local material fatigue. In addition, we determined material degradation manifested itself as localized remaining material expansion and/or contraction. Results have been validated by other non-destructive methods like digital strip projection. 2018 Proceedings of EWSHM 2018 9th European Workshop on Structural Health Monitoring (EWSHM) Manchester, UK 10.07.2018 13.07.2018 1 8 urn:nbn:de:kobv:b43-458926 https://creativecommons.org/licenses/by-nc/4.0/deed.de 2018-09-11 OPUS4-44599 Beitrag zu einem Tagungsband Beck, Uwe; Mitzkus, Anja; Sahre, Mario; Weise, Matthias; Köppe, Enrico; Bartholmai, Matthias; Basedau, Frank; Hofmann, Detlef; Schukar, Vivien Faser-basierter magneto-optischer Schicht-Sensor zum Monitoring von Bauteilen In Glasfasern eingeschriebene Bragg-Gitter (FBG: fibre-based Bragg gratings) sind über die Verschiebung der Bragg-Wellenlänge in der Lage, Stauchungen und Dehnungen von Glasfasern hochgenau zu erfassen. In Kompositwerkstoffe eingebettete faseroptische Sensoren können Bauteile bezüglich ihrer mechanischen Integrität überwachen und früh-zeitig Informationen über Materialveränderungen gewinnen. Um die Zuverlässigkeit eines solchen Sensors zu gewährleisten, ist es wichtig, die korrekte Funktion des Sensors im Verbund mit der Werkstoff-Matrix on-line und in-situ sicherzu-stellen. Im Rahmen des DFG-Projekts FAMOS² (FAser-basierter Magneto-Optischer SchichtSensor) wurde ein selbstdiagnosefähiger Schichtsensor entwickelt, der mit Hilfe von magnetostriktiven Aktorschichten aus Nickel bzw. Eisen-Nickel validiert werden kann. Der FAMOS²-Schichtsensor wird durch ein PVD (physical vapour deposition)/ECD (electro-chemical deposition) Hybridschichtsystem realisiert, das auf dem Fasermantel im Bereich des FBG haftfest, homogen und langzeitfunktional abzuscheiden ist. Dabei wird in einem ersten Schritt ein etwa 100 Nanometer dünnes PVD-Schichtsystem aus Chrom und Kupfer als Haftvermittler auf der Glasfaser bzw. als leitfähige Startschicht für den nachfolgenden ECD-Prozess abgeschieden. Um eine rotationssymmetrische Schich-tabscheidung zu gewährleisten, erfolgt während der PVD-Beschichtung eine Rotation der Glasfasern. In einem zweiten Schritt wird dann unter Verwendung eines klassischen Watts-Elektrolyten in einer speziell entwickelten ebenfalls rotationssymmetrisch aufgebau-ten ECD-Durchströmungszelle dann die etwa 30 Mikrometer dicke, magnetostriktive Ak-torschicht auf dem PVD-Schichtsystem abgeschieden, im Vergleich sowohl reine Nickel-Schichten als auch Nickel-Eisen-Schichten. Ein äußeres Magnetfeld dehnt die magnetostriktive Aktorschicht und damit auch die Faser reversibel. Diese Dehnung führt zu einer Verschiebung der Bragg-Wellenlänge, welche direkt mit der Stärke eines zu messenden oder zu Validierungszwecken vorgegebenen Magnetfeldes korreliert. Die Anpassung der Beschichtungsverfahren an die Fasergeome-trie und die mechanischen Eigenschaften der Hybridschichten werden hinsichtlich der me-chanischen Integrität des faseroptischen Sensors diskutiert und der Nachweis der Selbst-diagnosefähigkeit erbracht. Jena Herausgeber: INNOVENT e.V. 2018 13. ThGOT Thementage Grenz- und Oberflächentechnik und 11. Thüringer Biomaterial-Kolloquium 978-3-00-058187-8 13. ThGOT Thementage Grenz- und Oberflächentechnik und 11. Thüringer Biomaterial-Kolloquium Zeulenroda, Germany 13.03.2018 15.03.2018 1 5 2018-04-04 OPUS4-46333 Posterpräsentation Hofmann, Detlef; Basedau, Frank; Pötschke, Samuel; Breithaupt, Mathias Funktionsprinzip faseroptischer Sensoren Das Poster präsentiert die Grundlagen zur Funktionsweise optischer Fasern bzw. faseroptischer Sensoren, die im Rahmen eines Feldversuchs zum Einsatz kommen. 2018 Tag der offenen Tür auf dem Testgelände der BAM (BAM TTS) Horstwalde, Germany 29.09.2018 29.09.2018 2018-10-24 OPUS4-46334 Posterpräsentation Hofmann, Detlef; Basedau, Frank; Pötschke, Samuel; Breithaupt, Mathias Die durchleuchtete Brücke Das Poster gibt einen Überblick zum Themenfeldprojekt BLEIB und präsentiert ausgewählte Ergebnisse faseroptischer Messungen bei verschiedenen Belastungsszenarien an der Versuchsbrücke. 2018 Tag der offenen Tür auf dem Testgelände der BAM (BAM TTS) Horstwalde, Germany 29.09.2018 29.09.2018 2018-10-24 OPUS4-47738 Zeitschriftenartikel Mitzkus, Anja; Sahre, Mario; Basedau, Frank; Hofman, Detlef; Beck, Uwe Fiber Bragg Gratings for In-Situ Stress Monitoring of Electrochemical Deposition The in-situ monitoring of electrochemical deposition (ECD) processes is still a challenge regarding the measurement of the effective temperature of the substrate and the formation of mechanical stress in the layer under given plating conditions. Monitoring problems can be solved by applying a pre-coated fiber Bragg grating (FBG) to the electrolytic process as the shift of the Bragg wavelength is affected by both the temperature of the electrolyte near the substrate and the stress formation in the growing layer. The experimental FBG set-up and the quantitative determination of temperature- and stress-related strain is described for a nickel-iron electrolyte. Pennington, NJ Electrochemical Society 2019 Journal of The Electrochemical Society 166 6 B312 B315 10.1149/2.0111906jes 2019-04-08 OPUS4-51687 Beitrag zu einem Tagungsband Hofmann, Detlef; Basedau, Frank; Heidenreich, F.; Herten, M. Verwendung faseroptischer Messtechnik im Zuge wiederholter Eignungsprüfungen an Verpressankern Im Rahmen des Ausbaus des Dortmund-Ems-Kanals wurden an der Schleuse Gleesen Forschungsanker installiert, die Rückschlüsse auf das Tragverhalten in Folge des chemischen Angriffs kalklösender Kohlensäure geben sollen. Die Forschungsanker werden seit der Erstellung im Jahr 2017 mit verteilter faseroptischer Sensorik während der jährlichen Eignungsprüfungen untersucht. Die Ergebnisse der Jahre 2017 bis 2019 werden im Folgenden dargestellt. Institut für Geomechanik und Geotechnik, Technische Universität Braunschweig 2020 Messen in der Geotechnik 2020 978-3-948141-02-8 Messen in der Geotechnik 2020 Braunschweig, Germany 20.02.2020 21.02.2020 110 297 323 10.24355/dbbs.084-201912181435-0 2020-12-02 OPUS4-52476 Zeitschriftenartikel Hüsken, Götz; Pirskawetz, Stephan; Hofmann, Detlef; Basedau, Frank; Gründer, Klaus-Peter; Kadoke, Daniel The load-bearing behaviour of a reinforced concrete beam investigated by optical measuring techniques Bending beams and slabs are typical examples for structural elements used for reinforced concrete structures such as bridge girders, T-beams and bridge decks. Their strength related failure modes at maximum loading can be divided into bending and shear failure. The failure of beams loaded in bending can occur with or without indication. Therefore, conventional design concepts aim on failure modes with sufficient indication (e.g. large deflections or cracks), as it occurs in the case of secondary flexural compression failure. These indicating factors can also be used for Structural Health Monitoring (SHM) of civil infrastructure systems (e.g. bridges) to identify structural changes. In this context, non-destructive testing (NDT) methods offer different techniques for measuring deflections or crack formation and opening. However, profound knowledge on the determining failure modes of bending beams and their detection by NDT methods is required for the reliable application of SHM. Different NDT methods have been used in this study for analysing the load-bearing behaviour of a reinforced concrete beam in bending. The different measuring techniques are briefly described and their applicability is discussed by means of experimental results. For this purpose, the load-bearing behaviour of a reinforced concrete beam having a span of 2.75 m was investigated in a four-point bending flexural test at laboratory scale. The focus is on the characterization of determining failure modes by optical NDT and the comparison with classical measuring techniques (e.g. deformation measurements by displacement transducers). The bending beam was equipped with two single-mode (SM) sensor fibres. One fibre served as Distributed Optical Fibre Sensor (DOFS), whereas the other fibre contained Fibre Bragg Grating (FBG) sensors. In addition, optical deformation measurements using Digital Image Correlation (DIC) and Stereophotogrammetry (SP) were conducted. Springer 2021 Materials and Structures 54 3 Article 102 urn:nbn:de:kobv:b43-524762 10.1617/s11527-021-01699-6 https://creativecommons.org/licenses/by/4.0/deed.de 2021-04-21 OPUS4-11769 Beitrag zu einem Sammelband Gloetzl, R.; Hofmann, Detlef; Basedau, Frank; Habel, Wolfgang Udd, E. Geotechnical Pressure Cell Using a Long-Term Reliable High-Precision Fibre Optic Sensor Head Bellingham SPIE 2005 Smart structures and materials 2005 - Smart sensor technology and measurement systems 0-8194-5739-6 12th SPIE International Symposium "Smart Structures and Materials 2005 San Diego, CA, USA 2005-03-06 2005-03-10 5758 248 253 2016-02-19 OPUS4-39129 Zeitschriftenartikel Mitzkus, Anja; Sahre, Mario; Reinstädt, Philipp; Griepentrog, Michael; Beck, Uwe; Köppe, Enrico; Bartholmai, Matthias; Basedau, Frank; Hofmann, Detlef; Gong, Xin; Schukar, Vivien Altbekannter Watts-Elektrolyt, junge Hightech-Anwendung, Nickel- und Nickel-Eisen-Schichten als magnetostriktive Aktorschicht auf faseroptischen Sensoren Durch faseroptische Sensoren können Bauteile im Einsatz kontinuierlich überwacht und frühzeitig Informationen über Materialveränderungen gewonnen werden. Mittels einer magnetostriktiven Aktorschicht, welche den Sensor umhüllt, kann nun auch die korrekte Sensorfunktion jederzeit kontrolliert werden. Als Aktorschicht eignet sich galvanisch abgeschiedenes reines Nickel oder Nickel-Eisen in der Zusammensetzung 50:50. Um diese haftfest mit dem Sensor zu verbinden wurde ein ECD/PVD-Kombinationsschichtsystem entwickelt. Die mechanischen Eigenschaften der ECD-Schicht können sowohl mit einer auf die Fasergeometrie angepassten instrumentierten Eindringprüfung als auch einem 2-Punkt-Biegeversuch bestimmt werden. 2016 WoMAG 12 1 4 2017-02-09 OPUS4-35173 Beitrag zu einem Tagungsband Köppe, Enrico; Bartholmai, Matthias; Daum, Werner; Gong, Xin; Hofmann, Detlef; Basedau, Frank; Schukar, Vivien; Westphal, Anja; Sahre, Mario; Beck, Uwe New self diagnostic fiber optical sensor technique for structural health monitoring Fiber optic sensors have gained increasing importance in recent years and are well established in many areas of industrial applications. In this paper, we introduce a concept of a self-diagnostic fiber optic sensor. The presented sensor is to resolve the problems of embedded fiber optic sensors in complex structures and to enable the validation under operational conditions. For this purpose, different magnetostrictive coated fiber optic sensors were developed and various experiments were performed to verify their mode of operation and to determine the respective reproducibility. The measuring principle is illustrated by obtained experimental results, which showed a change in wavelength from 1 pm at a magnetic field strength change of 0.25 mT. In addition, the temperature characteristics of the implemented magnetostrictive sensor were analyzed and an experimental factor of 1.5 compared to a reference fiber optic sensor was determined. Zilina Faculty of Mechanical Engineering, Univerzity of Zilina, Slovakia 2015 32nd Danubia-Adria Symposium on advances in experimental mechanics (Proceedings) 978-80-554-1094-4 32nd Danubia-Adria Symposium on advances in experimental mechanics Starý Smokovec, Slovakia 22.09.2015 25.09.2015 1 2 2016-02-20 OPUS4-38634 Beitrag zu einem Tagungsband Schukar, Vivien; Gong, Xin; Hofmann, Detlef; Basedau, Frank; Köppe, Enrico; Bartholmai, Matthias; Westphal, Anja; Sahre, Mario; Beck, Uwe Berghmans, F.; Mignani, A. G. Modelling and simulation of a fibre Bragg grating strain sensor based on a magnetostrictive actuator principle A new concept for the self-diagnosis of embedded fiber Bragg grating (FBG) strain sensors was developed, simulated and experimentally tested. This concept is based on a magnetostrictive metallic layer directly coated on the fibre cladding over the grating segment of the FBG sensor, so that an on-demand external magnetic field in a millitesla scale can produce a controllable artificial strain as an indication signal for the remote optical interrogator. The relationship between the pre-defined magnetic field and its induced Bragg wavelength shift characterizes this validation concept. Any deviation of the local bonding state of the interfaces from the initial or/and any change of shear strain transferring mechanism from composite matrix to the optical fibre core will result in alterations in this sensitive relationship, and thus triggers an immediate alert for a further inspection. The finite element method is used to simulate the strain of this configuration as result of different values of the magnetic field in order to optimize the geometrical sensor parameters. The simulations are verified by experiments results. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only. SPIE Digital Library SPIE - the international society for optics and photonics 2016 Optical Sensing and Detection IV 9899 9781510601444 Optical Sensing and Detection IV Brüssel, Belgium 03.04.2016 07.04.2016 9899-39 10.1117/12.2224728 2016-12-09 OPUS4-20109 Beitrag zu einem Tagungsband Venugopalan, T.; Yeo, T. L.; Basedau, Frank; Henke, Anna-Sophia; Sun, T.; Grattan, K.T.V.; Habel, Wolfgang Evaluation and calibration of FBG-based relative humidity sensor designed for structural health monitoring In this paper, the evaluation and testing of a fibre optic relative humidity sensor specifically designed for structural health monitoring is discussed in detail. The sensor is based on a polymer coated Fibre Bragg Grating (FBG) where with the increase of the moisture level, the polymer coating swells and thus applies strain to the FBG, causing a Bragg wavelength shift. The device is designed so that the temperature effect on the humidity sensor can be compensated by the inclusion of a second un-coated FBG packaged inside the same sensor probe. The sensor thus produced has been tested extensively and calibrated using both a humidity chamber and standard salt solutions. The probe has demonstrated a very good performance for relative humidity measurements. Berlin ; Offenbach VDE-Verl. The International Society for Optical Engineering (SPIE) 2009 Proceedings of SPIE 7503 7503 750310-1 - 750310-5 10.1117/12.835611 2016-02-19 OPUS4-28854 Beitrag zu einem Tagungsband Schilder, Constanze; Kohlhoff, Harald; Hofmann, Detlef; Basedau, Frank; Habel, Wolfgang; Baeßler, Matthias; Niederleithinger, Ernst; Georgi, Steven; Herten, M. Jaroszewicz, L.R. Static and dynamic pile testing of reinforced concrete piles with structure integrated fibre optic strain sensors Static and dynamic pile tests are carried out to determine the load bearing capacity and the quality of reinforced concrete piles. As part of a round robin test to evaluate dynamic load tests, structure integrated fibre optic strain sensors were used to receive more detailed information about the strains along the pile length compared to conventional measurements at the pile head. This paper shows the instrumentation of the pile with extrinsic Fabry-Perot interferometers sensors and fibre Bragg gratings sensors together with the results of the conducted static load test as well as the dynamic load Tests and pile integrity tests. International society for optics and photonics (SPIE) 2013 EWOFS 2013 - 5th European workshop on optical fibre sensors (Proceedings) 8794 978-0-81949-634-8 EWOFS 2013 - 5th European workshop on optical fibre sensors Kraków, Poland 19.05.2013 22.05.2013 Paper 8794 - 181 700 703 10.1117/12.2026813 2016-02-20 OPUS4-29909 Beitrag zu einem Tagungsband Habel, Wolfgang; Schukar, Vivien; Steinke, F.; Basedau, Frank Ilki, A.; Motavalli, M.; Goksu, C.; Havranek, B. Investigation of the fiber-optic strain sensors' beahvior under offshore conditions to create standards for reliable application Istanbul, Turkey Eidgenössische Materialprüfungs- und Forschungsanstalt (EMPA) 2013 SMAR 2013 - 2nd Conference on smart monitoring, assessment and rehabilitation of civil structures (Proceedings) 978-3-033-04055-7 SMAR 2013 - 2nd Conference on smart monitoring, assessment and rehabilitation of civil structures Istanbul, Turkey 2013-09-09 2013-09-11 1 8(?) 2016-02-20 OPUS4-29912 Beitrag zu einem Tagungsband Habel, Wolfgang; Schukar, Vivien; Tkachenko, Viktoriya; Hofmann, Detlef; Basedau, Frank Xu, Y. L.; Zhu, S.; Xia, Y.; Ni, Y.Q.; Law, S.S.; Yin, J. H.; Su, Z.Q. Values gained from composite-embedded sensor fibres - trustworthy results or vague estimations; possibilities and limitations of getting reliable measurement results International society for structural health monitoring of intelligent infrastructure 2013 SHMII-6 - 6th International conference on structural health monitoring of intelligent infrastructure (Proceedings) 978-962-367-768-4 SHMII-6 - 6th International conference on structural health monitoring of intelligent infrastructure Hong Kong, China 2013-12-09 2013-12-11 1 11(?) 2016-02-20 OPUS4-29915 Beitrag zu einem Tagungsband Jentsch, H.; Schwartz, A.; Basedau, Frank; Bazrafshan, K.; Döring, H.; Großwig, S.; Hofmann, Detlef; Kowalle, G.; Kusche, Nadine; Lorenz, R.; Pfeiffer, T.; Sadaghiani, M.R.S.; Scholz, E.; Senze, A.; Tkachenko, Viktoriya; Witt, K. J. Xu, Y. L.; Zhu, S.; Xia, Y.; Ni, Y.Q.; Law, S.S.; Yin, J. H.; Su, Z.Q. Detection of slipping soil areas with embedded tiny vertical sensing rods International society for structural health monitoring of intelligent infrastructure 2013 SHMII-6 - 6th International conference on structural health monitoring of intelligent infrastructure (Proceedings) 978-962-367-768-4 SHMII-6 - 6th International conference on structural health monitoring of intelligent infrastructure Hong Kong, China 2013-12-09 2013-12-11 1 9(?) 2016-02-20 OPUS4-28570 Beitrag zu einem Tagungsband Kusche, Nadine; Schukar, Vivien; Hofmann, Detlef; Basedau, Frank; Habel, Wolfgang; Woschitz, H.; Lienhart, W. Jaroszewicz, L.R. Field examples for optical fibre sensor condition diagnostics based on distributed fibre-optic strain sensing Fibre optic sensors for monitoring in safety-relevant structures have to be validated in order to proof their reliability under typical structural load conditions. The reliable use of optical fibre sensors depends strongly on an appropriate and qualitative application. Diagnostics of the physical condition of embedded and surface-applied fibre optic strain sensors are demonstrated on field examples. Distributed strain measurement based on Rayleigh backscattering is used to determine breakage of the fibre, interface adhesion problems and to identify application related strain transfer mechanisms. International society for optics and photonics (SPIE) 2013 EWOFS 2013 - 5th European workshop on optical fibre sensors (Proceedings) 8794 978-0-81949-634-8 EWOFS 2013 - 5th European workshop on optical fibre sensors Kraków, Poland 19.05.2013 22.05.2013 Paper 8794 - 181 879433-1 879433-4 10.1117/12.2025567 2016-02-20 OPUS4-31039 Beitrag zu einem Tagungsband Steffen, Milan; Liehr, Sascha; Basedau, Frank; Krebber, Katerina López-Higuera, J.M.; Jones, J.; López-Amo, M.; Santos, J.L. Simultaneous vibration and quasi-distributed strain measurement using incoherent OFDR and extrinsic Fabry-Perot interferometers International society for optics and photonics (SPIE) 2014 OFS2014 - 23rd International conference on optical fibre sensors (Proceedings) 9157 OFS2014 - 23rd International conference on optical fibre sensors Santander, Spain 2014-06-02 2014-06-06 91576S-1 - 91576S-4 10.1117/12.2059616 2016-02-20 OPUS4-37131 Zeitschriftenartikel Köppe, Enrico; Bartholmai, Matthias; Daum, Werner; Gong, Xing; Hofmann, Detlef; Basedau, Frank; Schukar, Vivien; Westphal, Anja; Sahre, Mario; Beck, Uwe New self - diagnostic fiber optical sensor technique for structural health monitoring Fiber optic sensors have gained increasing importance in recent years and are well established in many areas of industrial applications. In this paper, we introduce a concept of a self-diagnostic fiber optic sensor. The presented sensor is to resolve the problems of embedded fiber optic sensors in complex structures and to enable the validation under operational conditions. For this purpose, different magnetostrictive coated fiber optic sensors were developed and various experiments were performed to verify their mode of Operation and to determine the respective reproducibility. The measuring principle is illustrated by obtained experimental results, which showed a change in wavelength from 1 pm at a magnetic field strength change of 0.25 mT. In addition, the temperature characteristics of the implemented magnetostrictive sensor were analyzed and an experimental factor of 1.5 compared to a reference fiber optic sensor was determined. 2016 Materials Today: Proceedings 3 32nd DANUBIA ADRIA SYMPOSIUM on Advances in Experimental Mechanics Starý Smokovec, Slovakia 22.09.2015 25.09.2015 4 1009 1013 10.1016/j.matpr.2016.03.038 2016-08-12 OPUS4-34544 Beitrag zu einem Tagungsband Habel, Wolfgang; Basedau, Frank; Hofmann, Detlef; Krebber, Katerina; Jentsch, H.; Senze, A. Ilki, A.; Motavalli, M.; Inci, P.; Köhli, M. Online-detection of slipping soil areas by embedded fiber-optic sensing rods Movements in geological areas are often caused by shear zones deep in the underground or by hardly observable slipping zones. Detection of movements reaching critical values is of crucial importance to avoid losses and harms. Optical sensor fibers with gauge lengths of several meters or even distributed fiber-optic sensors with gauge lengths of hundreds of meters allow detecting deformation of such zones with quite good resolution. The paper presents a new technology of detecting deformations and movements in soil or rock massifs. The core part of the sensing system is a tiny pultruded rod with an outer diameter of 3 mm to 6 mm. It contains two fiber-optic sensor systems. One sensor system is used for permanent online measurement and provides integral strain information along the whole length of the rod; in case of critical deformations, it provides a warning signal. The second sensing system uses fiber-optic Bragg grating (FBG) strain sensors located close to the expected shear zone. This measurement system will be activated after the warning signal has been initiated by the integral strain measurement system. The FBG strain sensor system records then resulting deformations in detail. The sensing rod containing both sensor systems can be installed in a borehole to detect beginning soil movements automatically. The electronic equipment is powered by a solar panel; the amount of deformation in soil or rock formations can be estimated from the strain change measured in the sensor fibers. The effectiveness of this warning system will be shown using the example of a critically sliding slope in an open brown coal pit in Germany. 2015 SMAR 2015 - 3rd Conference on smart monitoring, assessment and rehabilitation of civil structures (Proceedings) 978-3-905594-65-2 SMAR 2015 - 3rd Conference on smart monitoring, assessment and rehabilitation of civil structures Antalya, Turkey 07.09.2015 09.09.2015 Paper 222, 1 8 2016-02-20 OPUS4-34486 Beitrag zu einem Tagungsband Brandes, K.; Daum, Werner; Hofmann, Detlef; Basedau, Frank; Kubowitz, P. Innovative structural damage detection of bridges by least squares adjustment with constraints Zilina Faculty of Mechanical Engineering, Univerzity of Zilina, Slovakia 2015 32nd Danubia-Adria Symposium on advances in experimental mechanics (Proceedings) 978-80-554-1094-4 32nd Danubia-Adria Symposium on advances in experimental mechanics Starý Smokovec, Slovakia 2015-09-22 2015-09-25 18 19 2016-02-20 OPUS4-34793 Beitrag zu einem Tagungsband Brandes, K.; Kubowitz, P.; Daum, Werner; Hofmann, Detlef; Basedau, Frank Lagrange Multiplikator-Test zur Detektierung von zunehmender Strukturschädigung Mit einem auf Lagrange-Multipiikator-Tests basierenden Monitoring von Brücken ist es gelungen, in Belastungsversuchen an einer Holzbrücke (7,25 m Spannweite), an der relativ kleine Schädigungen künstlich herbeigeführt worden waren, die Zuverlässigkeit dieser Art des Monitorings zu bestätigen. Ausgangspunkte waren Messung von Durchbiegungen sowie Krümmungen und die Zusammenführung der jeweiligen Regression mit Nebenbedingungen, die den mechanischen Bedingungen gehorchen, unter Einschluss von Lagrange-Multiplikatoren, die sich als brauchbare Testparameter erwiesen. Dresden Technische Universität Dresden 2015 8. Symposium Experimentelle Untersuchungen von Baukonstruktionen 8. Symposium Experimentelle Untersuchungen von Baukonstruktionen Dresden, Germany 24.09.2015 24.09.2015 40 147 157 2016-02-20 OPUS4-36667 Zeitschriftenartikel Brandes, K.; Daum, Werner; Hofmann, Detlef; Basedau, Frank; Kubowitz, P. Innovative structural damage detection of bridges by least squares adjustment with constraints Long-term monitoring of bridges requires the early detection of spreading damage because very often the damage is not really visible. For many decades engineers and scientists relayed on dynamic methods especially modal ones. However, after fundamental tests by the U.S. FHWA in 1993, it became evident that more successful methods should be developed, but no innovation really happened. A substantial innovative detection method started four years ago from Lagrange Multiplier Testing which eventually resulted in experimental verification based on measurement of deflection and curvature of the bridge beam and together the methodological combination of both. Elsevier 2016 Materials Today: Proceedings 3 32nd DANUBIA ADRIA SYMPOSIUM on Advances in Experimental Mechanics Starý Smokovec – High Tatras, Slovakia 22.09.2015 25.09.2015 4 942 946 10.1016/j.matpr.2016.03.025 2016-06-24 OPUS4-55371 Beitrag zu einem Tagungsband Baensch, Franziska; Hofmann, Detlef; Johann, Sergej; Tiebe, Carlo; Basedau, Frank; Sturm, Patrick; Lay, Vera; Niederleithinger, Ernst Multi-sensor conception for safe sealing structures in underground repositories The project "SealWasteSafe" of the Bundesanstalt für Materialforschung und -prüfung (BAM, Berlin) deals with sealing structures applied for underground disposal of nuclear waste from two perspectives: (1) material improvement for application in sealing constructions and (2) feasibility study regarding multi-sensor approaches to ensure quality assurance and long-term monitoring. One specimen of 150 l made of alkali-activated material, which was found innovative and suitable for sealing constructions based on preliminary laboratory studies, and, for comparison purpose, another one made of salt concrete, are manufactured with an integrated multi-sensory setup for quality assurance and long-term-monitoring. The specimens were left in their cast form and additionally thermally insulated to simulate the situation in the repository. The multi-sensory concept comprises RFID technology embedded in the specimens suppling material temperature and moisture measurements, integrated fibre optic sensing allowing strain measurement and acoustic emission testing for monitoring possible crack formation. Overall, the suitability and the functionality of the sensors embedded into and attached to strongly alkaline (pH > 13 for the AAM) and salt corrosive (NaCl) environment was proven for the first 672 h. First temperature measurement based on RFID succeeded after 626 h for the alkali-activated material and after 192 h for the conventional salt concrete. Strain measurement based on distributed fibre optic sensing turned out the alkali-activated material with > 1 mm m-1 undergoing approximately twice the compression strain as the salt concrete with strains < 0.5 mm m-1. In contrast, the acoustic emission first and single hits representing crack formation in numbers, was found for alkali-activated material half of that detected at the salt concrete. 2022 SMIRT 26 Conference Proceedings SMIRT 26 Berlin/Potsdam, Germany 10.07.2022 15.07.2022 1 10 2022-07-25 OPUS4-31527 Beitrag zu einem Tagungsband Neumann, Patrick P.; Kohlhoff, Harald; Werner, Klaus-Dieter; Erdmann, Jessica; Eggeringhaus, Bärbel; Kammermeier, Michael; Schukar, Marcus; Basedau, Frank; Bartholmai, Matthias; Lazik, D.; Ebert, Sebastian Setup of a large scale soil test field with CO2 injection for testing a novel distributed subsurface monitoring system for gas storage areas One of the main unsolved issues of under-ground storages for, e.g., CO2, H2, and natural gas is the comprehensive surveillance of these areas with reasonable effort and costs. Conventional sensors (e.g., soil air probes or borehole probes), however, can only be used for punctual or locally limited measurements; further their application can cause structural influences (invasive application). In this paper, we describe in detail the setup of a CO2 injection soil test field. This test field will be used to enhance and validate an innovative ap-proach for distributed subsurface monitoring of gas storage areas. To the author's knowledge, this is the first time that, for this purpose, a test field is built in an application relevant scale. Verein Deutscher Ingenieure (VDI) 2014 31st Danubia-Adria Symposium on advances in experimental mechanics (Proceedings) 978-3-00-046740-0 31st Danubia-Adria Symposium on advances in experimental mechanics Kempten, Germany 24.09.2014 27.09.2014 238 239 2016-02-20