TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina A1 - Glötzl, R. ED - Boller, C. T1 - Temperature-corrected determination of mechanical deformations in geotechnical structures using Brillouin-based fiber optic sensors T2 - EWSHM'12 - 6th European workshop on structural health monitoring 2012 CY - Dresden, Germany DA - 2012-07-03 KW - Structural health monitoring KW - Brillouin scattering KW - Distributed sensor PY - 2012 SN - 978-3-940283-41-2 VL - 1 SP - 417 EP - 422 CY - Berlin AN - OPUS4-26311 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krebber, Katerina A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Nöther, N. A1 - Wendt, Mario A1 - Wosniok, Aleksander A1 - Daum, Werner T1 - Structural health monitoring by distributed fiber optic sensors embedded into technical textiles 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 are used for reinforcement of geotechnical and masonry structures. The embedded fiber optic sensors provide online information about the condition of the structure and about the occurrence and location of any damage or degradation.-------------------------------------------------------------------------------------------------------------------------------------------------------- Technische Textilien mit integrierten faseroptischen Sensoren eröffnen neue Möglichkeiten der Zustandsüberwachung (structural health monitoring) in Geotechnik und Ingenieurbau. Die verteilt messenden Sensoren basieren auf der Brillouin-Streuung in Glasfasern und auf der OTDR in polymeroptischen Fasern. Derartige 'intelligente' technische Textilien werden in erster Line zur Verstärkung von geotechnischen Bauwerken und von Gebäuden genutzt. Die integrierten Sensoren liefern eine zeitnahe Information über den bestimmungsgemäßen Zustand des Bauwerks sowie über die Entstehung und den Ort von lokalen Bauwerksschäden. KW - Fiber optic sensor KW - Distributed sensor KW - Brillouin scattering KW - Polymer optical fiber KW - Strain sensor KW - Smart geotextiles KW - Faseroptischer Sensor KW - Verteilter Sensor KW - Brillouin-Streuung KW - Polymeroptische Faser KW - Dehnungssensor KW - Intelligentes Geotextil PY - 2012 U6 - https://doi.org/10.1524/teme.2012.0238 SN - 0340-837X SN - 0178-2312 SN - 0171-8096 VL - 79 IS - 7-8 SP - 337 EP - 347 PB - Oldenbourg CY - München AN - OPUS4-26387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neumann, Patrick P. A1 - Wosniok, Aleksander A1 - Lazik, D. A1 - Bartholmai, Matthias T1 - Test field for the validation of a multifunctional sensor for distributed subsurface monitoring of gas storage areas N2 - BAM Federal Institute for Materials Research and Testing, in cooperation with the company MeGaSen UG carries out a research project to enhance and validate an innovative approach for distributed subsurface monitoring of gas storage areas. The concept combines different measurement technologies to one multifunctional sensor: membrane-based gas measurement technology for in-situ monitoring of gases in soil and fiber optical sensing of temperature and strain (as a measure for structural change). Key aspect of the research project is the first-time validation of the system in an application relevant dimension. For this purpose a 20 x 20 m2 test field is build. A comprehensive validation of the system is carried out by systematic variation of different parameters like position-dependent gasinjection, temperature and mechanical impact. T2 - Sensor 2013 - 16th International conference on sensors and measurement technology CY - Nürnberg, Germany DA - 14.05.2013 KW - Distributed multifunctional sensor KW - Subsurface monitoring KW - Gas storage areas KW - Membrane-based gas sensing KW - Fiber optical sensing PY - 2013 SN - 978-3-9813484-3-9 U6 - https://doi.org/10.5162/sensor2013/P2.2 N1 - Serientitel: AMA Conferences – Series title: AMA Conferences SP - 713 EP - 716 AN - OPUS4-28652 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Mizuno, Yosuke A1 - Krebber, Katerina A1 - Nakamura, K. T1 - L-BOFDA: a new sensor technique for distributed Brillouin sensing T2 - 5th European Workshop on Optical Fibre Sensors CY - Kraków, Poland DA - 2013-05-19 PY - 2013 AN - OPUS4-28788 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Simultaneous measurement of temperature and strain distribution using Brillouin scattering in dispersion-shifted fibers N2 - We studied Brillouin gain spectrum characteristics in dispersion-shifted fibers having compound GeO2-doping compositions in the fiber core to realize simultaneous measurement of distributed strain and temperature. Due to various dopant concentration alongside the radius of tested nonzero dispersion-shifted fibers several multiple Brillouin scattering resonances were observed in the stimulated Brillouin spectra arose through backscattering on higher acoustic modes which propagated along the fiber axis. As a result of the varying acoustic velocities, the Brillouin resonance peaks featured different temperature coefficients which can be used to accomplish the simultaneous measurement of fiber strain and temperature. We presented our first measurement results for NZDS Fujikura and LEAF Corning fiber and discussed the superior sensory suitability of the former fiber types. T2 - IEEE Sensors 2011 conference CY - Limerick, Ireland DA - 28.10.2011 KW - Fiber optic sensor KW - Spatial distributed sensor KW - Brillouin gain spectrum (BGS) KW - Nonzero dispersion-shifted fiber (NZDSF) KW - Brillouin sensor KW - BOTDA KW - BOFDA PY - 2011 SN - 978-1-4244-9288-6 SP - 1476 EP - 1479 AN - OPUS4-24828 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Simultaneous measurement of temperature and strain distribution using Brillouin scattering in dispersion-shifted fibers T2 - IEEE SENSORS 2011 Conference CY - Limerick, Ireland DA - 2011-10-28 PY - 2011 AN - OPUS4-24961 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Fiber optic system for monitoring large earth structures T2 - 2nd Workshop UrbanFlood 2011 CY - Amsterdam, Netherlands DA - 2011-11-03 PY - 2011 AN - OPUS4-24962 LA - deu 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 - CONF 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 PY - 2008 AN - OPUS4-18332 LA - deu 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 - 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 - Wosniok, Aleksander A1 - Nöther, Nils A1 - Thiele, E. T1 - Dyke monitoring using fiber sensor-based geosynthetics N2 - Dyke breaks - caused by e.g. Overflows or Slop breaks during long lasting high water gauge - Play a great role in a failure potential of extreme flood Events. Using conventional dyke condition Monitoring dyke messengers can undertake only a visual surface inspection. Thus defective Areas can oftentimes be discovered too late. A critical area in which failures due to soil displacement and moisture Penetration become more significant is located at a landside dyke foot. Geotextiles are integrated here as a Drainage in case of modern three-zone type of dyke. T2 - European Symposium on Flood Risk Management Research (EFRM 2007) CY - Dresden, Germany DA - 26.02.2007 PY - 2007 AN - OPUS4-14571 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nöther, Nils A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Sensorbasierte Geotextilien zur Deichertüchtigung T2 - DWA-RIMAX-Praktikertreffen CY - Potsdam, Germany DA - 2008-06-27 PY - 2008 AN - OPUS4-17654 LA - deu 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 - 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 U6 - 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 - CONF A1 - Wosniok, Aleksander A1 - Mizuno, Y. A1 - Krebber, Katerina A1 - Nakamura, K. ED - Jaroszewicz, L.R. T1 - L-BOFDA: a new sensor technique for distributed Brillouin sensing N2 - We propose a new scheme of Brillouin optical frequency-domain analysis (BOFDA) for distributed fiber-optic strain and temperature sensing, named linear-configured BOFDA (L-BOFDA). In conventional loop-configured BOFDA, light injection into both ends of a fiber under test (FUT) is needed for counter-propagation of pump and probe waves. In contrast, in L-BOFDA, pump and probe waves are injected into the same end of an FUT, and the probe wave Fresnelreflected (or mirror-reflected) at the other end of the FUT is exploited; thus, one-end access is feasible. We show proof-of-concept results of distributed strain measurement in a silica single-mode fiber with L-BOFDA, and discuss the signal-to-noise ratio degradation and the benefit in developing distributed Brillouin sensors based on polymer optical fibers. T2 - EWOFS 2013 - 5th European workshop on optical fibre sensors CY - Kraków, Poland DA - 19.05.2013 KW - Brillouin optical frequency-domain analysis (BOFDA) KW - L-BOFDA KW - Optical fiber sensing KW - Distributed strain measurement KW - Stimulated Brillouin scattering KW - Polymer optical fiber PY - 2013 U6 - https://doi.org/10.1117/12.2025378 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 8794 IS - Paper 8794 - 181 SP - 879431-1 EP - 879431-4 AN - OPUS4-28961 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Nöther, Nils A1 - Krebber, Katerina T1 - Distributed Fibre Optic Sensor System for Temperature and Strain Monitoring Based on Brillouin Optical-Fibre Frequency-Domain Analysis T2 - Eurosensors XXIII 2009 CY - Lausanne, Switzerland DA - 2009-09-06 PY - 2009 AN - OPUS4-20188 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 - 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 - 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 U6 - 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 - 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 - Wosniok, Aleksander T1 - Brillouin gain spectrum characterization for temperature compensation in fiber optic distributed strain T2 - 22nd International Conference on Optical Fiber Sensors CY - Beijing, China DA - 2012-10-15 PY - 2012 AN - OPUS4-26796 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina A1 - Glötzl, R. T1 - Brillouin-based Fiber Optic Sensor for Geotechnical Monitoring Applications T2 - Workshop on Civil Structural Health Monitoring Applications (CSHM-4) CY - Berlin, Germany DA - 2012-11-06 PY - 2012 AN - OPUS4-26946 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Brillouin gain spectrum characteristics for temperature compensation in fiber optic distributed strain T2 - 22nd International Conference on Optical Fiber Sensors (OFS-22) CY - Beijing, China DA - 2012-10-15 PY - 2012 AN - OPUS4-26908 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander ED - Liao, Y. ED - Jin, W. ED - Sampson, D.D. ED - Yamauchi, R. ED - Chung, Y. ED - Nakamura, K. ED - Rao, Y. T1 - Brillouin gain spectrum characteristics for temperature compensation in fiber optic distributed strain sensor T2 - OFS2012 - 22nd International conference on optical fiber sensors CY - Beijing, China DA - 2012-10-15 KW - Brillouin gain spectrum KW - BGS KW - Distributed Brillouin sensor KW - DBS KW - Fibre optic sensor KW - FOS KW - Brillouin optical frequency-domain analysis KW - BOFDA PY - 2012 U6 - https://doi.org/10.1117/12.974841 SN - 0277-786X SN - 1996-756X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 8421 SP - 84219T-1 - 84219T-4 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-26978 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina A1 - Glötzl, R. T1 - Temperature-corrected Determination of Mechanical Deformations in Geotechnical Structures Using Brillouin-based Fiber Optic Sensors T2 - 6th European Workshop on Structural Health Monitoring CY - Dresden, Germany DA - 2012-07-03 PY - 2012 AN - OPUS4-26463 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nöther, N. A1 - Wang, S. A1 - Wosniok, Aleksander A1 - Glötzl, R. A1 - Schneider-Glötzl, J. 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 - Distributed Brillouin sensing in optical fibers: Soil displacement monitoring using sensor-equipped geogrids N2 - This paper reports on the application of distributed Brillouin fiber optic sensing to the monitoring of geotechnical structures. The presented approach to Brillouin sensing offers an alternative to the common pulse-based measurements by using the frequency domain analysis. The focus of the research and field-testing work is to collect reliable structural health monitoring data from large-scale structures while preserving the System’s versatility in terms of being suitable for different application environments (soil structures, foundations, concrete construction works, pipelines etc.) and its robustness in being well functioning in harsh environments. Upon reviewing the presented application test, it is concluded that Brillouin frequency domain based monitoring, when applied to geotechnical structures, is capable of providing accurate strain readings representing deformations of the soil body, and reliable temperature readings for generating temperature profiles of the entire structure. An overview of the frequency domain analysis of Brillouin sensing and its digital implementation is given, along with the experiences and insights drawn from an open field test of sensor-equipped geogrid mats. T2 - SHMII-6 - 6th International conference on structural health monitoring of intelligent infrastructure CY - Hong Kong, China DA - 09.12.2013 KW - Structural health monitoring KW - Distributed sensing KW - Fiber-optic sensing KW - Brillouin sensing KW - Strain and temperature measurements KW - Sensor-equipped geosynthetics PY - 2013 SN - 978-962-367-768-4 SP - 290 EP - 295 AN - OPUS4-29914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Karapanagiotis, Christos T1 - Brillouin optical frequency-domain analysis for structural health monitoring N2 - We present our achievements in the development of distributed fiber optic sensing systems based on Brillouin optical frequency-domain analysis for structural health monitoring. The focus of the applications is on the gapless monitoring of geotechnical structures, large area infrastructures and electrical grids. The work includes the latest use of machine learning algorithms to reduce measurement time by coexistent increasing the measurement accuracy. T2 - 4th Workshop on Optomechanics and Brillouin Scattering CY - Erlangen, Germany DA - 14.06.2022 KW - Distributed sensing KW - BOFDA KW - Optical fiber sensor KW - Brillouin distributed fiber sensor PY - 2022 AN - OPUS4-55173 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Achievements and challenges of distributed polymer optical fiber sensors @BAM N2 - Monitoring of construction projects plays increasingly important role in the implementation of growing needs and requirements, especially in geologically difficult areas. This particularly concerns tunnelling and special civil engineering projects. The use of fiber optic sensors for structural health monitoring provides significant economic advantages regarding lower life-cycle costs of the civil infrastructure. We present our achievements in the development of distributed polymer optical fiber sensors based on Rayleigh and Brillouin scattering for early damage detection. T2 - POF Conference CY - Bilbao, Spain DA - 26.09.2022 KW - Distributed POF sensor KW - OTDR KW - OFDR KW - Smart geosynthetics PY - 2022 AN - OPUS4-56031 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Königsbauer, Korbinian A1 - Nöther, N. A1 - Schaller, M. B. A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Distributed POF sensors for structural health monitoring in civil construction applications N2 - In this paper, a cost-efficient distributed fiber optic measurement system based on Rayleigh scattering is presented. The distributed digital incoherent optical frequency domain reflectometry (I-OFDR) method is developed for detection of significantly large strain in the range from 3 % up to 10 % as required by end users. For this purpose, a vector network analyzer used in the I-OFDR is replaced by a compact and cost-effective digital data acquisition system. This digital emitting/receiving unit enables the recording of the complex transfer function carrying information about the local deformations along the entire sensing fiber. T2 - POF 2022 The 30th International Conference on Plastic Optical Fibers CY - Bilbao, Spain DA - 26.09.2022 KW - I-OFDR KW - PF-POF KW - Structural health monitoring KW - Rayleigh backscatter measurement KW - Strain detection PY - 2022 VL - 2022 SP - 152 EP - 155 AN - OPUS4-56060 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Königsbauer, Korbinian A1 - Wosniok, Aleksander A1 - Nöther, N. A1 - Schaller, B. T1 - Entwicklung eines praxistauglichen POF-basierten Messsystems mittels digitaler I-OFDR zur Dehnungsdetektion T1 - Development of a practicable POF-based measuring system using digital I-OFDR for strain detection N2 - Es wird ein faseroptisches Messsystem vorgestellt, welches auf Basis der Rayleigh-Rückstreumessung eine ortsauflösende Detektion von signifikant großen Dehnungen bei Bauvorhaben im von Anwendern geforderten Größenordnungsbereich von 3 % bis 10 % ermöglicht. Mit dem Verfahren der digitalen inkohärenten optischen Frequenzbereichsreflektometrie (I-OFDR) werden materialspezifische Vorteile robuster perfluorierter polymeroptischer Fasern (PF-POF) erschlossen. Für den angestrebten industriellen Einsatz für die Zustandsüberwachung im Bereich des Tunnel- und Spezialtiefbaus soll die spezifische Rückstreuzunahme in der PF-POF hochauflösend gemessen werden. Diese Veröffentlichung zeigt in ersten Projektergebnissen die Eignung des digitalen I-OFDR für eine Dehnungsdetektion von bis zu 10%. N2 - A fiber-optic measurement system is presented which, based on Rayleigh backscatter measurement, enables distributed detection of significantly large strains in construction projects in the range of 3 % to 10 % required by end users. The method of digital incoherent optical frequency domain reflectometry (I-OFDR) is used exploiting material-specific advantages of robust perfluorinated polymer optical fibers (PF-POF). For the intended industrial application for structural health monitoring in the field of tunnel construction and specialised civil and underground engineering, the specific backscatter increase in the PF-POF is to be measured with high resolution. This publication shows in first project results the suitability of the digital I-OFDR for strain detection up to 10%. T2 - 21. ITG/GMA-Fachtagung CY - Nuremberg, Germany DA - 10.05.2022 KW - Backscatter measurement KW - Optical fiber sensors KW - POF KW - I-OFDR KW - Strain measurement PY - 2022 SN - 978-3-8007-5835-7 SN - 0932-6022 VL - 303 SP - 139 EP - 143 PB - VDE VERLAG GMBH CY - Berlin · Offenbach AN - OPUS4-54851 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karapanagiotis, Christos A1 - Hicke, Konstantin A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Distributed humidity fiber-optic sensor based on BOFDA using a simple machine learning approach N2 - We report, to our knowledge for the first time, on distributed relative humidity sensing in silica polyimide-coated optical fibers using Brillouin optical frequency domain analysis (BOFDA). Linear regression, which is a simple and well-interpretable algorithm in machine learning and statistics, is utilized. The algorithm is trained using as features the Brillouin frequency shifts and linewidths of the fiber’s multipeak Brillouin spectrum. To assess and improve the effectiveness of the regression algorithm, we make use of machine learning concepts to estimate the model’s uncertainties and select the features that contribute most to the model’s performance. In addition to relative humidity, the model is also able to simultaneously provide distributed temperature information addressing the well-known cross-sensitivity effects. KW - Fiber optics sensors KW - Machine learning KW - Brillouin distributed sensing KW - Humidity sensing KW - Simultaneous temperature and humidity sensing PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-546294 VL - 30 IS - 8 SP - 12484 EP - 12494 PB - OPTICA AN - OPUS4-54629 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Distributed fiber optic radiation sensors N2 - In this work, we present our results achieved in several research activities for development of distributed fiber optic radiation sensors using glass and polymer optical fibers. The findings show that both the measurement of the radiation-induced attenuation (RIA) along the entire sensing fiber and the accompanying change in the refractive index of the fiber core can be used for distributed radiation monitoring. T2 - safeND CY - Online meeting DA - 10.11.2021 KW - Distributed fiber optic radiation sensors KW - Radiation-induced attenuation KW - Optical fiber sensor KW - Incoherent optical frequency domain reflectometry PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-537531 VL - 1 SP - 15 EP - 16 AN - OPUS4-53753 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Fibre optic sensors for monitoring tasks in a radiation environment N2 - The topic of the presentation are distributed fiber optic measurement techniques that can be used for long-term monitoring of strain, temperature and radiation distribution in the radiation environment. The fiber optic sensors applied to the surface of waste packages provide detection and localization of cracks. T2 - Workshop WP7.3 EU project PREDIS CY - Online meeting DA - 15.11.2021 KW - Distributed sensing KW - Fiber optic sensor KW - Radiation sensing fibers KW - Brillouin distributed fiber sensor KW - Distributed acoustic sensing PY - 2021 AN - OPUS4-53751 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Distributed fiber optic radiation sensors N2 - In this work, we present our results achieved in several research activities for development of fiber optic dosimeters. The findings show that both the measurement of the radiation-induced attenuation (RIA) along the entire sensing fiber and the accom panying change in the refractive index of the fiber core can be used for distributed radiation monitoring in the kGy and MGy range, respectively. Depending on the fiber type and material the RIA shows varying response to dose rates, environmental temperatures and the wavelength of the laser source used. T2 - safeND CY - Online meeting DA - 10.11.2021 KW - Distributed sensing KW - Fiber optic radiation sensor KW - Radiation sensing fibers KW - Radiation-induced attenuation PY - 2021 AN - OPUS4-53752 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Faseroptische Strahlungssensoren für kerntechnische Anwendungen N2 - Der Anstieg der Vielfalt nuklearer Anwendungen weit über die Bereiche der kerntechnischen Stromerzeugung erhöht die Relevanz der Entwicklung und Anwendung neuer Technologien zur Strahlungsüberwachung. Auch die offenen Sicherheitsfragen bei der Entsorgung radioaktiver Abfälle einschließlich Zwischen- und Endlagerungsproblematik verstärkt die Nachfrage nach effizienten Monitoringsystemen zum Schutz von Mensch und Umwelt vor ionisierender Strahlung. Aufgrund ihrer messtechnisch vorteilhaften Materialeigenschaften stellen die faseroptischen Strahlungssensoren eine vielversprechende Alternative zu traditionellen Dosimetern dar. Bedingt durch ihre kleinen Abmessungen, elektromagnetische Unempfindlichkeit und ihr geringes Gewicht können faseroptische Sensoren in einer harschen Umgebung an schwer zugänglichen Stellen eingesetzt werden. Darüber hinaus bietet diese Art der Sensoren die Möglichkeit der ortsverteilten Messung entlang der gesamten Sensorfaser. Somit kann durch eine einzelne optische Faser eine Vielzahl an punktuell messenden Sensoren ersetzt werden. Dieser Beitrag beschreibt die in der BAM vorangetriebenen Entwicklungen unterschiedlicher Sensorprinzipien, -lösungen und -verfahren zur Detektion ionisierender Strahlung. T2 - 2. Tage der Standortauswahl CY - Online meeting DA - 11.02.2021 KW - Faseroptischer Strahlungssensor KW - Ortsauflösende Fasersensorik KW - Strahlungsinduzierte optische Dämpfung KW - Gammastrahlung KW - Rayleigh-Streuung KW - Brillouin-Streuung PY - 2021 SP - 43 AN - OPUS4-52211 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Optical fibers for sensing applications: Towards ionizing radiation monitoring N2 - Overview about existing fiber optic sensing techniques including ionizing radiation monitoring. T2 - WP7 Meeting EU project PREDIS CY - Online meeting DA - 05.02.2021 KW - Fiber optic sensor KW - Radiation-induced attenuation KW - Radiation sensing fibers KW - Distributed sensing PY - 2021 AN - OPUS4-52090 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Jansen, R. A1 - Cheng, L. A1 - Chruscicki, Sebastian T1 - Ortsaufgelöste Zustandsüberwachung von Brückenbauwerken mittels faseroptischer Sensoren N2 - In der vorliegenden Studie wurde der Einfluss der statischen Verkehrsbelastung auf die geringen Durchbiegungseffekte in der Betonkonstruktion einer bestehenden Brücke mittels ortsauflösender faseroptischer Sensoren untersucht. Dabei tragen die Ergebnisse der an der Amsterdamer Brücke 705 durchgeführten Belastungstests wesentlich zum Verständnis des Strukturverhaltens bei. Das Konzept der statischen Belastung basierte auf dem Einsatz von zwei 36-Tonnen-Lastwagen, die an mehreren vorbestimmten Stellen auf der Brücke anhielten. Die auf diese Weise aufgebrachte Last führte zu ortsabhängigen kleinen Durchbiegungseffekten, die als lokale Längsdehnung der an der Unterseite der Brücke integrierten Sensorfaser aufgezeichnet wurden. Die reflektometrischen Messungen beruhten auf dem Prinzip genannt TW-COTDR (Tunable Wavelength Coherent Optical Time Domain Reflectometry). Die Messgenauigkeit lag im Bereich von 0,5 µm/m. T2 - DGZfP-Jahrestagung 2021 CY - Online meeting DA - 10.05.2021 KW - Frequenzbereichsreflektometrie KW - Ortsaufgelöste Fasersensorik KW - Rayleigh-Streuung PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-526752 UR - https://jahrestagung.dgzfp.de/Programm#P73 SP - 1 EP - 8 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) CY - Berlin AN - OPUS4-52675 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Jansen, R. A1 - Cheng, L. A1 - Chruscicki, Sebastian T1 - Ortsaufgelöste Zustandsüberwachung von Brückenbauwerken mittels faseroptischer Sensoren N2 - In der vorliegenden Studie wurde der Einfluss der statischen Verkehrsbelastung auf die geringen Durchbiegungseffekte in der Betonkonstruktion einer bestehenden Brücke mittels ortsauflösender faseroptischer Sensoren untersucht. Dabei tragen die Ergebnisse der an der Amsterdamer Brücke 705 durchgeführten Belastungstests wesentlich zum Verständnis des Strukturverhaltens bei. Das Konzept der statischen Belastung basierte auf dem Einsatz von zwei 36-Tonnen-Lastwagen, die an mehreren vorbestimmten Stellen auf der Brücke anhielten. Die auf diese Weise aufgebrachte Last führte zu ortsabhängigen kleinen Durchbiegungseffekten, die als lokale Längsdehnung der an der Unterseite der Brücke integrierten Sensorfaser aufgezeichnet wurden. Die reflektometrischen Messungen beruhten auf dem Prinzip genannt TW-COTDR (Tunable Wavelength Coherent Optical Time Domain Reflectometry). Die Messgenauigkeit lag im Bereich von 0,5 µm/m. T2 - DGZfP-Jahrestagung 2021 CY - Online meeting DA - 10.05.2021 KW - Ortsaufgelöste Fasersensorik KW - Frequenzbereichsreflektometrie KW - Rayleigh-Streuung PY - 2021 UR - https://jahrestagung.dgzfp.de/Programm#P73 AN - OPUS4-52632 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Sporea, D. A1 - Neguţ, D. A1 - Krebber, Katerina T1 - Gamma radiation influence on silica optical fibers measured by optical backscatter reflectometry and Brillouin sensing technique N2 - We have studied the influence of gamma rays on physical properties of different commercially available silica optical fibers stepwise irradiated up to a total dose of 100 kGy. The detection of radiation-induced changes in silica glass offers the possibility of using selected optical fibers as distributed radiation sensors. The measurements performed by us were based on optical backscatter reflectometry and Brillouin distributed sensing. The measurement methods enable an analysis of radiation-induced modification of the group refractive index and density of the optical fibers. The most distinct physical effect observed by us concerns the increase of the optical attenuation with rising total radiation doses. Quantitative measurement results indicate a crucial impact of fiber dopants on radiation-induced physical and sensory characteristics of silica optical fibers affected by differences in fiber fabrication techniques. Based on the obtained results, the suitability of distributed Brillouin sensing for dosimetry applications seems to be improved by modifying the refractive index profile of the fiber core. T2 - Sixth European Workshop on Optical Fibre Sensors CY - Limerick, IRL DA - 31.05.2016 KW - Brillouin frequency shift KW - Lonizing radiation KW - Gamma radiation KW - Radiation dosimetry KW - Optical fiber sensor KW - Brillouin scattering KW - Distributed measurement KW - Backscatter reflectometry PY - 2016 SN - 978-1-5106-0219-9 U6 - https://doi.org/10.1117/12.2236678 SN - 0277-786X VL - 9916 SP - Article Number: 99162J PB - Spie-Int Soc Optical Engineering CY - Bellingham, WA, USA AN - OPUS4-37083 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Sporea, D. A1 - Neguţ, D. A1 - Krebber, Katerina T1 - Gamma radiation influence on silica optical fibers measured by optical backscatter reflectometry and Brillouin sensing technique N2 - We have studied the influence of gamma rays on physical properties of different commercially available silica optical fibers stepwise irradiated up to a total dose of 100 kGy. The detection of radiation-induced changes in silica glass offers the possibility of using selected optical fibers as distributed radiation sensors. The measurements performed by us were based on optical backscatter reflectometry and Brillouin distributed sensing. The measurement methods enable an analysis of radiation-induced modification of the group refractive index and density of the optical fibers. The most distinct physical effect observed by us concerns the increase of the optical attenuation with rising total radiation doses. Quantitative measurement results indicate a crucial impact of fiber dopants on radiation-induced physical and sensory characteristics of silica optical fibers affected by differences in fiber fabrication techniques. Based on the obtained results, the suitability of distributed Brillouin sensing for dosimetry applications seems to be improved by modifying the refractive index profile of the fiber core. T2 - Sixth European Workshop on Optical Fibre Sensors CY - Limerick, IRL DA - 31.05.2016 KW - Brillouin frequency shift KW - Ionizing radiation KW - Gamma radiation KW - Radiation dosimetry KW - Optical fiber sensor KW - Brillouin scattering KW - Distributed measurement KW - Backscatter reflectometry PY - 2016 AN - OPUS4-37088 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 - Schukar, Marcus A1 - Wendt, Mario A1 - Witt, Jens A1 - Wosniok, Aleksander T1 - Technology and applications of smart technical textiles based on fibre optic sensors N2 - Technical textiles with embedded fibre optic sensors habe been developed for the purposes of the structural health monitoring in geotechnical and civil engineering as well as for healthcare monitoring in the medical sector. The paper shows selected examples of using such sensor-based smart textiles for different applications. T2 - International conference "Optical sensors" CY - Karlsruhe, Germany DA - 2010-06-21 PY - 2010 IS - STuC2.pdf SP - 1 EP - 2(?) AN - OPUS4-21567 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 - 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 U6 - 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 - Wosniok, Aleksander A1 - Krywult, L. T1 - Monitoring konstrukcji ziemnych przy zastosowaniu rozlozonych przestrzennie swiatlowodowych sensorow optycznych, zintegrowanych w geosyntetykach. Monitoring of eartwork structures using spatial distributed fibre optic sensors embedded in geosynthetics T2 - 34th Winter School of Rock Mechanics and Geoengineering CY - Kudowa-Zdrój, Poland DA - 2011-03-14 PY - 2011 AN - OPUS4-24063 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Glötzl, R. A1 - Glötzl, R. A1 - Krebber, Katerina A1 - Krywult, L. T1 - Optical Distributed Sensing Systems and possible Applications in the Geotechnical Measuring Field T2 - XIV Dams Monitoring International Conference 2011 CY - Walbrzych, Poland DA - 2011-06-13 PY - 2011 AN - OPUS4-24064 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Glötzl, R. A1 - Schneider Glötzl, J. A1 - Wosniok, Aleksander A1 - Krebber, Katerina A1 - Krywult, L. ED - Wintera, J. ED - Kosik, A. ED - Wity, A. T1 - Optical distributed sensing systems and possible applications in geotechnical measuring N2 - In comparison with traditional measuring Systems (pressure cells, piezometers and inclinometers which produce only point measurements) fibre optic sensors are well suited for spatiallydistributed monitoring purposes. The very tiny optical fibres of a diameter of less then 1 mm can operate as sensors in strong electromagnetic fields, under “harsh” explosive and Chemical environments and under ionizing radiation. T2 - XIV Dam monitoring international conference 'safetyof dams - new challenges' ('Bezpieczenstwo zapór - nowe wyzwania') CY - Walbrzych, Poland DA - 13.06.2011 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 - Geotxtiles KW - Technical textiles PY - 2011 SN - 978-83-61102-53-3 N1 - Serientitel: Monografie - Instytutu Meteorologii i Gospodarki Wodnej – Series title: Monografie - Instytutu Meteorologii i Gospodarki Wodnej IS - Chapter 6 SP - 173 EP - 180 AN - OPUS4-24066 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 - 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 - JOUR A1 - Kasinathan, M. A1 - Wosniok, Aleksander A1 - Krebber, Katerina A1 - Babu Rao, C. T1 - Optical fiber defect detection using Brillouin optical time domain analyser N2 - A new technique for optical fiber defect detection using Brillouin distributed fiber optic sensor (DFOS) has been proposed and experimentally demonstrated in this paper. This technique is based on stimulated Brillouin scattering (SBS), which offers three wave interaction in single mode optical fiber (SMF -10 μm/125 μm acrylic coated fiber). The nonlinear effect of SBS is manipulated to locate the defect in optical fiber using distributed sensing technology. Various kind of defects may be present in optical fibers. This paper details a case study on observation of a defect, which manifests its presence in certain temperature values. The detail of defect detection through distributed fiber sensor using the SBS has been brought out. SBS is sensitive to temperature and strain. In order to study the effect of defect in distributed fiber sensor as function of temperature and strain, the distributed pre-strained and unstrained optical fiber is subjected to temperature variation and corresponding measurements are obtained with Brillouin optical time domain analyser (BOTDA). This technique enables the utilization of Brillouin parameters, such as decreased amplitude, frequency and increased linewidth in the defect region of the fiber length. The fiber defect location can be determined with spatial resolution accuracy of less than 50 cm of using BOTDA technique. KW - Stimulated Brillouin scattering KW - Distributed sensor KW - Optical fiber KW - Brillouin Optical Time Domain Analysis PY - 2016 SN - 0019-5596 VL - 54 IS - 9 SP - 565 EP - 570 PB - NISCAIR AN - OPUS4-37914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kasinathan, M. A1 - Babu Rao, C. A1 - Murali, N. A1 - Jayakumar, T. A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Bond monitoring in temperature dependent applications using Brillouin optical time domain analyser N2 - Adhesive bond has to be evaluated for its integrity over a range of temperature. Adhesive is being used to bond the sensors with structures. There is no validated technique to test its performance. In this paper, we propose a Brillouin Optical Time Domain Analyzer (BOTDA) based methodology to detect temperature-induced adhesive bond failure below room temperature using distributed fiber optic sensor. The differential coefficient of thermal expansion of the structure and fiber sensor can lead to bond failure at low temperature. Optical fiber impregnated in the structure will experience differential temperature/strain due to debond of the adhesive. This leads to the frequency and amplitude decomposition of the Brillouin spectra. This is a good indication for real-time monitoring of the integrity of a bond. KW - Adhesive bond KW - Brillouin scattering KW - optical fiber sensor KW - Brillouin optical time domain analysis KW - distributed sensor PY - 2016 U6 - https://doi.org/10.1007/s12596-015-0266-5 VL - 45 IS - 1 SP - 44 EP - 49 PB - Springer AN - OPUS4-37923 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fuggini, C. A1 - Zangani, D. A1 - Wosniok, Aleksander A1 - Krebber, Katerina A1 - Franitza, P. A1 - Gabino, L. A1 - Weigand, F. T1 - Innovative approach in the use of geotextiles for failures prevention in railway embankments N2 - Maintenance and renewal costs of a typical railway, track and substructure represents 50–60% of the total costs of such infrastructure over its entire service life. Innovations in track and substructure are therefore fundamental to achieve a significant impact on the overall cost reduction for the railways. Therefore new solutions for track improvements that are effective and that can minimize the interruption of traffic are needed. Moreover, failures of railway embankments happened recently in different regions of the world. Such events, such as the one happened in UK in February 2013 (http://www.bbc.co.uk/news/uk-england-south-yorkshire-21441070), are showing the importance of monitoring track and infrastructure coupled with the use of numerical models for the localization of the critical areas and the design of appropriate countermeasures. Indeed embankment failures, landslides and uneven settlements and similar events are becoming much more common than in the past due to climate changes, and this requires the infrastructure managers to look from a different perspective infrastructure maintenance issues. What was previously consider as “extreme” is now “common” and thus actions need to be taken to be ready when such events will happen. The aim is to mitigate their effects on the infrastructure and to minimize disruptions to train services and reduce maintenance costs to restore the normal service conditions. If this mental change happens, then the need for solutions and techniques for global asset monitoring and ground stabilization will probably increase. Among the others, geotextiles and geogrids for soil reinforcement used in combination with condition monitoring techniques have the potential for minimizing catastrophic events, whilst at the same time providing a good balance among costs and benefits (i.e. sustainability). The paper describe a case study where the use of multifunctional geotextiles, able to provide both strengthening and monitoring functions, has been tested along a railroad near the city of Chemnitz (Germany). The results are here reported to show the potential use and the innovative aspect of this solution. T2 - 6th Transport Research Arena (TRA) CY - Warsaw, Poland DA - 18.04.2016 KW - smart geotextile KW - failure prevention KW - railway embankment KW - fiber optic sensor KW - distributed sensor PY - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-379256 VL - 14 SP - 1875 EP - 1883 PB - Elsevier B.V. AN - OPUS4-37925 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Distributed Brillouin fiber optic sensor system for long-term structural health T2 - XVI Technical Dam Control International Conference CY - Wierchomla Mala, Polanc DA - 2015-09-29 PY - 2015 AN - OPUS4-34494 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina ED - Karabay, G. ED - Kara, S. T1 - Smart geosynthetics for structural health monitoring using fully distributed fiber optic sensors N2 - We report on the development of a complete system for structural health monitaring of large-scale geotechnical structures. The system uses Brillouin frequency domain analysis (BOFDA) for distributed measurement of strain and temperature along glass optical fibers (GOFs) by determining the so-called Brillouin frequency shift (BFS). ln a number of research activities we managed to optimize the BOFDA measurement setup regarding the spatial resolution and the accuracy of the measured quantities. Moreover, we realized a simultaneaus measurement of strain and temperature by using nonzero dispersion-shifted fibers (NZDSFs) with several multiple Brillouin scattering resonances. ln cooperation with our German and ltalian industry partners we finally succeeded in fabricating low-attenuation smart geosynthetics as a sensor component of a fully distributed Brillouin-based fiber optic monitaring system. T2 - 6th International Technical Textiles Congress CY - Izmir, Turkey DA - 14.10.2015 KW - Brillouin scattering KW - Distributed sensor KW - Fiberoptic sensor KW - Optical fiber KW - Structural health monitoring PY - 2015 SN - 978-975-441-448-6 SP - 215 EP - 218 PB - Meta Basim Pr. AN - OPUS4-34772 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Smart Geosynthetics for Structural Health Monitoring Using Fully Distributed Fiber Optic Sensors T2 - 6th International Technical Textiles Congress CY - Izmir, Turkey DA - 2015-10-14 PY - 2015 AN - OPUS4-34825 LA - deu 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 - CHAP A1 - Wosniok, Aleksander ED - Peng, G.D. T1 - Distributed Brillouin Sensing: Frequency-Domain Techniques N2 - The substantial progresses in fiber-optic communications in combination with the increasing economic and political interest in structural health monitoring have led to a commercial establishment of distributed Brillouin sensing. The sensor systems, mainly based on the time-domain techniques, have been successfully implemented in the areas such as pipeline leak detection, geohazard effects, and ground movement detection. This chapter introduces a further advancement in the area of Brillouin sensing in the frequency domain. The so-called Brillouin optical frequency-domain analysis (BOFDA) offers crucial perspectives in terms of dynamic range and cost efficiency. The main principle of the frequency-domain approach takes advantage of the reversibility between the time and frequency domain given by a Fourier transform in the analysis of linear systems. The hereby presented overview gives a summary of the benefits and challenges of frequency-domain measurements closely tied to the narrowband recording of the complex transfer function. This function relates the counterpropagating pump and probe laser light along the sensor fiber providing the pulse response of the measurement system by applying the inverse Fourier transform (IFT). The strain or temperature distribution can be then determined from the retrieved Brillouin frequency shift (BFS) profile along the fiber. KW - Distributed Brillouin Sensing KW - Brillouin optical frequency-domain analysis KW - BOFDA PY - 2018 SN - 978-981-10-1477-2 U6 - https://doi.org/10.1007/978-981-10-1477-2_8-1 VL - 2018 SP - 1 EP - 25 PB - Springer Nature CY - Singapore AN - OPUS4-45044 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schreier, Andy A1 - Wosniok, Aleksander A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - Humidity-induced Brillouin frequency shift in perfluorinated polymer optical fibers N2 - We report, to our knowledge, for the first time on humidity-induced Brillouin frequency shifts in perfluorinated graded index polymer optical fibers. A linear relation between Brillouin frequency shift and humidity was observed. Furthermore, the humidity coefficient of the Brillouin frequency shift is demonstrated to be a function of temperature (-107 to -64 kHz/%r.h. or -426 to -49 kHz m3/g in the range of 20 to 60 °C). An analytical description proves temperature and humidity as two mutually independent effects on the Brillouin frequency shift. KW - Brillouin KW - Polymer optical fibre KW - Humidity PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-457165 SN - 1094-4087 VL - 26 IS - 17 SP - 22307 EP - 22314 PB - Optical Society of America AN - OPUS4-45716 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Smart Geosynthetics Based on Distributed Fiber Optic Sensors in Geotechnical Engineering N2 - Smart geosynthetics with embedded optical fibers as distributed sensors provide solutions both for applications in geotechnical engineering and for cost-effective monitoring of critical infrastructures. The incorporation of glass or polymer optical fibers (GOFs or POFs) in geotextiles and geogrids allows early detection of mechanical deformations, temperature and humidity. This paper presents selected examples of smart geosynthetics based on Brillouin and Rayleigh scattering effects in incorporated fiber optic sensors for monitoring of large geotechnical structures like dikes, dams, railways, embankments or slopes. The focus of the presented work is on real field tests of measurement capability with respect to the chosen measurement principle and used fiber type. KW - Polymer optical fiber (POF) KW - Smart geosynthetics KW - Fiber optic sensor KW - Distributed sensing KW - Glass optical fiber (GOF) PY - 2019 SN - 0046-5828 SP - 91 EP - 95 PB - Southeast Asian Geotechnical Society CY - Bangkok AN - OPUS4-48068 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Distributed fiber optic sensing for structural health monitoring of pipelines and structures in oil and gas industry N2 - Introduction of the state-of-the-art measurement technologies for distributed fiber optic sensing used for structural health monitoring of pipelines and structures in oil and gas industry. T2 - Workshop mit Federal University of Rio de Janeiro und Vallourec Group Brasil CY - Berlin, Germany DA - 20.05.2019 KW - Pipeline monitoring KW - Distributed Brillouin sensing KW - Fiber optic sensor PY - 2019 AN - OPUS4-48048 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wosniok, Aleksander A1 - Skoczowsky, Danilo A1 - Schukar, Marcus A1 - Pötzsch, Sina A1 - Pötschke, Samuel A1 - Krüger, Simone T1 - Fiber optic sensors for high-temperature measurements on composite tanks in fire N2 - For the purpose of increasing payload and reduce freight cost, lightweight composite tank containers used for Transportation have been progressively developed during the last years. Compared to conventionally produced cylindrical steel tanks, the fiber-reinforced solutions allow greater flexibility in the tank design. Despite a number of further material-related benefits of fiber-reinforced composites as non-conductive and non-magnetic behavior as well as corrosion resistance and high strength, the optimization of their thermal degradation properties during combustion is still a challenge. To improve the fire performance of lightweight composite containers, special intumescent fire protection coatings can be applied onto the outside tank surface. This paper presents fire tests on glass-fiber-reinforced plastic transport tanks with complex geometries sheltered with different surface-applied fire protection systems. To evaluate the fire resistance of the tank structures, a fiber optic monitoring system was developed. This system is based on distributed temperature measurements using high-Resolution optical backscatter reflectometry and pointwise reference measurements using fiber Bragg gratings. Thereby, all the fiber optic sensors were directly integrated in the composite layer structure of the tanks. The focus of the presented work is on the demonstration of capability of fiber optic monitoring system in such high-temperature application. Moreover, the fiber optic measurements provide new insights into the efficiency of intumescent coating applied for fire protection of fiber-reinforced plastic transport tanks. KW - Fire resistance KW - Composite material KW - Glass-fiber-reinforced plastic transport tank KW - Distributed fiber optic sensing KW - Optical backscatter reflectometry KW - Fiber optic sensor PY - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-481972 SN - 2190-5452 SN - 2190-5479 SP - 1 EP - 8 PB - Springer Nature AN - OPUS4-48197 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Jansen, R. A1 - Chen, L. A1 - Toet, P. A1 - Doppenberg, E. A1 - De Jong, W. A1 - Chruscicki, Sebastian T1 - Static load monitoring of a concrete bridge using a high-precision distributed fiber optic sensor system N2 - In the present study, the impact of static traffic loading on the slight deflection effects in the concrete structure of an existing bridge has been investigated using distributed fiber optic sensors. In the face of increasing traffic density and severe traffic loading, the results of the load tests on the Amsterdam bridge 705 make an important contribution to the understanding of its structural behavior. The concept of the static loading was based on the use of two 36-ton trucks stopped on the bridge at multiple pre-determined locations. The load applied in this way led to location-dependent small deflection effects recorded as longitudinal strain of the sensing fiber embedded at the underside of the bridge. The measurements were performed with a commercially-available solution based on Tunable Wavelength Coherent Optical Time Domain Reflectometry with the measurement accuracy in the range of 0.5 µm/m. T2 - 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures CY - Potsdam, Germany DA - 27.08.2019 KW - Bridge monitoring KW - Distributed fiber optic sensing KW - Static load monitoring KW - TW-COTDR PY - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-490408 SP - 1 EP - 8 AN - OPUS4-49040 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Petrov, Sergej A1 - Neumann, Patrick P. A1 - Werner, Klaus-Dieter A1 - Wosniok, Aleksander A1 - Lazik, D. A1 - Bartholmai, Matthias ED - Nicoletto, G. ED - Pastrama, S.D. ED - Emri, I. T1 - Concept for investigating mechanical and thermal impacts on distributed subsurface gas monitoring N2 - A multifunctional sensor in line shape was developed and introduced in previous work for measuring of gas concentrations, temperature change, and strain. A current field study focuses on a spatially distributed monitoring of subsurface CO 2 gas storage sites in near real time. Mechanical impacts, e.g., caused by construction work, denudation, and seismic activity, can affect the integrity of underground gas storage sites. Thermal or moisture impacts, e.g., caused by weather conditions, can influence the gas Distribution behavior. In this paper, we briefly describe the setup of a CO 2 injection soil test field. This setup contains actuating elements for the investigation of mechanical and thermal impacts on distributed subsurface gas monitoring. A concept is given for evaluating these impacts and first experimental results are presented. T2 - 32nd DANUBIA ADRIA SYMPOSIUM on Advances in Experimental Mechanics CY - Starý Smokovec, Slovakia DA - 22.09.2015 KW - Linear sensor KW - Distributed sensor KW - Monitoring of CO 2 KW - Subsurface monitoring KW - Gas storage areas KW - Membrane-based gas sensing KW - Fibre optical sensing PY - 2016 U6 - https://doi.org/10.1016/j.matpr.2016.03.060 SN - 2214-7853 VL - 3 IS - 4 SP - 1124 EP - 1128 PB - Elsevier Ltd. AN - OPUS4-35688 LA - eng 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 - CHAP A1 - Wosniok, Aleksander ED - Werneck, M.M. ED - da Silva Barros Allil, R.C T1 - POF Sensors for Structural Health Monitoring N2 - The ever more ambitious strategic goals of meeting the requirements in ensuring technical safety and security of civil structures have resulted in flourishing development of innovative structural health monitoring (SHM) technologies for early damage diagnosis and prognosis. At the same time, implementing SHM systems provides tangible economic benefits derived from lower life-cycle costs associated with reduction in the maintenance, repair and insurance expenses. Due to the large size and harsh environmental conditions common to most civil structures, the broad range of favorable physical-mechanical properties of POFs allow for customized monitoring solutions for a wide variety of applications. In addition to common SHM-related advantages of optical fibers including their electromagnetic immunity, small size, lightweight as well as spark-free and non-conductive characteristics, POFs offer better bending and fracture resistance then their glass-counterparts. Particularly, the improved robustness of POFs, their ease of handling, low Young’s Modulus and high elastic limit of 10% compared to 1% in silica glass [1] are relevant to practical applications. Depending on the composition, dopants, drawing process and geometry [2], strain measurement up to 45% [3] or even above 100% [4,5] has been demonstrated with standard POFs. Therefore, the dominant market expected for POF sensors includes monitoring of high-strain-rate deformations in earthwork structures, crack detection in concrete and masonry structures [6] or overstressing in high-rise steel structures exposed to moisture, corrosion, leakage, fatigue, vibration, fire, overflow, earthquake and intentional damage. For fracture monitoring within concrete structures, the sensory usage of POFs becomes especially favorable since the extremely alkaline environment of concrete mixtures is well known to be corrosive to standard silica glass optical fibers (GOFs) [1,7]. Most of advanced distributed sensing techniques are commonly based on Rayleigh backscatter reflectometry using commercially available multimode (MM) POFs. Such typical MM POFs range from a step-index (SI) poly(methyl methacrylate) (PMMA) POF having a core diameter of 1 mm to a low-loss graded-index (GI) perfluorinated (PF) POF based on poly(perfluorobutenyl-vinylether) also known as CYTOP [8] with a 50 µm core diameter. The relatively low optical attenuation value of 30 dB/km at 1.3 µm [9,10] makes PFGI POFs also interesting for distributed Brillouin sensing [11-14]. Compared to GOFs, PFGI POFs offer better potential for temperature measurement and have comparably low theoretical attenuation limit [15]. Therefore, POF-based distributed Brillouin sensing is expected to play an important role in the future of SHM, especially at high-strain ranges. The significance of the Brillouin measurment technique can be also enhanced by further development of the single-mode (SM) POFs which are still subject of research and are used for coherent detection techniques [6]. Furthermore, SM PMMA POFs have been characterized in a Mach-Zehnder interferometer setup for strain values up to 15.8% [16,17]. The current development of SM perfluorinated and microstructured POFs (mPOFs) represents an immense promise for quasi-distributed dynamic measurement at high strain levels based on fiber Bragg grating (FBG) technology. While SM mPOFs with optical losses of about 1 dB/m can be fabricated [6], the SM PF POFs presented by Zhou et al. feature low attenuation of even less than 0.2 dB/m in the wavelength range of 1.41 µm to 1.55 µm [18]. At the same time, the SM PF POFs have the potential for improved thermal stability compared to their PMMA counterparts [19]. This whole chapter provides a comprehensive overview on current POF-based sensing principles and SHM technologies, highlighting their diverse applications in civil engineering structures. In the application-related context, close attention is paid to the development of smart sensor-based geotextiles and geogrids. Such geosynthetics-integrated distributed POF sensors have proven to be a promising solution for two- or even tree-dimensional monitoring of critical high mechanical deformations in both geotechnical and masonry structures. Moreover, geosynthetics in the form of nonwoven geotextiles as well as polymer-based geogrids used as carrier materials for POF sensors enable optimized load transfer from the monitored structure to the measuring fiber without losing their original functionality. In other words, smart geosynthetics provide a cost-efficient dual solution for, on the one hand, well-established increase of structure stability and decrease of erosion effects, on the other hand, early-warning and detection capabilities in the prevention and elimination of potential hazards and lasting damages. KW - Plastic Optical Fiber Sensor KW - OTDR KW - Brillouin Sensing KW - Interferometric Sensor KW - FBG KW - Long Period Grating KW - Smart Geosynthetics PY - 2020 SN - 978-1-13829-853-8 SP - 267 EP - 283 PB - CRC Press Taylor & Francis Group CY - Boca Raton, FL, USA AN - OPUS4-50561 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Jansen, R. A1 - Chen, L. A1 - Toet, P. A1 - Doppenberg, E. A1 - De Jong, W. A1 - Chruscicki, Sebastian T1 - Static load monitoring of a concrete bridge using a high-precision distributed fiber optic sensor system N2 - In the present study, the impact of static traffic loading on the slight deflection effects in the concrete structure of an existing bridge has been investigated using distributed fiber optic sensors. In the face of increasing traffic density and severe traffic loading, the results of the load tests on the Amsterdam bridge 705 make an important contribution to the understanding of its structural behavior. The concept of the static loading was based on the use of two 36-ton trucks stopped on the bridge at multiple pre-determined locations. The load applied in this way led to location-dependent small deflection effects recorded as longitudinal strain of the sensing fiber embedded at the underside of the bridge. The measurements were performed with a commercially-available solution based on Tunable Wavelength Coherent Optical Time Domain Reflectometry with the measurement accuracy in the range of 0.5 µm/m. T2 - 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures CY - Potsdam, Germany DA - 27.08.2019 KW - Distributed fiber optic sensing KW - Bridge monitoring KW - TW-COTDR KW - Static load monitoring PY - 2019 AN - OPUS4-48779 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Messgenauigkeit und Reproduzierbarkeit bei der Messung der Brillouin-Frequenzverschiebung für die faseroptische Bestimmung der Temperaturverteilung N2 - Auf der Grundlage der in DIN EN 61757-2-2:2017 beschriebenen Standardisierungsmethoden wurden in dieser Arbeit wichtige Leistungsparameter von vier kommerziellen Messsystemen zur ortsaufgelösten faseroptischen Erfassung der temperatur- und dehnungsabhängigen Brillouin-Frequenzverschiebung untersucht. Gemäß der oben genannten Norm konzentrierte sich hier die Ermittlungsprüfung auf messtechnische Aspekte reiner Temperaturmessungen. Dabei diente die Ermittlung von einem festgelegten Satz dreier Betriebsverhaltenskenngrößen in Form von quantitativen Angaben des Messfehlers, der Wiederholgenauigkeit sowie der räumlichen Unsicherheit einem Vergleich der getesteten Messsysteme. Alle faseroptischen Messungen wurden mit einer Faserschleife ausgeführt, d. h. als Sensorkonfiguration der Messfaser wurde eine Schleifenanordnung gewählt. Die Messverfahren der getesteten Messysteme basierten somit auf der Brillouin-optischen Zeit- bzw. Frequenzbereichsanalyse. Die Betriebsverhaltenskenngrößen wurden ferner bei unterschiedlichen Werten zweier messtechnischer Parameter, des Frequenzschrittes und der Mittelungsrate, für Standardeinstellungen der Laserleistungswerte der in die Sensorfaser einzukoppelnden Laserlichtsignale ermittelt. Auf diesem Weg lassen sich relevante Aussagen zur Optimierung der Messgenauigkeiten in Bezug auf Messdauer treffen. T2 - 20.GMT/ITG-Fachtagung Sensoren und Messsysteme 2019 CY - Nuremberg, Germany DA - 25.06.2019 KW - Faseroptischer Sensor KW - Ortsaufgelöste Brillouin-Sensorik KW - Verteilte faseroptische Temperaturmessung KW - Brillouin-Frequenzverschiebung KW - Betriebsverhaltenskenngrößen PY - 2019 AN - OPUS4-48345 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Messgenauigkeit und Reproduzierbarkeit bei der Messung der Brillouin-Frequenzverschiebung für die faseroptische Bestimmung der Temperaturverteilung N2 - Auf der Grundlage der in DIN EN 61757-2-2:2017 beschriebenen Standardisierungsmethoden wurden in dieser Arbeit wichtige Leistungsparameter von vier kommerziellen Messsystemen zur ortsaufgelösten faseroptischen Erfassung der temperatur- und dehnungsabhängigen Brillouin-Frequenzverschiebung untersucht. Gemäß der oben genannten Norm konzentrierte sich hier die Ermittlungsprüfung auf messtechnische Aspekte reiner Temperaturmessungen. Dabei diente die Ermittlung von einem festgelegten Satz dreier Betriebsverhaltenskenngrößen in Form von quantitativen Angaben des Messfehlers, der Wiederholgenauigkeit sowie der räumlichen Unsicherheit einem Vergleich der getesteten Messsysteme. Alle faseroptischen Messungen wurden mit einer Faserschleife ausgeführt, d. h. als Sensorkonfiguration der Messfaser wurde eine Schleifenanordnung gewählt. Die Messverfahren der getesteten Messysteme basierten somit auf der Brillouin-optischen Zeit- bzw. Frequenzbereichsanalyse. Die Betriebsverhaltenskenngrößen wurden ferner bei unterschiedlichen Werten zweier messtechnischer Parameter, des Frequenzschrittes und der Mittelungsrate, für Standardeinstellungen der Laserleistungswerte der in die Sensorfaser einzukoppelnden Laserlichtsignale ermittelt. Auf diesem Weg lassen sich relevante Aussagen zur Optimierung der Messgenauigkeiten in Bezug auf Messdauer treffen. T2 - 20. GMA/ITG-Fachtagung Sensoren und Messsysteme 2019 CY - Nuremberg, Germany DA - 25.06.2019 KW - Faseroptischer Sensor KW - Ortsaufgelöste Brillouin-Sensorik KW - Verteilte faseroptische Temperaturmessung KW - Brillouin-Frequenzverschiebung KW - Betriebsverhaltenskenngrößen PY - 2019 SN - 978-3-9819376-0-2 U6 - https://doi.org/10.5162/sensoren2019/P2.1 SP - 656 EP - 662 PB - AMA Service GmbH CY - Wunstorf AN - OPUS4-48346 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Faseroptische Strahlungssensoren für kerntechnische Anwendungen N2 - Faseroptische Strahlungssensoren ermöglichen ein räumlich verteiltes Online-Monitoring entlang der gesamten Sensorfaser. Verschiedene Messverfahren nutzen überwiegend zwei durch die ionisierende Strahlung in optischen Fasern induzierte Effekte, d. h. die Erhöhung der optischen Dämpfung und die damit verbundene Veränderung des Brechungsindex des Fasermaterials. Die Sensitivität der Strahlungssensoren lässt sich je nach Anwendung durch die Wahl der Dotierstoffe im Glasfaserkern sowie der Art des Polymermaterials des POF-Sensors beeinflussen. Ferner ist die Sensitivität auch durch den Betrieb bei geeigneten Wellenlängen einstellbar. Bei dem sensorischen Einsatz von faseroptischen Sensoren muss auch die vorhandene Ausheilung des Sensors sowie die Abhängigkeit der erfassten Messsignale von der Temperatur und der Dosisleistung berücksichtigt werden. T2 - 2. Tage der Standortauswahl CY - Online meeting DA - 11.02.2021 KW - Faseroptischer Strahlungssensor KW - Ortsauflösende Fasersensorik KW - Strahlungsinduzierte optische Dämpfung PY - 2021 AN - OPUS4-52112 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Faseroptische Strahlungssensoren für kerntechnische Anwendungen N2 - Faseroptische Strahlungssensoren ermöglichen ein räumlich verteiltes Online-Monitoring entlang der gesamten Sensorfaser. Verschiedene Messverfahren nutzen überwiegend zwei durch die ionisierende Strahlung in optischen Fasern induzierte Effekte, d. h. die Erhöhung der optischen Dämpfung und die damit verbundene Veränderung des Brechungsindex des Fasermaterials. Die Sensitivität der Strahlungssensoren lässt sich je nach Anwendung durch die Wahl der Dotierstoffe im Glasfaserkern sowie der Art des Polymermaterials des POF-Sensors beeinflussen. Ferner ist die Sensitivität auch durch den Betrieb bei geeigneten Wellenlängen einstellbar. Bei dem sensorischen Einsatz von faseroptischen Sensoren muss auch die vorhandene Ausheilung des Sensors sowie die Abhängigkeit der erfassten Messsignale von der Temperatur und der Dosisleistung berücksichtigt werden. T2 - 2. Tage der Standortauswahl CY - Online meeting DA - 11.02.2021 KW - Faseroptischer Strahlungssensor KW - Ortsauflösende Fasersensorik KW - Strahlungsinduzierte optische Dämpfung PY - 2021 AN - OPUS4-52113 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Schreier, Andy A1 - Krebber, Katerina T1 - Distributed BOFDA measurement on an 86 m long perfluorinated polymer optical fiber N2 - We present our research on the development of a Brillouin optical frequency-domain analysis (BOFDA) using a perfluorinated graded-index polymer optical fiber (PFGI-POF) as a sensing fiber. The described works include investigations both on the selection of the setup components with respect to mode coupling effects and on the impact of the humidity cross-sensitivity. The suitability of the developed POF-based BOFDA is proved by a distributed measurement on an 86 m long PFGI-POF recorded with the spatial resolution of 6 m. T2 - 28th International Conference on Plastic Optical Fibers CY - Yokohama, Japan DA - 20.11.2019 KW - Brillouin sensing KW - BOFDA KW - Perfluorinated graded-index polymer optical fiber KW - PFGI-POF PY - 2019 SP - 27 EP - 28 AN - OPUS4-49865 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Schreier, Andy A1 - Krebber, Katerina T1 - Distributed BOFDA measurement on an 86 m long perfluorinated polymer optical fiber N2 - We present our research on the development of a Brillouin optical frequency-domain analysis (BOFDA) using a perfluorinated graded-index polymer optical fiber (PFGI-POF) as a sensing fiber. The described works include investigations both on the selection of the setup components with respect to mode coupling effects and on the impact of the humidity cross-sensitivity. The suitability of the developed POF-based BOFDA is proved by a distributed measurement on an 86 m long PFGI-POF recorded with the spatial resolution of 6 m. T2 - 28th International Conference on Plastic Optical Fibers CY - Yokohama, Japan DA - 20.11.2019 KW - Brillouin sensing KW - BOFDA KW - Perfluorinated graded-index polymer optical fiber KW - PFGI-POF PY - 2019 AN - OPUS4-49866 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Multifunktionale Geokunststoffe - nachhaltige Zustandsüberwachung durch ortsaufgelöste faseroptische Sensoren N2 - Vorstellung von Entwicklungsarbeiten zum Thema sensorbasierte Geokunststoffe mit integrierten faseroptischen Sensoren. T2 - 14. Bautextilien-Symposium BAUTEX 2020 CY - Chemnitz, Germany DA - 29.01.2020 KW - Intelligente Geokunststoffe KW - Sensorbasierte Geokunststoffe KW - Faseroptischer Sensor KW - Ortsverteilter Sensor PY - 2020 AN - OPUS4-50321 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karapanagiotis, Christos A1 - Wosniok, Aleksander A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Time-Efficient Convolutional Neural Network-Assisted Brillouin Optical Frequency Domain Analysis N2 - To our knowledge, this is the first report on a machine-learning-assisted Brillouin optical frequency domain analysis (BOFDA) for time-efficient temperature measurements. We propose a convolutional neural network (CNN)-based signal post-processing method that, compared to the conventional Lorentzian curve fitting approach, facilitates temperature extraction. Due to its robustness against noise, it can enhance the performance of the system. The CNN-assisted BOFDA is expected to shorten the measurement time by more than nine times and open the way for applications, where faster monitoring is essential. KW - Fiber-optic sensors KW - Machine learning KW - Temperature and strain monitoring KW - Brillouin distributed sensing PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-524631 VL - 21 IS - 8 SP - 2724 PB - MDPI AN - OPUS4-52463 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Liehr, Sascha T1 - Health monitoring of geotechnical structures by distributed fiber optic sensors N2 - Health monitoring of ground movement via highly sensitive fiber optic sensors allows operators to detect early potential or ongoing failures in critical geotechnical structures. Particularly, the fiber optic sensors can be embedded in geosynthetics which are nowadays widely used in many geotechnical applications including earth dikes, railway embankments, landfill liners, quarries and mines. Thereby, such smart geosynthetics can be used for reinforcement, layer separation, filtration or drainage while the embedded fiber optic sensors provide information about the condition of the geotechnical structures in real time. The paper highlights the results achieved in this innovative field in the framework of several German and European projects. The presented measurement methods for long-term monitoring are based on Brillouin scattering in silica glass optical fibers (GOFs) and optical time domain reflectometry (OTDR) in polymer optical fibers (POFs). T2 - AMA Conferences 2017 Sensor 2017 CY - Nürnberg, Germany DA - 30.05.2017 KW - Fiber optic sensor KW - Distributed sensor KW - Smart geosynthetics KW - Brillouin sensor KW - OTDR PY - 2017 SN - 978-3-9816876-4-4 U6 - https://doi.org/10.5162/sensor2017/B7.4 SP - 280 EP - 285 PB - AMA Service GmbH CY - Wunstorf AN - OPUS4-40514 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Liehr, Sascha T1 - Health monitoring of geotechnical structures by distributed fiber optic sensors N2 - Health monitoring of ground movement via highly sensitive fiber optic sensors allows operators to detect early potential or ongoing failures in critical geotechnical structures. Particularly, the fiber optic sensors can be embedded in geosynthetics which are nowadays widely used in many geotechnical applications including earth dikes, railway embankments, landfill liners, quarries and mines. Thereby, such smart geosynthetics can be used for reinforcement, layer separation, filtration or drainage while the embedded fiber optic sensors provide information about the condition of the geotechnical structures in real time. The paper highlights the results achieved in this innovative field in the framework of several German and European projects. The presented measurement methods for long-term monitoring are based on Brillouin scattering in silica glass optical fibers (GOFs) and optical time domain reflectometry (OTDR) in polymer optical fibers (POFs). T2 - AMA Conferences 2017 Sensor 2017 CY - Nürnberg, Germany DA - 30.05.2017 KW - Fiber optic sensor KW - Distributed sensor KW - Smart geosynthetics KW - Brillouin sensor KW - OTDR PY - 2017 AN - OPUS4-40523 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Smart geosynthetics for structural health monitoring applications N2 - Responding to a growing need for intelligent monitoring of critical geotechnical and civil infrastructures, new multifunctional geotextiles and geogrids with integrated optical fibers were developed and investigated within several research projects. Such smart two-dimensional geosynthetics intercorporating optical fibers as distributed sensors provide solutions both for soil reinforcement, erosion control, drainage or environmental protection and for cost-effective monitoring of critical mechanical deformations and temperature distribution in geotechnical and masonry structures at the same time. The integrated fiber optic sensors provide online information about the condition of the monitored structure and about the occurrence and localization of any damage or degradation for the purpose of preventing a total collapse. The optical fibers have a serious advantage over other kinds of sensors due to their fibrous nature, so they can be ideally processed like standard textile yarns. The monitoring of extended geotechnical structures like dikes, dams, railways, embankments or slopes requires sensor technologies with measurement lengths of at least some hundred meters which can be realized by the use of silica fibers. However, the integration of silica fibers into geosynthetics during the manufacturing process experienced problems of sensor brittleness, low strain range not exceeding 2 % and bending-related attenuation increase optimized to the value of 1.5 dB/km. Unlike silica fibers, the integration of polymer optical fibers (POFs) into various geosynthetics was easily achieved free of bending losses enabling distributed high strain measurements up to 40 % using PMMA POFs. The first industrial product GEDISE based on a geogrid with integrated PMMA POFs is on the market. Due to the five times lower attenuation of low-loss perfluorinated graded-index POFs (PFGI-POFs), compared to PMMA POFs, the measurement range can be extended to 500 m. The low-loss PFGI-POFs offer the possibility of implementation of Brillouin optical fiber frequency domain analysis (BOFDA) which will significantly improve the measurement accuracy and spatial resolution in comparison with existing POF-based distributed measurement methods like POF OTDR. The development of a distributed Brillouin system based on PFGI-POFs is in progress. T2 - The Fiber Society’s Spring 2017 Conference CY - Institut für Textiltechnik der RWTH Aachen, Germany DA - 17.05.2017 KW - Smart geosynthetics KW - Sensor-based geotextiles KW - Fiber optic sensor KW - Distributed sensing PY - 2017 AN - OPUS4-40319 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schreier, Andy A1 - Liehr, Sascha A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Investigation on the influence of humidity on stimulated Brillouin backscattering in perfluorinated polymer optical fibers N2 - In this paper perfluorinated graded-index polymer optical fibers are characterized with respect to the influence of relative humidity changes on spectral transmission absorption and Rayleigh backscattering. The hygroscopic and thermal expansion coefficient of the fiber are determined to be CHE = (7.4 +/- 0.1) 10^-6 %r.h.^-1 and CTE = (22.7 +/- 0.3) 10^-6 K^-1, respectively. The influence of humidity on the Brillouin backscattering power and linewidth are presented for the first time to our knowledge. The Brillouin backscattering power at a pump wavelength of 1319 nm is affected by temperature and humidity. The Brillouin linewidth is observed to be a function of temperature but not of humidity. The strain coefficient of the BFS is determined to be CS = (146.5 +/- 0.9) MHz/% for a wavelength of 1319 nm within a strain range from 0.1 % to 1.5 %. The obtained results demonstrate that the humidity-induced Brillouin frequency shift is predominantly caused by the swelling of the fiber over-cladding that leads to fiber straining. KW - Brillouin KW - Polymer optical fibre KW - Humidity PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-465932 SN - 1424-8220 VL - 18 IS - 11 SP - 3952, 1 EP - 12 PB - MDPI CY - Basel, Switzerland AN - OPUS4-46593 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Smart geosynthetics for structural health monitoring applications N2 - Responding to a growing need for intelligent monitoring of critical geotechnical and civil infrastructures, new multifunctional geotextiles and geogrids with integrated optical fibers were developed and investigated within several research projects. Such smart two-dimensional geosynthetics intercorporating optical fibers as distributed sensors provide solutions both for soil reinforcement, erosion control, drainage or environmental protection and for cost-effective monitoring of critical mechanical deformations and temperature distribution in geotechnical and masonry structures at the same time. The integrated fiber optic sensors provide online information about the condition of the monitored structure and about the occurrence and localization of any damage or degradation for the purpose of preventing a total collapse. T2 - The Fiber Society's Spring 2017 Conference CY - Institut für Textiltechnik der RWTH Aachen, Germany DA - 17.05.2017 KW - Smart geosynthetics KW - Sensor-based geotextiles KW - Fiber optic sensor KW - POF sensor KW - Distributed sensing PY - 2017 SP - 43 AN - OPUS4-42560 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 - CONF A1 - Wosniok, Aleksander T1 - Ortsverteilte faseroptische Messtechnik N2 - Vorstellung und Anwendung ortsverteilter Messverfahren für faseroptische Zustandsüberwachung von Bauwerken T2 - Angewandte Forschung im Bauwesen — Anwenderkonferenz CY - Berlin,Germany DA - 22.09.2017 KW - Fasersensorik KW - Ortsverteilte Messtechnik KW - Ortsaufgelöste Messung PY - 2017 AN - OPUS4-42141 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Intelligente Geokunststoffe – Nachhaltige Zustandsüberwachung durch ortsaufgelöste faseroptische Messsysteme N2 - Vorstellung von Entwicklungsarbeiten zum Thema sensorbasierte Geokunststoffe mit integrierten faseroptischen Sensoren. T2 - IAB-Baustoff-FORUM 2019 CY - Weimar IAB, Germany DA - 06.03.2019 KW - Faseroptischer Sensor KW - Verteilter Sensor KW - Ortsaufgelöste Messung KW - Intelligente Geokunststoffe PY - 2019 AN - OPUS4-47508 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schreier, Andy A1 - Liehr, Sascha A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Comparison of solution approaches for distributed humidity sensing in perfuorinated graded-index polymer optical fibers N2 - We compare four different sensing solutions suitable for distributed fiber optic humidity sensing in per uorinated graded-index polymer optical fibers (PFGI-POFs). Compared to silica fbers, polymer optical fibers over advantageous beneffits including signifficantly higher break down strain, fracture toughness and humidity sensitivity. Various humidity-related effects in PFGI-POFs have been reported in the last years including measured attenuation and length changes as well as Brillouin frequency and Bragg wavelength shifts. The four aforementioned methods could serve as a basis for distributed and quasi-distributed humidity sensing and are described here closely with an emphasis on plausible cross effects to temperature and strain. The main focus of this paper lies on the comparison of four approaches with regard to method complexity, sensitivity to humidity, spatial resolution, real-time capability and effort to compensate for cross effects. T2 - SPIE Optics + Optoelectronics CY - Prague, Czech Republic DA - 01.04.2019 KW - Distributed sensing KW - Humidity KW - Polymer optical fibre PY - 2019 SN - 978-1-5106-2723-9 U6 - https://doi.org/10.1117/12.2522307 SN - 0277-786X SN - 1996-756X SP - 1102808-1 EP - 1102808-9 PB - SPIE AN - OPUS4-47844 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Richard A1 - Oehrl, A. A1 - Wischerhoff, E. A1 - Wosniok, Aleksander A1 - Schukar, Marcus T1 - Fiber-Optic Thermoresponsive Polymer-based Temperature Sensor for Process Monitoring N2 - We present a high-precision fiber-optic temperature sensor based on a polymer possessing a Lower Critical Solution Temperature (LCST) in aqueous solution encapsulated in a capillary. For a temperature higher than the LCST the transparent homogenous polymer solution changes into a suspension which forms an opaque fluid. The resulting temperature-dependent turbidity influences the transmission characteristics measured using a simple fiber-optic system. The presented development provides a small-sized, robust temperature sensor, patented by the BAM (patent nr.: EP 3 043 161 B1), easy to integrate in many application fields, especially for process monitoring. T2 - European Workshop on Optical Fibre Sensors (EWOFS 2023) CY - Mons, Belgium DA - 23.05.2023 KW - Thermoresponsive polymer KW - Aqueous polymer solution KW - Temperature sensor KW - LCST KW - POF PY - 2023 AN - OPUS4-57739 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Königsbauer, Korbinian A1 - Wosniok, Aleksander A1 - Nöther, N. A1 - Schaller, M. B. T1 - POF-based digital I-OFDR for strain detection in road construction N2 - We report on the development of a field-proven distributed fiber optic sensing system for structural health monitoring in road construction and civil engineering. The system is based on a cost-efficient digital incoherent optical frequency domain reflectometry (I-OFDR) for distributed strain detection along a polymer optical fiber. In this method, the strain-induced backscatter increase in a graded-index multimode perfluorinated polymer optical fiber (PF-POF) is determined by measuring the complex transfer function of the sensing fiber using a compact digital data acquisition unit. T2 - European Workshop on Optical Fibre Sensors (EWOFS 2023) CY - Mons, Belgium DA - 23.05.2023 KW - Digital I-OFDR KW - Perfluorinated polymer optical fiber KW - Smart geosynthetics KW - Structural health monitoring KW - Road construction KW - Civil engineering PY - 2023 U6 - https://doi.org/10.1117/12.2678436 SP - 1264326-1 PB - SPIE AN - OPUS4-57592 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Königsbauer, Korbinian A1 - Krebber, Katerina A1 - Schaller, M.B. A1 - Färber, J. A1 - Nöther, N. T1 - POF-based monitoring system using digital I-OFDR for strain detection in road construction N2 - We present a prototype of a distributed POF sensing system for strain detection in road construction and civil engineering ready to be used in practical applications. The system is based on a cost-efficient digital incoherent optical frequency domain reflectometry (I-OFDR). In this approach, the strain-induced changes in the Rayleigh backscattering profile along a perfluorinated polymer optical fiber (PF-POF) are determined by measuring the complex transfer function of the sensing fiber using a compact digital data acquisition unit. The digital unit replaces an oversized vector network analyzer (VNA) enabling suitability of the measurement system for out-door use and providing a significant reduction of the total system costs at the same time. The entire sensor con-cept includes the use of geosynthetics with integrated PF-POFs as two-dimensional sensor structures for geotech-nical applications. The robustness and the functionality of the distributed POF I-OFDR sensors were proven in the field. The field test involved embedding of two geomats, each with two polymer optical sensor loops, into the embankment of the federal road B 91 in a section near Leipzig. The measurements conducted after the sensor-based geomats had been installed confirmed both the potential of such smart geosynthetics and the functionali-ty of the digital I-OFDR prototype. T2 - POF2023 CY - Cork, Irland DA - 17.09.2023 KW - Digital I-OFDR KW - Distriubuted polymer optical fiber sensor KW - Smart geosynthetics KW - Strain detection KW - Structural health monitoring PY - 2023 AN - OPUS4-58423 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Königsbauer, Korbinian A1 - Nöther, N. A1 - Färber, J. A1 - Schaller, M.-B. A1 - Krebber, K. T1 - Verteilte POF-basierte faseroptische Sensoren zur Infrastrukturüberwachung in der Geotechnik N2 - Wir präsentieren unsere Forschungsergebnisse zur Entwicklung eines faseroptischen Sensorsystems mit polymeroptischen Fasern integriert in Geokunststoffe für die Überwachung von geotechnischen Anlagen. Das Sensorsystem dient der räumlichen Auflösung lokaler Dehnungsereignisse im für Anwender signifikanten Größenordnungsbereich von 3 % bis 10 %. Das gesamte Sensorkonzept besteht aus einem praxistauglichen Messsystem basierend auf der digitalen inkohärenten optischen Frequenzbereichsreflektometrie (I-OFDR) und einer Sensormatte in Form eines Geotextils mit integrierten faseroptischen perfluorierten polymeroptischen Fasern (PF-POFs). T2 - DGZfP Fachtagung Bauwerksdiagnose 2024 CY - Berlin, Germany DA - 29.02.2024 KW - Ortsverteilte faseroptische Sensorik KW - Optische Frequenzbereichsreflektometrie KW - Bauwerksüberwachung KW - Sensorbasierte Geokunststoffe PY - 2024 AN - OPUS4-59633 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -