TY - JOUR A1 - Baensch, Franziska A1 - Baer, Wolfram A1 - Wossidlo, Peter A1 - Habib, Abdel Karim T1 - Damage evolution detection in a pipeline segment under bending by means of acoustic emission N2 - A steel pipeline segment of 2.5 m length was subjected to quasi-static four-point bending load in three steps for studying the initial cracking and damage accumulation based on the Acoustic Emission (AE) technique and by the direct current potential drop (DCPD) technique. For the latter, a new post-test analysis method was established. AE is found more sensitive to crack initiation than DCPD. Formation of mesoscopic and macroscopic cracks as well as their closure and the resulting friction generate weighted peak frequencies below 400 kHz, whereas microscopic cracking produces AE with broad band spectra identifiable by weighted peak frequencies above 400 kHz. Critical states alike the maximum load level and the leak opening were accompanied by peak amplitudes above 85 dBAE. This rather fundamental study provides a data base for possibly developing advanced strategies of detection and alarm systems based on acoustic monitoring of pipelines, or at least, steel structures. KW - Crack KW - Accoustic emission KW - Frequency domain KW - Potential drop technique KW - Fracture PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-565171 SN - 0308-0161 VL - 201 IS - 104863 SP - 1 EP - 9 PB - Elsevier Science CY - Amsterdam AN - OPUS4-56517 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stajanca, Pavol A1 - Baensch, Franziska A1 - Baer, Wolfram A1 - Chruscicki, Sebastian A1 - Homann, Tobias A1 - Seifert, Stefan A1 - Schmidt, Dirk A1 - Weltschev, Margit A1 - Wossidlo, Peter A1 - Habib, Abdel Karim T1 - Monitoring of pipes by distributed acoustic fibre optic sensors – A large-scale test on a pipeline under realistic operation condition N2 - The monitoring of oil and gas pipelines by means of distributed fibre optic sensors is becoming common. The most recent development in the field of fibre optic sensing is the distributed acoustic sensing (DAS), which allows to detect and to localize third party threats to pipelines. For this purpose, fibre optic telecommunication cables located close to the pipelines are usually used. However, DAS carries a far greater potential for continuous condition monitoring of pipelines. The interdisciplinary research project AGIFAMOR (Ageing Infrastructures – Fibre Optic Monitoring of Pipes) at BAM investigates a new technical approach to extend the application field of DAS towards the detection and localization of acoustic signals that indicate critical alterations and certain damage scenarios originated from within the pipeline or the pipe wall. Therefore, the optical fibre sensors are applied onto the pipe itself and the application procedure towards an optimal acoustic signal transduction is optimized. A number of laboratory scale experiments were performed focusing on the signal transmission of acoustic signals as well as the detection of damages in the pipe wall by means of DAS. Furthermore, real-scale tests on a pipeline DN100 of 38m length have been carried out at the BAM test site for technical safety (BAM-TTS) to study the detection and localization of leaks and of changing flow profiles due to corrosion or sedimentation processes. T2 - 13th Pipeline Technology Conference CY - Berlin, Germany DA - 12.03.2018 KW - Pipeline monitoring KW - Distributed acoustic sensing KW - Fiber optic sensing PY - 2018 SN - 2198-428X SP - Poster session, paper 9, 1 EP - 8 PB - EITEP (Euro Institute for Information and Technology Transfer in Environmental Protection) CY - Hannover AN - OPUS4-44519 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Baensch, Franziska A1 - Baer, Wolfram A1 - Chruscicki, Sebastian A1 - Homann, Tobias A1 - Prager, Jens A1 - Schmidt, Dirk A1 - Stajanca, Pavol A1 - Weltschev, Margit A1 - Wossidlo, Peter A1 - Habib, Abdel Karim T1 - AGIFAMOR: Anwendung der verteilten akustischen und faseroptischen Sensorik zur kontinuierlichen Überwachung von Rohrleitungen - Teil 2: Technische Hintergründe - Schadensursachen und Prüfeinrichtungen N2 - Schäden an Rohrleitungen können zu hohen Umweltbelastungen und wirtschaftlichen Schäden führen. Um die dauerhafte Verfügbarkeit der Infrastruktur zu gewährleisten, wird im Rahmen des Projekts AGIFAMOR an der Bundesanstalt für Materialforschung und -prüfung (BAM) erprobt, inwiefern das Verfahren der verteilten akustischen faseroptischen Sensorik (Distributed acoustic sensing – DAS) zur kontinuierlichen Überwachung von Rohrleitungen eingesetzt werden kann. Neben der DAS werden erprobte Verfahren der zerstörungsfreien Prüfung wie Schallemissionsanalyse (SEA) und Beschleunigungssensoren eingesetzt. An dieser Stelle soll detailliert auf die Hauptschadensursachen an Rohrleitungen, den Versuchsstand zur mechanischen Belastung von Rohren sowie die Möglichkeiten zu Untersuchungen im Realmaßstab eingegangen werden. KW - Schadensursachen an Rohrleitungen KW - Monitoring von Rohrleitungen KW - Verteilte Faseroptische Sensorik KW - Rohrbiegeprüfstand KW - Leckage PY - 2018 SN - 2191-0073 VL - 8 IS - 3 SP - 24 EP - 29 PB - Springer VDI-Verlag GmbH & Co. KG CY - Düsseldorf AN - OPUS4-44507 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hussels, Maria-Teresa A1 - Chruscicki, Sebastian A1 - Arndt, Detlef A1 - Scheider, Swen A1 - Prager, Jens A1 - Homann, Tobias A1 - Habib, Abdel Karim T1 - Localization of transient events threatening pipeline integrity by fiber-optic distributed acoustic sensing N2 - Pipe integrity is a central concern regarding technical safety, availability, and environmental compliance of industrial plants and pipelines. A condition monitoring system that detects and localizes threats in pipes prior to occurrence of actual structural failure, e.g., leakages, especially needs to target transient events such as impacts on the pipe wall or pressure waves travelling through the medium. In the present work, it is shown that fiber-optic distributed acoustic sensing (DAS) in conjunction with a suitable application geometry of the optical fiber sensor allows to track propagating acoustic waves in the pipeline wall on a fast time-scale. Therefore, short impacts on the pipe may be localized with high fidelity. Moreover, different acoustic modes are identified, and their respective group velocities are in good agreement with theoretical predications. In another set of experiments modeling realistic damage scenarios, we demonstrate that pressure waves following explosions of different gas mixtures in pipes can be observed. Velocities are verified by local piezoelectric pressure transducers. Due to the fully distributed nature of the fiber-optic sensing system, it is possible to record accelerated motions in detail. Therefore, in addition to detection and localization of threatening events for infrastructure monitoring, DAS may provide a powerful tool to study the development of gas explosions in pipes, e.g., investigation of deflagration-to-detonation-transitions (DDT). KW - Distributed acoustic sensing (DAS) KW - Distributed vibrations sensing (DVS) KW - Fiber-optic sensing KW - Condition monitoring KW - Pipeline integrity KW - Gas explosion PY - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-488555 SN - 1424-8220 VL - 19 IS - 15 SP - 3322, 1 EP - 20 PB - MDPI CY - Basel, CH AN - OPUS4-48855 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tschirschwitz, Rico A1 - Krentel, Daniel A1 - Kluge, Martin A1 - Askar, Enis A1 - Habib, Abdel Karim A1 - Kohlhoff, Harald A1 - Krüger, Simone A1 - Neumann, Patrick P. A1 - Rudolph, Miachael A1 - Schoppa, André A1 - Storm, Sven-Uwe A1 - Szczepaniak, Mariusz ED - Aga, Diana ED - Daugulis, Andrew ED - Li Puma, Gianluca ED - Lyberatos, Gerasimos ED - Tay, Joo Hwa ED - Lima, Éder Claudio T1 - Hazards from failure of CNG automotive cylinders in fire N2 - Compressed natural gas (CNG) is a widely used automotive fuel in a variety of countries. In case of a vehicle fire where the safety device also malfunctions, a failure of the CNG automotive cylinder could occur. Such a cylinder failure is associated with severe hazards for the surrounding environment. Firstly, a comprehensive analysis is given below, summarizing various accidents involving CNG automotive cylinders and their consequences. In an extensive experimental program, 21 CNG automotive cylinders with no safety device were tested. Of the 21, burst tests were carried out on 5 Type III and 5 Type IV cylinders. Furthermore, fire tests with 8 Type III and 3 Type IV cylinders were conducted. Apart from cylinder pressure, inner temperature and cylinder mantle temperature, the periphery consequences, such as nearfield blast pressure and fragmentation are documented. The maximum measured overpressure due to a Type III cylinder failure was p = 0.41 bar. Each traceable fragment was georeferenced. All-in-all, fragment throw distances of d > 300 m could be observed. As one key result, it can be stated that the tested Type IV CNG cylinders showed less critical failure behavior then the Type III cylinders under fire impingement. KW - CNG KW - Composite cylinder KW - Gas cylinder KW - Tank failure KW - Fragments PY - 2019 U6 - https://doi.org/10.1016/j.jhazmat.2018.12.026 SN - 0304-3894 SN - 1873-3336 VL - 367 SP - 1 EP - 7 PB - Elsevier CY - New York City, New York, USA AN - OPUS4-47135 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Baensch, Franziska A1 - Baer, Wolfram A1 - Chruscicki, Sebastian A1 - Homann, Tobias A1 - Prager, Jens A1 - Schmidt, Dirk A1 - Stajanca, Pavol A1 - Weltschev, Margrit A1 - Wosidlo, Peter A1 - Habib, Abdel Karim T1 - AGIFAMOR: Anwendung der akustischer und faseroptischer Sensorik zur Überwachung von Rohrleitungen; Teil 3: Technische Hintergründe - Messmethoden N2 - Schäden an Rohrleitungen können zu hohen Umweltbelastungen und wirtschaftlichen Schäden führen. Um die dauerhafte Verfügbarkeit der Infrastruktur zu gewährleisten, wird im Rahmen des Projekts AGIFAMOR an der Bundesanstalt für Materialforschung und -prüfung (BAM) erprobt, inwiefern das Verfahren der verteilten akustischen faseroptischen Sensorik (Distributed acoustic sensing - DAS) zur kontinuierlichen Überwachung von Rohrleitungen verwendet werden kann. Neben der DAS werden erprobte Verfahren der zerstörungsfreien Prüfung wie Schallemissionsanalyse (SEA) und Beschleunigungssensoren eingesetzt. An dieser Stelle soll detailliert auf die unterschiedlichen Messverfahren und deren spezifischen Einsatz im Rahmen des Projektes eingegangen werden. KW - Verteilten akustischen faseroptischen Sensorik KW - Überwachung von Rohrleitungen KW - Zerstörungsfreie Prüfung KW - Schallemissionsanalyse KW - Beschleunigungssensorik PY - 2018 SN - 2191-0073 VL - 8 IS - 5 SP - 29 EP - 35 PB - Springer-VDI-Verl. CY - Düsseldorf AN - OPUS4-45933 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baensch, Franziska A1 - Baer, Wolfram A1 - Wossidlo, Peter A1 - Habib, Abdel Karim T1 - Non-threshold acoustic emission analysis of damage evolution in pipe segments of steel S355J2H under bending load N2 - Four-point bending tests were carried out to analyze the acoustic characteristics of damage development in pipe segments made of steel, grade S355J2H, being 2.5 m long with an outer diameter of 168 mm and 16 mm wall thickness. To induce stable crack growth, the pipe segments were pre-damaged by a 90°circumferential notch in the middle of the pipe length. While the pipe was quasi-statically loaded, microscopic damage and plastic deformation accumulated to form a macroscopic crack that grew through the pipe wall until leakage. For acoustic emission (AE) monitoring, four broadband sensors of type VS 900 M were mounted close to the notch. Continuous AE signal detection was performed by the non-threshold method. Advantages and disadvantages of the non-threshold AE monitoring compared to a commonly employed method analyzing only signals exceeding a predefined threshold are discussed. The results of AE analysis are compared to additional information on the crack growth detected by the direct current potential drop (DCPD) technique. These studies were carried out in the course of the interdisciplinary research project AGIFAMOR, Ageing infrastructures - distributed acoustic monitoring of pipes at BAM. T2 - 33rd European Conference on Acoustic Emission Testing CY - Senlis, France DA - 12.09.2018 KW - Acoustic emissions (AE) KW - Four-point bending test KW - Steel pipe KW - Crack initiation KW - Crack growth PY - 2018 SP - 340 EP - 347 CY - France, Senlis AN - OPUS4-45960 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baensch, Franziska A1 - Baer, Wolfram A1 - Chruscicki, Sebastian A1 - Habib, Abdel Karim A1 - Homann, Tobias A1 - Hussels, Maria-Teresa A1 - Prager, Jens A1 - Schmidt, Dirk A1 - Stajanca, Pavol A1 - Weltschev, Margit A1 - Wossidlo, Peter T1 - Feasibility study - Continuous monitoring of pipes using distributed acoustic and fibre optic sensors N2 - The feasibility study „AGIFAMOR. Ageing infrastructures – distributed acoustic monitoring of pipes” is an interdisciplinary research project at BAM internally financed from 2015 to 2018. Therefore, the quite young fibre optic sensing technology of distributed acoustic sensing (DAS) was investigated to possibly be extended towards a global condition monitoring system for pipelines operating in real time. DAS is a highly dynamic fibre optic sensing technology based on the method of coherent optical time domain reflectometry (C-OTDR). DAS allows capturing strain changes in the range of kHz. For the experimental work, the most suitable application yielding an optimum sensitivity was proven by wrapping a standard single-mode silica fibre around the pipe. The DAS sensitivity was investigated regarding the detection of 1) incidents that initiate propagation of acoustic waves in the pipe wall, 2) changes inside the pipeline causing altered flow and 3) damage development in the pipe wall. Therefore, several testing setups in laboratory as well as in real scale were realized. For comparison purposes, experiments were accompanied by acoustic emission analyses and by measurements with accelerometers. DAS was found to be very sensitive to gas ignition and its propagation across the pipe. Furthermore, the ability of DAS to detect and localize acoustic signals associated with pipeline leakage was demonstrated. The detection of crack formation and propagation within the pipe wall by means of DAS was studied during bending tests on several pipe segments, but was not proven so far with certainty. As expected, these studies turned out as the most difficult challenge due to the random occurrence and transient nature of microscopic damage phenomena. T2 - Proceedings of the International Symposium on Structural Health Monitoring and Nondestructive Testing CY - Saarbrücken, Germany DA - 04.10.2018 KW - Accelerometers KW - Acoustic emission KW - Fibre optic acoustic sensing KW - Continous monitoring KW - Bending tests on pipe segments KW - Leak detection PY - 2018 SP - Paper 21 AN - OPUS4-46375 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stajanca, Pavol A1 - Chruscicki, Sebastian A1 - Homann, Tobias A1 - Seifert, Stefan A1 - Schmidt, Dirk A1 - Habib, Abdel Karim T1 - Detection of leak-induced pipeline vibrations using fiber-optic distributed acoustic sensing N2 - In the presented work, the potential of fiber-optic distributed acoustic sensing (DAS) for detection of small gas pipeline leaks (<1%) is investigated. Helical wrapping of the sensing fiber directly around the pipeline is used to increase the system sensitivity for detection of weak leak-induced vibrations. DAS measurements are supplemented with reference accelerometer data to facilitate analysis and interpretation of recorded vibration signals. The results reveal that a DAS system using direct fiber application approach is capable of detecting pipeline natural vibrations excited by the broadband noise generated by the leaking medium. In the performed experiment, pipeline vibration modes with acceleration magnitudes down to single ug were detected. Simple leak detection approach based on spectral integration of time-averaged DAS signals in frequency domain was proposed. Potential benefits and limitations of the presented monitoring Approach were discussed with respect to its practical applicability. We demonstrated that the approached is potentially capable of detection and localization of gas pipeline leaks with leak rates down to 0.1% of the pipeline flow volume and might be of interest for monitoring of short- and medium-length gas pipelines. KW - Distributed acoustic sensing KW - DAS KW - Distributed vibration sensing KW - DVS KW - Fiber-optic sensors KW - Pipeline monitoring KW - Leak detection KW - Pipeline vibrations PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-457953 UR - http://www.mdpi.com/1424-8220/18/9/2841 SN - 1424-8220 VL - 18 IS - 9 SP - 2841, 1 EP - 18 PB - MDPI AN - OPUS4-45795 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tschirschwitz, Rico A1 - Krentel, Daniel A1 - Kluge, Martin A1 - Askar, Enis A1 - Habib, Abdel Karim A1 - Kohlhoff, Harald A1 - Krüger, Simone A1 - Neumann, Patrick P. A1 - Rudolph, Michael A1 - Schoppa, André A1 - Storm, Sven-Uwe A1 - Szczepaniak, Mariusz T1 - Experimental investigation of consequences of LPG vehicle tank failure under fire conditions N2 - In case of a vehicle fire, an installed LPG (liquefied petroleum gas) tank with a malfunctioning safety device poses severe hazards. To investigate the consequences in case of tank failure, we conducted 16 tests with toroidal shaped LPG vehicle tanks. Three tanks were used for a Hydraulic Burst Test under standard conditions. Another three tanks were equipped with a statutory safety device and were subjected to a gasoline pool fire. The safety device prevented tank failure, as intended. To generate a statistically valid dataset on tank failure, ten tanks without safety devices were exposed to a gasoline pool fire. Five tanks were filled to a level of 20 %; the re-maining five were filled to a level of 100 %. In order to gain information on the heating process, three tem-perature readings at the tank surface, and three nearby flame temperatures were recorded. At distances of l = (7; 9; 11) m to the tank, the overpressure of the shock wave induced by the tank failure and the unsteady tem-peratures were measured. All ten tanks failed within a time of t < 5 min in a BLEVE (boiling liquid expanding vapor explosion). Seven of these resulted directly in a catastrophic failure. The other three resulted in partial failure followed by catastrophic failure. A near field overpressure at a distance of l = 7 m of up to p = 0.27 bar was measured. All ten tests showed massive fragmentation of the tank mantle. In total, 50 fragments were found. These 50 fragments make-up 88.6 % of the original tank mass. Each fragment was georeferenced and weighed. Fragment throwing distances of l > 250 m occurred. For the tanks with a fill level of 20 %, the average number of fragments was twice as high as it was for the tanks that were filled completely. KW - Blast wave KW - BLEVE KW - Consequences KW - Explosion KW - LPG PY - 2018 UR - https://authors.elsevier.com/a/1XnFv_Ld32ewKu U6 - https://doi.org/10.1016/j.jlp.2018.09.006 SN - 0950-4230 VL - 56 SP - 278 EP - 288 PB - Elsevier CY - Kidlington - Oxford AN - OPUS4-46238 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -