Dokument-ID Dokumenttyp Autoren/innen Persönliche Herausgeber/innen Haupttitel Abstract Auflage Verlagsort Verlag Herausgeber (Institution) Erscheinungsjahr Titel des übergeordneten Werkes Jahrgang/Band ISBN Veranstaltung Veranstaltungsort Beginndatum der Veranstaltung Enddatum der Veranstaltung Ausgabe/Heft Erste Seite Letzte Seite URN DOI Lizenz Datum der Freischaltung OPUS4-28570 Beitrag zu einem Tagungsband Kusche, Nadine; Schukar, Vivien; Hofmann, Detlef; Basedau, Frank; Habel, Wolfgang; Woschitz, H.; Lienhart, W. Jaroszewicz, L.R. Field examples for optical fibre sensor condition diagnostics based on distributed fibre-optic strain sensing Fibre optic sensors for monitoring in safety-relevant structures have to be validated in order to proof their reliability under typical structural load conditions. The reliable use of optical fibre sensors depends strongly on an appropriate and qualitative application. Diagnostics of the physical condition of embedded and surface-applied fibre optic strain sensors are demonstrated on field examples. Distributed strain measurement based on Rayleigh backscattering is used to determine breakage of the fibre, interface adhesion problems and to identify application related strain transfer mechanisms. International society for optics and photonics (SPIE) 2013 EWOFS 2013 - 5th European workshop on optical fibre sensors (Proceedings) 8794 978-0-81949-634-8 EWOFS 2013 - 5th European workshop on optical fibre sensors Kraków, Poland 19.05.2013 22.05.2013 Paper 8794 - 181 879433-1 879433-4 10.1117/12.2025567 2016-02-20 OPUS4-28748 Vortrag Schukar, Vivien Reliability analysis of fibre optic sensors for monitoring of industrial facilities; keynote lecture 2013 Coteq, 12th Conference on Technology Equipment Coteq, 12th Conference on Technology Equipment Porto de Galinhas, Brazil 2013-06-18 2013-06-21 2016-02-20 OPUS4-27966 Vortrag Schukar, Vivien Faseroptische Sensoren in Sicherheit und Technik 2013 JENAer Carl-Zeiss-Optikkolloquium JENAer Carl-Zeiss-Optikkolloquium Jena, Germany 2013-03-18 2013-03-18 2016-02-20 OPUS4-28607 Vortrag Schukar, Vivien Fibre Optic Sensor Activities at BAM 2013 BAM - Universidade Tecnológica Federal do Paraná (UTFPR) - Meeting BAM - Universidade Tecnológica Federal do Paraná (UTFPR) - Meeting Berlin, Germany 2013-05-24 2013-05-24 2016-02-20 OPUS4-24512 Beitrag zu einem Tagungsband Kusche, Nadine; Schukar, Vivien; Schilder, Constanze; Köppe, Enrico; Habel, Wolfgang Chang, F.-K. Development and qualification of FBG-based strain patches and rosettes A fibre Bragg grating (FBG) strain patch specially adapted for long-term and high-strain applications was developed and characterised. Additionally, in the case of unknown main stress axis, two fibre optic strain rosettes were developed. The design concept for the patch and the rosettes is based on a glass fibre reinforced plastic (gfrp) carrier material. The patches were characterised due to their strain gauge factor and fatigue behaviour. As a result, FBG strain patches with linear strain behaviour and excellent fatigue resistance were developed and can be used as part of a monitoring system for aerospace structures or wind turbine power plants. The rosettes were designed to be small in geometrical size and their strain transfer behaviour was characterised. DEStech Publications, Inc. 2011 IWSHM 2011 - 8th International workshop on structural health monitoring 2011 (Proceedings) 2 978-1-60595-053-2 8th International workshop on structural health monitoring 2011 Stanford, CA, USA 13.09.2011 15.09.2011 1457 1465 2016-02-19 OPUS4-24655 Beitrag zu einem Tagungsband Habel, Wolfgang; Schukar, Vivien; Kusche, Nadine Calibration facility for quality certification of surface-attached fiber optic and electrical strain sensors Strain measurement in structures witli the purpose of long-term structurai health inonitoring must provide reliable inforination about the structure's behavior over the whole period of use. The user must be sure that installed sensors are validated and work to the utmost satisfactiou. For this purpose, sensor Systems are tested using special facilities. Bccause it is not easy to characterize the strain transfer quality from the host structure into surface-applied strain sensors, a unique testing facility has been developed. Originally developed for fiber Bragg grating based sensors, the KALFOS facility (= calibration of fiber optic sensors) can also be used for electrical strain sensors. Calibration ineasurements are referenced by unbinsed Digital Image Correlation (D1C) and Electronic Speckle Pattern Interferometer (ESPI) methods. The strain transfer behavior can experimentally be analyzed and investigated under combined thermal and mechanical loading conditions and allows revealing wealuiesses in couimonly used attachment methodologies. The deformation of all members (particularly the coating/substrate - adhesive combination) in the sensing area is physically independently gained and recorded. Results achievcd allow precise description of the strain transfer function, Validation of the longterm strain sensor characteristics, matching of specific measurement requirements with environmental conditions, and, moreover, the verification of Standards for use of strain sensors. Institute of Electrical and Electronics Engineers (IEEE) 2011 IEEE Sensors 2011 conference (Proceedings) 978-1-4244-9288-6 IEEE Sensors 2011 conference Limerick, Ireland 28.10.2011 31.10.2011 1337 1340 10.1109/ICSENS.2011.6127253 2016-02-19 OPUS4-24656 Beitrag zu einem Tagungsband Habel, Wolfgang; Schukar, Vivien; Tkachenko, Viktoriya How do application-related issues influence the reliability of fiber optic strain measurements? Fibre optic strain sensors are increasingly used and sensor systems are provided with specifications. Even if the performance is well specified, the strain characteristics of the sensor, strain transfer factor, mechanical stability under thermal influences, the performance of applied strain sensors can seriously differ from virgin sensor's the performance. The contribution will focus on issues that can deteriorate the sensor function or reduce the reliability of measurement results. Aspects are considered how to come to reliable strain measurements and how to validate strain measurements of applied sensors. Related to this topic, European activities like the recently started European COST TD1001 action, called (OfSeSa) will be presented. Institute of Electrical and Electronics Engineers (IEEE) 2011 IEEE Sensors 2011 conference (Proceedings) 978-1-4244-9288-6 IEEE Sensors 2011 conference Limerick, Ireland 28.11.2011 31.10.2011 947 950 2016-02-19 OPUS4-24643 Beitrag zu einem Tagungsband Habel, Wolfgang; Kusche, Nadine; Münzenberger, Sven; Schukar, Vivien KALFOS - a validation facility for strain transfer characterization of surface-applied strain sensors Strain sensors embedded in or attached to structural components have to measure the real deformation of the structure over the whole period of use. The user must know how reliably installed sensors provide strain measurement results. For this purpose, test facilities or coupon tests are used. In order to characterize the strain transfer quality from the host structure into surface-applied strain sensors, a unique testing facility has been developed. This facility can be used both for fiber optic and resistance strain sensors. Originally developed for fiber Bragg grating based sensors, the KALFOS facility (=calibration of fiber optic sensors) uses Digital Image Correlation (DIC) and Electronic Speckle Pattern Interferometer (ESPI) as unbiased referencing methods. It is possible to determine experimentally the strain transfer mechanism under combined thermal and mechanical loading conditions. This experimental characterization method will reveal weaknesses in commonly used strain sensors, and the investigation of the material systems used for fiber optic and other strain sensors (particularly the coating/substrate - adhesive combination). The KALFOS facility allows matching of specific measurement requirements with environmental conditions. SAE International 2011 SAE 2011 AeroTech Congress & Exhibition SAE 2011 AeroTech Congress & Exhibition Toulouse, France 18.10.2011 21.10.2011 Paper 2011-01-2606 1 7 10.4271/2011-01-2606 2016-02-19 OPUS4-25309 Beitrag zu einem Tagungsband Habel, Wolfgang; Schukar, Vivien Ramos, G. A. Validation of strain sensors to achieve reliable measurement results Fiber optic strain sensors are increasingly used and sensor Systems are provided with specifications. Even if the performance is well specified, the strain characteristics of the sensor, strain transfer factor, mechanical stability under thermal influences, the performance of applied strain sensors can seriously differ from virgin sensor's the performance. Therefore the contribution considers validation issues to come to reliable strain measurements and how to validate strain measurements of applied sensors. A new validation facility will be presented. Mexico City National Autonomous University of Mexico 2011 SHMII-5 - 5th International conference on structural health monitoring of intelligent infrastructure (Proceedings) SHMII-5 - 5th International conference on structural health monitoring of intelligent infrastructure Cancún, Mexico 11.12.2011 15.12.2011 Session 20, Topic 2.3 1 13 2016-02-19 OPUS4-27627 Zeitschriftenartikel Schukar, Vivien; Kusche, Nadine; Kalinka, Gerhard; Habel, Wolfgang Field deployable fiber bragg grating strain patch for long-term stable health monitoring applications 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. Basel MDPI 2013 Applied sciences 3 1 39 54 urn:nbn:de:kobv:b43-276271 10.3390/app3010039 http://creativecommons.org/licenses/by/3.0/de/deed.de 2016-02-20 OPUS4-27709 Vortrag Schukar, Vivien Faseroptische Sensorik für die Bewertung von Materialien und Überwachung von Strukturen 2013 DGZFP-Kursus Zerstörungsfreie Prüfung Stufe 3 (BC 3 K M3) DGZFP-Kursus Zerstörungsfreie Prüfung Stufe 3 (BC 3 K M3) Berlin, Germany 2013-02-07 2013-02-07 2016-02-20 OPUS4-29289 Vortrag Schukar, Vivien Investigation of complex load cases on the measurement signal of optical fibre sensors embedded in composite materials 2013 1st International Workshop on Embedded Optical Sensors for Composite Materials 1st International Workshop on Embedded Optical Sensors for Composite Materials Gent, Belgium 2013-10-07 2013-10-08 2016-02-20 OPUS4-22086 Posterpräsentation Schukar, Vivien How reliable do fibre Bragg grating patches perform as strain sensors? 2010 4th European Workshop on Optical Fibre Sensors 4th European Workshop on Optical Fibre Sensors Oporto, Portugal 2010-09-08 2010-09-10 2016-02-19 OPUS4-26639 Zeitschriftenartikel Schukar, Vivien; Kadoke, Daniel; Kusche, Nadine; Münzenberger, Sven; Gründer, Klaus-Peter; Habel, Wolfgang Validation and qualification of surface-applied fibre optic strain sensors using application-independent optical techniques 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. Bristol IOP Publ. Ltd. 2012 Measurement science and technology 23 8 085601-1 - 085601-9 10.1088/0957-0233/23/8/085601 2016-02-19 OPUS4-26909 Vortrag Schukar, Vivien Fasersensorik-Schwerpunkte und -Aktivitäten in der Bundesanstalt für Materialforschung und -prüfung 2012 Workshop intelligeNDTE-BAM-"Windenergie" Workshop intelligeNDTE-BAM-"Windenergie" Berlin, Germany 2012-10-10 2012-10-10 2016-02-19 OPUS4-25486 Zeitschriftenartikel Schukar, Vivien; Kusche, Nadine; Habel, Wolfgang How reliably do fiber Bragg grating patches perform as strain sensors? 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. New York, NY, USA Institute of Electrical and Electronics Engineers (IEEE) 2012 IEEE Sensors Journal 12 1 128 132 10.1109/JSEN.2011.2139202 2016-02-19 OPUS4-27321 Beitrag zu einem Tagungsband Schilder, Constanze; Kusche, Nadine; Schukar, Vivien; Habel, Wolfgang Liao, Y.; Jin, W.; Sampson, D.D.; Yamauchi, R.; Chung, Y.; Nakamura, K.; Rao, Y. Experimental qualification and validation of fibre optic strain sensors 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. Bellingham, Wash. SPIE, the International Society for Optical Engineering 2012 OFS2012 - 22nd International conference on optical fiber sensors (Proceedings) OFS2012 - 22nd International conference on optical fiber sensors Beijing, China 2012-10-15 2012-10-19 8421 1 4(?) 10.1117/12.968801 2016-02-20 OPUS4-29908 Beitrag zu einem Tagungsband Habel, Wolfgang; Schukar, Vivien; Mewis, Franziska; Kohlhoff, Harald Yang, M.; Wang, D.; Rao, Y. Experimental validation of applied strain sensors - importance, methods and still unsolved challenges Fiber-optic strain sensors are increasingly used in very different technical fields. Sensors are provided with specifications defined by the manufacturer or ascertained by the interested user. If deformation sensors are to be used to evaluate the long-term behavior of safety-relevant structures or to monitor critical structure components, their performance and signal stability must be of high quality to enable reliable data recording. The measurement system must therefore be validated according to established technical rules and standards before its application and after. In some cases, not all details of the complex characteristic and performance of applied fiber-optic sensors are sufficiently understood, or can be validated because of a lack of knowledge and methods to check the sensors' behavior. This contribution focusses therefore on the importance of serious validation in avoiding a decrease or even deterioration of the sensors' function. Methods for validation of applied sensors are discussed and should reveal weaknesses in validation of embedded or integrated fiber-optic deformation and/or strain sensors. An outlook to some research work that has to be carried out to ensure a well-accepted practical use of fiber-optic sensors is given. International society for optics and photonics (SPIE) 2013 4th Asia Pacific optional sensors conference (Proceedings) 8924 4th Asia Pacific optional sensors conference Wuhan, China 2013-10-15 2013-10-18 892410-1 - 892410-6 10.1117/12.2036591 2016-02-20 OPUS4-29909 Beitrag zu einem Tagungsband Habel, Wolfgang; Schukar, Vivien; Steinke, F.; Basedau, Frank Ilki, A.; Motavalli, M.; Goksu, C.; Havranek, B. Investigation of the fiber-optic strain sensors' beahvior under offshore conditions to create standards for reliable application Istanbul, Turkey Eidgenössische Materialprüfungs- und Forschungsanstalt (EMPA) 2013 SMAR 2013 - 2nd Conference on smart monitoring, assessment and rehabilitation of civil structures (Proceedings) 978-3-033-04055-7 SMAR 2013 - 2nd Conference on smart monitoring, assessment and rehabilitation of civil structures Istanbul, Turkey 2013-09-09 2013-09-11 1 8(?) 2016-02-20 OPUS4-29911 Beitrag zu einem Tagungsband Habel, Wolfgang; Schukar, Vivien; Kusche, Nadine Peters, K.J.; Ecke, W.; Matikas, T.E. The role of experimental validation in achieving reliable measurement data with applied FBG strain sensors Fiber-optic strain sensors are increasingly used in very different technical fields. Sensors are provided with specifications defined by the manufacturer or ascertained by the interested user. In some cases, sensor specification is not sufficiently validated and must therefore additionally be validated in a laboratory, primarily to ensure reliable measurement information over the intended period of operation. Even if the performance of delivered sensor is well specified, the sensor's strain characteristics and the performance of an applied sensor can significantly differ from the virgin sensor's performance. In this case, applied sensors do not provide full reliability and lead sometimes to uncertain measurement results. This contribution will therefore focus on the role of validation in avoiding a decrease or even deterioration of the sensor function of applied sensors. Experimental validation - not only modelling - is very important, however, before experimental investigations are planned knowledge about key issues and problems that influence the measurement results must be available. Few aspects to be considered and investigated will be discussed. Selected experimental facilities to reveal weaknesses in the sensor function will be described; an outlook to open questions is given. International society for optics and photonics (SPIE) 2013 Smart sensor phenomena, technology, networks, and systems integration 2013 (Proceedings) 8693 Smart sensor phenomena, technology, networks, and systems integration 2013 San Diego, CA, USA 2013-03-10 2013-03-14 Paper 12 86930C-1 - 86930C-11 10.1117/12.2009677 2016-02-20 OPUS4-29912 Beitrag zu einem Tagungsband Habel, Wolfgang; Schukar, Vivien; Tkachenko, Viktoriya; Hofmann, Detlef; Basedau, Frank Xu, Y. L.; Zhu, S.; Xia, Y.; Ni, Y.Q.; Law, S.S.; Yin, J. H.; Su, Z.Q. Values gained from composite-embedded sensor fibres - trustworthy results or vague estimations; possibilities and limitations of getting reliable measurement results International society for structural health monitoring of intelligent infrastructure 2013 SHMII-6 - 6th International conference on structural health monitoring of intelligent infrastructure (Proceedings) 978-962-367-768-4 SHMII-6 - 6th International conference on structural health monitoring of intelligent infrastructure Hong Kong, China 2013-12-09 2013-12-11 1 11(?) 2016-02-20 OPUS4-29916 Zeitschriftenartikel Habel, Wolfgang; Schukar, Vivien; Kusche, Nadine Fibre-optic strain sensors are making the leap from lab to industrial use-reliability and validation as a precondition for standards Currently, fibre-optic sensors (FOSs) are commonly used if special requirements make the application of electrical sensors impossible, or economic benefit is promised. The scientific background of FOS technology is well developed; however, there are still some restrictions with respect to long-term reliable use. For 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. This paper will focus on important aspects, such as when FOSs may be used under real practical conditions, and will present validation methodologies to evaluate the overall quality of the sensor system's function. It will also indicate the lack of knowledge and methods to be elaborated to promote the use of FOS. Bristol IOP Publ. Ltd. 2013 Measurement science and technology 24 094006-1 - 094006-13 10.1088/0957-0233/24/9/094006 2016-02-20 OPUS4-29452 Zeitschriftenartikel Schukar, Vivien; Baitinger, Eugen; Kusche, Nadine; Steinke, F.; Habel, Wolfgang Use of spectral conditions to separate strain and temperature effects in fibre Bragg grating sensors embedded in load-carrying anisotropic laminates This work presents a further development of the methods of simultaneous determination of temperature and axial strain using a single fibre Bragg grating (FBG). The reflected spectrum of composite-embedded FBG sensors has been analyzed in order to separate temperature and load effects. We found out that during the curing process of the laminates, a superstructure has been introduced on the FBG. Analyzing this effect, a temperature and strain separation was implemented by simply calculating and comparing the integrated intensity of the spectral response signal. A mathematical four-parametric model has been developed to calculate the reflected spectrum of a superstructured fibre Bragg grating. The mathematically achieved data has been evaluated with experimentally determined data from fibre Bragg gratings embedded in glass-fibre reinforced composite materials. Norwell, Mass. Springer 2013 Experimental mechanics 54 3 421 429 10.1007/s11340-013-9773-y 2016-02-20 OPUS4-29424 Zeitschriftenartikel Schilder, Constanze; Kusche, Nadine; Schukar, Vivien; Münzenberger, Sven; Habel, Wolfgang Experimental qualification by extensive evaluation of fibre optic strain sensors Fibre optic strain sensors used in practical applications have to provide reliable measurements. Therefore, the applied sensor and the sensor systems must be validated experimentally. This can be achieved with facilities which use physically independent measurement systems in order to avoid the influences caused by the application of a reference sensor. This paper describes the testing methods of the specially developed validation facility KALFOS for the qualification and evaluation of surface-applied strain sensors. For reliable sensor results, the performance of fibre optic strain patches with and without FBG under combined thermal and mechanical loading was investigated. Additionally, the strain gauge factor of the fibre optic strain patches with FBG was determined experimentally and compared to the specified strain gauge factor. These results will be the basis for the development of guidelines and standards concerning the application of the sensors. Bristol IOP Publ. Ltd. 2013 Measurement science and technology 24 9 094005-1 094005-7 10.1088/0957-0233/24/9/094005 2016-02-20 OPUS4-37131 Zeitschriftenartikel Köppe, Enrico; Bartholmai, Matthias; Daum, Werner; Gong, Xing; Hofmann, Detlef; Basedau, Frank; Schukar, Vivien; Westphal, Anja; Sahre, Mario; Beck, Uwe New self - diagnostic fiber optical sensor technique for structural health monitoring Fiber optic sensors have gained increasing importance in recent years and are well established in many areas of industrial applications. In this paper, we introduce a concept of a self-diagnostic fiber optic sensor. The presented sensor is to resolve the problems of embedded fiber optic sensors in complex structures and to enable the validation under operational conditions. For this purpose, different magnetostrictive coated fiber optic sensors were developed and various experiments were performed to verify their mode of Operation and to determine the respective reproducibility. The measuring principle is illustrated by obtained experimental results, which showed a change in wavelength from 1 pm at a magnetic field strength change of 0.25 mT. In addition, the temperature characteristics of the implemented magnetostrictive sensor were analyzed and an experimental factor of 1.5 compared to a reference fiber optic sensor was determined. 2016 Materials Today: Proceedings 3 32nd DANUBIA ADRIA SYMPOSIUM on Advances in Experimental Mechanics Starý Smokovec, Slovakia 22.09.2015 25.09.2015 4 1009 1013 10.1016/j.matpr.2016.03.038 2016-08-12 OPUS4-30769 Posterpräsentation Schukar, Vivien Temperatur-Selbstkompensation von integrierten FBG-Dehnungssensoren zur Zustandsüberwachung von Hochleistungsverbundwerkstoffen 2013 DGZfP-Jahrestagung 2014 DGZfP-Jahrestagung 2014 Potsdam, Germany 2013-05-26 2013-05-28 2016-02-20 OPUS4-30768 Posterpräsentation Schukar, Vivien Delamination-diagnosis-method for adhesively surface-applied FBG strain sensors 2014 23rd International Conference on Optical Fibre Sensors 23rd International Conference on Optical Fibre Sensors Santander, Spain 2014-06-02 2014-06-06 2016-02-20 OPUS4-22421 Posterpräsentation Schukar, Vivien Experimental Validation Technique for Strain Transfer Characterisation of Fibre Bragg Grating based Strain Sensors This examination deals with the validation faciliy KALFOS and the ESPI reference system. 2010 Photonics 2010, International Conference on Fiber Optics and Photonics Photonics 2010, International Conference on Fiber Optics and Photonics Guwahati, India 11.12.2010 15.12.2010 2016-02-19 OPUS4-22985 Beitrag zu einem Sammelband Habel, Wolfgang; Schukar, Vivien Reliability issues when using fibre optic strain sensors for materials investigations and structural monitoring Reliable measurement results with fibre optic sensors require profound knowledge of physical mode of function, of materials used and appropriate application. There is often serious discrepancy between use in laboratory environment and on site. The paper identifies important aspects to be considered and shows ways to transfer innovations onto practical use. Indian Institute of Technology 2010 Photonics 2010 - 10th International conference on fiber optics & photonics 978-81-309-1719-1 Photonics 2010 - 10th International conference on fiber optics & photonics Guwahati, India 2010-12-11 2010-12-15 1 4 2016-02-19 OPUS4-23007 Beitrag zu einem Sammelband Schukar, Vivien; Münzenberger, Sven; Gründer, Klaus-Peter; Habel, Wolfgang Experimental validation technique for strain transfer characterisation of fibre bragg grating based strain sensors A unique testing facility (KALFOS) using ESPI (electronic speckle pattern interferometery) as a referencing method has been realized for the characterisation of the strain transfer process from a component under load into surface applied fibre Bragg grating based strain sensors. The strain transfer mechanism can be described experimentally, while matching specific measurement requirements and environmental conditions. Indian Institute of Technology 2010 Photonics 2010 - 10th International conference on fiber optics & photonics 978-81-309-1719-1 Photonics 2010 - 10th International conference on fiber optics & photonics Guwahati, India 2010-12-11 2010-12-15 Poster\255_SEN_Schukar_V_G_1_full 1 4 2016-02-19 OPUS4-24271 Beitrag zu einem Tagungsband Habel, Wolfgang; Schukar, Vivien Ecke, W.; Peters, K.J.; Matikas, T.E. FOS standards and testing methods to validate fibre optic strain measurements Fiber optic sensors are increasingly used because of their outstanding performance or if special requirements avoid the application of conventional electrical sensors. The scientific background for optical fiber sensors is well developed; however, the characteristic of sensors applied in rather harsh environment are almost always different from characteristics determined in laboratory or before its installation. In order to achieve long-term stable function and reliable measurement data after application and under harsh environmental conditions, guidelines for characterization and specification of sensor components are needed as well as methodologies for testing the sensor performance must be developed. Performance tests carried out revealed that there are still some restrictions with respect to long-term reliable use: first, some sensor products available on the market are not very often appropriately characterized, described and validated; second, application procedures are not always defined due to a lack of understanding the micromechanical issues in the interface zone between sensor and measuring object. Application procedures and profound knowledge of materials behaviour are necessary to get results from the sensor that can be reliably used. The paper describes first guidelines to prove the quality of fiber optic strain sensors, a testing facility developed for unbiased tests and certification of surface-applied sensors as well as result from comparison of commercially available strain sensors. The International Society for Optical Engineering (SPIE) 2011 Smart sensor phenomena, technology, networks, and systems 2011 (SPIE-Proceedings) 7982 978-0-8194-8547-2 SPIE-Conference 'Smart sensor phenomena, technology, networks, and systems 2011' San Diego, CA, USA 06.03.2011 10.03.2011 79820O-1 79820O-12 10.1117/12.881238 2016-02-19 OPUS4-37670 Beitrag zu einem Tagungsband Schukar, Vivien; Köppe, Enrico; Hofmann, Detlef; Westphal, Anja; Sahre, Mario; Gong, Xin; Bartholmai, Matthias; Beck, Uwe Magnetic field detection with an advanced FBG-based sensor device A high-performance fiber Bragg grating-based (FBG) sensor device has been developed for the detection of small magnetic fields. Based on a smart multilayer jacket around the fibre over the physical length of the FBG, magnetic fields generated by rotating machine parts, power generators or power cable can be easily detected, analysed and evaluated. Consequently, this innovative, on-line and non-contact inspection method results in an increase in quality and reliability of high-performing machine parts, devices and cables. The basic physical principle is based on a magnetostrictive multilayer system that strains the high-resolution FBG element in presence of magnetic fields. Subsequently, a fixed relationship between induced magnetic field and wavelength change of the FBG element describes the characteristic sensitivity curve. Intensive tests regarding characterisation of this magnetic field FBG sensor have been carried out and its performance has been evaluated. Elsevier Ltd. 2016 30th Eurosensors Conference - EUROSENSORS 2016 168 30th Eurosensors Conference, EUROSENSORS 2016 Budapest, Hungary 04.09.2016 07.09.2016 1270 1274 urn:nbn:de:kobv:b43-376703 10.1016/j.proeng.2016.11.445 http://creativecommons.org/licenses/by-nc-nd/3.0/de/deed.de 2017-01-05 OPUS4-37642 Posterpräsentation Bartholmai, Matthias; Schukar, Vivien Intelligent automatic validation of structure-integrated fibre optic strain sensors Identification of physical faulty fibre optic strain sensors embedded in safety-relevant structures or systems and detection of abnormal measurement data to prevent misinterpretation of critical operating parameters and misleading of management and control systems. 2016 33rd Danubia- Adria Symposium on Advances in Experimental Mechanics Portorož, Slovenia 20.09.2016 23.09.2016 2016-10-05 OPUS4-37645 Beitrag zu einem Tagungsband Schukar, Vivien; Köppe, Enrico; Hofmann, Detlef; Westphal, Anja; Sahre, Mario; Beck, Uwe; Gong, Xing; Bartholmai, Matthias Aulova, Alexandra; Rogelj Ritonja, A.; Emri, I. A contribution to intelligent automatic validation of structure-integrated fibre optic strain sensors Sensors integrated into devices and structures provide essential data to control, optimize or manage machines and structural components. In the last years, processes, applications and machine parts became more and more intelligent. Consequently, the need for sensor validation increased significantly in order to rely on sensor data and measurement results. Structure-integrated fibre optic strain sensors, such as fiber Bragg gratings (FBG), are of special interest in the composite manufacturing industry. This type of sensor makes it possible to gain information and to collect measurement data about entire production processes and whole life-time cycles of composite-made machine parts and structures. However, validation concepts and approaches for this type of sensors are barely reported in literature. Furthermore, all the reported activities have the drawback that the sensor diagnosis strategy is implemented as limited mathematical models and/or complex time-consuming spectral analysis tools which are applied in data post-processing loops. However, to automate sensor validation and to apply real-time and in-field sensor fault detection, it is necessary to acquire measurement data and information about the measurement reliability at the same time. Ljubljana Narodna in univerzitetna knjižnica, Ljubljana 2016 33rd Danubia- Adria Symposium on Advances in Experimental Mechanics - BOOK OF ABSTRACTS 978-961-94081-0-0 33rd Danubia- Adria Symposium on Advances in Experimental Mechanics Portorož, Slovenia 20.09.2016 23.09.2016 180 181 2016-10-05 OPUS4-38634 Beitrag zu einem Tagungsband Schukar, Vivien; Gong, Xin; Hofmann, Detlef; Basedau, Frank; Köppe, Enrico; Bartholmai, Matthias; Westphal, Anja; Sahre, Mario; Beck, Uwe Berghmans, F.; Mignani, A. G. Modelling and simulation of a fibre Bragg grating strain sensor based on a magnetostrictive actuator principle A new concept for the self-diagnosis of embedded fiber Bragg grating (FBG) strain sensors was developed, simulated and experimentally tested. This concept is based on a magnetostrictive metallic layer directly coated on the fibre cladding over the grating segment of the FBG sensor, so that an on-demand external magnetic field in a millitesla scale can produce a controllable artificial strain as an indication signal for the remote optical interrogator. The relationship between the pre-defined magnetic field and its induced Bragg wavelength shift characterizes this validation concept. Any deviation of the local bonding state of the interfaces from the initial or/and any change of shear strain transferring mechanism from composite matrix to the optical fibre core will result in alterations in this sensitive relationship, and thus triggers an immediate alert for a further inspection. The finite element method is used to simulate the strain of this configuration as result of different values of the magnetic field in order to optimize the geometrical sensor parameters. The simulations are verified by experiments results. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only. SPIE Digital Library SPIE - the international society for optics and photonics 2016 Optical Sensing and Detection IV 9899 9781510601444 Optical Sensing and Detection IV Brüssel, Belgium 03.04.2016 07.04.2016 9899-39 10.1117/12.2224728 2016-12-09 OPUS4-39129 Zeitschriftenartikel Mitzkus, Anja; Sahre, Mario; Reinstädt, Philipp; Griepentrog, Michael; Beck, Uwe; Köppe, Enrico; Bartholmai, Matthias; Basedau, Frank; Hofmann, Detlef; Gong, Xin; Schukar, Vivien Altbekannter Watts-Elektrolyt, junge Hightech-Anwendung, Nickel- und Nickel-Eisen-Schichten als magnetostriktive Aktorschicht auf faseroptischen Sensoren Durch faseroptische Sensoren können Bauteile im Einsatz kontinuierlich überwacht und frühzeitig Informationen über Materialveränderungen gewonnen werden. Mittels einer magnetostriktiven Aktorschicht, welche den Sensor umhüllt, kann nun auch die korrekte Sensorfunktion jederzeit kontrolliert werden. Als Aktorschicht eignet sich galvanisch abgeschiedenes reines Nickel oder Nickel-Eisen in der Zusammensetzung 50:50. Um diese haftfest mit dem Sensor zu verbinden wurde ein ECD/PVD-Kombinationsschichtsystem entwickelt. Die mechanischen Eigenschaften der ECD-Schicht können sowohl mit einer auf die Fasergeometrie angepassten instrumentierten Eindringprüfung als auch einem 2-Punkt-Biegeversuch bestimmt werden. 2016 WoMAG 12 1 4 2017-02-09 OPUS4-44599 Beitrag zu einem Tagungsband Beck, Uwe; Mitzkus, Anja; Sahre, Mario; Weise, Matthias; Köppe, Enrico; Bartholmai, Matthias; Basedau, Frank; Hofmann, Detlef; Schukar, Vivien Faser-basierter magneto-optischer Schicht-Sensor zum Monitoring von Bauteilen In Glasfasern eingeschriebene Bragg-Gitter (FBG: fibre-based Bragg gratings) sind über die Verschiebung der Bragg-Wellenlänge in der Lage, Stauchungen und Dehnungen von Glasfasern hochgenau zu erfassen. In Kompositwerkstoffe eingebettete faseroptische Sensoren können Bauteile bezüglich ihrer mechanischen Integrität überwachen und früh-zeitig Informationen über Materialveränderungen gewinnen. Um die Zuverlässigkeit eines solchen Sensors zu gewährleisten, ist es wichtig, die korrekte Funktion des Sensors im Verbund mit der Werkstoff-Matrix on-line und in-situ sicherzu-stellen. Im Rahmen des DFG-Projekts FAMOS² (FAser-basierter Magneto-Optischer SchichtSensor) wurde ein selbstdiagnosefähiger Schichtsensor entwickelt, der mit Hilfe von magnetostriktiven Aktorschichten aus Nickel bzw. Eisen-Nickel validiert werden kann. Der FAMOS²-Schichtsensor wird durch ein PVD (physical vapour deposition)/ECD (electro-chemical deposition) Hybridschichtsystem realisiert, das auf dem Fasermantel im Bereich des FBG haftfest, homogen und langzeitfunktional abzuscheiden ist. Dabei wird in einem ersten Schritt ein etwa 100 Nanometer dünnes PVD-Schichtsystem aus Chrom und Kupfer als Haftvermittler auf der Glasfaser bzw. als leitfähige Startschicht für den nachfolgenden ECD-Prozess abgeschieden. Um eine rotationssymmetrische Schich-tabscheidung zu gewährleisten, erfolgt während der PVD-Beschichtung eine Rotation der Glasfasern. In einem zweiten Schritt wird dann unter Verwendung eines klassischen Watts-Elektrolyten in einer speziell entwickelten ebenfalls rotationssymmetrisch aufgebau-ten ECD-Durchströmungszelle dann die etwa 30 Mikrometer dicke, magnetostriktive Ak-torschicht auf dem PVD-Schichtsystem abgeschieden, im Vergleich sowohl reine Nickel-Schichten als auch Nickel-Eisen-Schichten. Ein äußeres Magnetfeld dehnt die magnetostriktive Aktorschicht und damit auch die Faser reversibel. Diese Dehnung führt zu einer Verschiebung der Bragg-Wellenlänge, welche direkt mit der Stärke eines zu messenden oder zu Validierungszwecken vorgegebenen Magnetfeldes korreliert. Die Anpassung der Beschichtungsverfahren an die Fasergeome-trie und die mechanischen Eigenschaften der Hybridschichten werden hinsichtlich der me-chanischen Integrität des faseroptischen Sensors diskutiert und der Nachweis der Selbst-diagnosefähigkeit erbracht. Jena Herausgeber: INNOVENT e.V. 2018 13. ThGOT Thementage Grenz- und Oberflächentechnik und 11. Thüringer Biomaterial-Kolloquium 978-3-00-058187-8 13. ThGOT Thementage Grenz- und Oberflächentechnik und 11. Thüringer Biomaterial-Kolloquium Zeulenroda, Germany 13.03.2018 15.03.2018 1 5 2018-04-04 OPUS4-32662 Beitrag zu einem Tagungsband Habel, Wolfgang; Schukar, Vivien; Hofmann, Detlef Requirements to establish fibre-optic sensors for monitoring of structures Fibre-optic sensors need to be more established in the sensor market. Their advantages have unquestionably been verified by numerous demonstrations. However, there are some open questions leading now and then to restraints in the user's community. The paper dicusses examples where fibre-optic sensors provide outstanding knowledge about the structure's behaviour, but application is often challenging. Requirements are listed and open questions to be solved are discussed. Short outlook to standards useful for better design, characterization and application is given. Standards are the basis for establiching SHM systems, especially for safety-critical structural diagnostics. Inria 2014 EWSHM 2014 - 7th European workshop on structural health monitoring (Proceedings) EWSHM 2014 - 7th European workshop on structural health monitoring Nantes, France 08.07.2014 11.07.2014 2330 2337 2016-02-20 OPUS4-35173 Beitrag zu einem Tagungsband Köppe, Enrico; Bartholmai, Matthias; Daum, Werner; Gong, Xin; Hofmann, Detlef; Basedau, Frank; Schukar, Vivien; Westphal, Anja; Sahre, Mario; Beck, Uwe New self diagnostic fiber optical sensor technique for structural health monitoring Fiber optic sensors have gained increasing importance in recent years and are well established in many areas of industrial applications. In this paper, we introduce a concept of a self-diagnostic fiber optic sensor. The presented sensor is to resolve the problems of embedded fiber optic sensors in complex structures and to enable the validation under operational conditions. For this purpose, different magnetostrictive coated fiber optic sensors were developed and various experiments were performed to verify their mode of operation and to determine the respective reproducibility. The measuring principle is illustrated by obtained experimental results, which showed a change in wavelength from 1 pm at a magnetic field strength change of 0.25 mT. In addition, the temperature characteristics of the implemented magnetostrictive sensor were analyzed and an experimental factor of 1.5 compared to a reference fiber optic sensor was determined. Zilina Faculty of Mechanical Engineering, Univerzity of Zilina, Slovakia 2015 32nd Danubia-Adria Symposium on advances in experimental mechanics (Proceedings) 978-80-554-1094-4 32nd Danubia-Adria Symposium on advances in experimental mechanics Starý Smokovec, Slovakia 22.09.2015 25.09.2015 1 2 2016-02-20 OPUS4-50418 Forschungsbericht Schukar, Vivien; Bartholmai, Matthias; Beck, Uwe Abschlussbericht zum DFG-Projekt „FAMOS²" FAser-basierter Magneto-Optischer SchichtSensor Der Mangel an Anwendungsrichtlinien und Validierungsverfahren für struktur-eingebettete faseroptische Dehnungssensoren, insbesondere auf Faser-Bragg-Gitter (FBG)-Basis, führte bislang dazu, dass diese Sensoren trotz ihrer hervorragenden Eigenschaften im Bereich der kommerziellen Material- und Strukturüberwachung nur in geringem Umfange eingesetzt wurden. Fragen zur Degradation der Sensoren unter Beanspruchung, Alterung durch klimatische Einflüsse und Enthaftung infolge Belastung der Struktur konnten bisher nur theoretisch simuliert oder anhand exemplarischer Proben für einzelne einflussnehmende Parameter im Labor untersucht werden. Die Erfassung des Sensorverhaltens im Bauteil unter komplexen Umwelteinflüssen während des Bauteilbetriebes, um damit eine Aussage zur Zuverlässigkeit der Sensormessdaten zu gewinnen, war bisher nicht möglich. Im Forschungsprojekt FAMOS² wurde deshalb von 2014 bis 2018 die Realisierung eines Autodiagnoseverfahrens für faseroptische Dehnungssensoren erarbeitet, um die Funktionszuverlässigkeit und Langzeitstabilität der Sensoren während des Bauteilbetriebes innerhalb einer Bauteilstruktur bewerten zu können. Im Rahmen des Forschungsprojektes wurde gezeigt, dass ein FBG-Sensor mit einer speziell angepassten magnetostriktiven Schicht magnetisch so angeregt werden kann, dass mit einer zugeschnittenen Messmethodik zu jedem Zeitpunkt eine Bewertung der Sensorzuverlässigkeit unter Betriebsbedingungen möglich ist. Die auf den Sensor aufgebrachte magnetostriktive Schicht erzeugt bei Anregung mit einem passenden Magnetfeld eine gepulste, synthetische Dehnung. Diese Dehnung steht in einem definierten Verhältnis zum anregenden Magnetfeld und wird optisch über die Verschiebung der Bragg-Wellenlänge ausgelesen. Die Konstanz dieses Verhältnisses stellt dann ein Maß für die korrekte Funktionsfähigkeit des Sensors dar. Das Beschichtungs-verfahren, das magnetische Anregungs- und optische Ausleseverfahren, wie auch die Validierung des Sensors unter Berücksichtigung faseroptischer Effekte wurden während des Projekts konzeptionell entwickelt, aufgebaut und charakterisiert. Qualitativ kann mit diesem Verfahren zunächst eine Gut-/Schlecht-Beurteilung des Sensors vorgenommen werden. Perspektivisch bietet das Verfahren jedoch auch die Möglichkeit, verschiedene Versagensmechanismen bestimmen und klassifizieren zu können. Es zeichnete sich schon während des Projektverlaufs ab, dass sich aus den erzielten Ergebnissen über das Autodiagnoseverfahren hinaus weitere Anwendungsmöglichkeiten für den Einsatz des kombinierten magnetostriktiv-faseroptischen Sensorprinzips, beispielsweise als reiner Magnetfeldsensor, ergeben. Nach Abschluss dieses Forschungsprojekts besteht nun die Möglichkeit, den Funktionszustand faseroptischer Dehnungssensoren jederzeit unabhängig von Alter, Belastung oder Kenntnis eines Referenzzustands zu einem bestimmten Zeitpunkt bestimmen zu können. Aufbauend auf diesen Ergebnissen können weiterführende Forschungen die Messmethodik vertiefend charakterisieren und weitere Anwendungsfälle erschließen. 2018 1 28 2020-02-19 OPUS4-41583 Zeitschriftenartikel Schukar, Vivien; Köppe, Enrico; Hofmann, Detlef; Mitzkus, Anja; Gong, Xin; Sahre, Mario; Bartholmai, Matthias; Beck, Uwe Emri, Igor A contribution to intelligent automatic validation of structure-integrated fibre optic strain sensors An auto-validation tool for the reliability quantification of materials integrated fiber Bragg grating (FBG) strain sensors have been developed and tested. The FBG strain sensor was jacketed with a magnetostrictive layer based on iron-nickel which, when excited by a specific magnetic field, adds an artificial strain to the sensor. The fixed relationship between magnetic induction and wavelength shift of the FBG strain sensor characterizes the bond strength and adhesion between the sensor and the surrounding structure. Due to an easily applicable magnetic field, it is possible to validate the sensor performance in a non-contact, fast way without disturbing the data-acquisition process. Elsevier Ltd. 2017 Materials Today: Proceedings 4 33nd Danubia Adria Symposium on Advances in Experimental Mechanics Portorož, Slovenia 20.09.2016 23.09.2016 5, Part 1 5935 5939 10.1016/j.matpr.2017.06.073 2017-08-24