TY - JOUR A1 - Habel, Wolfgang R. A1 - Krebber, Katerina A1 - Daum, Werner T1 - Results in standardization of FOS to support the use of SHM systems N2 - 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. T2 - Sixth European Workshop on Optical Fibre Sensors CY - Limerick, Ireland DA - 30.05.2016 KW - Fiber-optic sensor KW - Standard KW - Temperature KW - Strain KW - Monitoring KW - Structural health KW - Application PY - 2016 U6 - https://doi.org/10.1117/12.2236863 SN - 0277-786X VL - 9916 SP - 991625-1 EP - 991625-4 AN - OPUS4-37053 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brandes, K. A1 - Daum, Werner A1 - Hofmann, Detlef A1 - Kubowitz, P. T1 - Lagrange multiplier test for structural damage of bridges N2 - Detecting spreading damage in bridges is a demanding task for engineers today when the ageing infrastracture of industriaiized countries is degradating more and more. To successfully deal with tbis problem, a really advanced method has been elaborated basing on Langrange Multiplier (LM) tests and following the principle of simplicity by Hilbert and extending comments by Helmholtz refering to a combination of measurement and analytical treatment. Finally, an easy mathematical fonnation has been created. T2 - 31st Danubia-Adria Symposium on advances in experimental mechanics CY - Kempten, Germany DA - 24.09.2014 PY - 2014 SN - 978-3-00-046740-0 SP - 213 EP - 214 AN - OPUS4-31725 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klunker, André A1 - Köppe, Tabea A1 - Daum, Werner T1 - Different numerical methods around the SHPB experiment N2 - The Split Hopkinson Pressure Bar (SHPB) is a materials testing apparatus primarily designed for the analysis of viscoplastic material behavior at very high strain rates. Because of its complexity it is common practice to simplify the underlying exact mechanical theory by making strong assumptions. On the one hand this has to be done to achieve any results at all on the other hand one commits systematic errors. Therefore we utilize different numerical and Simulation methods to analyze and minimize these errors. T2 - 31st Danubia-Adria Symposium on advances in experimental mechanics CY - Kempten, Germany DA - 24.09.2014 PY - 2014 SN - 978-3-00-046740-0 N1 - Geburtsname von Köppe, Tabea: Wilk, T. - Birth name of Köppe, Tabea: Wilk, T. SP - 189 EP - 190 AN - OPUS4-31726 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Köppe, Tabea A1 - Daum, Werner T1 - Pulse shaping and alignment tests with the split Hopkinson pressure bar for validation N2 - The Split Hopkinson Pressure Bar (SHPB) is a method for material characterization which works at strain rates from 102 - 104 1/s. This method can be used for example in the field of military engineering, in the field of deformation technology, automobile indurstry, aerospace industry or in other industrial fields. Controlled tests with the SHPB device enable Information about the dynamic material deformaion behaviour in the named strain rate area. The setup of the SHPB is not standarized and the measurement principle is dependent on simplifications. Due to this amongst others the problem with the dispersion of the measurement signal occurs. Furthermore it is possible that measurement uncertainties appear caused by the misalignment of the SHPB setup. In this work the influence of the alignment and a dispersion correction by pulse shaping is presented. On the one side for the alignment calibration tests are done. And on the other side for the dispersion influence correction with pulse shaping tests are done with TiA16V4. This material was choosen due to the fact that it can be compared with existing literature data. T2 - 31st Danubia-Adria Symposium on advances in experimental mechanics CY - Kempten, Germany DA - 24.09.2014 PY - 2014 SN - 978-3-00-046740-0 N1 - Geburtsname von Köppe, Tabea: Wilk, T. - Birth name of Köppe, Tabea: Wilk, T. SP - 242 EP - 243 AN - OPUS4-31730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Appajaiah, Anilkumar A1 - Wachtendorf, Volker A1 - Daum, Werner T1 - Climatic exposure of polymer optical fibers: Thermooxidative stability characterization by chemiluminescence N2 - The optical transmission stability was investigated for commercially available polymer optical fibers (POFs) which were exposed to a climate of 92°C and 95% relative humidity for about 3300 h. The optical transmission stability of POFs was correlated to their thermooxidative stability. POFs possessed identical core material, poly(methyl methacrylate), but they differed in the materials used for the claddings. The optical transmission was measured online using a prototype device called multiplexer. The chemiluminescence (CL) technique was applied to characterize the thermooxidative stability and degradation of POFs. CL analysis reveals the thermooxidative degradation of bare POFs (core and cladding), predominantly of the claddings, as a result of climatic exposure. Ultraviolet-visible transmittance measurements demonstrated more changes in the claddings as compared to the cores due to degradation. The CL and optical measurements data indicated that the optical transmission stability of POFs was dependent mainly on the thermooxidative stability of the claddings and their chemical compositions. KW - Ageing KW - Polymer optical fiber KW - Degradation KW - Chemiluminescence KW - Transparency PY - 2007 U6 - https://doi.org/10.1002/app.23955 SN - 0021-8995 SN - 1097-4628 VL - 103 IS - 3 SP - 1593 EP - 1601 PB - Wiley InterScience CY - Hoboken, NJ AN - OPUS4-19072 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brandes, K. A1 - Daum, Werner A1 - Hofmann, Detlef A1 - Basedau, Frank A1 - Kubowitz, P. T1 - Innovative structural damage detection of bridges by least squares adjustment with constraints T2 - 32nd Danubia-Adria Symposium on advances in experimental mechanics CY - Starý Smokovec, Slovakia DA - 2015-09-22 PY - 2015 SN - 978-80-554-1094-4 SP - 18 EP - 19 CY - Zilina AN - OPUS4-34486 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, Frank A1 - Köppe, Enrico A1 - Daum, Werner T1 - Tracking deformation history in split Hopkinson pressure bar testing N2 - 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. T2 - 32nd Danubia-Adria Symposium on advances in experimental mechanics CY - Starý Smokovec, Slovakia DA - 22.09.2015 KW - Digitale Bildkorrelation (DIC) KW - Dynamische Tests KW - Spannungs-Dehnungs-Kurve KW - Digital image correlation (DIC) KW - Dynamic testing KW - Split Hopkinson pressure bar (SHPB) KW - Stress-strain curve PY - 2016 U6 - https://doi.org/10.1016/j.matpr.2016.03.017 SN - 2214-7853 VL - 3 IS - 4 SP - 1139 EP - 1143 PB - Elsevier CY - Oxford AN - OPUS4-34487 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brandes, K. A1 - Daum, Werner A1 - Hofmann, Detlef A1 - Basedau, Frank A1 - Kubowitz, P. T1 - Innovative structural damage detection of bridges by least squares adjustment with constraints N2 - 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. T2 - 32nd DANUBIA ADRIA SYMPOSIUM on Advances in Experimental Mechanics CY - Starý Smokovec – High Tatras, Slovakia DA - 22.09.2015 KW - Damage detection of bridges KW - Monitoring KW - Lagrange multiplier test PY - 2016 U6 - https://doi.org/10.1016/j.matpr.2016.03.025 SN - 2214-7853 VL - 3 IS - 4 SP - 942 EP - 946 PB - Elsevier AN - OPUS4-36667 LA - eng 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 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 - JOUR A1 - Maiwald, Michael A1 - Daum, Werner T1 - Trends in der prozessanalytischen Messtechnik N2 - Eine gleich bleibend effektive Nutzung von Anlagen, Rohstoffen und Energie in Verbindung mit der optimalen Prozessführung sind die wichtigsten Voraussetzungen für globale Wettbewerbsvorteile der Prozessindustrie. Unternehmen aus den Bereichen Chemie, Pharmazie, Petrochemie, Gasverarbeitung, Lebensmittel-, Zellstoff-, Papier-, Glas-, Stahl- und Zementherstellung sowie ihren Zulieferern haben den Einsatz zuverlässiger Prozessautomation für eine gute Prozessführung erkannt. Überlegene Verfahren stützen sich zunehmend auf prozessanalytische Messtechnik zur Kontrolle und präventiven Sicherstellung der geforderten Produktqualität. Gleichzeitig ermöglicht sie eine ständige Verbesserung des Wissens über den Prozess und erhöhen die Prozess- und Anlagensicherheit. PY - 2011 U6 - https://doi.org/10.1524/teme.2011.9026 SN - 0340-837X SN - 0178-2312 SN - 0171-8096 VL - 78 IS - 12 SP - 547 EP - 548 PB - Oldenbourg CY - München AN - OPUS4-25262 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -