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 OPUS4-37131 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 OPUS4-37053 Zeitschriftenartikel Habel, Wolfgang R.; Krebber, Katerina; Daum, Werner Results in standardization of FOS to support the use of SHM systems Measurement and data recording systems are important parts of a holistic Structural Health Monitoring (SHM) system. New sensor technologies such as fiber-optic sensors are often used; however, standards (or at least guidelines) are not yet available or internationally approved. This lack in standardization makes the acceptance of FOS technologies in complex SHM systems substantially difficult. A standard family for different FOS technologies is therefore being developed that should help to design SHM systems in an optimal way. International standardization activities take place in several standardization bodies such as IEC and ASTM, and within SHM societies such as ISHMII. The paper reports on activities in standardization of fiber-optic sensors, on results already achieved, and on newly started projects. Combined activities of fiber sensor experts and SHM experts from Civil Engineering are presented. These contributions should help owners of structures as well as developers of sensors and monitoring systems to select effective and validated sensing technologies. Using these standards, both parties find recommendations how to proceed in development of SHM systems to evaluate the structural behavior based on e.g. standardized fiber optic sensors, and to derive necessary measures, e.g. the optimal maintenance strategy. SPIE 2016 Proc. SPIE 9916 Sixth European Workshop on Optical Fibre Sensors 9916 Sixth European Workshop on Optical Fibre Sensors Limerick, Ireland 30.05.2016 31.05.2016 991625-1 991625-4 10.1117/12.2236863 2016-08-04 OPUS4-37646 Beitrag zu einem Tagungsband Bartholmai, Matthias; Werner, Klaus-Dieter; Kohlhoff, Harald; Helmerich, Rosemarie; Daum, Werner Aulova, Alexandra; Rogelj Ritonja, A.; Emri, I. Long-Term measurement of vertical displacements at the outer concrete bridges of the Berlin Main Station Berlin Main Station is the largest multi-level station in Europe. Its daily passenger number amounts to over 300.000. Structures built for such a large number of people require a high-level safety standard. The station was built on the inner city site of the historic Lehrter Bahnhof. The conditions for building and start of operation were challenging by several reasons. The typical sandy ground with a high level of groundwater makes the permanent static stability of such a complex structure difficult. Several completed, ongoing, and planned construction activities in the immediate vicinity of the station influence the ground settlement of the whole area. On basis of the structural design an impact prediction was calculated, which expected certain vertical displacements particularly between the single columns of the outer concrete bridges of the building. These columns support the glass roof construction, which only allows a defined limit of displacement. In order to avoid damage, a concept for monitoring and adjusting potentially occurring displacements was developed for installation at the outer bridges of the station. 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 166 167 2016-10-05 OPUS4-34487 Zeitschriftenartikel Richter, Frank; Köppe, Enrico; Daum, Werner Tracking deformation history in split Hopkinson pressure bar testing The stress vs. strain curve of materials is affected the rate of imposed straining. Among the methods for dynamic testing the technique known as 'split Hopkinson pressure bar' (SHPB) has evolved into the most widely used one to exert high-speed straining. The theory behind it comprises simple equations to compute stress and strain. The reliability of the strain analysis can be assessed by digital image correlation (DIC). The present results indicate that the visually observed strain is smaller than predicted by theory. Oxford Elsevier 2016 Materials Today: Proceedings 3 32nd Danubia-Adria Symposium on advances in experimental mechanics Starý Smokovec, Slovakia 22.09.2015 25.09.2015 4 1139 1143 10.1016/j.matpr.2016.03.017 2016-02-20 OPUS4-36667 Zeitschriftenartikel Brandes, K.; Daum, Werner; Hofmann, Detlef; Basedau, Frank; Kubowitz, P. Innovative structural damage detection of bridges by least squares adjustment with constraints Long-term monitoring of bridges requires the early detection of spreading damage because very often the damage is not really visible. For many decades engineers and scientists relayed on dynamic methods especially modal ones. However, after fundamental tests by the U.S. FHWA in 1993, it became evident that more successful methods should be developed, but no innovation really happened. A substantial innovative detection method started four years ago from Lagrange Multiplier Testing which eventually resulted in experimental verification based on measurement of deflection and curvature of the bridge beam and together the methodological combination of both. Elsevier 2016 Materials Today: Proceedings 3 32nd DANUBIA ADRIA SYMPOSIUM on Advances in Experimental Mechanics Starý Smokovec – High Tatras, Slovakia 22.09.2015 25.09.2015 4 942 946 10.1016/j.matpr.2016.03.025 2016-06-24