TY - CONF A1 - Kowarik, Stefan A1 - Hicke, Konstantin A1 - Chruscicki, Sebastian A1 - Schukar, Marcus A1 - Breithaupt, Mathias A1 - Lämmerhirt, A. A1 - Pohl, P. A1 - Schubert, M. ED - Cranch, G. ED - Wang, A. ED - Digonnet, M. ED - Dragic, P. T1 - Train monitoring using distributed fiber optic acoustic sensing N2 - We use distributed acoustic sensing to determine the velocity of trains from train vibration patterns using artificial neural network and conventional algorithms. The velocity uncertainty depends on track conditions, train type and velocity. T2 - 27th International Conference on Optical Fiber Sensors (OFS) CY - Meeting was canceled DA - 08.06.2020 KW - Train monitoring KW - Distributed acoustic sensing KW - DAS KW - Distributed fiber optic sensing PY - 2020 SN - 978-1-55752-307-5 DO - https://doi.org/10.1364/OFS.2020.T3.25 SP - 1 EP - 4 PB - The Optical Society (Optical Society of America) CY - Washington D.C., USA AN - OPUS4-50758 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neumann, Patrick P. A1 - Kohlhoff, Harald A1 - Werner, Klaus-Dieter A1 - Erdmann, Jessica A1 - Eggeringhaus, Bärbel A1 - Kammermeier, Michael A1 - Schukar, Marcus A1 - Basedau, Frank A1 - Bartholmai, Matthias A1 - Lazik, D. A1 - Ebert, Sebastian T1 - Setup of a large scale soil test field with CO2 injection for testing a novel distributed subsurface monitoring system for gas storage areas N2 - One of the main unsolved issues of under-ground storages for, e.g., CO2, H2, and natural gas is the comprehensive surveillance of these areas with reasonable effort and costs. Conventional sensors (e.g., soil air probes or borehole probes), however, can only be used for punctual or locally limited measurements; further their application can cause structural influences (invasive application). In this paper, we describe in detail the setup of a CO2 injection soil test field. This test field will be used to enhance and validate an innovative ap-proach for distributed subsurface monitoring of gas storage areas. To the author’s knowledge, this is the first time that, for this purpose, a test field is built in an application relevant scale. T2 - 31st Danubia-Adria Symposium on advances in experimental mechanics CY - Kempten, Germany DA - 24.09.2014 KW - Large scale soil test field KW - Subsurface monitoring KW - Gas storage areas KW - Membrane-based gas sensing KW - Fiber optical sensing PY - 2014 SN - 978-3-00-046740-0 SP - 238 EP - 239 AN - OPUS4-31527 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stajanca, Pavol A1 - Cetinkaya, O. A1 - Schukar, Marcus A1 - Mergo, P. A1 - Krebber, Katerina T1 - Climatic stability of polymer optical fibers for sensing applications N2 - Systematic investigation of annealing behavior of drawn PMMA fibers was performed. Dynamics of annealing process were measured under different environmental conditions by fiber longitudinal shrinkage monitoring. Process was found to follow stretched exponential decay function indicating heterogeneous nature of underlying molecular dynamics. Consequences of fiber annealing for climatic stability of polymer optical fiber-based sensors are discussed, emphasizing importance of fiber controlled post-fabrication annealing. Dependence of induced fiber shrinkage on annealing time, temperature and fiber drawing conditions is investigated and interpreted. In addition, strong influence of humidity on annealing process was observed, which was not recognized in previous studies. This further highlights role of fiber post-fabrication thermal treatment with respect to intended operating conditions. T2 - POF 2015 - 24th International conference on plastic optical fibers CY - Nuremberg, Germany DA - 22.09.2015 KW - Polymer optical fibers KW - Polymethyl methacrylate KW - Climatic stability KW - Fiber annealing PY - 2015 SP - 209 EP - 212 AN - OPUS4-34422 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schukar, Marcus T1 - Novel fibre optic temperature sensors based on thermoresponsive polymers T2 - 24th International Conference on Plastic Optical Fibers CY - Nuremberg, Germany DA - 2015-09-22 PY - 2015 AN - OPUS4-34378 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schukar, Marcus A1 - Grzemba, Birthe A1 - Krebber, Katerina A1 - Luber, M. T1 - Integration technology of POF sensors into composites for structural health monitoring N2 - We have investigated the application technology of polymer optical fibers (POF) as sensors integrated into respectively applied onto composites for structural health monitoring by using different manufacturing methods and several types of POF. T2 - POF 2009 - 18th International conference on plastic optical fibers CY - Sydney, Australia DA - 2009-09-07 KW - Optische Polymerfasern (POF) KW - Fasersensorik KW - Structural Health Monitoring KW - Faserverbundwerkstoffe KW - OTDR KW - Faser-Integration PY - 2009 IS - Session 1 (S1_25) SP - 1 EP - 4 CY - Sydney, Australia AN - OPUS4-19915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Poisel, H. A1 - Luber, M. A1 - Ziemann, O. A1 - Diez, J. A1 - Bloos, M. A1 - Bachmann, A. A1 - Schukar, Marcus T1 - Applications of a POF elongation sensor N2 - The principle of a low-cost but nevertheless powerful POF elongation sensor has already been described in the recent years [1, 2, 3]. The measurement of the phase shift of a signal of a modulated light source which is coupled into two different POF, one being stretched, yields information of the elongation with a resolution of up to 10-5. Analyzing the temporal or frequency behaviour of the signal gives additional information. Since the phase measurement can allow for frequencies up to 2 GHz, the vibrational analysis of macroscopic structures can be extended to several kHz very easily, limited mainly by the signal processing electronics. Thus we processed data of a sensing system applied to a 39 m rotor blade of a wind power generator and could resolve the various frequencies related to different exciting conditions, e.g. the appearance of a beat signal when the blade was externally excited by a mechanical system with a frequency close but not identical to the Eigen frequency of the blade. T2 - POF 2009 - 18th International conference on plastic optical fibers CY - Sydney, Australia DA - 2009-09-07 KW - Optische Polymerfasern (POF) KW - Fasersensorik KW - Structural health monitoring KW - Faserverbundwerkstoffe KW - Phasenmesstechnik KW - Faser-Integration PY - 2009 IS - Session 1 (S1_25) SP - 1 EP - 5 CY - Sydney, Australia AN - OPUS4-19917 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Oliveira, Rui A1 - Schukar, Marcus A1 - Krebber, Katerina A1 - Michaud, V. T1 - Development of adaptive composites with embedded plastic optic fibres N2 - This study discusses the development of advanced composite materials with sensing capabilities obtained from the embedment of long period gratings in microstructured plastic optical fibres (mPOF-LPG). The mPOF-LPG was embedded in a carbon fibre reinforced polymer (CFRP) unidirectional laminate manufactured in autoclave. Processing steps were established in order to insure that mPOF does not suffer significant optical and structural degradation. The strain and temperature responses of the embedded mPOF-LPG were investigated. T2 - ICRACM 2010 - 3rd International conference on recent advances in composite materials CY - Limoges, France DA - 2010-12-13 KW - Polymer composites KW - Optical fibre sensors KW - mPOF-LPG KW - SHM PY - 2010 IS - Polymer composite session / FP-Oliveira SP - 1 EP - 6 AN - OPUS4-23040 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Krebber, Katerina A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Witt, Jens A1 - Schukar, Marcus ED - Ecke, Wolfgang ED - Kara J. Peters, ED - Norbert G. Meyendorf, T1 - Smart technical textiles with integrated POF sensors N2 - Fiber optic sensors based on polymer optical fibers (POF) take advantage of the high elasticity and high break-down strain of POF. Because of their outstanding elastic properties, POF are well suited for integration into technical textiles like geotextiles and medical textiles. Smart textiles with incorporated POF sensors, able to sense various mechanical and physical quantities, can be realized. The integration of POF as a sensor into geotextiles for monitoring of displacement of soil is very attractive since POF can be used for distributed strain measurement of strain values of more than 40 %. An online monitoring of critical mechanical deformations of geotechnical structures like dikes, dams, slopes, embankments as well as of masonry structures can be ensured. Medical textiles that incorporate POF sensors can control vital physiological parameters like respiratory movement and can be used for wearable health monitoring of patients requiring a continuous medical assistance and treatment. The biocompatibility of POF is an important criterion for selecting POF as a medical sensor. The paper shows selected examples of using POF sensors for the mentioned monitoring purposes. T2 - Smart Sensor Phenomena, Technology, Networks, and Systems 2008 CY - San Diego, California, USA DA - 2008-03-10 KW - Fiber optic sensors KW - Polymer optical fibers (POF) KW - POF sensors KW - Geotextiles KW - Medical textiles KW - Strain sensor KW - Respiratory monitoring KW - POF OTDR KW - Distributed sensor KW - Geotechnical structures PY - 2008 SN - 978-0-8194-7119-2 DO - https://doi.org/10.1117/12.776758 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 6933 IS - 6933 SP - 69330V-1 - 69330V-15 PB - SPIE CY - Bellingham AN - OPUS4-17680 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Oliveira, Rui A1 - Schukar, Marcus A1 - Krebber, Katerina A1 - Michaud, V. T1 - Advanced composite materials with embedded POF sensors for structural health monitoring N2 - A long period grating (LPG) mechanically imprinted in a microstructured polymer optical fibre (mPOF) is embedded in a carbon fibre reinforced polymer (CFRP) unidirectional laminate. Processing steps were established in order to ensure that mPOF does not suffer significant degradation. The strain and temperature responses of the embedded mPOF-LPG were then investigated. T2 - POF 2010 - 19th International conference on plastic optical fibers CY - Yokohama, Japan DA - 2010-10-19 PY - 2010 IS - P-25 SP - 1 EP - 4 AN - OPUS4-22381 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Schukar, Marcus A1 - Wendt, Mario A1 - Witt, Jens T1 - Distributed POF sensors - recent progress and new challenges N2 - The potential of the use of POF as distributed sensors in several application fields has been successfully demonstrated. The distributed POF sensors have moved from the laboratory to the field. The paper presents the recent progress in the development of distributed POF sensors and addresses the main challenges to this innovative technology. T2 - POF 2010 - 19th International conference on plastic optical fibers CY - Yokohama, Japan DA - 2010-10-19 PY - 2010 IS - Sensors-2 SP - 1 EP - 4 AN - OPUS4-22305 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schukar, Marcus T1 - Climatic investigations of microstructured polymer optical fibers N2 - - Behaviour of MPOF under climatic influences (e.g. temperature, humidity) is an important criterium for the use of MPOF as sensors or for communication - Different types of MPOF with varying hole structures were tested: I. Multimode MPOF (type 1) II. Graded index MPOF (type 2) T2 - 18th International Conference on Plastic Optical Fibers CY - Sydney, Australia DA - 07.09.2009 PY - 2009 AN - OPUS4-20485 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grillet, A. A1 - Kinet, D. A1 - Witt, Jens A1 - Schukar, Marcus A1 - Krebber, Katerina A1 - Pirotte, F. A1 - Depré, A. T1 - Optical fibre sensors embedded into medical textiles for monitoring of respiratory movements in MRI environment T2 - EWOFS 2007 - 3rd European Workshop on Optical Fibre Sensors CY - Napoli, Italy DA - 2007-07-04 KW - Respiration sensor KW - Fibre optic sensor KW - POF KW - POF sensor KW - Bending sensor KW - Strain sensor KW - OTDR KW - Medical textiles PY - 2007 SN - 9780819467614 SN - 0277-766X VL - 6619 SP - 66191R-1 - 66191R-4 AN - OPUS4-15842 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Witt, Jens A1 - Bunge, C.-A. A1 - Schukar, Marcus A1 - Krebber, Katerina T1 - Real-time strain sensing based on POF OTDR N2 - We investigate two real-time strain sensing principles based on the optical time-domain reflectometry (OTDR) in polymer optical fibres (POF). The first sensing principle uses the increase of the level of backscattered light in a stretched POF. The second sensing principle uses the effect of losses due to bending. T2 - 16th International Conference on Plastic Optical Fibers (POF 2007) CY - Turin, Italy DA - 2007-09-10 KW - Strain sensor KW - Fibre optic sensor KW - POF sensor KW - OTDR KW - Strain rate PY - 2007 SP - 210 EP - 213 PB - International Cooperative of Plastic Optical Fibers (ICPOF) CY - Turin, Italy AN - OPUS4-15922 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schukar, Marcus A1 - Krebber, Katerina A1 - Scheer, M. ED - Bernd Henning, T1 - Strahlungsüberwachung mit Faser-Bragg-Gitter-Sensoren am Elektronenspeicherring BESSY II T2 - 21. Messtechnisches Symposium des Arbeitskreises der Hochschullehrer für Messtechnik e.V, CY - Paderborn, Deutschland DA - 2007-09-20 KW - Faser-Bragg-Gitter KW - Fasersensoren KW - Strahlungssensoren KW - Strahlungseffekte KW - Strahlungsdosimetrie KW - Elektronenspeicherring PY - 2007 SN - 978-3-8322-6539-7 SP - 178 EP - 189 PB - Shaker CY - Aachen AN - OPUS4-16314 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Witt, Jens A1 - Schukar, Marcus A1 - Krebber, Katerina ED - Gerald Gerlach, ED - Peter Hauptmann, T1 - Polymeroptische Fasersensoren in der Medizintechnik T2 - 8. Dresdner Sensor-Symposium CY - Dresden, Deutschland DA - 2007-12-10 KW - OTDR KW - POF KW - Faseroptischer Sensor KW - Atmungssensor PY - 2007 SN - 978-3-940046-45-1 N1 - Serientitel: Dresdner Beiträge zur Sensorik – Series title: Dresdner Beiträge zur Sensorik VL - 29 IS - 29 SP - 223 EP - 226 PB - TUDpress, Verlag der Wissenschaften GmbH CY - Dresden AN - OPUS4-16427 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karapanagiotis, Christos A1 - Schukar, Marcus A1 - Krebber, Katerina T1 - Verteilte faseroptische Sensoren zur Zustandsüberwachung von Verbundwerkstoff-Druckbehältern T1 - Distributed fiber optic sensors for structural health monitoring of composite pressure vessels N2 - In diesem Beitrag geben wir einen umfassenden Überblick über unsere Forschung auf dem Gebiet der verteilten faseroptischen Sensorik für die strukturelle Zustandsüberwachung von Wasserstoffdruckbehältern aus Verbundwerkstoffen. Insbesondere zeigen wir, wie die Integration von faseroptischen Sensoren in Druckbehälter aus Verbundwerkstoffen die Sicherheit erhöht und gleichzeitig die Wartungskosten senkt. Die geringe Größe von Lichtwellenleitern ermöglicht ihre Integration in Verbundwerkstoffstrukturen während des Herstellungsprozesses, wodurch eine kontinuierliche Überwachung sowie eine präzise Erkennung und Lokalisierung von Strukturschäden während des Betriebs der Druckbehälter ermöglicht wird. Wir erörtern auch das Potenzial modernster Signalverarbeitungsmethoden und des maschinellen Lernens für die Weiterentwicklung der vorausschauenden Instandhaltung. Die von uns vorgestellten Anwendungen von faseroptischen Sensoren zeigen, dass sie einen wichtigen Beitrag zur Energiewende hin zu erneuerbaren Energien leisten können. KW - Verteilte faseroptische Sensoren KW - Verbundwerkstoffe KW - Wasserstoff-Druckbehälter KW - Strukturüberwachung KW - Maschinelles Lernen PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596290 DO - https://doi.org/10.1515/teme-2023-0170 SN - 0171-8096 SP - 1 EP - 12 AN - OPUS4-59629 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heimann, Jan A1 - Yilmaz, Bengisu A1 - Charmi, Amir A1 - Duffner, Eric A1 - Schukar, Marcus A1 - Prager, Jens T1 - Structural Health Monitoring (SHM) for continuous monitoring of hydrogen pressure vessels N2 - While hydrogen is one of the most promising energy carriers, the safety of hydrogen storage technology remains one of the most important factors for technological and societal approval. While the engineering safety factors of the pressure vessels are kept high, the periodic inspection and the limited lifetime are making the application very costly considering manpower, time, money, and material waste. The development of an integrated structural health monitoring system can allow an easy transition from the current situation to cost-effective predictive maintenance. Hence, we propose to integrate three different SHM systems into hydrogen pressure vessels, namely guided wave ultrasonics, acoustic emission, and fibre optic sensing, to continuously monitor the condition and integrity. In this work, we evaluated the condition of a Type IV composite overwrapped pressure vessel using ultrasonic guided wave propagation. We mounted fifteen piezo-electric wafers on the composite cylinder by shaping three rings containing five sensors each. We acquired data from the sensor network following different boundary conditions with artificial damages on the selected locations. The data were evaluated with guided wave tomography techniques using ultrasonic features (amplitude, frequency, etc.) as well as artificial intelligence (AI). The results suggest that both traditional guided wave fusion techniques and AI-based characterization methods can detect artificial damages. In future work, it is planned to integrate acoustic emission and fibre optic sensing. Moreover, the measurement and the test results will be implemented into a digital twin to derive trends and make predictions on the damage propagation as well as the remaining useful lifetime. This work has received funding from German Ministry of Economic Affairs and Climate Actions within the QI-Digital initiative (www.qi-digital.de). T2 - SCHALL 23 CY - Wetzlar, Germany DA - 21.03.2023 KW - Structural Health Monitoring KW - Ultrasonic Guided Waves KW - Composite Overwrapped Pressure Vessel KW - Hydrogen PY - 2023 AN - OPUS4-58026 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 - Schilling, Richard A1 - Oehrl, A. A1 - Wischerhoff, E. A1 - Schukar, Marcus T1 - A fibre optic temperature sensor based on thermoresponsive polymer N2 - We present a temperature sensor based on a polymer exhibiting a Lower Critical Solution Temperature (LCST) in aqueous solution encapsulated in a capillary. Parameters are chosen such that the solution exhibits a cloud point in a temperature range of 30° C to 39°C. The characteristic of thermoresponsive polymers with an LCST, is that above that temperature phase separation of the polymer takes place which leads to a temperature-dependent formation of a cloudy suspension. An optical intensity measurement over the desired temperature range is established by an increase of optical attenuation inside the polymer solution caused by a rising temperature. For our purpose, the polymer capillary is connected to transmitter and receiver via a Polymer Optical Fibre (POF). Our intensity measurement is, to the best of our knowledge, a novel method and can be considered simple when compared to existing fibre-based temperature measurement techniques. Due to the lack of electrical components at the probe, this sensor is suitable for measurements in strong electromagnetic fields and environments for which flying sparks are hazardous, i.e., inflammable fluids or gases. Furthermore, all manufactured sensors share the same temperature dependence and, therefore, are well-suited for comparative measurement, e.g., flow measurement systems. With the given temperature range, a body temperature measurement is also suitable. 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 DO - https://doi.org/https://doi.org/10.1117/12.2678418 SP - 12643-69 PB - SPIE CY - Bellingham, Wash. AN - OPUS4-57735 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Karapanagiotis, Christos A1 - Schukar, Marcus A1 - Breithaupt, Mathias A1 - Krebber, Katerina T1 - Monitoring of composite pressure vessels using surface applied distributed fiber optic sensors N2 - In this paper, we report on surface-applied distributed fibre optic sensors for monitoring composite pressure vessels designed for hydrogen storage. Previous reports have revealed that integrating optical fibres within vessel composite structures effectively enables the monitoring of structural behavior throughout their lifetime. However, integrating optical fibres during the manufacturing process is complex and time-consuming. Therefore, we aim to simplify this process by attaching the optical fibres to the vessel’s surface. This method is significantly more timeefficient than the integration process and can be applied to any vessel. Our results demonstrate that surface-applied fibre optic sensors can detect and precisely localise damage. Additionally, signs of damage can be recognised even before the damage occurs. Predictive maintenance using fibre optic sensors could reduce premature maintenance costs and periodic inspections while increasing safety and extending the vessel’s useful service life. The role of machine learning in predictive maintenance is also discussed. T2 - 20th Sensors & their Applications Conference CY - Limerick, Ireland DA - 11.08.2024 KW - Hydrogen KW - Fiber optic sensors KW - Composites KW - Machine learning KW - Structural health monitoring PY - 2024 SP - 1 EP - 4 AN - OPUS4-60911 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stajanca, Pavol A1 - Woyessa, G. A1 - Schukar, Marcus A1 - Bang, O. A1 - Krebber, Katerina T1 - Response of microstructured plastic optical fiber Bragg grating to gamma radiation N2 - Response of PMMA-based plastic optical fiber Bragg grating (FBG) to gamma radiation is investigated for the first time. FBG wavelength shift as large as 150 pm is observed for irradiation to 18 kGy. T2 - 5th Workshop on specialty optical fibers and their applications CY - Limassol, Cyprus DA - 11.10.2017 KW - Fiber Bragg gratings KW - Optical sensing and sensors KW - Plastic optical fibers KW - Gamma radiation PY - 2017 SP - Poster 19, 1 EP - 2 AN - OPUS4-42586 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eisermann, René A1 - Schukar, Marcus A1 - Nagel, Lukas A1 - Hickmann, Stefan A1 - Munzke, Dorit A1 - Trappe, Volker T1 - Characterising the material degradation of inner pressure-loaded GFRP-tube specimens using distributed strain sensing N2 - Glass-fibre-reinforced plastics (GFRP) are commonly used for the construction of pressure vessels and tanks for example in automotive and aerospace industries. Especially for pressure vessels used for the storage of natural gas or hydrogen with operation pressures up to 700 bar, an early material fatigue detection is of great interest. Measuring the distributed strain profile of GFRP structures helps to understand and detect material fatigue. In this article, we demonstrate the great potential of swept wavelength interferometry (SWI) based distributed strain sensing for the monitoring of pressure vessels made from GFRP. A resin transfer molding (RTM) process was used to manufacture GFRP-tube specimens. Commercial optical fibres with polyimid coating were glued to the surface externally in circumferential and axial direction. A cyclic load of up to 150 bar was applied to the samples using a servo-hydraulic test bench. Comparing the loaded and unloaded test conditions, we determined up to 2 % elongation in circumferential direction. We demonstrate reliable distributed strain measurements with sub-centimetre spatial resolution. By monitoring these high-resolution strain profiles, we were able to detect local material degradation that manifested itself as localized strain changes. Crucially, the material Degradation could be detected already after 75 % of dat the fatigue life before a crack appeared that led to leakage. T2 - Sensoren und Messsysteme - 19. ITG/GMA-Fachtagung CY - Nürnberg, Germany DA - 26.06.2018 KW - Distributed fibre optic sensors KW - Optical backscatter reflectometry KW - Swept wavelength interferometry (SWI) KW - Structural health monitoring (SHM) KW - Composite structures KW - Optical fibre PY - 2018 UR - https://ieeexplore.ieee.org/document/8436172/ SN - 978-3-8007-4683-5 SP - 239 EP - 242 PB - VDE VERLAG GMBH CY - Berlin AN - OPUS4-45887 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus A1 - Großwig, S. A1 - Weber, U. A1 - Krebber, Katerina T1 - Monitoring acoustic events in boreholes using wavelengthscanning coherent optical time domain reflectometry in multimode fiber N2 - A distributed acoustic sensor (DAS) based on wavelength-scanning coherent optical time domain reflectometer (WS-COTDR) is tested in an underground gas storage based on a multimode fiber for the first time to the best of our knowledge. The WS-COTDR acquires the reflection spectrum by scanning the wavelength of the laser and uses the spectra to calibrate strain. It overcomes the fading problem which is common for all DAS systems, and possesses the advantage of simple configuration and low-cost. The working principle of the system is well explained and the measurement results are presented. Various artificial and natural acoustic events have been successfully detected by the WS-COTDR. Such a sensor demonstrates several advantages over the traditional DAS systems, so it is supposed to be widely used in the oil and gas industry. T2 - EAGE GeoTech 2021 Second EAGE Workshop on Distributed Fibre Optic Sensing CY - Online meeting DA - 01.03.2021 KW - Leakage detection KW - Distributed acoustic sensing KW - Distributed fiber optic sensing PY - 2021 DO - https://doi.org/10.3997/2214-4609.202131010 SP - Paper 10, 1 PB - European Association of Geoscientists & Engineers CY - Houten, Niederlande AN - OPUS4-52248 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus A1 - Großwig, S. A1 - Weber, U. A1 - Krebber, Katerina T1 - Monitoring acoustic events in boreholes using wavelengthscanning coherent optical time domain reflectometry in multimode fiber N2 - A distributed acoustic sensor (DAS) based on wavelength-scanning coherent optical time domain reflectometer (WS-COTDR) is tested in an underground gas storage based on a multimode fiber for the first time to the best of our knowledge. The WS-COTDR acquires the reflection spectrum by scanning the wavelength of the laser and uses the spectra to calibrate strain. It overcomes the fading problem which is common for all DAS systems, and possesses the advantage of simple configuration and low-cost. The working principle of the system is well explained and the measurement results are presented. Various artificial and natural acoustic events have been successfully detected by the WS-COTDR. Such a sensor demonstrates several advantages over the traditional DAS systems, so it is supposed to be widely used in the oil and gas industry. T2 - EAGE GeoTech 2021 CY - Online meeting DA - 01.03.2021 KW - Borehole monitoring KW - Distributed fiber sensing KW - Acoustic sensing PY - 2021 DO - https://doi.org/10.3997/2214-4609.202131010 SP - 1 EP - 5 AN - OPUS4-52152 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krebber, Katerina A1 - Weege, S. A1 - Großwig, S. A1 - Obermöller, M. A1 - Perk, M. A1 - Lu, Xin A1 - Schukar, Marcus A1 - Weber, U. A1 - Pfeiffer, T. A1 - Rembe, M. T1 - Kombinierte faseroptische Messungen in Bohrlöchern helfen bei der Detektion von Kleinstleckagen N2 - Seit November 2019 läuft ein breit angelegtes und vom BMWi gefördertes ZIM-Kooperationsprojekt zwischen der Bundesanstalt für Materialforschung und -prüfung (BAM), der IAB'Weimar gGmbH, der GKSO GmbH & Co. Projekt KG, der DEEP.KBB GmbH sowie der Rembe Consulting PartG mbB. Ziel des Forschungsvorhabens sind sowohl die Lokalisierung als auch die Quantifizierung insbesondere sehr kleiner Leckagen in einer Bohrlochverrohrung durch die Nutzung faseroptischer Messtechnik. Durch Messdatenkopplung und den Wegfall bewegungsbedingter Nachteile einer Messsonde werden wesentlich präzisere Ergebnisse zur Bewertung der Bohrlochintegrität als üblich erwartet. T2 - DGMK/ÖGEW-Frühjahrstagung 2020 CY - Meeting was canceled DA - 15.04.2020 KW - Wasserstoffspeicher KW - Kavernenspeicher KW - Verteilte faseroptische akustische Sensorik PY - 2020 VL - 6 SP - 43 EP - 43 PB - DVV Media Group CY - Hamburg AN - OPUS4-52233 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus A1 - Krebber, Katerina T1 - Characterizing vibration response of fiber cables for distributed acoustic sensing N2 - The vibration responses of two fiber cables are characterized up to 16 kHz and compared with a standard tight-buffered 900 um fiber. The response of the cables is suppressed due to the cable protection. T2 - 27th International Conference on Optical Fiber Sensors (OFS-27) CY - Alexandria, VA, USA DA - 29.08.2022 KW - Distributed fiber sensing KW - Acoustic sensing KW - Response characterization PY - 2022 AN - OPUS4-56099 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus A1 - Weege, S. A1 - Roske, T. A1 - Krebber, Katerina T1 - Leakage detection at a borehole simulator using distributed acoustic sensing N2 - A distributed acoustic sensing system is used to detect the leakage in a borehole simulator by measuring the leakage induced vibration. The leakage location can be clearly determined by frequency spectrum analysis. T2 - 27th International Conference on Optical Fiber Sensors (OFS-27) CY - Alexandria, VA, USA DA - 29.08.2022 KW - Leakage detection KW - Structural health monitoring KW - Distributed fiber sensing KW - Distributed acoustic sensing PY - 2022 SP - 1 EP - 4 PB - Optica CY - Washington D.C., USA AN - OPUS4-56097 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus A1 - Krebber, Katerina T1 - Characterizing vibration response of fiber cables for distributed acoustic sensing N2 - The vibration responses of two fiber cables are characterized up to 16 kHz and compared with a standard tight-buffered 900 um fiber. The response of the cables is suppressed due to the cable protection T2 - 27th International Conference on Optical Fiber Sensors (OFS-27) CY - Alexandria, VA, USA DA - 29.08.2022 KW - Response characterization KW - Distributed fiber sensing KW - Acoustic sensing PY - 2022 SP - 1 EP - 4 PB - Optica CY - Washington D.C., USA AN - OPUS4-56096 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus A1 - Weege, S. A1 - Roske, T. A1 - Krebber, Katerina T1 - Leakage detection at a borehole simulator using distributed acoustic sensing N2 - A distributed acoustic sensing system is used to detect the leakage in a borehole simulator by measuring the leakage induced vibration. The leakage location can be clearly determined by frequency spectrum analysis. T2 - 27th International Conference on Optical Fiber Sensors (OFS-27) CY - Alexandria, VA, USA DA - 29.08.2022 KW - Structural health monitoring KW - Distributed fiber sensing KW - Distributed acoustic sensing KW - Leakage detection PY - 2022 AN - OPUS4-56098 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Popiela, Bartosz A1 - Günzel, Stephan A1 - Schukar, Marcus A1 - Mair, Georg W. A1 - Krebber, Katerina A1 - Seidlitz, Holger T1 - Impact of internal pressure control during manufacturing on residual stresses and safety performance of type 4 pressure vessels N2 - Composite pressure vessels are commonly manufactured using the wet filament winding process, where various process parameters can influence the performance of the finished component. In this study two designs of wet filament wound 6.8-liter type 4 composite pressure vessels were manufactured. Both differ only by the internal pressure used during the filament winding, which primarily influences the residual stress state in the composite structure. An extensive experimental study was carried out, including 10 slow burst tests and strain measurements with fiber optic sensors. Significant differences can be observed in the performance of the two designs even though the used stacking sequence, materials and other manufacturing parameters are the same for both designs. A discussion of the differences in the behavior of both cylinder types is provided, including the strain distribution in slow burst tests and failure mechanism. KW - Residual stresses KW - Slow burst tests KW - Filament winding KW - Type 4 composite pressure vessels KW - Hydrogen PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-626663 DO - https://doi.org/10.1016/j.jcomc.2025.100581 SN - 2666-6820 VL - 17 SP - 1 EP - 9 PB - Elsevier B.V. CY - Amsterdam, Netherlands AN - OPUS4-62666 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wang, Kun A1 - Lu, Xin A1 - Schukar, Marcus A1 - Hicke, Konstantin T1 - Water absorption effects on distributed temperature sensing using polyimide-coated optical fiber N2 - Polyimide-coated fibers are becoming more popular for distributed temperature sensing (DTS) because this coating can withstand much higher temperatures than the standard acrylate coating. As a hygroscopic material, polyimide can absorb water from the air, changing its properties, which may result in a modified temperature response of the sensing fiber. This study investigates the effect of water absorption on the performance of polyimide-coated optical fibers with different sizes and properties. The thermal response of these fibers was determined experimentally from 20°C to 90°C at a broad relative humidity level ranging from 10% to 90%. The results show that all the fibers experienced a decrease in temperature sensitivity as humidity increased, with the most noticeable non-linear spectral shift observed at higher humidity levels. These findings highlight the importance of optimizing fiber design and coating properties to balance stability and sensitivity, ensuring the reliable performance of DTS systems under extreme environmental conditions. T2 - 29th International Conference on Optical Fiber Sensors CY - Porto, Portugal DA - 26.05.2025 KW - Humidity sensing KW - Distributed temperature sensing KW - Optical fiber sensors KW - Temperature sensing KW - Water absorption KW - Polyimide-coated fiber PY - 2025 SN - 978-1-5106-9187-2 DO - https://doi.org/10.1117/12.3062748 VL - 13639 SP - 136393W-1 EP - 136393W-4 PB - SPIE AN - OPUS4-63642 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Schukar, Marcus T1 - Humidity response analysis of optical fibers with hygroscopic coatings based on Lamé’s equations N2 - Optical fibers with hygroscopic coatings are widely used for humidity sensing, where the coating expands upon absorbing water, inducing strain in the fiber. This strain is then used to determine humidity. However, previous studies have oversimplified the strain generation process. A comprehensive three-dimensional model of the mechanical interaction between the coating and the fiber is built based on Lamé’s equations. An analytical expression for the induced strain is derived. The proposed model predicts larger humidity-induced strain compared to the reported ones, given the same Young’s modulus or coefficient of humidity expansion for the coating. Interestingly, the effect of coating thickness on strain response are quite similar for both methods. Experimental validation using fibers with a polyimide coating shows strong agreement with the theoretical predictions. T2 - 29th International Conference on Optical Fiber Sensors CY - Porto, Portugal DA - 26.05.2025 KW - Reflectometry KW - Distributed fiber sensing KW - Humidity sensors KW - Lamé’s equations KW - Optical fiber sensors KW - Structural health monitoring KW - Rayleigh scattering PY - 2025 SN - 978-1-5106-9188-9 DO - https://doi.org/10.1117/12.3060891 VL - 13639 SP - 1 EP - 4 PB - SPIE AN - OPUS4-63257 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Munzke, Dorit A1 - Duffner, Eric A1 - Eisermann, René A1 - Schukar, Marcus A1 - Schoppa, André A1 - Szczepaniak, Mariusz A1 - Strohhäcker, J. A1 - Mair, Georg W. T1 - Monitoring of type IV composite pressure vessels with multilayer fully integrated optical fiber based distributed strain sensing N2 - We present the results of distributed fiber optic strain sensing for condition monitoring of a hybrid type IV composite fully wrapped pressure vessel using multilayer integrated optical fibers. Distributed strain sensing was performed for a total number of 252,000 load cycles until burst of the vessel. During this ageing test material fatigue could be monitored and spatially localized. Critical material changes were detected 17,000 cycles before material failure. Results have been validated by acoustic emission analysis. T2 - 12th International Conference on Composite Science and Technology (ICCST12) CY - Sorrento, Italy DA - 08.05.2019 KW - Hybrid composite pressure vessel KW - Distributed fiber optic sensing KW - Acoustic emission analysis KW - Structural health monitoring PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-516772 DO - https://doi.org/10.1016/j.matpr.2020.02.872 SN - 2214-7853 VL - 34 SP - 217 EP - 223 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-51677 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eisermann, René A1 - Basedau, Frank A1 - Kadoke, Daniel A1 - Gründer, Peter A1 - Schoppa, André A1 - Lehr, Christian A1 - Szczepaniak, Mariusz A1 - John, Sebastian A1 - Schukar, Marcus A1 - Munzke, Dorit A1 - Mair, Georg W. T1 - Distributed strain sensing with sub-centimetre resolution for the characterisation of structural inhomogeneities and material degradation of industrial high-pressure composite cylinders N2 - Fibre-reinforced plastics (FRP) especially carbon-fibre-reinforced polymer (CFRP) and glass-fibre-reinforced polymer (GFRP) are commonly used materials in high pressure vessels and storage units for automotive and aerospace purposes. Optical fibres are suitable to be integrated or directly applied to the surface of FRP components. Using optical fibres it is possible to monitor the distributed strain profiles and changes within the fatigue life of a pressure vessel to ensure the operational safety. Within artificial ageing experiments we used swept wavelength interferometry (SWI) based distributed strain sensing for the monitoring of commercial high-pressure composite cylinder. This artificial ageing was performed using test conditions of 503bar pressure load (service pressure 300 bar) and 89 °C for 100 h. The polyimide coated optical fibres were glued to the surface externally in circumferential and axial direction. Using distributed strain sensing (DSS) material expansion of over 0.5% were monitored with sub-centimetre spatial resolution. Within the circumferential direction we observed up to 10 % local fluctuation compared to the median strain caused by inhomogeneous material expansion, which could cause local material fatigue. In addition, we determined material degradation manifested itself as localized remaining material expansion and/or contraction. Results have been validated by other non-destructive methods like digital strip projection. T2 - 9th European Workshop on Structural Health Monitoring (EWSHM) CY - Manchester, UK DA - 10.07.2018 KW - Distributed fibre optic sensors KW - Optical backscatter reflectometry KW - Swept wavelength interferometry (SWI) KW - Structural health monitoring (SHM) KW - Composite structures KW - Optical fibre PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-458926 SP - 1 EP - 8 AN - OPUS4-45892 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Popiela, Bartosz A1 - Schukar, Marcus A1 - Breithaupt, Mathias A1 - Günzel, Stephan A1 - Mair, Georg W. A1 - Krebber, Katerina A1 - Seidlitz, Holger T1 - Embedding of Fiber Optic Sensors Under Industrial Conditions and Distributed Strain Sensing in Type 4 Composite Pressure Vessels N2 - The number of in-operation composite pressure vessels is increasing, partly due to their attractiveness for on-board compressed gas storage and transport applications. A possible way to maintain the highest safety levels is through the structural health monitoring of the composite cylinders. Here, the use of fiber optic sensors appears to be a promising approach. However, the integration of the optical fibers into the composite structure of a pressure vessel has been shown to be challenging. In this study, insights on the embedding of optical fibers in the composite structure under industrial conditions are provided. A protection concept for the ingress and egress of the optical fibers is presented. Finally, the results from destructive slow burst tests are evaluated, showing no clear trend in the impact of the embedded optical fibers on the performance of composite pressure vessels. T2 - 24th International Conference on Composite Materials CY - Baltimore, Maryland, USA DA - 04.08.2025 KW - Composite KW - Pressure vessel KW - Filament winding KW - Fiber optic sensors PY - 2025 SP - 3710 EP - 3717 AN - OPUS4-63886 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Witt, Jens A1 - Narbonneau, F. A1 - Schukar, Marcus A1 - Krebber, Katerina A1 - De Jonckheere, J. A1 - Jeanne, M. A1 - Kinet, D. A1 - Paquet, B. A1 - Depré, A. A1 - D´Angelo, L.T. A1 - Thiel, T. A1 - Logier, R. T1 - Medical textiles with embedded fiber optic sensors for monitoring of respiratory movement N2 - For patients under Magnetic Resonance Imaging (MRI) spontaneous respiration is constantly at risk of being impaired by anesthetic drugs or by upper airway obstruction. Therefore, continuous monitoring of the breathing activity is needed to assess adequate ventilation or to detect specific obstruction patterns. The paper describes three MRI compatible respiration sensors based on pure optical technologies developed within the EU FP6 project OFSETH. The sensors are based on fiber Bragg gratings, optical time-domain reflectometry and macrobending effects. The developed smart medical textiles can sense elongation up to 3% while maintaining the stretching properties of the textile substrates for patient's comfort. The OFSETH harness allows a continuous measurement of abdominal and thoracic respiration movement while all vitals organs are free for medical staff actions. The sensors were tested in MRI environment and on healthy adults. KW - Fiber optic sensor KW - Polymer optical fiber (POF) sensor KW - Respiratory sensor KW - Smart medical textile KW - MRI KW - Smart textile KW - Healthcare monitoring KW - Optical sensor KW - FBG PY - 2012 DO - https://doi.org/10.1109/JSEN.2011.2158416 SN - 1530-437X SN - 1558-1748 VL - 12 IS - 1 SP - 246 EP - 254 CY - New York, NY, USA AN - OPUS4-25649 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Witt, Jens A1 - Schukar, Marcus A1 - Krebber, Katerina A1 - Demuth, J. A1 - Pazoutová, H. A1 - Sasek, L. A1 - Santostefano, N. A1 - Fiore, L. A1 - Uotila, J. A1 - Pietrowski, P. T1 - POF sensors for personal protective equipment (PPE) N2 - This paper reports about the EU project i-Protect in which fibre optic sensors for measuring heart rate, respiratory rate and skin temperature are being developed. The sensors and monitoring units are integrated into underwear and are communicating wireless via body area network and communication unit with the rescue command centre. All sensors can be removed from the underwear to allow washing the textile. T2 - POF 2012 - 21st International conference on plastic optical fibers CY - Atlanta, Georgia, USA DA - 10.09.2012 KW - Physiological sensor KW - Heart rate KW - Respiratory rate KW - Photoplethysmography KW - Technical textile PY - 2012 SP - 333 EP - 338 AN - OPUS4-27397 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karapanagiotis, Christos A1 - Heimann, Jan A1 - Duffner, Eric A1 - Charmi, Amir A1 - Schukar, Marcus A1 - Hashemi, Seyedreza A1 - Prager, Jens T1 - Towards predictive maintenance of hydrogen pressure vessels based on multi-sensor data N2 - In this paper, we report on a sensor network for structural health monitoring (SHM) of Type IV composite overwrapped pressure vessels (COPVs) designed for hydrogen storage. The sensor network consists of three different SHM sensing technologies: ultrasonic guided waves (GW), acoustic emission (AE) testing, and distributed fiber optic sensors (DFOS). We present an experimental setup for a lifetime test, where a COPV is subjected to cyclic loading. Data from all sensors are collected and centrally evaluated. The COPV failed after approximately 60,000 load cycles, and the sensor network proved capable of detecting and localizing the damage even before the failure of the COPV. This multi-sensor approach offers significantly more channels of information and could therefore enable a transition from costly and time-consuming periodic inspections to more efficient and modern predictive maintenance strategies, including artificial intelligence (AI)-based evaluation. This not only has a positive effect on operational c KW - Ffiber optic sensors KW - Acoustic emission KW - Guided waves KW - Hydrogen KW - Digital twin KW - Structural health monitoring PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618948 DO - https://doi.org/10.58286/30513 SP - 1 EP - 8 PB - NDT.net AN - OPUS4-61894 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 - TY - JOUR A1 - Lu, Xin A1 - Schukar, Marcus T1 - Humidity response of optical fibres with hygroscopic coatings and its temperature dependence N2 - Optical fibres with hygroscopic coatings are widely used in structural health monitoring to acquire the humidity information. Water absorption-induced coating expansion leads to a strain change in the silica fibre, which can be measured by point and distributed strain fibre sensors and used to quantify the environmental humidity. In this paper, the strain transfer from the coating to the fibre is described by both 1D and 3D models. The impact of the coating property on the humidity induced strain is theoretically analysed. Since the properties of the sensing fibre are temperature-dependent, the humidity response obtained by the strain-based approach may change under different thermal conditions. The humidity response of fibres with different polyimide coatings is characterized by a commercial optical frequency domain reflectometer under different temperature conditions. The experimental results confirm the temperature dependence of the humidity response as the sensitivity of all the tested fibres decreases as the temperature increases. KW - Rayleigh scattering KW - Humidity sensor KW - Optical fibre sensors KW - Optical frequency domain reflectometer PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-629735 DO - https://doi.org/10.1088/2515-7647/adc85f VL - 7 IS - 2 SP - 1 EP - 11 PB - IOP Publishing Ltd CY - Bristol, UK AN - OPUS4-62973 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Karapanagiotis, Christos A1 - Schukar, Marcus A1 - Breithaupt, Mathias A1 - Hicke, Konstantin T1 - Toward a Digital Twin of Hydrogen Pressure Vessels Enabled by Distributed Fiber Optic Sensors N2 - We present a digital replica of a hydrogen pressure vessel enabled by distributed fiber optic sensors (DFOS). This digital replica dynamically displays and updates the vessel’s structural condition by calculating strain residuals defined as the difference between the measured DFOS strain and the expected strain based on pressure data. As an example, we show the ability of the DFOS to detect and localize damage caused by drilling six holes into the vessel’s body. This digital replica represents a foundational step toward a fully integrated digital twin for predictive maintenance and remaining lifetime prognosis. T2 - Sensor and Measurement Science International (SMSI) 2025 CY - Nuremberg, Germany DA - 06.05.2025 KW - fiber optic sensors KW - digital twin KW - structural health monitoring KW - hydrogen KW - machine learning PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-633885 UR - https://www.ama-science.org/proceedings/details/5962 SN - 978-3-910600-06-5 DO - https://doi.org/10.5162/SMSI2025/C6.1 SP - 165 EP - 166 PB - AMA Service GmbH CY - Wunstorf AN - OPUS4-63388 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stajanca, Pavol A1 - Cetinkaya, O. A1 - Schukar, Marcus A1 - Mergo, P. A1 - Webb, D. J. A1 - Krebber, Katerina T1 - Molecular alignment relaxation in polymer optical fibers for sensing applications N2 - A systematic study of annealing behavior of drawn PMMA fibers was performed. Annealing Dynamics were investigated under different environmental conditions by fiber longitudinal shrinkage monitoring. The shrinkage process was found to follow a stretched exponential decay function revealing the heterogeneous nature of the underlying molecular dynamics. The complex dependence of the fiber shrinkage on initial degree of molecular alignment in the fiber, annealing time and temperature was investigated and interpreted. Moreover, humidity was shown to have a profound effect on the annealing process, which was not recognized previously. Annealing was also shown to have considerable effect on the fiber mechanical properties associated with the relaxation of molecular alignment in the fiber. The consequences of fiber annealing for the climatic stability of certain polymer optical fiber-based sensors are discussed, emphasizing the importance of fiber controlled pre-annealing with respect to the foreseeable operating conditions. KW - Polymer optical fibers KW - Optical fiber sensor climatic stability KW - Thermal annealing KW - Molecular alignment relaxation KW - Humidity induced annealing PY - 2016 DO - https://doi.org/10.1016/j.yofte.2015.12.006 SN - 1068-5200 VL - 28 SP - 11 EP - 17 PB - Academic Press CY - Orlando AN - OPUS4-35288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stajanca, Pavol A1 - Sporea, D. A1 - Mihai, L. A1 - Negut, D. A1 - Schukar, Marcus A1 - Krebber, Katerina ED - Bunge, C.-A. ED - Kruglov, R. T1 - Gamma radiation induced effects in perfluorinated polymer optical fibers for sensing applications N2 - Radiation induced attenuation in perfluorinated polymer optical fiber was investigated as a potential mean for online. in situ gamma radiation monitoring. Spectral dependence of radiation induced attenuation was measured in the visible and near infrared range. Attenuation spectrum exhibits sharp increase both towards the ultraviolet and infrared side of the spectrum with 3 distinct peaks around 1400 nm. The fiber sensitivity to gamma radiation was further evaluated at two commonly used IR wavelengths (1310nm and l550nm} by pre- and post-irradiation optical time-domain reflectometry measurements. The examined fiber is sensitive up to lOO kGy of total absorbed dose with only minor saturation towards the large dose values. The influence of gamma radiation on the fiber mechanical properties was studied as well. Up to the maximal dose of 100 kGy, no significant deterioration of fiber strength and elasticity was observed. T2 - 3rd International POF Modelling Workshop CY - Nuremberg, Germany DA - 21.09.2015 KW - Perfluorinated POF KW - Gamma radiation KW - Radiation induced losses KW - Radiation dosimetry PY - 2015 SN - 978-3739214993 SP - 95 EP - 103 PB - Books on Demand GmbH CY - Norderstedt AN - OPUS4-35287 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stajanca, Pavol A1 - Lacraz, A. A1 - Kalli, K. A1 - Schukar, Marcus A1 - Krebber, Katerina ED - Berghmans, F. ED - Mignani, A. G. T1 - Strain sensing with femtosecond inscribed FBGs in perfluorinated polymer optical fibers N2 - In this work, the potential of fiber Bragg gratings (FBGs) in low-loss perfluorinated polymer optical fibers (PF-POFs) is explored. The FBG is femtosecond-inscribed in a commercial multi-mode (MM) PF-POF based on Cytop® polymer. Femtosecond inscription leads to creation of a highly saturated grating with a number of higher order reflection Peaks visible throughout the visible and near-infrared spectral region. For 2 mm long FBG having a pitch of 2.2895 μm, a total of nine higher-order MM reflection bands are visible spanning from 1548 nm (4th order) to 520 nm (12th order). Strain sensitivity was measured for 6 peak bands in 500-900 nm region, where relatively low cost CCD based spectrometers and broadband LEDs are available. Strain sensitivity increases almost linearly with increasing initial peak wavelength, growing from 4.82 ± 0.02 nm/% measured for 12th order peak at 517 nm to 8.12 ± 0.04 nm/% measured for 7th order peak at 883 nm. These values correspond to roughly 20 % higher sensitivity than silica FBGs exhibit in this spectral range. The gratings in PF-POFs combine the higher strain sensitivity and low-loss operation while maintaining the mechanical advantages of polymer optical fibers. Therefore, they hold a high potential for considerable broadening of polymer optical fiber Bragg gratings application range. T2 - Photonics Europe 2016, Optical Sensing and Detection IV CY - Brussels, Belgium DA - 03.04.2016 KW - Fiber Bragg gratings KW - Fiber optics sensors KW - Perfluorinated polymer optical fiber KW - Cytop KW - Strain sensitivity PY - 2016 SN - 978-1-5106-0144-4 DO - https://doi.org/10.1117/12.2225081 SN - 0277-786X VL - 9899 SP - 989911-1 EP - 989911-7 PB - SPIE AN - OPUS4-35926 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lu, Xin A1 - Chruscicki, Sebastian A1 - Schukar, Marcus A1 - Münzenberger, Sven A1 - Krebber, Katerina T1 - Application of Intensity-Based Coherent Optical Time Domain Reflectometry to Bridge Monitoring N2 - Although distributed fiber sensing techniques have been widely used in structural health monitoring, the measurement results of bridge monitoring, particularly under destructive testing, have rarely been reported. To the best of our knowledge, this paper is the first report of distributed vibration measurement results, which we obtained during a three-day destructive test on an abolished bridge. A coherent optical time domain reflectometry (COTDR) was used to acquire the vibration information while the bridge was being sawed. The obtained signal was analyzed in time and frequency domain. Some characteristics of the sawing-induced vibration were retrieved by the short-time Fourier transform; the vibration exhibited several high frequency components within the measured range up to 20 kHz and all the components appeared in the same time slot. Some unexpected signals were also detected. Thorough analysis showed that they are quite different from the sawing-induced vibration and are believed to originate from internal damage to the bridge (probably the occurrence of cracks). KW - Destructive testing KW - Structural health monitoring KW - Distributed fiber sensing KW - Distributed acoustic sensing PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-547451 DO - https://doi.org/10.3390/s22093434 VL - 22 IS - 9 SP - 3434 PB - MDPI AN - OPUS4-54745 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Steffen, Milan A1 - Schukar, Marcus ED - Jaroszewicz, L.R. T1 - Integration of Cu-coated single-mode optical fiber into carbon/PEEK composite for distributed structural health monitoring based on Rayleigh backscatter reflectometry N2 - In this paper a technique for integrating copper coated silica optical fibers into AS-4/PEEK composite for Structural Health Monitoring (SHM) is presented. The integration steps are described in detail. X-ray and microscopic images indicate a successfully integrated optical fiber which does not seem to affect the fiber/matrix distribution around it. Optical backscatter reflectometry shows losses of approximately 2dBm-1 along the integrated parts of the optical fiber due to temperature induced shrinkage of the composite. T2 - EWOFS 2013 - 5th European workshop on optical fibre sensors CY - Kraków, Poland DA - 19.05.2013 KW - SHM KW - Optical KW - Fiber KW - Rayleigh KW - OFDR KW - Composite KW - Copper coating PY - 2013 DO - https://doi.org/10.1117/12.2025280 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - Paper 8794 - 181 SP - 879430-1 EP - 879430-6 AN - OPUS4-28627 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kinet, D. A1 - Witt, Jens A1 - Grillet, A. A1 - Schukar, Marcus A1 - Krebber, Katerina A1 - Giannone, D. A1 - Pirotte, F. T1 - Silica Fibre Bragg Grating Sensor Embedded into a Textile Fabric for Large Strain Applications N2 - A FBG written on standard silica fibre, with coating transparent at 248nm, was integrated on an elastic textile fabric. The so-formed optical gauge showed a linear relationship when strained up to 40%. T2 - Bragg Gratings, Photosensitivity and Poling in Glass Waveguides (BGPP) and Nonlinear Photonics (NP) Topical Meeting and Tabletop Exhibit 2007 CY - Quebec City, Quebec, Canada DA - 2007-09-02 KW - Silica Fibre KW - Fibre Bragg Grating KW - Fibre Optic Sensor KW - Strain Sensor KW - FBG KW - Textile Fabric KW - Large Strain Application PY - 2007 SN - 1-55752-847-0 SP - 1 EP - 3 AN - OPUS4-16008 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schukar, Marcus T1 - Faser-Bragg-Gitter-Sensoren überwachen Strahlung am Elektronenspeicherring BESSY II. N2 - Untersuchung der Eignung von FBG-Strahlungssensoren zur verteilten Überwachung auftretender ionisierender Strahlung an Elektronenspeicherringen. Test des Messverfahrens am Undulator U 49/1 des Elektronenspeicherrings BESSY II T2 - 8. Dresdner Sensorsymposium CY - Dresden, Germany DA - 10.02.2007 PY - 2007 AN - OPUS4-16291 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schukar, Marcus A1 - Krebber, Katerina A1 - Scheer, M. ED - Gerald Gerlach, ED - Peter Hauptmann, T1 - Faser-Bragg-Gitter-Sensoren überwachen Strahlung am Elektronenspeicherring BESSY II T2 - 8. Dresdner Sensor-Symposium CY - Dresden, Deutschland DA - 2007-12-10 KW - Faser-Bragg-Gitter KW - Fasersensoren KW - Strahlungssensoren KW - Strahlungseffekte KW - Strahlungsdosimetrie KW - Elektronenspeicherring PY - 2007 SN - 978-3-940046-45-1 N1 - Serientitel: Dresdner Beiträge zur Sensorik – Series title: Dresdner Beiträge zur Sensorik IS - 29 SP - 141 EP - 144 PB - TUDpress, Verlag der Wissenschaften GmbH CY - Dresden AN - OPUS4-16375 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schukar, Marcus T1 - Strahlungsüberwachung mit Faser-Bragg-Gitter-Sensoren am Elektronenespeicherring BESSY II T2 - XXI. Messtechnisches Symposium des AHMT CY - Paderborn, Germany DA - 2007-09-20 PY - 2007 AN - OPUS4-16290 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -