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 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 - TY - CONF A1 - Schukar, Vivien A1 - Gong, Xin A1 - Hofmann, Detlef A1 - Basedau, Frank A1 - Köppe, Enrico A1 - Bartholmai, Matthias A1 - Westphal, Anja A1 - Sahre, Mario A1 - Beck, Uwe ED - Berghmans, F. ED - Mignani, A. G. T1 - Modelling and simulation of a fibre Bragg grating strain sensor based on a magnetostrictive actuator principle N2 - 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. T2 - Optical Sensing and Detection IV CY - Brüssel, Belgium DA - 03.04.2016 KW - Fiber Bragg gratings KW - Actuators KW - Modeling and simulation KW - Finite element methods PY - 2016 SN - 9781510601444 DO - https://doi.org/10.1117/12.2224728 SN - 0277-786X SN - 1996-756X VL - 9899 SP - 9899-39 PB - SPIE Digital Library AN - OPUS4-38634 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Schukar, Vivien T1 - Intelligent automatic validation of structure-integrated fibre optic strain sensors N2 - 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. T2 - 33rd Danubia- Adria Symposium on Advances in Experimental Mechanics CY - Portorož, Slovenia DA - 20.09.2016 KW - Fiber bragg grating KW - Magnetic field KW - Magnetostrictive metal coating KW - Self-diagnostic fiber optical sensor PY - 2016 AN - OPUS4-37642 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schukar, Vivien A1 - Köppe, Enrico A1 - Hofmann, Detlef A1 - Westphal, Anja A1 - Sahre, Mario A1 - Beck, Uwe A1 - Gong, Xing A1 - Bartholmai, Matthias ED - Aulova, Alexandra ED - Rogelj Ritonja, A. ED - Emri, I. T1 - A contribution to intelligent automatic validation of structure-integrated fibre optic strain sensors N2 - 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. T2 - 33rd Danubia- Adria Symposium on Advances in Experimental Mechanics CY - Portorož, Slovenia DA - 20.09.2016 KW - Fiber bragg grating KW - Magnetic field KW - Magnetostrictive metal coating KW - Self-diagnostic fiber optical sensor PY - 2016 SN - 978-961-94081-0-0 SP - 180 EP - 181 CY - Ljubljana AN - OPUS4-37645 LA - eng 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 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 - JOUR A1 - Habel, Wolfgang A1 - Schukar, Vivien A1 - Kusche, Nadine T1 - Fibre-optic strain sensors are making the leap from lab to industrial use-reliability and validation as a precondition for standards N2 - 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. KW - Fibre-optic sensor KW - Application KW - Reliability KW - Validation KW - Strain transfer KW - Standards KW - Guideline PY - 2013 DO - https://doi.org/10.1088/0957-0233/24/9/094006 SN - 0957-0233 SN - 1361-6501 VL - 24 SP - 094006-1 EP - 094006-13 PB - IOP Publ. Ltd. CY - Bristol AN - OPUS4-29916 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Schukar, Vivien A1 - Mewis, Franziska A1 - Kohlhoff, Harald ED - Yang, M. ED - Wang, D. ED - Rao, Y. T1 - Experimental validation of applied strain sensors - importance, methods and still unsolved challenges 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. 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. T2 - 4th Asia Pacific optional sensors conference CY - Wuhan, China DA - 15.10.2013 KW - Fiber-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/10.1117/12.2036591 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 8924 SP - 892410-1 EP - 892410-6 AN - OPUS4-29908 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Schukar, Vivien A1 - Steinke, F. A1 - Basedau, Frank ED - Ilki, A. ED - Motavalli, M. ED - Goksu, C. ED - Havranek, B. T1 - Investigation of the fiber-optic strain sensors' beahvior under offshore conditions to create standards for reliable application N2 - The application of fiber-optic sensors in offshore environment is a big challenge. Especially if sensors have to be installed in the tidal zone and components are exposed to extreme environmental attacks as well as mechanical loads. There are no sufficient experience on how to test selected materials, how to handle application and how remotely to assess the function of installed sensors operating several decades during summer and winter time. It has to be feared that installed sensor components could be damaged in case of heavy storms and strong waves or due to ice drift. Another danger is the biological attack to sensors. Not only the high amount of salt and UV radiation could degrade the protecting materials of sensor systems, it is well-known that sea biological influences such as barnacles and other types of fouling perturb the proper function of sensors or even lead to failure. In Germany, a research project is being carried out to investigate the specific offshore influences to fiber-optic sensor systems with the objective to develop evaluation strategies and corresponding testing procedures and standards. The paper describes first results after harsh test cycles and gives first bullets for a corresponding standard for application in offshore environment. T2 - SMAR 2013 - 2nd Conference on smart monitoring, assessment and rehabilitation of civil structures CY - Istanbul, Turkey DA - 09.09.2013 KW - Fibre-optic sensor KW - Strain sensor KW - Reliability KW - Durability KW - Sensor characteristics KW - Offshore application KW - Harsh impacts PY - 2013 SN - 978-3-033-04055-7 SP - 1 EP - 8(?) CY - Istanbul, Turkey AN - OPUS4-29909 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 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 - 10.03.2013 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 - EP - 86930C-11 AN - OPUS4-29911 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 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 -