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 OPUS4-24643 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 OPUS4-24271 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 OPUS4-24655 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 OPUS4-24512 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