TY - CONF A1 - Habel, Wolfgang T1 - Complex monitoring system for long-term evaluation of prestressed bridges in the new Lehrter Bahnhof in Berlin. T2 - Invited presentation at the 2nd International Conference "RELIABILITY, SAFETY AND DIAGNOSTIC OF TRANSPORT STRUCTURES AND MEANS" at the University of Pardubice. CY - Pardubice, Czech Republic DA - 2005-07-07 PY - 2005 AN - OPUS4-11633 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Habel, Wolfgang A1 - Niemann, Joachim A1 - Hille, Falk ED - Waßmuth, W. T1 - Langzeitmonitoring der äußeren Brücken des Hauptbahnhofs KW - Monitoring KW - Sensor KW - Bauwerksicherheit PY - 2006 SN - 3-7771-0349-7 SP - 116 EP - 123 PB - Eurailpress Tetzlaff-Hestra CY - Hamburg AN - OPUS4-14067 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Habel, Wolfgang R. T1 - Faseroptische Sensoren für hochaufgelöste Verformungsmessungen in der Zementsteinmatrix N2 - Steife Faser-Bragg-Gitter-Sensoren und bewegliche Faser-Mikrodistometer (extrinsische Fabry-Pérot-Interferometer-Sensoren) bieten der Baustoff-Forschung und der baubegleitenden Qualitätssicherung einzigartige Möglichkeiten, Mikroverformungen in der Zementsteinmatrix nahezu rückwirkungsfrei bereits zum Beginn der Erstarrung und ebenso nach der Erhärtung zu messen. Zuverlässige Meßaussagen im Zementsteingefüge erfordern jedoch eine gezielte Dimensionierung sowie ausreichende Haftung in der Matrix. Die Arbeit beschreibt die physikalischen Grundlagen der Sensoren und definiert Dimensionierungskriterien. Der Einfluss der betonchemischen Beanspruchung auf Festigkeit und Langzeitstabilität der eingebetteten Sensorfasern (Glas, Coating) wird untersucht. T3 - BAM Forschungsberichtreihe - 246 PY - 2004 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-2040 SN - 978-3-89701-567-6 SN - 0938-5533 VL - 246 SP - 1 EP - 204 PB - Wirtschaftsverlag NW CY - Bremerhaven AN - OPUS4-204 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gabler, M. A1 - Tkachenko, Viktoriya A1 - Küppers, S. A1 - Kuka, G.G. A1 - Habel, Wolfgang A1 - Milwich, M. A1 - Knippers, J. ED - Peters, K.J. ED - Ecke, W. ED - Matikas, T.E. T1 - Automatically produced FRP beams with embedded FOS in complex geometry: process, material compatibility, micromechanical analysis, and performance tests N2 - The main goal of the presented work was to evolve a multifunctional beam composed out of fiber reinforced plastics (FRP) and an embedded optical fiber with various fiber Bragg grating sensors (FBG). These beams are developed for the use as structural member for bridges or industrial applications. It is now possible to realize large scale cross sections, the embedding is part of a fully automated process and jumpers can be omitted in order to not negatively influence the laminate. The development includes the smart placement and layout of the optical fibers in the cross section, reliable strain transfer, and finally the coupling of the embedded fibers after production. Micromechanical tests and analysis were carried out to evaluate the performance of the sensor. The work was funded by the German ministry of economics and technology (funding scheme ZIM). Next to the authors of this contribution, Melanie Book with Röchling Engineering Plastics KG (Haren/Germany) and Katharina Frey with SAERTEX GmbH & Co. KG (Saerbeck/Germany) were part of the research group. T2 - Smart sensor phenomena, technology, networks, and systems integration 2012 (SPIE-Proceedings) CY - San Diego, USA DA - 26.04.2012 KW - Engineering KW - Fiber Bragg gratings (FBG) KW - Fiber reinforced polymers (FRP) KW - Optical fibers KW - Embedded sensors KW - Sensor-matrix interaction PY - 2012 SN - 978-0819490032 DO - https://doi.org/10.1117/12.915489 N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 8346 SP - 83460B-1 - 83460B-14 AN - OPUS4-27727 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Hofmann, Detlef A1 - Basedau, Frank T1 - Rückwirkungsarme faseroptische Dehnungssensoren für weiche Materialien und Verbundwerkstoffe T2 - GESA-Symposium 1999 CY - Warnemünde, Deutschland DA - 1999-05-06 KW - Faseroptische Dehnungssensoren PY - 1999 SN - 3-18-091463-7 SN - 0083-5560 N1 - Sprachen: Deutsch/Englisch - Languages: German/English SP - 103 EP - 112 PB - VDI-Verl. CY - Düsseldorf AN - OPUS4-790 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schukar, Vivien A1 - Kadoke, Daniel A1 - Kusche, Nadine A1 - Münzenberger, Sven A1 - Gründer, Klaus-Peter A1 - Habel, Wolfgang T1 - Validation and qualification of surface-applied fibre optic strain sensors using application-independent optical techniques N2 - Surface-applied fibre optic strain sensors were investigated using a unique validation facility equipped with application-independent optical reference systems. First, different adhesives for the sensor's application were analysed regarding their material properties. Measurements resulting from conventional measurement techniques, such as thermo-mechanical analysis and dynamic mechanical analysis, were compared with measurements resulting from digital image correlation, which has the advantage of being a non-contact technique. Second, fibre optic strain sensors were applied to test specimens with the selected adhesives. Their strain-transfer mechanism was analysed in comparison with conventional strain gauges. Relative movements between the applied sensor and the test specimen were visualized easily using optical reference methods, digital image correlation and electronic speckle pattern interferometry. Conventional strain gauges showed limited opportunities for an objective strain-transfer analysis because they are also affected by application conditions. KW - Fiber Bragg grating KW - Surface application KW - Qualification KW - Strain transfer KW - Digital image correlation KW - Electronic speckle pattern interferometry PY - 2012 DO - https://doi.org/10.1088/0957-0233/23/8/085601 SN - 0957-0233 SN - 1361-6501 VL - 23 IS - 8 SP - 085601-1 EP - 085601-9 PB - IOP Publ. Ltd. CY - Bristol AN - OPUS4-26639 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schukar, Vivien A1 - Kusche, Nadine A1 - Habel, Wolfgang T1 - How reliably do fiber Bragg grating patches perform as strain sensors? N2 - In Germany, the first guideline for the use of fiber Bragg grating strain sensors, 'Optical Strain Sensor based on Fiber Bragg Grating' (Berlin, Germany: Beuth-Verlag, 2010), has been developed by the GESA guideline group of VDI, 'The Association of German Engineers' and published by Beuth-Verlag. This guideline provides the basic specifications of this sensor type and the sensor characteristics, which have to be known for a reliable sensor performance. In conformity to this guideline, experimental investigations on the strain transfer characteristics of fiber Bragg grating patches have been carried out. A comparison between patches and resistance strain gauges during tensile tests and combined temperature and tensile loading was carried out. The evaluated strain gauge factor and the temperature sensitivity of the strain gauge factor have been compared to the manufacturer's data. The overall performance of the patches has been evaluated. The experimental investigations showed that there are considerable disagreements between the manufacturer's specifications and the observed characteristics. KW - Fiber Bragg grating KW - Strain gauge KW - Strain transfer KW - Validation PY - 2012 DO - https://doi.org/10.1109/JSEN.2011.2139202 SN - 1530-437X SN - 1558-1748 VL - 12 IS - 1 SP - 128 EP - 132 CY - New York, NY, USA AN - OPUS4-25486 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rohwetter, Philipp A1 - Lothongkam, Chaiyaporn A1 - Siebler, Daniel A1 - Habel, Wolfgang T1 - Faseroptische Sensoren zur akustischen Detektion von Teilentladungen in hochspannungstechnischen Anlagen und Betriebsmitteln T1 - Fibre optic sensors for the detection of partial discharge in high voltage facilities and equipment N2 - Konventionelle elektrische Verfahren zur Erfassung von Teilentladungen (TE) in hochspannungstechnischen Bauteilen und Betriebsmitteln erfordern elektromagnetisch ungestörte Messbedingungen und sind für die Überprüfung von Anla-gen während des laufenden Betriebs nicht unproblematisch. Daher werden für Prüfung und Überwachung im Feld zu-nehmend unkonventionelle elektromagnetische (HF, VHF, UHF) und akustische Detektionsverfahren eingesetzt. Wegen ihrer prinzipiellen Immunität gegen elektromagnetische Störungen sind darüber hinaus faseroptische Verfahren der TE-Detektion in Erprobung. Im vorliegenden Beitrag werden zwei Typen akustisch-faseroptischer Sensoren (a-FOS) vorgestellt und auf ihre Eignung untersucht, Teilentladungen in elastomeren Isolierkörpern, wie etwa Silikon-Feldsteuerelementen von Kabelgarnituren, zu detektieren. Die hier präsentierten Laborergebnisse zeigen, dass die zur Detektion von TE mit kritischer Intensität (z.B. in Kabelgarnituren) notwendige Empfindlichkeit erreicht werden kann. Darauf basierend wird das Potential der faseroptisch-akustischen Detektion von TE in der hochspannungstechnischen Zustandsüberwachung allein und in Kombination mit fasergekoppelten fluoreszenzoptischen Sensoren diskutiert. N2 - Conventional methods for the detection of partial discharge (PD) in high voltage devices and equipment require electromagnetically quiet conditions of measurement and hence are not unproblematic in testing operational equipment under typical conditions encountered in a high voltage plant. Therefore, non-conventional, electromagnetic (HF, VHF, UHF), and acoustic methods find increasing use in field testing and monitoring. Additionally, because of their inherent immunity against electromagnetic interference, fibre-optic methods for detecting PD are being tested. This paper introduces two types of acoustic fibre-optic sensors (a-FOS) and reports on tests of their ability to detect PD in elastomeric insulations such as silicone stress cones used in cable accessories. The laboratory results presented here show that sensitivities can be reached which are sufficient for the detection of critically intense PD, for example in cable accessories. Based on this the potential of fibre-optic acoustic detection of PD in the condition monitoring of high voltage Equipment is discussed, also for the case of a scheme combining a-FOS with fibre-coupled optical sensors. T2 - Diagnostik elektrischer Betriebsmittel CY - Fulda, Germany DA - 15.11.2012 PY - 2012 UR - http://www.vde-verlag.de/proceedings-de/453465075.html SN - 978-3-8007-3465-8 SP - 1 EP - 6 PB - VDE Verlag GmbH AN - OPUS4-27391 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rohwetter, Philipp A1 - Kielau, T. A1 - Lothongkam, Chaiyaporn A1 - Heidmann, G. A1 - Habel, Wolfgang ED - Liao, Y. ED - Jin, W. ED - Sampson, D.D. ED - Yamauchi, R. ED - Chung, Y. ED - Nakamura, K. ED - Rao, Y. T1 - All fibre-optic simultaneous detection of optical and acoustic emission from partial discharges in silicone elastomer N2 - In high-voltage facilities of power stations and transmission networks, discharge activities leading to catastrophic failure can occur. Early detection of partial discharges (PD) in polymeric insulations of HV cable terminations and joints is therefore increasingly important. This paper describes a monitoring methodology to detect PD activity in silicone elastomer by two independent fibre-optic sensor types. Fluorescent fibre-based sensors are sensitive to plasma optical emission already at the onset of PD while an acoustic fibre-optic sensor responds to acoustic emission from the PD during its progression. The sensitivities of both sensor types are compared, and it is demonstrated that they provide complementary information for fibre-optic sensor-based monitoring of high-voltage cable accessories.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only. T2 - OFS2012 - 22nd International conference on optical fiber sensors CY - Beijing, China DA - 15.10.2012 KW - Fiber optic sensors KW - Plasma KW - Sensors KW - Fibre-optic condition monitoring KW - Partial discharge KW - Acoustic emission KW - High-voltage breakdown KW - Silicone elastomer KW - Stress cone KW - Fluorescent fibre KW - High voltage cable accessories PY - 2012 DO - https://doi.org/10.1117/12.974941 SN - 0277-786X SN - 1996-756X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 8421 SP - 8421B9-1 EP - 8421B9-4 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-27323 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schukar, Vivien A1 - Kusche, Nadine A1 - Kalinka, Gerhard A1 - Habel, Wolfgang T1 - Field deployable fiber bragg grating strain patch for long-term stable health monitoring applications N2 - A fiber Bragg grating (FBG) strain patch specially adapted for long-term and high-strain applications has been developed and characterized. The design concept for the patch is based on a glass-fiber reinforced plastic (gfrp) carrier material. The developed concept for the FBG integration into the carrier material was derived from reliable integration procedure of FBG sensors into composite structures. The patches' temperature sensitivity, strain gauge factor, fiber–matrix interface adhesion and fatigue behavior were characterized. As a result, FBG strain patches with linear temperature and strain behavior, as well as excellent fatigue resistance, were developed and can be used as part of a monitoring system for advanced composite materials in aerospace structures or wind turbine power plants. KW - Fiber Bragg grating KW - Patch KW - Strain gauge factor KW - Temperature sensitivity KW - Push-out test KW - Validation KW - Fatigue behavior PY - 2013 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-276271 DO - https://doi.org/10.3390/app3010039 SN - 2076-3417 VL - 3 IS - 1 SP - 39 EP - 54 PB - MDPI CY - Basel AN - OPUS4-27627 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilder, Constanze A1 - Kohlhoff, Harald A1 - Hofmann, Detlef A1 - Habel, Wolfgang ED - Boller, C. T1 - Structure-integrated fibre-optic strain wave sensor for pile testing and monitoring of reinforced concrete piles N2 - Reinforced concrete piles are used when structures are constructed on soft ground, because it is necessary to transfer the loads into deeper strata with a sufficient bearing capacity. Usually, static and dynamic pile tests are carried out in order to determine the pile’s behaviour and possible damages. The dynamic measurements can show the bearing behaviour and the structural integrity by using the theory of one-dimensional wave propagation. Commonly, the sensors are installed on the top of the pile head or embedded near the pile head. With the purpose of receiving more precise information about the pile features, now, a string of sensors is embedded at different levels of the pile. A fibre optic strain wave sensor has already been developed by Schallert. The sensor is based on the principle of the extrinsic Fabry-Perot interferometer and was already tested in laboratory and full-scale field tests with precast driven piles. It was possible to detect the introduced deformation caused by the static loading and the dilatational wave during dynamic low-strain as well as high-strain loading. Although the full-scale tests were successful, the high demands on the economy of the sensor required the optimisation of the sensor design. After laboratory tests with the optimised sensor, a cast-in-situ bored pile has been built at the BAM Test Site Technical Safety in Horstwalde, South of Berlin. In order to enable the comparison of the signals, additional fibre Bragg grating sensors, temperature sensors and resistance strain gauge sensors are embedded into the pile. In this paper, the optimised sensor and the setup of the cast-in-situ bored pile along with results of the conducted pile tests are shown together with an outlook on further field-tests in progress. T2 - EWSHM'12 - 6th European workshop on structural health monitoring 2012 CY - Dresden, Germany DA - 03.07.2012 PY - 2012 SN - 978-3-940283-41-2 VL - 1 SP - 523 EP - 530 CY - Berlin AN - OPUS4-26279 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilder, Constanze A1 - Kusche, Nadine A1 - Schukar, Vivien A1 - Habel, Wolfgang ED - Liao, Y. ED - Jin, W. ED - Sampson, D.D. ED - Yamauchi, R. ED - Chung, Y. ED - Nakamura, K. ED - Rao, Y. T1 - Experimental qualification and validation of fibre optic strain sensors N2 - Strain sensors used in practical applications must provide reliable measurement data. To achieve this, sensor systems must be validated by using experimental facilities that enable physically independent statements about the performance of the sensor components. The paper describes qualification and validation procedures using a special facility to qualify surface-applied strain sensors and to achieve reliable sensor results. Based on examples concerning fibre optic strain sensor patches with and without FBG sensors, the determination of the strain gauge factor also under combined thermal and mechanical loading will be presented. These results are the basis for development of guidelines and standards. T2 - OFS2012 - 22nd International conference on optical fiber sensors CY - Beijing, China DA - 15.10.2012 KW - Fiber Bragg gratings KW - Sensors PY - 2012 DO - https://doi.org/10.1117/12.968801 SN - 0277-786X SN - 1996-756X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 8421 SP - 1 EP - 4 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-27321 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang ED - Boller, C. T1 - Advances in developing standards for fibre-optic sensors N2 - Fibre optic sensors provide a great potential in different industrial as well as research fields. They are always then increasingly used if special requirements avoid the application of conventional electrical sensors. The scientific background for optical fibre sensors is well developed; however, not all users are already convinced that fibre optic sensors enable long-term stable function under harsh environmental conditions. There are still some restrictions with respect to long-term reliable use: first, some sensor products available on the market are sometimes not appropriately characterized and described. Second, application procedures are not always well validated due to a lack of understanding the mechanical, physical or chemical issues in the interface zone between sensor and measuring object. Industrial users therefore need standardized description of the sensor system performance, recommendations what aspects have to be considered for reliable application and operation of sensors, and finally how to handle the application of sensors under possibly harsh environmental conditions. Technical rules must be provided. First guidelines for the appropriate specification and use of fibre optic sensors have been developed and published. Several European and international activities have been launched to push the development of further standards for special applications. The paper informs about successful standardization activities. Worldwide running relevant guideline activities are presented. An outlook on important research activities to come to substantiated statements in standards is given. T2 - EWSHM'12 - 6th European workshop on structural health monitoring 2012 CY - Dresden, Germany DA - 03.07.2012 KW - Standardization KW - Fibre-optic sensors KW - Validation KW - Reliability KW - Calibration PY - 2012 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-274953 SN - 978-3-940283-41-2 IS - Tu.4.C.2 SP - 1 EP - 9 CY - Berlin AN - OPUS4-27495 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang ED - Liao, Y. ED - Jin, W. ED - Sampson, D.D. ED - Yamauchi, R. ED - Chung, Y. ED - Nakamura, K. ED - Rao, Y. T1 - Fiber-optic strain sensors are making the leap from lab to industrial use - reliability and validation as precondition for standards N2 - Fiber-optic sensors are increasingly used if special requirements avoid the application of electrical sensors, or economic benefit is promised. The scientific background is well developed; however, there are some restrictions with respect to long-term reliable use. For a widespread practical use, sensor products must be manufactured, characterized and validated according to standards. Guidelines on how to apply sensors and evaluate their operation on-site including special facilities to evaluate applied sensors are needed. The paper will present validation methods to evaluate the quality of sensor systems function. It will also indicate lacks of knowledge and methods to be filled to promote the use of FOS. T2 - OFS2012 - 22nd International conference on optical fiber sensors CY - Beijing, China DA - 15.10.2012 KW - Application KW - Fiber optic sensor KW - Validation KW - Qualification KW - Strain transfer KW - Standards KW - Guideline KW - Fiber optics KW - Reliability KW - Sensors PY - 2012 DO - https://doi.org/10.1117/12.981530 SN - 0277-786X SN - 1996-756X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 8421 SP - 84210H-1 EP - 84210H-12 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-27258 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -