TY - CONF A1 - Habel, Wolfgang A1 - Schukar, Vivien A1 - Tkachenko, Viktoriya A1 - Hofmann, Detlef A1 - Basedau, Frank ED - Xu, Y. L. ED - Zhu, S. ED - Xia, Y. ED - Ni, Y.Q. ED - Law, S.S. ED - Yin, J. H. ED - Su, Z.Q. T1 - Values gained from composite-embedded sensor fibres - trustworthy results or vague estimations; possibilities and limitations of getting reliable measurement results T2 - SHMII-6 - 6th International conference on structural health monitoring of intelligent infrastructure (Proceedings) T2 - SHMII-6 - 6th International conference on structural health monitoring of intelligent infrastructure CY - Hong Kong, China DA - 2013-12-09 KW - Composite materials KW - Embedded sensors KW - Monitoring KW - Early damage detection KW - Validation KW - Reliability KW - Maintenance KW - Repair PY - 2013 SN - 978-962-367-768-4 SP - 1 EP - 11(?) AN - OPUS4-29912 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Schukar, Vivien ED - Ramos, G. A. T1 - Validation of strain sensors to achieve reliable measurement results T2 - SHMII-5 - 5th International conference on structural health monitoring of intelligent infrastructure (Proceedings) N2 - 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. T2 - SHMII-5 - 5th International conference on structural health monitoring of intelligent infrastructure CY - Cancún, Mexico DA - 11.12.2011 PY - 2011 IS - Session 20, Topic 2.3 SP - 1 EP - 13 PB - National Autonomous University of Mexico CY - Mexico City AN - OPUS4-25309 LA - eng 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 JF - Measurement science and technology 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 - 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 - Baitinger, Eugen A1 - Kusche, Nadine A1 - Steinke, F. A1 - Habel, Wolfgang T1 - Use of spectral conditions to separate strain and temperature effects in fibre Bragg grating sensors embedded in load-carrying anisotropic laminates JF - Experimental mechanics N2 - 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. KW - Fibre Bragg grating KW - Patch KW - Four-parametric KW - model KW - Superstructure KW - Temperature KW - Strain PY - 2013 DO - https://doi.org/10.1007/s11340-013-9773-y SN - 0014-4851 SN - 1741-2765 VL - 54 IS - 3 SP - 421 EP - 429 PB - Springer CY - Norwell, Mass. AN - OPUS4-29452 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Schukar, Vivien A1 - Kusche, Nadine ED - Peters, K.J. ED - Ecke, W. ED - Matikas, T.E. T1 - The role of experimental validation in achieving reliable measurement data with applied FBG strain sensors T2 - Smart sensor phenomena, technology, networks, and systems integration 2013 (Proceedings) N2 - 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. T2 - Smart sensor phenomena, technology, networks, and systems integration 2013 CY - San Diego, CA, USA DA - 2013-03-10 KW - Fibre-optic sensor KW - Strain sensor KW - Reliability KW - Durability KW - Sensor characteristics KW - Application-related changes KW - Adhesive stability KW - Validation PY - 2013 DO - https://doi.org/10.1117/12.2009677 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 8693 IS - Paper 12 SP - 86930C-1 - 86930C-11 AN - OPUS4-29911 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schukar, Vivien A1 - Baitinger, Eugen A1 - Kusche, Nadine A1 - Mewis, Franziska T1 - Temperatur-Selbstkompensation von integrierten FBG-Dehnungssensoren zur Zustandsüberwachung von Hochleistungsverbundwerkstoffen T2 - DGZfP-Jahrestagung 2014 T2 - DGZfP-Jahrestagung 2014 CY - Potsdam, Germany DA - 2013-05-26 PY - 2013 AN - OPUS4-30769 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Schukar, Vivien A1 - Hofmann, Detlef T1 - Requirements to establish fibre-optic sensors for monitoring of structures T2 - EWSHM 2014 - 7th European workshop on structural health monitoring (Proceedings) N2 - 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. T2 - EWSHM 2014 - 7th European workshop on structural health monitoring CY - Nantes, France DA - 08.07.2014 KW - Monitoring KW - Fibre-optic sensor KW - Reliability KW - Application PY - 2014 SP - 2330 EP - 2337 AN - OPUS4-32662 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Habel, Wolfgang A1 - Schukar, Vivien T1 - Reliability issues when using fibre optic strain sensors for materials investigations and structural monitoring T2 - Photonics 2010 - 10th International conference on fiber optics & photonics N2 - 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. T2 - Photonics 2010 - 10th International conference on fiber optics & photonics CY - Guwahati, India DA - 2010-12-11 KW - Fibre optic sensors KW - Reliability KW - Validation KW - Calibration KW - Long-term stability KW - Materials behaviour KW - Speckle-interferometry KW - 3D-image correlation KW - Strain measurement PY - 2010 SN - 978-81-309-1719-1 SP - 1 EP - 4 AN - OPUS4-22985 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schukar, Vivien A1 - Portella, Pedro Dolabella A1 - Habel, Wolfgang A1 - Baitinger, Eugen T1 - Reliability analysis of fibre optic sensors for monitoring of industrial facilities; keynote lecture T2 - Coteq, 12th Conference on Technology Equipment T2 - Coteq, 12th Conference on Technology Equipment CY - Porto de Galinhas, Brazil DA - 2013-06-18 PY - 2013 AN - OPUS4-28748 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Köppe, Enrico A1 - Bartholmai, Matthias A1 - Daum, Werner A1 - Gong, Xin A1 - Hofmann, Detlef A1 - Basedau, Frank A1 - Schukar, Vivien A1 - Westphal, Anja A1 - Sahre, Mario A1 - Beck, Uwe T1 - New self diagnostic fiber optical sensor technique for structural health monitoring T2 - 32nd Danubia-Adria Symposium on advances in experimental mechanics (Proceedings) N2 - 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. T2 - 32nd Danubia-Adria Symposium on advances in experimental mechanics CY - Starý Smokovec, Slovakia DA - 22.09.2015 PY - 2015 SN - 978-80-554-1094-4 SP - 1 EP - 2 CY - Zilina AN - OPUS4-35173 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -