TY - CONF A1 - Rohwetter, Philipp A1 - Eisermann, René A1 - Krebber, Katerina ED - Kalinowski, H.J. ED - Fabris, J.L. ED - Bock, W.J. T1 - Distributed acoustic sensing: Towards partial discharge monitoring N2 - We report on the successful application of distributed acoustic sensing (DAS) to the detection of partial discharge (PD). A detection limit of about 1 nC discharge magnitude was achieved for PD in a real-scale model of a high voltage termination. Dedicated ultrasonic fibre-optic transducers were interrogated using coherent optical time-domain Rayleigh backscatter reflectometry (C-OTDR). Random quadrature demodulation was employed for retrieving relevant acoustic information from the raw C-OTDR backscatter traces. To our knowledge, our results are a first-time demonstration that quasi-distributed fibre-optic acoustic sensing is a candidate technology for the acoustic partial discharge monitoring of power cable joints and terminations. T2 - OFS2015 - 24rd International conference on optical fibre sensors CY - Curitiba, Brazil DA - 28.09.2015 KW - Distributed acoustic sensing KW - Coherent Rayleigh OTDR KW - Partial discharge KW - Acoustic emission KW - Silicone elastomer KW - Stress cone KW - High voltage cable accessories PY - 2015 SN - 9781628418392 DO - https://doi.org/10.1117/12.2194850 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 2015/9634 SP - 96341C-1 EP - 96341C-4 PB - SPIE CY - Bellingham, WA, USA AN - OPUS4-34407 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Liehr, Sascha A1 - Krebber, Katerina A1 - Steffen, Milan A1 - Wosniok, Aleksander T1 - Fördermaßnahme KMU-innovativ: Informations- und Kommunikationstechnologie (IKT), EMS-261-003 (Digital OFDR - Entwicklung der digitalen Frequenzbereichsanalyse zur verteilten Rückstreumessung in optischen Fasern-Teilvorhaben: Sensorverfahren und Systembetrachtung / Schlussbericht zum Teilvorhaben KW - Digital OFDR KW - Verteilte Rückstreumessung KW - Frequenzbereichsanalyse PY - 2015 IS - BAM Vh 8158 SP - 1 EP - 45 CY - Berlin AN - OPUS4-34170 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Distributed Brillouin fiber optic sensor system for long-term structural health monitoring N2 - We report on the development of a distributed fiber optical sensor system for structural health monitoring of largc-scale geotechnical and civil infrastructures. The system is based on Brillouin frequency domain analysis (BOFDA) for distributed measurement of strain and temperature along Standard silica optical fibers used as sensors. By additional incorporation of the fiber optic sensors in geosynthetics, two-dimensional sensors can be realized. Such smart geosynthetics can be used for reinforeerneut of geotechnical and masonry structures and the embedded fiber optic sensors can provide information about the condition of the structures and detect the presence of any damages and destructions in real time. T2 - 16th International conference 'Technical dam control' CY - Wierchomla Mala, Poland DA - 29.09.2015 KW - Distributed fiber optical sensor KW - Brillouin frequency domain analysis KW - Smart geosynthetics KW - Structural health monitoring PY - 2015 SN - 978-83-64979-09-5 SP - 271 EP - 278 AN - OPUS4-34728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schreier, Andy A1 - Jeschke, T. A1 - Petermann, K. A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Analytical model for mode-based insertion loss in ball-lensed coupling of graded-index silica and polymer fibres N2 - Analytical model for ball-lensed couplers to calculate the insertion loss for each optical mode. The basis for the calculation are commercial perfluorinated polymer optical (PFGI-POFs) and silica based fibres (SOFs). The modal power distribution for given misalignments are presented as well as the reflection-based losses at all optical interfaces. Additionally, the ball-lensed interconnection between PFGI-POF and SOF was theoretically demonstrated. T2 - POF 2017: 26th International Conference on Plastic Optical Fibres CY - Aveiro, Portugal DA - 13.09.2017 KW - Polymer optical fibre KW - Optical connector PY - 2017 VL - 2017 SP - 1 EP - 4 AN - OPUS4-41979 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Henschel, H. A1 - Hoeffgen, S.K. A1 - Krebber, Katerina A1 - Kuhnhenn, J. A1 - Weinand, U. T1 - Influence of Fiber Composition and Grating Fabrication on the Radiation Sensitivity of Fiber Bragg Gratings N2 - The radiation-induced Bragg wavelength shift (BWS) was measured with type I gratings made of 12 fibers with very different composition, i.e., of fibers with an extremely different radiation-induced attenuation. With two of the fibers fabrication parameters like laser intensity, hydrogen loading, and annealing conditions after grating inscription were varied. With another fiber type I and type II gratings were made by a completely different process. With gratings made under identical conditions of the 12 fibers the radiation-induced BWS only varied by about a factor of three. Varying the fabrication parameters led to BWS differences up to nearly a factor of ten. KW - Fiber Bragg gratings KW - Gamma radiation KW - Optical fiber sensor KW - Radiation effects PY - 2008 DO - https://doi.org/10.1109/TNS.2008.2001039 SN - 0018-9499 SN - 1558-1578 VL - 55 IS - 4 SP - 2235 EP - 2242 PB - Institute of Electrical and Electronics Engineers (IEEE) CY - New York, NY, USA AN - OPUS4-18570 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Glötzl, R. A1 - Schneider-Glötzl, J. A1 - Gabino, L. A1 - Krywult, L. ED - Bernadette Havranek, ED - Masoud Motavalli, ED - Urs Meier, T1 - Distributed polymer optical fiber sensors in geotextiles for monitoring of earthwork structures T2 - 4th International conference on structural health monitoring of intelligent infrastructure CY - Zurich, Switzerland DA - 2009-07-22 KW - Distributed sensor KW - Optical fiber sensor KW - Geotextile KW - Technical textile KW - POF sensor KW - Structural health monitoring KW - SHM KW - OTDR KW - Fiber optic sensors KW - Polymer optical fibers (POF) KW - Strain sensor PY - 2009 SN - 978-3-905594-52-2 IS - Paper 520 SP - 1 EP - 7(?) CY - Zurich, Switzerland AN - OPUS4-19787 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Liehr, Sascha A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Münich, J.C. A1 - Stempniewski, L. A1 - Metschies, H. ED - Bernadette Havranek, ED - Masoud Motavalli, ED - Urs Meier, T1 - Distributed polymer optical fiber sensors integrated in technical textiles for monitoring of masonry structures T2 - 4th International conference on structural health monitoring of intelligent infrastructure CY - Zurich, Switzerland DA - 2009-07-22 KW - Structural health monitoring KW - Fiber optic sensors KW - OTDR KW - Polymer optical fibers (POF) KW - POF sensors KW - Distributed sensor KW - Strain sensor KW - Technical textiles KW - Masonry PY - 2009 SN - 978-3-905594-52-2 IS - Paper 521 SP - 1 EP - 7(?) CY - Zurich, Switzerland AN - OPUS4-19788 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Liehr, Sascha A1 - Lenke, Peter A1 - Wendt, Mario T1 - Distributed POF sensors for structural health monitoring - First practical applications and field tests results N2 - Distributed POF sensors based on OTDR have been developed for SHM purposes of geotechnical and masonry structures. The first field tests conducted at a creeping slope and a brick building have proved the functionality of the sensors. T2 - POF 2009 - 18th International conference on plastic optical fibers CY - Sydney, Australia DA - 2009-09-07 PY - 2009 IS - Session 1 (S1_25) SP - 1 EP - 6 CY - Sydney, Australia AN - OPUS4-19914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schukar, Marcus A1 - Grzemba, Birthe A1 - Krebber, Katerina A1 - Luber, M. T1 - Integration technology of POF sensors into composites for structural health monitoring N2 - We have investigated the application technology of polymer optical fibers (POF) as sensors integrated into respectively applied onto composites for structural health monitoring by using different manufacturing methods and several types of POF. T2 - POF 2009 - 18th International conference on plastic optical fibers CY - Sydney, Australia DA - 2009-09-07 KW - Optische Polymerfasern (POF) KW - Fasersensorik KW - Structural Health Monitoring KW - Faserverbundwerkstoffe KW - OTDR KW - Faser-Integration PY - 2009 IS - Session 1 (S1_25) SP - 1 EP - 4 CY - Sydney, Australia AN - OPUS4-19915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina ED - Fu-Kuo Chang, T1 - POF sensors integrated in technical textiles for monitoring of earthwork structures and masonry T2 - Structural health monitoring 2009 - 7th International workshop on structural health monitoring CY - Stanford, CA, USA DA - 2009-09-09 KW - Distributed strain sensor KW - Optical fiber sensor KW - Geotextile KW - Technical textiles KW - POF sensor KW - Structural health monitoring KW - SHM KW - OTDR PY - 2009 SN - 978-1-60595-007-5 VL - 2 SP - 1739 EP - 1746 PB - DEStech Publications, Inc. AN - OPUS4-19960 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Nöther, Nils A1 - Krebber, Katerina T1 - Incoherent optical frequency domain reflectometry and distributed strain detection in polymer optical fibers N2 - We present, to our knowledge for the first time, the possibility of measuring the backscatter signal of perfluorinated polymer optical fibers (POF) using an incoherent optical frequency domain reflectometry (OFDR) technique. The OFDR setup is described and it is shown that the dynamic range and measurement speed are superior to standard OTDR systems. It is shown for the first time that distributed detection of strain in POF is possible using the OFDR technique. KW - Optical frequency domain reflectometry KW - OFDR KW - OTdr KW - Polymer optical fibers KW - POF KW - Fiber sensors KW - Distributed sensors KW - Strain sensors PY - 2010 DO - https://doi.org/10.1088/0957-0233/21/1/017001 SN - 0957-0233 SN - 1361-6501 VL - 21 IS - 1 SP - 017001-1 - 017001-4 PB - IOP Publ. Ltd. CY - Bristol AN - OPUS4-21625 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - A novel technique for quasi-distributed and dynamic length change measurement in optical fibers N2 - We present a novel technique to measure length changes between multiple reflection points in optical fibers. The technique allows for dynamic measurement up to 1kHz and a resolution better than 1µm. T2 - International conference "Optical sensors" CY - Karlsruhe, Germany DA - 2010-06-21 PY - 2010 DO - https://doi.org/10.1364/SENSORS.2010.STuB5 IS - STuB5 SP - 1 EP - 2 AN - OPUS4-21626 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Nöther, Nils A1 - Wendt, Mario A1 - Wosniok, Aleksander T1 - Protection of critical infrastructure using fiber optic sensors embedded in technical textiles N2 - Terrorists and criminals more and more attack and destroy important infrastructures like routes, railways, bridges, tunnels, dikes and dams, important buildings. Therefore, reliable on-line and long-term monitoring systems are required to protect such critical infrastructures. Fiber optic sensors are well-suited for that. They can be installed over many kilometers and are able to measure continuously distributed strain, pressure, temperature and further mechanical and physical quantities. The very tiny optical fibers can be integrated into structures and materials and can provide information about any significant changes or damages of the structures. These so-called smart materials and smart structures are able to monitor itself or its environment. Particularly smart technical textiles with embedded fiber optic sensors have become very attractive because of their high importance for the structural health monitoring of geotechnical and masonry infrastructures. Such textiles are usually used for reinforcement of the structures; the embedded fiber optic sensors provide information about the condition of the structures and detect the presence of any damages and destructions in real time. Thus, critical infrastructures can be preventively protected. The paper will introduce this innovative field and will present the results achieved within several German and European projects. T2 - Fiber optic sensors and applications VII CY - Orlando, FL, USA DA - 2010-04-07 KW - Distributed sensors KW - Brillouin sensors KW - Polymer optical fibers (POF) KW - POF sensors KW - POF OTDR KW - Strain sensors KW - Technical textiles KW - Geotextiles KW - Fiber optic sensors PY - 2010 SN - 9780819481412 DO - https://doi.org/10.1117/12.851013 SN - 0277-786X VL - 7677 IS - 767707 SP - 1 EP - 14 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-21675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - A novel quasi-distributed fibre optic displacement sensor for dynamic measurement N2 - We present a novel technique based on incoherent optical frequency domain reflectometry (OFDR) to measure length changes quasi-distributed between reflection points in optical fibres. The technique enables length changes to be measured with a resolution better than 1 µm and allows for static and dynamic measurement capabilities up to 2 kHz. We demonstrate that dynamic measurements of multiple fibre sections can be conducted independently from each other with high precision. Due to the precise and dynamic measurement capabilities, the proposed sensor system is expected to open new fields of application, especially in the structural-health-monitoring sector. Possible applications are discussed in the paper. KW - Strain sensor KW - Optical frequency domain reflectometry KW - OFDR KW - Optical fibre KW - Fibre sensors KW - Quasi-distributed sensors KW - Dynamic strain measurement PY - 2010 UR - http://iopscience.iop.org/0957-0233/21/7/075205/pdf/0957-0233_21_7_075205.pdf DO - https://doi.org/10.1088/0957-0233/21/7/075205 SN - 0957-0233 SN - 1361-6501 VL - 21 IS - 7 SP - 075205-1 - 075205-6 PB - IOP Publ. Ltd. CY - Bristol AN - OPUS4-21812 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Oliveira, Rui A1 - Schukar, Marcus A1 - Krebber, Katerina A1 - Michaud, V. T1 - Development of adaptive composites with embedded plastic optic fibres N2 - This study discusses the development of advanced composite materials with sensing capabilities obtained from the embedment of long period gratings in microstructured plastic optical fibres (mPOF-LPG). The mPOF-LPG was embedded in a carbon fibre reinforced polymer (CFRP) unidirectional laminate manufactured in autoclave. Processing steps were established in order to insure that mPOF does not suffer significant optical and structural degradation. The strain and temperature responses of the embedded mPOF-LPG were investigated. T2 - ICRACM 2010 - 3rd International conference on recent advances in composite materials CY - Limoges, France DA - 2010-12-13 KW - Polymer composites KW - Optical fibre sensors KW - mPOF-LPG KW - SHM PY - 2010 IS - Polymer composite session / FP-Oliveira SP - 1 EP - 6 AN - OPUS4-23040 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Lenke, Peter A1 - Liehr, Sascha A1 - Nöther, Nils A1 - Wendt, Mario A1 - Wosniok, Aleksander A1 - Schneider-Gloetzl, J. A1 - Gloetzl, R. T1 - Distributed fibre optic sensors embedded in technical textiles for monitoring of geotechnical and masonry structures T2 - Monitoring technologies workshop - MoDeRn (Proceedings) CY - Troyes, France DA - 2010-06-07 PY - 2010 IS - OP.7 SP - 71 EP - 72 AN - OPUS4-23041 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Krebber, Katerina A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Witt, Jens A1 - Schukar, Marcus ED - Ecke, Wolfgang ED - Kara J. Peters, ED - Norbert G. Meyendorf, T1 - Smart technical textiles with integrated POF sensors N2 - Fiber optic sensors based on polymer optical fibers (POF) take advantage of the high elasticity and high break-down strain of POF. Because of their outstanding elastic properties, POF are well suited for integration into technical textiles like geotextiles and medical textiles. Smart textiles with incorporated POF sensors, able to sense various mechanical and physical quantities, can be realized. The integration of POF as a sensor into geotextiles for monitoring of displacement of soil is very attractive since POF can be used for distributed strain measurement of strain values of more than 40 %. An online monitoring of critical mechanical deformations of geotechnical structures like dikes, dams, slopes, embankments as well as of masonry structures can be ensured. Medical textiles that incorporate POF sensors can control vital physiological parameters like respiratory movement and can be used for wearable health monitoring of patients requiring a continuous medical assistance and treatment. The biocompatibility of POF is an important criterion for selecting POF as a medical sensor. The paper shows selected examples of using POF sensors for the mentioned monitoring purposes. T2 - Smart Sensor Phenomena, Technology, Networks, and Systems 2008 CY - San Diego, California, USA DA - 2008-03-10 KW - Fiber optic sensors KW - Polymer optical fibers (POF) KW - POF sensors KW - Geotextiles KW - Medical textiles KW - Strain sensor KW - Respiratory monitoring KW - POF OTDR KW - Distributed sensor KW - Geotechnical structures PY - 2008 SN - 978-0-8194-7119-2 DO - https://doi.org/10.1117/12.776758 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 6933 IS - 6933 SP - 69330V-1 - 69330V-15 PB - SPIE CY - Bellingham AN - OPUS4-17680 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Krebber, Katerina A1 - Seeger, M. A1 - Thiele, E. A1 - Metschies, H. A1 - Gebreselassie, B. A1 - Münich, J.C. A1 - Stempniewski, L. ED - Francis Berghmans, ED - Mignani, Anna Grazia ED - Cutolo, Antonello ED - Patrick P. Meyrueis, ED - Thomas P. Pearsall, T1 - Distributed strain measurement with polymer optical fibers integrated into multifunctional geotextiles N2 - Fiber optic sensors based on polymer optical fibers (POF) have the advantage of being very elastic and robust at the same time. Unlike silica fibers, standard PMMA POF fibers can be strained to more than 40% while fully maintaining their light guiding properties. We investigated POF as a distributed strain sensor by analysing the backscatter increase at the strained section using the optical time domain reflectometry (OTDR) technique. This sensing ability together with its high robustness and break-down strain makes POF well-suited for integration into technical textiles for structural health monitoring purposes. Within the European research project POLYTECT (Polyfunctional textiles against natural hazards) technical textiles with integrated POF sensors, among others sensors are being developed for online structural health monitoring of geotechnical structures. Mechanical deformation in slopes, dams, dikes, embankments and retrofitted masonry structures is to be detected before critical damage occurs. In this paper we present the POF strain sensor properties, reactions to disturbing influences as temperature and bends as well as the results of the different model tests we conducted within POLYTECT. We further show the potential of perfluorinated graded-index POF for distributed strain sensing with increased spatial resolution and measurement lengths. T2 - Optical Sensors 2008 CY - Strasbourg, France DA - 2008-04-07 KW - Fiber optic sensors KW - OTDR KW - Polymer optical fibers (POF) KW - POF sensors KW - Distributed sensor KW - Strain sensor KW - Geotextiles KW - Structural health monitoring PY - 2008 SN - 978-0-8194-7201-4 DO - https://doi.org/10.1117/12.780508 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 7003 IS - 7003 SP - 700302-1 - 700302-15 PB - SPIE CY - Bellingham AN - OPUS4-17951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Distributed POF Sensors for Structural Health Monitoring - First Practical Applications and Field Tests Results. Invited Paper T2 - 18th International Conference on POF CY - Sydney, Australia DA - 2009-09-09 PY - 2009 AN - OPUS4-20193 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Nöther, Nils A1 - Krebber, Katerina ED - Juergen Brugger, ED - Danick Briand, T1 - Distributed fibre optic sensor system for temperature and strain monitoring based on Brillouin optical-fibre frequency-domain analysis T2 - EUROSENSORS XXIII: sensors, actuators and micro/nanosystems CY - Lausanne, Switzerland DA - 2009-09-06 KW - BOFDA KW - Sideband technique KW - Fibre optic sensors KW - Distributed Brillouin sensors KW - Stimulated Brillouin scattering KW - Nonlinear optics PY - 2009 SN - 1876-6196 SP - 1 EP - 4(?) AN - OPUS4-20235 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Wendt, Mario A1 - Krebber, Katerina ED - Jones, J. ED - Culshaw, B. ED - Ecke, W. ED - López-Higuera, J.M. ED - Willsch, R. T1 - Distributed perfluorinated POF strain sensor using OTDR and OFDR techniques T2 - 20th International conference on optical fibre sensors (Proceedings of SPIE) CY - Edinburgh, Scotland, UK DA - 2009-10-05 KW - Distributed strain sensor KW - Optical fiber sensor KW - Polymer optical fiber KW - POF sensor KW - Structural health monitoring KW - OTDR KW - OFDR PY - 2009 SN - 978-0-8194-7814-6 SN - 0277-786X SP - 75036G-1 - 75036G-4 PB - SPIE, the International Society for Optical Engineering AN - OPUS4-20289 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Seeger, M. A1 - Thiele, E. A1 - Metschies, H. A1 - Gebreselassie, B. A1 - Münich, J.C. T1 - Polymer optical fiber sensors for distributed strain measurement and application in structural health monitoring N2 - Polymer optical fiber (POF) sensors have the unique ability to measure high strain distributed along the fiber up to 40% using the optical time-domain reflectometry (OTDR) technique. Both, standard PMMA fibers and perfluorinated (PF) graded-index (GI) POF are introduced and evaluated in potential use and applicability. Further, distributed length change measurement based on cross-correlation analysis of the characteristic fiber signature of PF POF is introduced. We conclude the advances in distributed POF strain sensors technology with respect to application in structural health monitoring. Special focus is on the sensor integration into technical textiles for health monitoring of geotechnical structures and masonry structures. Measurement results of sensor-equipped textiles in different model tests are presented, displacement of soil and cracks in retrofitted masonry structures are detected and evaluated. KW - Distributed strain sensor KW - Optical fiber sensor KW - POF sensors KW - Structural health monitoring PY - 2009 DO - https://doi.org/10.1109/JSEN.2009.2018352 SN - 1530-437X SN - 1558-1748 VL - 9 IS - 11 SP - 1330 EP - 1338 CY - New York, NY, USA AN - OPUS4-20311 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Glötzl, R. A1 - Schneider-Glötzl, J. A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Gabino, L. A1 - Krywult, J. ED - Klapperich, Herbert ED - Jacob, Dieter ED - Azzam, Rafig ED - Wolf, Rainer T1 - Eine neue Geotextilmessmatte mit verteilter Sensortechnik im Einsatz - Suche einer geeigneten Baustelle, Einbauerfahrungen und erste Ergebnisse T2 - 4. Symposium Umweltgeotechnik & 5. Freiberger Geotechnik-Kolloquium & Fachausstellung CY - Freiberg, Deutschland DA - 2009-06-04 PY - 2009 SN - 1613-4753 IS - Publication 7 SP - 1 EP - 9(?) CY - Freiberg AN - OPUS4-20400 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Glötzl, R. A1 - Schneider-Glötzl, J. A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Gabino, L. A1 - Krywult, J. A1 - Krywult, L. T1 - First results of a field test in Belchatow brown coal mine to investigate creeping slopes T2 - VI. International brown coal mining congress "Brown coal - energy - environment - future" CY - Belchatów, Poland DA - 2009-05-18 PY - 2009 SN - 978-83-88316-85-2 SP - 57 EP - 64 PB - Art-Teskt CY - Kraków, Poland AN - OPUS4-20401 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kasinathan, Murugesan A1 - Rao, C.B. A1 - Murali, N. A1 - Jayakumar, T. A1 - Raj, B. A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Analysis of stimulated Brillouin scattering characteristics in frequency domain T2 - ICOP 2009 - International conference on optics & photonics CY - Chandigarh, India DA - 2009-10-30 KW - BOFDA KW - Fibre optic sensors KW - Distributed Brillouin sensors KW - Stimulated Brillouin scattering KW - Nonlinear optics PY - 2009 SP - 1 EP - 5(?) AN - OPUS4-21150 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kasinathan, Murugesan A1 - Rao, C.B. A1 - Murali, N. A1 - Jayakumar, T. A1 - Raj, B. A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Use of Brillouin optical time domain analyser in testing of adhesive bonding T2 - SENNET`09 - International conference on sensors and related networks CY - Vellore, India DA - 2009-12-08 KW - Brillouin KW - Frequency domain analysis KW - Time domain analysis KW - Adhesive KW - Bond evaluation KW - Temperature KW - Strain KW - Distributed sensor PY - 2009 SP - 190 EP - 192 CY - Vellore, India AN - OPUS4-21151 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Wendt, Mario A1 - Krebber, Katerina T1 - Distributed strain measurement in perfluorinated polymer optical fibres using optical frequency domain reflectometry N2 - We present the latest advances in distributed strain measurement in perfluorinated polymer optical fibres (POFs) using backscatter techniques. Compared to previously introduced poly(methyl methacrylate) POFs, the measurement length can be extended to more than 500 m at improved spatial resolution of a few centimetres. It is shown that strain in a perfluorinated POF can be measured up to 100%. In parallel to these investigations, the incoherent optical frequency domain reflectometry (OFDR) technique is introduced to detect strained fibre sections and to measure distributed length change along the fibre with sub-millimetre resolution by applying a cross-correlation algorithm to the backscatter signal. The overall superior performance of the OFDR technique compared to the optical time domain reflectometry in terms of accuracy, dynamic range, spatial resolution and measurement speed is presented. The proposed sensor system is a promising technique for use in structural health monitoring applications where the precise detection of high strain is required. KW - Distributed strain sensor KW - Optical fibre sensor KW - Polymer optical fibre KW - POF sensor KW - Structural health monitoring KW - OTDR KW - OFDR PY - 2010 DO - https://doi.org/10.1088/0957-0233/21/9/094023 SN - 0957-0233 SN - 1361-6501 VL - 21 IS - 9 SP - 094023-1 - 094023-6 PB - IOP Publ. Ltd. CY - Bristol AN - OPUS4-22379 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Krebber, Katerina ED - Santos, J.L. ED - Culshaw, B. ED - López-Higuera, J.M. ED - MacPherson, W.N. T1 - A novel fiber optic technique for quasi-distributed and dynamic measurement of length change and refractive index N2 - We present a novel technique for dynamic and simultaneous measurement of displacement and refractive indices at multiple reflection points in optical fibers. This quasi-distributed sensor is based on the incoherent optical frequency domain reflectometry (I-OFDR) technique and allows for m-resolution length change measurement and precise refractive index measurement. We show that the dynamic measurement ability and the simple sensor design allows for new applications in the field of structural health monitoring and chemical process control. T2 - 4th European workshop on optical fibre sensors CY - Porto, Portugal DA - 2010-09-08 KW - Quasi-distributed sensor KW - Strain sensor KW - Length change measurement KW - Optical fiber sensor KW - Refractive index sensor KW - Structural health monitoring KW - OFDR PY - 2010 SN - 978-0-8194-8083-5 DO - https://doi.org/10.1117/12.866325 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 7653 SP - 76532V-1 - 76532V-4 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-22380 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Oliveira, Rui A1 - Schukar, Marcus A1 - Krebber, Katerina A1 - Michaud, V. T1 - Advanced composite materials with embedded POF sensors for structural health monitoring N2 - A long period grating (LPG) mechanically imprinted in a microstructured polymer optical fibre (mPOF) is embedded in a carbon fibre reinforced polymer (CFRP) unidirectional laminate. Processing steps were established in order to ensure that mPOF does not suffer significant degradation. The strain and temperature responses of the embedded mPOF-LPG were then investigated. T2 - POF 2010 - 19th International conference on plastic optical fibers CY - Yokohama, Japan DA - 2010-10-19 PY - 2010 IS - P-25 SP - 1 EP - 4 AN - OPUS4-22381 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - Quasi-distributed and dynamic length change measurement in polymer optical fibers N2 - We present a novel technique based on the incoherent optical frequency domain reflectometry (l-OFDR) technique for dynamic (2 kHz) and quasi-distributed length change measurement in polymer optical fibers (POF). The extreme strain sensing capabilities (> 125 %) and cyclic load behaviour of perfluorinated POF are investigated using this technique. T2 - POF 2010 - 19th International conference on plastic optical fibers CY - Yokohama, Japan DA - 2010-10-19 PY - 2010 IS - Sensors-2 SP - 1 EP - 4 AN - OPUS4-22382 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Wendt, Mario A1 - Krebber, Katerina T1 - Distributed strain and length change measurement in POF using optical frequency domain reflectometry N2 - We show that the incoherent optical frequency domain (l-OFDR) technique provides superior performance compared to standard OTDR techniques in terms of spatial resolution and measurement time. The distributed strain measurement capabilities of perfluorinated POF up 100 % strain are shown and distributed length change measurement using correlation techniques and OFDR are presented. T2 - POF 2010 - 19th International conference on plastic optical fibers CY - Yokohama, Japan DA - 2010-10-19 PY - 2010 IS - Sensors-2 SP - 1 EP - 4 AN - OPUS4-22383 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Schukar, Marcus A1 - Wendt, Mario A1 - Witt, Jens T1 - Distributed POF sensors - recent progress and new challenges N2 - The potential of the use of POF as distributed sensors in several application fields has been successfully demonstrated. The distributed POF sensors have moved from the laboratory to the field. The paper presents the recent progress in the development of distributed POF sensors and addresses the main challenges to this innovative technology. T2 - POF 2010 - 19th International conference on plastic optical fibers CY - Yokohama, Japan DA - 2010-10-19 PY - 2010 IS - Sensors-2 SP - 1 EP - 4 AN - OPUS4-22305 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - The impact of temperature and humidity on the backscatter profile of PMMA POF N2 - In this paper the influence of combined temperature and strain changes as well as changes of moisture content on polymer optical fibers made of polymethyl methacrylat (PMMA) is investigated. The increase of the scattering coefficient with increasing temperature for various strain levels is observed and quantified. The measurement results of influence of humidity on scattering intensity of PMMA-POF encourage to porpose these as a distributed humidity sensor. T2 - POF 2010 - 19th International conference on plastic optical fibers CY - Yokohama, Japan DA - 2010-10-19 KW - POF distributed sensing Rayleigh KW - Humiditiy KW - OTDR KW - Strain PY - 2010 SP - 1 EP - 7(?) AN - OPUS4-22685 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Liehr, Sascha A1 - Krebber, Katerina ED - Santos, J.L. ED - Culshaw, B. ED - López-Higuera, J.M. ED - MacPherson, W.N. T1 - Distributed humidity sensing based on Rayleigh scattering in polymer optical fibers N2 - In this document a new distributed sensor based on Rayleigh scattering in polymer optical fibers (POF) is proposed and first measurement results of the proposed sensor are shown. Different from Silica glas optical fibers POF absorb high quantities of water resulting in a change of their molecular structure and thereby reducing the present small scattering centers in areas of high humidity. The interdependence between scattering intensity and relative humidity is being investigated in case of steady cycles as well as stepwise changes of humidity and in the presence of moisture. A quantitative measure of humidity and scattering is presented. T2 - 4th European workshop on optical fibre sensors CY - Porto, Portugal DA - 2010-09-08 KW - POF KW - Distributed sensing KW - Rayleigh KW - Scattering KW - OTDR KW - Humidity PY - 2010 SN - 978-0-8194-8083-5 DO - https://doi.org/10.1117/12.866279 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 7653 SP - 76533X-1 - 76533X-4 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-22686 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Narbonneau, F. A1 - De Jonckheere, J. A1 - Jeanne, M. A1 - Kinet, D. A1 - Witt, Jens A1 - Krebber, Katerina A1 - Paquet, B. A1 - Depré, A. A1 - D´Angelo, L.T. A1 - Thiel, T. A1 - Logier, R. ED - Popp, J. T1 - OFSETH: Optical technologies embedded in smart medical textile for continuous monitoring of respiratory motions under magnetic resonance imaging N2 - The potential impact of optical fiber sensors embedded into medical textiles for the continuous monitoring of the patient during Magnetic Resonance Imaging (MRI) is now proved. We report how two pure optical technologies can successfully sense textile elongation between, 0% and 3%, while maintaining the stretching properties of the textile substrates for a good comfort of the patient. Investigating influence of different patients' morphology as well as textile integration issues to let free all vitals organs for medical staff actions, the OFSETH harness allows a continuous measurement of respiration movements. For example, anaesthesia for MRI examination uses the same drugs as for any surgical procedure. Even if spontaneous respiration can be preserved most of the time, spontaneous respiration is constantly at risk of being impaired by anaesthetic drugs or by upper airway obstruction. Monitoring of the breathing activity is needed to assess adequate ventilation or to detect specific obstruction patterns. Moreover artefacts due to physiological motions induce a blooming effect on the MRI result. The use of synchronisation devices allows reducing these effects. Positioned at certain strategic places according to the investigated organ, the presented sensors could constitute an efficient and adapted solution for respiratory synchronisation of the MRI acquisition. KW - MRI KW - Smart textile KW - Healthcare monitoring KW - Optical sensor KW - FBG KW - Respiratory sensor PY - 2010 SN - 9780819481887 DO - https://doi.org/10.1117/12.854386 VL - 7715 SP - 77151D-1 - 77151D-12 AN - OPUS4-22839 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wosniok, Aleksander A1 - Krywult, L. A1 - Liehr, Sascha A1 - Krebber, Katerina A1 - Wendt, Mario A1 - Chrost, A. T1 - Monitoring konstrukcji ziemnych przy zastosowaniu rozlozonych przestrzennie swiatlowodowych sensorów optycznych, zintegrowanych w geosyntetykach KW - Fibre optic sensor KW - Spatial distributed sensor KW - Polymer optical fibre (POF) KW - Glass optical fibre (GOF) KW - POF OTDR KW - Brillouin sensor KW - BOTDA KW - BOFDA KW - Fibre Bragg grating (FBG) KW - Geosynthetics KW - Geotextiles KW - Technical textiles PY - 2011 UR - http://journals.bg.agh.edu.pl/GORNICTWO/2011-02/GG_2011_2_63.pdf SN - 1732-6702 SN - 0138-0990 VL - 35 IS - 2 SP - 597 EP - 604 PB - Uczelniane Wydawn. Naukowo-Dydaktyczne AGH CY - Kraków AN - OPUS4-23418 LA - pol AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thiele, E. A1 - Erth, H. A1 - Helbig, R. A1 - Werth, K. A1 - Glötzl, R. A1 - Schneider, J. A1 - Nöther, Nils A1 - Wosniok, Aleksander A1 - Krebber, Katerina A1 - Schlurmann, T. A1 - Saathoff, F. T1 - Sensitive Textilstrukturen zur Deichüberwachung T2 - BAUTEX 2008, 8. Sächsisches Bautextilien-Symposium "Bauen mit Geokunststoffen" CY - Chemnitz, Deutschland DA - 2008-01-24 PY - 2008 SP - 1 EP - 5 CY - Chemnitz AN - OPUS4-17448 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - Improvements of the distributed strain sensor based on optical time domain reflectometry measurement in polymer optical fibers N2 - Sensing characteristics of standard polymer optical fibers (POF) are further studied using the optical time domain reflectometry (OTDR) technique. The level of the backscattering inside POF, which highly increases at locations where strain is applied to the fiber, is further investigated with respect to spectral behavior, strain rate and span of time from the stretching event. An algorithem to overcome the problem of the decrease of spatial resolution as a result of pulse broadening due to modal disperion, is proposed. The research is carried out on the background of the development of a new strain sensor that is integrated in technical textiles. T2 - 17th International Conference on Plastic Optical Fibers (POF 2008) CY - Santa Clara, California, USA DA - 2008-08-25 KW - Distributed strain sensor KW - Optical fiber sensor KW - POF KW - Scatter KW - PMMA KW - Spatial resolution PY - 2008 IS - Paper 1 SP - 1 EP - 5 AN - OPUS4-18210 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina T1 - Perfluorinated graded-index polymer optical fibers for distributed measurement of strain N2 - Recently, we have proposed, to our knowledge for the first time, to use perfluorinated graded-index polymer optical fiber (POF) for distributed measurement of strain. Thanks to their low attenuation and low modal dispersion compared to standard-POF, this fiber type allows to extend the measurement length to more than 500 meters at increased spatial resolution. In this paper, two mechanisms for strain sensing are introduced. As in standard PMMA POF, strain in the fiber can be detected by evaluating the local backscatter increase occurring at strained fiber sections. Further, we propose, to our knowledge for the first time, a true distributed length change measurement in POF using cross-correlation analysis of the fiber’s characteristic backscatter signature. Using this technique, it is possible to measure relative displacement between different fiber sections avoiding signal fading failures that are inherent in other measurement principles. Cross-sensitivities to the sensor signal, as fiber bends and temperature, are investigated and quantified. T2 - 17th International Conference on Plastic Optical Fibers (POF 2008) CY - Santa Clara, California, USA DA - 2008-08-25 KW - Distributed strain sensor KW - Optical fiber sensor KW - Perfluorinated POF KW - POF sensors PY - 2008 IS - Paper 64 SP - 1 EP - 5 AN - OPUS4-18209 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Nöther, Nils A1 - Wosniok, Aleksander A1 - Krebber, Katerina ED - Francis Berghmans, ED - Mignani, Anna Grazia ED - Cutolo, Antonello ED - Patrick P. Meyrueis, ED - Thomas P. Pearsall, T1 - A distributed fiber optic sensor system for dike monitoring using Brillouin frequency domain analysis T2 - Optical Sensors 2008, April 7-10, 2008 CY - Strasbourg, France DA - 2008-04-07 KW - BOFDA KW - Brillouin sensing KW - Distributed strain measurement KW - Dike monitoring KW - Sensor-based geotextiles KW - Fibre optic sensors KW - Distributed sensors KW - Brillouin scattering PY - 2008 SN - 978-0-8194-7201-4 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 7003 SP - 700303-1 - 700303-9 PB - SPIE CY - Bellingham AN - OPUS4-18274 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wosniok, Aleksander A1 - Nöther, Nils A1 - Krebber, Katerina A1 - Thiele, E. T1 - Distributed monitoring of mechanical deformation in river dikes T2 - EUROSENSORS XXII CY - Dresden, Germany DA - 2008-09-07 KW - Fiber optic sensor KW - Distributed Brillouin sensor KW - Dike monitoring PY - 2008 SN - 978-3-00-025217-4 SP - 1457 EP - 1460 AN - OPUS4-18322 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Nöther, Nils A1 - Wosniok, Aleksander A1 - Krebber, Katerina A1 - Thiele, E. ED - Ecke, Wolfgang ED - Kara J. Peters, ED - Norbert G. Meyendorf, T1 - A distributed fiber optic sensor system for dike monitoring using Brillouin optical frequency domain analysis N2 - We report on the development of a complete system for spatially resolved detection of critical soil displacement in river embankments. The system uses Brillouin frequency domain analysis (BOFDA) for distributed measurement of strain in silica optical fibers. Our development consists of the measurement unit, an adequate coating for the optical fibers and a technique to integrate the coated optical fibers into geotextiles as they are commonly used in dike construction. We present several laboratory and field tests that prove the capability of the system to detect areas of soil displacement as small as 2 meters. These are the first tests of truly distributed strain measurements on optical fibers embedded into geosynthetics. T2 - Smart Sensor Phenomena, Technology, Networks, and Systems 2008 CY - San Diego, California, USA DA - 2008-03-10 KW - BOFDA KW - Brillouin sensing KW - Distributed strain measurement KW - Dike monitoring KW - Sensor-based geotextiles KW - Fiber optic sensors KW - Distributed sensors KW - Brillouin scattering PY - 2008 SN - 978-0-8194-7119-2 DO - https://doi.org/10.1117/12.775133 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 6933 SP - 69330T-1 - 69330T-9 PB - SPIE CY - Bellingham AN - OPUS4-18250 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Nöther, Nils A1 - Wosniok, Aleksander A1 - Krebber, Katerina A1 - Thiele, E. ED - W. Ostachowicz, ED - J. Holnicki-Szulc, ED - C. Mota Soares, T1 - Dike monitoring using fiber sensor-based geosynthetics N2 - We report on the development of distributed fiber sensors and their integration into geosynthetics as they are commonly used in the construction of dikes and dams for flood protection. The sensing system uses Stimulated Brillouin Scattering (SBS) in silica optical fibers. Using the Brillouin frequency analysis, the system is capable of detecting changes in both strain and temperature along the optical fibers. The strain experienced by the optical fibers corresponds to the deformation of the geosynthetics in case of a critical soil displacement. To satisfy requirements of dike structures, the system will be optimized to detect soil displacement with a spatial resolution of 5 m or less over a length in the range of 10 km. These rather modest requirements leave space for optimization on resolution of the measurement values, measurement time and cost efficiency. To our knowledge, this is the first distributed fiber sensor using SBS that is especially designed for the monitoring of soil displacement in dikes which is made possible by a novel method for the integration of optical fibers into different types of geosynthetics. T2 - 3. ECCOMAS Thematic Conference on Smart Structures and Materials CY - Gdansk, Poland DA - 2007-07-09 KW - Fiber optic sensors KW - Dike monitoring KW - SBS KW - Distributed strain sensors KW - Distributed brillouin sensors KW - Geosynthetics PY - 2007 SN - 978-83-88237-03-4 IS - Paper 03 SP - 1 EP - 13 PB - Institute of Fluid-Flow Machinery CY - Gda´nsk AN - OPUS4-18253 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Krebber, Katerina T1 - Optical Fibre Sensor Application in Civil and Geotechnical Engineering T2 - 1. Asian-Pacific Conference on Optical Fibre Sensors and 3rd International Symposium on Advances & Trends in Fiber Optics CY - Chengdu, China DA - 2008-11-07 PY - 2008 AN - OPUS4-18336 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lenke, Philipp A1 - Krebber, Katerina ED - Jones, J. ED - Culshaw, B. ED - Ecke, W. ED - López-Higuera, J.M. ED - Willsch, R. T1 - A new model to calculate the Rayleigh scattering profiles in polymer optical fibers for distributed strain sensing N2 - This paper presents new methods to calculate and interpret Rayleigh scattering profiles in polymer optical fibers (POF) recorded by optical time domain reflectometry (OTDR). In contrast to Silica glass optical fibers (GOF), POF experience inhomogeneous stress when being strained, resulting in small scattering centers which allow for a new distributed sensor based on POF. New methods to overcome issues like blurring due to modal dispersion, uncertainties due to inhomogenious losses in the fiber and signal degradation due to viscoelastic creep in the polymer, are presented, for the first time to our knowledge. T2 - 20th International conference on optical fibre sensors (Proceedings of SPIE) CY - Edinburgh, Scotland, UK DA - 2009-10-05 KW - POF KW - Distributed sensing KW - Rayleigh KW - Scattering KW - OTDR KW - Distributed strain sensor KW - Optical fiber sensor KW - PMMA KW - Spatial resolution PY - 2009 SN - 978-0-8194-7814-6 DO - https://doi.org/10.1117/12.835361 SN - 0277-786X SP - 75036I-1 - 75036I-4 PB - SPIE, the International Society for Optical Engineering AN - OPUS4-20496 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nöther, Nils A1 - Lenke, Philipp A1 - Krebber, Katerina ED - Jones, J. ED - Culshaw, B. ED - Ecke, W. ED - López-Higuera, J.M. ED - Willsch, R. T1 - A novel signal restoration method in the frequency domain to enhance spatial resolution in distributed Brillouin sensing T2 - 20th International conference on optical fibre sensors (Proceedings of SPIE) CY - Edinburgh, Scotland, UK DA - 2009-10-05 KW - Fiber-optic sensing KW - Distributed Brillouin sensing KW - Spatial resolution KW - Deconvolution PY - 2009 SN - 978-0-8194-7814-6 SN - 0277-786X SP - 75032F-1 - 75032F-4 PB - SPIE, the International Society for Optical Engineering AN - OPUS4-20467 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Nöther, Nils A1 - Wosniok, Aleksander A1 - Krebber, Katerina A1 - Thiele, E. ED - Bernadette Havranek, ED - Masoud Motavalli, ED - Urs Meier, T1 - A distributed fiber-optic sensing system for monitoring of large geotechnical structures T2 - 4th International conference on structural health monitoring of intelligent infrastructure CY - Zurich, Switzerland DA - 2009-07-22 KW - Structural health monitoring KW - Distributed sensing KW - Geotextiles KW - Dike monitoring PY - 2009 SN - 978-3-905594-52-2 SP - 1 EP - 9 CY - Zurich, Switzerland AN - OPUS4-20468 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider-Gloetzl, J. A1 - Gloetzl, R. A1 - Krebber, Katerina A1 - Liehr, Sascha A1 - Wendt, Mario A1 - Wosniok, Aleksander T1 - Geotechnical monitoring of construction activities by distributed fiber optic sensors embedded in geotextiles T2 - 5th European workshop on structural-health-monitoring 2010 CY - Sorrento, Italy DA - 2010-06-29 KW - Foundation engineering KW - Geotechnical monitoring KW - Smart textiles KW - Distributed fiber optic sensors KW - POF sensors KW - Brillouin sensors PY - 2010 IS - SS4-07 SP - 1 EP - 6 AN - OPUS4-21872 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Nöther, Nils A1 - Wendt, Mario A1 - Wosniok, Aleksander ED - Santos, J.L. ED - Culshaw, B. ED - López-Higuera, J.M. ED - MacPherson, W.N. T1 - Distributed fiber optic sensors embedded in technical textiles for structural health monitoring N2 - Technical textiles with embedded distributed fiber optic sensors have been developed for the purposes of structural health monitoring in geotechnical and civil engineering. The distributed fiber optic sensors are based on Brillouin scattering in silica optical fibers and OTDR in polymer optical fibers. Such "smart" technical textiles can be used for reinforcement of geotechnical and masonry structures and the embedded fiber optic sensors can provide information about the condition of the structures and detect the presence of any damages and destructions in real time. Thus, structural health monitoring of critical geotechnical and civil infrastructures can be realized. The paper highlights the results achieved in this innovative field in the framework of several German and European projects. T2 - 4th European workshop on optical fibre sensors CY - Porto, Portugal DA - 2010-09-08 KW - Fiber optic sensor KW - Distributed sensor KW - Brillouin sensor KW - Polymer optical fibers (POF) KW - POF sensor KW - POF OTDR KW - Strain sensor KW - Technical textiles KW - Geotextiles PY - 2010 SN - 978-0-8194-8083-5 DO - https://doi.org/10.1117/12.868052 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 7653 SP - 76530A-1 - 76530A-12 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-21948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Distributed fibre optic sensors embedded in technical textiles for monitoring of geotechnical and masonry structures T2 - European Workshop on Monitoring Technologies (MoDeRn) - Potential Application to Monitoring of Geological Repositories for Radioactive Waste CY - Troyes, France DA - 2010-06-07 PY - 2010 AN - OPUS4-22023 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Distributed fiber optic sensors embedded in technical textiles for structural health monitoring T2 - 4th European Workshop on Optical Fibre Sensors (EWOFS) CY - Oporto, Portugal DA - 2010-09-08 PY - 2010 AN - OPUS4-22059 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -