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 - 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 DO - 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 - 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 - Wosniok, Aleksander 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 T1 - Distributed polymer optical fiber sensors using digital I-OFDR for geotechnical infrastructure health monitoring N2 - We present a distributed polymer optical fiber sensor system for deformation monitoring of geotechnical infrastructure. The sensor system is based on the digital incoherent optical frequency domain reflectometry (I-OFDR) for the detection of local strain events along a perfluorinated polymer optical fiber (PF-POF) used as a sensing fiber. For the best possible load transfer, the PF-POFs were integrated onto geosynthetics which pose a sensor carrier for the sensing fiber. By using elastic PF-POF instead of a standard glass fiber as a sensing fiber the strain range of geosynthetics-integrated fiber optic sensors could be extended up to 10 % in accordance with the end-user requirements. T2 - 11th European Workshop on Structural Health Monitoring CY - Potsdam, Germany DA - 10.06.2024 KW - Digital I-OFDR KW - Distributed polymer optical fiber sensor KW - Distributed strain sensing KW - Smart geosynthetics KW - Structural health monitoring PY - 2024 AN - OPUS4-60308 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Königsbauer, Korbinian A1 - Nöther, Nils A1 - Färber, Jan A1 - Schaller, M.-Barbara A1 - Krebber, Katerina T1 - Distributed polymer optical fiber sensors using digital I-OFDR for geotechnical infrastructure health monitoring N2 - We present a distributed polymer optical fiber sensor system for deformation monitoring of geotechnical infrastructure. The sensor system is based on the digital incoherent optical frequency domain reflectometry (I-OFDR) for the detection of local strain events along a perfluorinated polymer optical fiber (PF-POF) used as a sensing fiber. For the best possible load transfer, the PF-POFs were integrated onto geosynthetics which pose a sensor carrier for the sensing fiber. By using elastic PF-POF instead of a standard glass fiber as a sensing fiber the strain range of geosynthetics-integrated fiber optic sensors could be extended up to 10 % in accordance with the end-user requirements. T2 - 11th European Workshop on Structural Health Monitoring CY - Potsdam, Germany DA - 10.06.2024 KW - Digital I-OFDR KW - Distributed polymer optical fiber sensor KW - Ddistributed strain sensing KW - Smart geosynthetics KW - Structural health monitoring PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603096 SP - 1 EP - 7 PB - NDT.net AN - OPUS4-60309 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 N2 - Structural Health Monitoring based on distributed Brillouin measuring techniques has been playing bigger and bigger role for applications in large-scale critical structures over the last decade. The Brillouin sensing techniques make use of low-loss single-mode optical fibers as distributed sensors allowing compound strain and temperature profile discrimination along the measured section even over several tens of kilometers. Thereby, the measured Brillouin frequency shift (BFS) features much stronger dependence on the longitudinal strain in the sensor fiber than on the temperature distribution along the fiber optic sensor. By detection of slight structural changes in monitored civil structures, such as dams, pipelines and tunnels, the influence of temperature on the measured BFS cannot be neglected. In simple cases of fiber optic sensors embedded deeply enough into earth structures no significant temperature gradients caused by weather conditions such as sunrays could be observed. The temperature contributes here only to the signal offset and the local mechanical deformations arisen due to soil displacement can be read directly from the distribution of the BFS. Also special cable solutions for separate determination of temperature and strain have been tested by us under field conditions. The use of two separate optical fibers for strain and temperature detection limits the spatial resolution and measurement accuracy in the determination of both physical quantities. In search of the optimal sensory solution for monitoring of mechanical deformations taking into account the temperature component in the measured signal the use of so called nonzero dispersion-shifted fibers has been investigated in several laboratory tests. Due to different doping concentration in the core new resonance acoustic modes can propagate in such optical fibers which results in multipeak structure in the Brillouin gain spectrum (BGS). The appearance of more than one resonance peak in the BGS offers the possibility to realize simultaneous measurement of longitudinal strain and temperature by analysis of applicable BFSs as function of both physical quantities using only one low cost optical fiber. T2 - EWSHM'12 - 6th European workshop on structural health monitoring 2012 CY - Dresden, Germany DA - 03.07.2012 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 - 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 - 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 - 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 - Wosniok, Aleksander T1 - Distributed fiber optic strain sensing for structural health monitoring of 70 MPa hydrogen vessels N2 - We report on the development and testing of 70 MPa hydrogen pressure vessels with integrated fiber optic sensing fibers for automotive use. The paper deals with the condition monitoring of such composite pressure vessels (CPVs) using the optical backscatter reflectometry (OBR) applied for a distributed fiber optic strain sensing along fully integrated polyimide-coated single-mode glass optical fiber (SM-GOF). The sensing fibers were embedded into the vessel structure by wrapping them over the polymer liner during the manufacturing process of the carbon fiber reinforced polymer (CFRP). Detecting local strain events by the integrated fiber optic sensors can be an opportunity for monitoring the material degradation of CPVs under static and cyclic loading. T2 - 11th European Workshop on Structural Health Monitoring CY - Potsdam, Germany DA - 10.06.2024 KW - Fiber optic sensor KW - Distributed strain sensing KW - Composite pressure vessel KW - Structural health monitoring KW - Fiber-reinforced plastics PY - 2024 AN - OPUS4-60307 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - WP6 Different Components and System Prototyping N2 - We report on the development and testing of 70 MPa hydrogen pressure vessels with integrated fibre optic sensors for automotive use as a part of the European SH2APED project. The most research results were achieved in the framework of the Work Package 6. T2 - General Assembly Project SH2APED CY - Brussels, Belgium DA - 25.09.2024 KW - Composite pressure vessel KW - Fibre optic sensor KW - Distributed strain sensing KW - Structural health monitoring KW - Optical backscatter reflectometry PY - 2024 AN - OPUS4-61212 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander T1 - Distributed fibre optic strain sensing for structural health monitoring of composite pressure vessels N2 - We report on the development and testing of 70 MPa hydrogen pressure vessels with integrated fibre optic sensors for automotive use. The research results were achieved in the framework of the European project SH2APED. T2 - Stakeholders' Workshop SH2APED CY - Brussels, Belgium DA - 26.09.2024 KW - Composite pressure vessel KW - Fibre optic sensor KW - Distributed strain sensing KW - Structural health monitoring KW - Fibre-reinforced plastics PY - 2024 AN - OPUS4-61211 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Schukar, Marcus A1 - Woody, Paul A1 - Wang, Bin A1 - Breithaupt, Mathias A1 - Kriegsmann, Andreas T1 - Distributed fiber optic strain sensing for structural health monitoring of 70 MPa hydrogen vessels N2 - We report on the development and testing of 70 MPa hydrogen pressure vessels with integrated fiber optic sensing fibers for automotive use. The paper deals with the condition monitoring of such composite pressure vessels (CPVs) using the optical backscatter reflectometry (OBR) applied for a distributed fiber optic strain sensing along fully integrated polyimide-coated single-mode glass optical fiber (SM-GOF). The sensing fibers were embedded into the vessel structure by wrapping them over the polymer liner during the manufacturing process of the carbon fiber reinforced polymer (CFRP). Detecting local strain events by the integrated fiber optic sensors can be an opportunity for monitoring the material degradation of CPVs under static and cyclic loading. T2 - 11th European Workshop on Structural Health Monitoring CY - Potsdam, Germany DA - 10.06.2024 KW - Fiber optic sensor KW - Distributed strain sensing KW - Composite pressure vessel KW - Structural health monitoring KW - Fiber-reinforced plastics PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603105 SP - 1 EP - 8 PB - NDT.net AN - OPUS4-60310 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -