TY - CONF A1 - Gottschalk, Götz-Friedrich A1 - Chaurasia, Prashant Kumar A1 - Goecke, Sven-Frithjof T1 - Zero-defect Printing with DED-GMA via Adaptive Controls N2 - Gas metal arc assisted directed energy deposition (DED-GMA) is a metal additive manufacturing process for fabricating large-scale parts with a higher printing rate. An accurate monitoring and control of the melt pool geometric features is critical for printing zero-defect parts. In this study, the melt pool thermography is used for the real-time detection of the melt pool boundary, centreline, and transient cooling time using an efficient deep learning technique. The presented real-time process monitoring and control methodology using deep learning allows adaptive control of the DED-GMA process. T2 - Twenty-Second International Conference on Flow Dynamics (ICFD 2025) CY - Sendai, Japan DA - 10.11.2025 KW - Additive manufacturing KW - DED-Arc KW - Monitoring KW - Control PY - 2025 SP - 1332 EP - 1335 AN - OPUS4-64837 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neugum, Tim A1 - Stelzner, Ludwig A1 - Häßler, Dustin A1 - Zehfuß, Jochen A1 - Hothan, Sascha T1 - Application of the substructure method to assess the fire resistance of thermally restrained columns N2 - Usually, the fire resistance of load-bearing structural elements is determined by single members testing. A mechanical load is applied to the member in a force-controlled manner and is maintained constant throughout the fire test. After applying the mechanical load, the thermal exposure starts according to the ISO 834 fire curve. In this conventional test method, no interaction between the tested member and the entire building structure is considered. In buildings, the surrounding structure can restrain the thermal expansion of a member in case of fire. This may have both positive and negative effects on the fire resistance of this structural element. Several years ago, the Institute for Sustainability and Innovation in Structural Engineering (ISISE) at the University of Coimbra in Portugal and the Bundesanstalt für Materialforschung und prüfung (BAM) in Germany carried out fire tests on circular and square steel-reinforced concrete columns with restrained thermal expansion. BAM´s column test furnace allows the specimen to be subjected to thermal exposure and mechanical loading simultaneously. In addition, this device has a substructure test module, which can also provide restrained test conditions. In an ongoing research project at BAM and Technische Universität Braunschweig, the effect of restrained test conditions on the behaviour of steel-reinforced columns under fire exposure is further investigated. T2 - 8th International RILEM Workshop on Concrete Behaviour due to Fire Exposure CY - Krakow, Poland DA - 18.09.2025 KW - Substructure method KW - Surrounding structure KW - Fire resistance KW - Restrained columns KW - Concrete PY - 2025 SP - 1 EP - 2 AN - OPUS4-64582 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winkler, Nicolas P. A1 - Neumann, Patrick P. A1 - Schaffernicht, E. A1 - Lilienthal, A. J. T1 - Heterogeneous Sensor Networks: Challenges and Insights from an Industrial Scenario N2 - Monitoring airborne pollutants is critical for occupational health, particularly in industrial environments where workers are exposed to hazardous emissions. Traditional measurements are typically limited to single-day campaigns, resulting in extremely sparse temporal data. Low-cost sensor networks offer a way to increase spatial and temporal resolution but are limited by issues of accuracy and reliability. To address this, we present a wireless heterogeneous sensor network that integrates low-cost stationary nodes with high-quality sensors on mobile platforms, including ground and aerial robots. We deploy this system in a hot rolling mill facility and evaluate its performance under real-world conditions. Field experiments reveal dynamic pollutant patterns, such as altitude-dependent PM2.5 gradients and temperature fluctuations. By introducing synchronized “rendezvous” events between mobile and stationary nodes, we demonstrate correlation capabilities of sensors. Our spatiotemporal analysis shows that, despite limitations of mobile sensing, strategically combining heterogeneous data sources enables capturing pollutant dynamics in complex industrial settings. T2 - IEEE SENSORS 2025 CY - Vancouver, BC, Kanada DA - 19.10.2025 KW - Environmental monitoring KW - Sensor data fusion KW - Sensor system networks KW - Mobile robotics PY - 2025 SN - 979-8-3315-4467-6 SP - 1 EP - 4 PB - IEEE CY - Piscataway, NJ, USA AN - OPUS4-64501 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gaal, Mate A1 - Ahmadzadeh, Majid A1 - Weise, Matthias T1 - Air-coupled ultrasonic transmission using thermoacoustic transmitters and optical microphones N2 - Background, Motivation and Objective Air-coupled ultrasonic transducers are usually applied for testing of some lightweight components. To increase the bandwidth or air-coupled testing systems and thus increase their application range, thermoacoustic transducers can be paired with optical microphones in a transmission mode. Thermoacoustic transmitters are based on the thermal excitation of sound waves, while optical microphones are based on laser interferometry and Fabri-Pérot etalon. We studied the spectrum and the efficiency of the transmission of an air gap using a thermoacoustic transmitter and an optical microphone. Statement of Contribution/Methods Thermoacoustic transmitters with an electrically conductive layer of indium tin oxide (ITO) on a curved quartz glass substrate were developed. Their sound field was measured using a commercially available optical microphone Eta450 Ultra based on Fabri-Perot etalon. The curvature and the conductive layer thickness of the thermoacoustic transmitter were systematically varied to investigate their impact on the sound field and the spectrum of the measured signal for frequencies up to 1 MHz. The transmitters were excited using rectangular burst signals with a varied width. We examined the influence of all parameters on the focusing, spectrum, and sensitivity. The directivity of the microphone was evaluated as well. Results/Discussion The focusing of the sound fields of all transmitters most strongly depends on the curvature radius of the substrate. The spectrum recorded in the focus of each transducer has several maxima and minima, as shown in the left-hand diagram, which are mostly a consequence of the irregularities of the microphone spectrum. These irregularities are visible also in the directivity diagram on the right, which was recorded by rotating the microphone. The 20 dB bandwidth of the measurement system covers the range up to about 1 MHz, depending strongly on the width of the excitation pulse (left-hand diagram). This highlights a key advantage of thermoacoustic transmitters: their spectral characteristics can be controlled through the excitation conditions, offering a potentially broader range of applications compared to conventional air-coupled transmitters. One promising example is localized ultrasound spectroscopy based on the detection of local resonances. T2 - IEEE International Ultrasonic Symposium CY - Utrecht, The Netherlands DA - 15.09.2025 KW - Air-coupled ultrasound KW - Thermoacoustic transmitter KW - Sound field PY - 2025 SP - 1 EP - 4 AN - OPUS4-64541 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - George, Joyal K. A1 - von Wangenheim, Kristian A1 - Kaplan, Felix A1 - Schneider, Ronald A1 - Hindersmann, Iris ED - Lienhart, Werner ED - Krüger, Markus T1 - Monitoring of civil engineering structures - current and future use cases N2 - Monitoring represents an effective approach for addressing the diverse challenges associated with the maintenance of civil engineering structures. It contributes to improving both the availability and safety of these structures. By increasing the amount of information available about the structure, monitoring supports better-informed decisions regarding its preservation. Due to the complexity of monitoring applications, specific use cases are outlined. A key advantage of these use cases is that new technologies can be tested within well-defined and limited scopes. The use cases monitoring of known, localized damage, monitoring of known deficits identified through reassessment or resulting from outdated design procedures and monitoring aimed at assessing traffic loads and their effects currently account for the majority of implemented monitoring measures. Their practical implementation is demonstrated through case studies from the Brandenburg State Road Authority. Additional use cases, such as monitoring to support structural inspections and monitoring of major structures, such as large viaducts, are gaining importance, with initial practical examples already present in Europe. Future applications reveal potential for expanded use, particularly in the context of monitoring to support predictive lifecycle management. This will become increasingly important in the implementation of digital twins, as announced in the national BIM master plan. Furthermore the concept of a Birth Certificate is intended to establish a reference state of the structure prior to commissioning, which can then be used for comparison with future measurements over time. The integration and interaction of these individual use cases pave the way for the implementation of digital twins. T2 - 13th International Conference on Structural Health Monitoring of Intelligent Infrastructure CY - Graz, Austria DA - 01.09.2025 KW - Structural Health Monitoring KW - Use Cases KW - Bridges KW - Digital Twin PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-644422 DO - https://doi.org/10.3217/978-3-99161-057-1-033 SP - 203 EP - 208 PB - Verlag der Technischen Universität Graz CY - Graz AN - OPUS4-64442 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neugum, Tim A1 - Stelzner, Ludwig A1 - Häßler, Dustin A1 - Zehfuß, Jochen A1 - Hothan, Sascha T1 - Berücksichtigung der Tragwerksumgebung bei Brandversuchen an Stahlbetonstützen N2 - Das Tragwerk eines Gebäudes ist aus einzelnen Bauteilen zusammengesetzt. Insbesondere bei lokalen Brandereignissen bauen sich durch die Ausdehnung der vom Brand betroffenen Bauteile gegen das umgebende kältere Gesamttragwerk Zwangsbeanspruchungen auf. Bei konventionellen Brandprüfungen werden diese Zwangsbeanspruchungen in der Regel nicht berücksichtigt, da die Prüfsystematik auf Einzelbauteilprüfungen bei konstanter mechanischer Last ausgelegt ist. Die Prüfung komplexer, realmaßstäblicher Tragwerke ist oftmals nicht möglich. Die Interaktion des Einzelbauteils mit dem umgebenden Tragwerk kann sich sowohl positiv als auch negativ auf den Feuerwiderstand auswirken. Als nachteilig ist der thermische Zwang und die daraus resultierende Lasterhöhung zu nennen. Gleichzeitig kann eine Stauchung der Stütze zu einer Umlagerung von Kräften in das umgebende Tragwerk führen und damit den Versagenszeitpunkt der Stütze verzögern. Mit Hilfe der Substrukturtechnik kann das Verhalten einer Stütze im Brandfall unter Berücksichtigung der Interaktion mit dem umgebenden Tragwerk analysiert werden. In einem gemeinsamen DFG-Vorhaben der Bundesanstalt für Materialforschung und -prüfung (BAM) und dem Institut für Baustoffe, Massivbau und Brandschutz (iBMB) der TU Braunschweig werden 14 Stahlbetonstützen mit freier und behinderter axialer Ausdehnung untersucht. Auf Basis eines realen Gebäudes werden unter anderem die Steifigkeit, welche das umgebende Tragwerk repräsentiert, der Lastausnutzungsgrad und die Brandeinwirkung variiert. Mit dem Ziel das Stützenverhalten unter thermischem Zwang im Detail zu analysieren, erfolgen Brandversuche und numerische Simulationsberechnungen. Dabei werden die erforderlichen mechanischen Materialeigenschaften des Betons bei erhöhten Temperaturen aus experimentellen Daten abgeleitet. Der Beitrag liefert einen Einblick in die experimentellen und numerischen Ergebnisse. Es zeigt sich, dass die behinderte axiale Ausdehnung und die Möglichkeit einer Lastumlagerung bei Stauchung der Stütze einen erheblichen Einfluss auf das Versagen im Brandfall haben. Die mittels Substrukturtechnik erzeugte Zwängung des umgebenden Tagwerks führt zu einem Anstieg der Axialkraft in der Stütze sowie einer Abnahme der maximalen Stützenausdehnung. Gleichzeitig setzt die Stauchung der Stütze früher ein. Wird eine Stütze-Tragwerk-Interaktion auch für den Stauchungsbereich der Stütze angesetzt, kann der Vorteil einer Lastumlagerung genutzt werden. Somit kann trotz einer höheren mechanischen Belastung während der Ausdehnungsphase der Stütze ein späterer Versagenszeitpunkt als bei einer konventionell geprüften Stütze erreicht werden. T2 - Symposiums Heißbemessung – Structural Fire Engineering 2025 CY - Braunschweig, Germany DA - 29.09.2025 KW - Substrukturtechnik KW - Stahlbetonstützen KW - Feuerwiderstand KW - Stützenbrandversuche KW - Numerik PY - 2025 SP - 38 EP - 52 PB - TU Braunschweig AN - OPUS4-64581 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lehmann Schlag, Jens A1 - Burkert, Andreas A1 - Köstermann, U. T1 - Einsatz von Duplexstählen in Straßentunneln: Verbesserung der Sicherheit und Dauerhaftigkeit N2 - Die vorgestellten Ergebnisse eines gemeinsamen Forschungsvorhabens der BAM, Straßen.NRW, LSBG, ISER und weiteren Partnern zeigen geeignete Duplexstähle für die Betriebs- und Sicherheitsausstattung in Straßentunneln, die in einer Parameterstudie in mehreren Straßentunneln umfassend untersucht worden sind. Spaltkorrosion war dabei die maßgebliche Korrosionsart und wurde als Bewertungskriterium herangezogen. Die Werkstoffgruppe CRC III mit einem PRE(N)-Wert von 24 bis 27 zeigte in den Untersuchungen eine nur ungenügende Spaltkorrosionsbeständigkeit. Das für die Wahrscheinlichkeit der Spaltkorrosionsbeständigkeit anzustrebende 95 %-Quantil wird erst bei PRE(N) > 34 erreicht. Die Erkenntnisse aus der Parameterstudie wurden in einem Pilotprojekt von Straßen.NRW umgesetzt, bei dem unter anderem Strahlventilatoren vollständig aus Duplexstahl 1.4462 gefertigt worden sind. Dadurch soll eine Nutzungsdauer von mindestens 35 Jahren sichergestellt werden. T2 - STUVA Tagung 2025 CY - Hamburg, Germany DA - 25.11.2025 KW - Korrosion KW - Tunnel KW - Atmosphärische Korrosion KW - Nichtrostender Stahl KW - Auslagerung PY - 2025 SN - 978-3-96892-327-7 VL - 61 SP - 335 EP - 340 PB - Studiengesellschaft für Tunnel und Verkehrsanlagen e.V. STUVA CY - Köln AN - OPUS4-64983 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schackmann, Oliver A1 - Márquez Reyes, Octavio A1 - Memmolo, Vittorio A1 - Lozano, Daniel A1 - Prager, Jens A1 - Moll, Jochen A1 - Kraemer, Peter T1 - Intelligent damage detection in composite pressure vessels under varying environmental and operational conditions N2 - Despite proven approaches available in the literature, structural health monitoring by ultrasonic guided waves under varying environmental and operational conditions is still challenging. The use of machine learning approaches is discussed in this work, considering the complex problem of experimental damage detection under varying load conditions in a composite overwrapped pressure vessel for hydrogen storage. Specifically, unsupervised methods originally developed for image and time series classification are combined with ensemble voting to conceive reliable damage detection technique. This enables the effective combination of the predictions of multiple transducer pairs, even with a limited number of strong individual classifiers. A performance demonstration of the technique is presented using a real damage scenario dataset. T2 - IEEE 12th International Workshop on Metrology for AeroSpace (MetroAeroSpace) CY - Napoli, Italy DA - 18.06.2025 KW - Guided ultrasonic waves KW - Structural health monitoring KW - Artificial intelligence KW - Hydrogen storage PY - 2025 SN - 979-8-3315-0152-5 DO - https://doi.org/10.1109/MetroAeroSpace64938.2025.11114628 SN - 2575-7490 SP - 608 EP - 613 AN - OPUS4-64894 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eiz Eddin, Ahmad A1 - Stelzner, Ludwig A1 - Häßler, Dustin A1 - Hothan, Sascha T1 - Tragfähigkeit und Abplatzverhalten von Carbonbeton bei hohen Temperaturen N2 - Zur Bewertung der Biegetragfähigkeit dünnwandiger, carbonbewehrter Betonbauteile unter Temperatureinfluss wurden 4-Punkt-Biegeversuche in drei thermischen Konfigurationen durchgeführt. Die Ergebnisse zeigen, dass bei Raumtemperatur kein signifikanter Einfluss der Vorspannung auf die Bruchkraft vorliegt. Mit steigender Temperatur nimmt die Biegetragfähigkeit infolge des Festigkeitsverlustes von Beton und Carbonbewehrung sowie durch das Schmelzen der Tränkungsmatrix deutlich ab. Zwei Versagensmechanismen konnten identifiziert werden, d.h. Zugversagen bei hoher Vorspannung und Verbundversagen bei niedriger Vorspannung. Die Abnahme der Verbundfestigkeit ist auf das Erweichen der Tränkungsmatrix bei Überschreitung der Glasübergangstemperatur zurückzuführen. Bei Temperaturen oberhalb von etwa 200 °C ist keine Tränkungsmatrix und daraus resultierende Verbundwirkung mehr vorhanden. Darüber hinaus wurden im Rahmen von Abplatzversuchen drei Schutzmaßnahmen zur Vermeidung von Betonabplatzungen im Brandfall untersucht, d.h. reaktives Brandschutzsystem (RBS), zementgebundene Brandschutzplatten sowie Zugabe von Polypropylenfasern (PP-Fasern) zur Betonmischung. Die Ergebnisse zeigen, dass der Typ des Carbongeleges die Wirksamkeit der Schutzmaßnahmen beinflusst. Während die Zugabe von PP-Fasern das Abplatzen bei beiden untersuchten Gelegetypen verhindern konnte, war dies bei RBS und Brandschutzplatten nur bei einem Gelegetyp erfolgreich. Die Ursache der Abplatzungen ist auf das temperaturbedingte Schmelzen und die damit einhergehende Volumenzunahme der im Gelege Q85 vorhandenen Hilfsfäden zurückzuführen. Dies führt zu einer Rissbildung parallel zur brandbeanspruchten Betonoberfläche. Der Dampfdruck im Beton ist trotz reduzierter Erwärmungsgeschwindigkeit zu hoch, weshalb es zum Abplatzen kommt. Im Gegensatz dazu bewirkt das Schmelzen der PP-Fasern eine Erhöhung der Permeabilität des Betons. Dadurch kann der entstehende Wasserdampf frühzeitig entweichen, sodass der Dampfdruck unterhalb der kritischen Schwelle bleibt, die für das Abplatzen erforderlich wäre. T2 - Symposium Heißbemessung 2025 CY - Braunschweig, Germany DA - 29.09.2025 KW - Carbonbeton KW - Biegetragfähigkeit KW - Abplatzverhalten PY - 2025 SP - 1 EP - 13 PB - Institut für Baustoffe, Massivbau und Brandschutz (iBMB), Technische Universität Braunschweig CY - Braunschweig, Deutschland AN - OPUS4-64882 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neumann, Patrick P. A1 - Winkler, Nicolas P. A1 - Nerger, Tino A1 - Lohrke, Heiko A1 - Bartholmai, Matthias T1 - Robotic Olfaction in Action: Field Applications and Results from Current Research N2 - In recent decades, robotics, particularly in environmental monitoring, has made significant advances. Robots of various forms and sizes have become essential tools for data collection in environmental research. Mobile Robot Olfaction (MRO) involves mobile robots equipped with gas sensors and requires the integration of multiple disciplines, including signal processing, machine perception, autonomous navigation, and pattern recognition. Common applications of MRO include mapping gas distributions, locating and detecting gas sources, and tracking gas plumes. Aerial Robot Olfaction (ARO) is a specialized branch of MRO that adapts these concepts to aerial robots, addressing the challenges of airborne gas sensing. This presentation highlights recent developments and results from ongoing research projects in MRO and ARO, with a focus on real-world deployment scenarios and the challenges encountered in practice. T2 - Drohnen in der Zerstörungsfreien Prüfung CY - Magdeburg, Germany DA - 26.11.2025 KW - Ground and Aerial robots KW - Gas distribution mapping KW - Gas source localization KW - Gas Tomography KW - Mobile Robotic Olfaction PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-648928 UR - https://www.ndt.net SP - 1 EP - 15 PB - DGZfP AN - OPUS4-64892 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hille, Falk A1 - Schneider, Ronald A1 - Simon, Patrick A1 - Herrmann, Ralf A1 - Baeßler, Matthias ED - Döhler, Michael ED - Mélot, Adrien ED - Aenlle Lopez, Manuel T1 - System identification and model calibration of a steel road bridge N2 - The Bundesanstalt für Materialforschung und -prüfung (BAM), in cooperation with the Netherlands Organization for Applied Scientific Research (TNO), is working on a framework for integrating frequently updated structural models into an asset management process for bridge structures. A multi-span steel road bridge was selected as a test case for the development of this framework. In order for the structural model to represent the real behavior of the bridge with sufficient accuracy, model calibration is required. In this case, we have planned to calibrate the model based on the dynamic response of the bridge. To determine its dynamic properties, a multi-setup operational modal analysis was performed on one of the bridge spans. In parallel, a structural model of the span was developed based on the available design and service life information. Both eigenfrequencies and mode shapes were used as reference parameters to calibrate the model. A sensitivity analysis was performed to identify the most influential design parameters. Subsequently, a genetic algorithm was applied for minimizing the difference between measured and simulated characteristic responses. In the proposed paper, we summarize the measurements as well as the determination of the modal response of the bridge and describe the process of calibration of the structural model using the identified dynamic response. T2 - 11th International Operational Modal Analysis Conference (IOMAC 2025) CY - Rennes, France DA - 20.05.2025 KW - Bridge structure KW - Operational modal analysis KW - Model calibration PY - 2025 SN - 978-84-09-75120-4 SP - 114 EP - 121 PB - International Group of Operational Modal Analysis CY - Gijón, Spain AN - OPUS4-64416 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz A1 - Said, Samir A1 - Rohrmann, Rolf ED - Döhler, Michael T1 - Modal analysis of road and rail bridges for damage detection and resonance prediction N2 - In the 1980s, the Federal Institute of Material Research and Testing started with modal analysis measurements of some bridges before and after repair. For one of the bridges, a structural health monitoring was installed 1994 which is still working up to now. It has been modified and extended several times. The monitoring was extended from the critical span to three neighbouring spans. A modal analysis of the whole bridge with seven spans have been done three times, twice together with EMPA of Switzerland. Additional calibration measurements have been done and additional evaluation procedures have been implemented for the monitoring of the steadily increasing loads from the road traffic. Additional sensors were installed such as strain gauges, crack-width, and temperature sensors. The strong influence of the temperature on the natural frequencies has been studied over the years. Later, a temperature compensation has been established and a weak aging trend has been found in the monitoring data. Now, the bridge will be demolished and replaced by a new bridge. Some results of this long-term monitoring will be shown and possible damages (changes of the pre-stress or the support structure) will be discussed. A second application of modal analysis will be demonstrated: the prediction of the resonances due to passing trains. The response of a bridge to passing trains can be calculated in frequency domain as the multiplication of three spectra, the axle sequence spectrum of the train, the transfer function of the bridge, and the modal force spectrum of a single passing load. A resonance occurs if a maximum of the train spectrum coincides with the maximum of the bridge spectrum. The amplitude at this resonance is strongly influenced by the modal force spectrum which is identical to the frequency or wavenumber spectrum of the corresponding mode shape. Therefore, modal analysis from calculation, impact measurements, wind and train measurements are necessary for the prediction of the resonance occurrence and amplification. Examples of mode shape spectra for single or multi-span bridges with simply supported or continuous spans will be shown, and some relations between mode shapes and resonance amplifications will be concluded. T2 - 11th International Operational Modal Analysis Conference (IOMAC) CY - Rennes, France DA - 20.05.2025 KW - Bridge monitoring KW - Multi-span bridges KW - Damage detection KW - Resonance PY - 2025 SP - 39 EP - 46 PB - INRIA CY - Rennes AN - OPUS4-63473 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz A1 - Song, Jiaojiao T1 - Analysis of intact and damaged (floating) slab tracks by finite-element boundary-element models and by measurements N2 - The damage detection and repair control have become important tasks for slab tracks. Different intact and damaged slab tracks have been investigated theoretically and experimentally for train passages and hammer impacts. The following damages have been considered: The loss of contact between the sleeper and the track slab, between the track slab and the base slab, and between the base slab and the base layer. At first, a slab track with a gap between the track slab and the base layer has been calculated by the combined finite-element boundary-element method which correctly incorporates the behaviour of the infinite soil. The basic results are the track displacements of the rail, the track slab, and the base layer along the track which are caused by a single axle load. These solutions are properly superposed for to get the complete train load. The influence of track and soil parameters and of the track damage has been analysed. For the intact track, the compliance of the soil is dominant whereas the track bending stiffness becomes more important for the damaged track. By comparing the calculated results with the measurements, the length of the gap could be quantified. A slab track with a loose sleeper (without contact to the supporting track slab) was analysed by the transfer function between the displacements and the hammer force (receptance functions) where a resonance appeared in case of the damage. Differences between the different track elements confirmed the detection of the damage. A floating slab track with a thin rubber layer has been investigated for a possible gap between the base slab and the base layer. The behaviour of the intact track has been calculated by a wavenumber-domain method, and the same behaviour has been found in the measurements at several track sections, indicating that there is no damage. Finally, a floating slab track with steel springs and viscous fluid dampers has been measured in the Tongji laboratory. The modes of the floating track slab and the transfer function with corresponding resonances have been calculated and successfully compared with results from wheelset drop tests. T2 - Third International Conference on Rail Transportation (ICRT2024) CY - Shanghai, China DA - 07.08.2024 KW - Railway track KW - Damage KW - Vibration measurement KW - Finite element method KW - Boundary element method KW - Frequency response function KW - Moving load response KW - Floating slab track PY - 2025 SN - 978-0-7844-8594-1 SP - 591 EP - 600 AN - OPUS4-61267 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Thoralf A1 - Lehmann Schlag, Jens A1 - Burkert, Andreas T1 - KorroPad®-Ein Kurzzeitprüfverfahren zur Qualitätssicherung der Oberflächen- und Schweißnahtnachbearbeitung nichtrostender Stähle N2 - Die Ausbildung einer stabilen Passivschicht ist entscheidend für den Korrosionsschutz nichtrostender Stähle. KorroPad® bietet eine schnelle, zerstörungsfreie Bewertung der Passivschichtstabilität und ist seit 2025 als DIN 50024 genormt. Die Methode ermöglicht eine 15‑minütige Vor‑Ort‑Prüfung ohne Spezialwissen und schließt die Lücke zwischen teuren Laborverfahren und fehlender prozessbegleitender Qualitätssicherung. Der Beitrag beschreibt Funktionsprinzip, Anwendung sowie Beispiele aus der Oberflächen- und Schweißnahtbearbeitung. T2 - 43. Vortrags- und Diskussionstagung Werkstoffprüfung 2025 CY - Dresden, Germany DA - 26.11.2025 KW - KorroPad KW - Nichtrostender Stahl KW - Korrosion KW - Passivität PY - 2025 SN - 978-3-88355-454-9 VL - 43 SP - 1 EP - 7 PB - DGM Deutsche Gesellschaft für Materialkunde e.V. CY - Sankt Augustin AN - OPUS4-64933 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klaus, Christian A1 - Soruco Aloisio, Ricardo A1 - Koch, Claudia A1 - Prellwitz, Matthias T1 - Towards Safety and Accuracy of Hydrogen Refuelling Stations through Digital Twins N2 - This paper presents digital quality infrastructure methods for hydrogen refueling stations using the Asset Administration Shell as a standardized digital twin. Implemented at BAM’s test platform, it integrates real-time sensor data, calibration certificates, and compliance documents to support traceable, interoperable asset management. In combination with AI and semantic tools, the system will enable predictive maintenance, remote audits, and improved safety. This approach reduces downtime, enhances transparency, and offers a scalable model demonstrating the potential of digital twins in advancing metrological traceability and operational efficiency in hydrogen technologies. T2 - IMEKO TC-6 International Conference on Metrology and Digital Transformation - M4DConf 2025 CY - Benevento, Italy DA - 03.09.2025 KW - Datenintregration KW - IT KW - Verwaltungsschale KW - Infrastruktur KW - OT KW - Open Source KW - Software PY - 2025 UR - https://www.m4dconf.org/ UR - https://www.sciencedirect.com/journal/measurement-digitalization SP - 1 EP - 6 AN - OPUS4-64951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grohmann, Maria A1 - Niederleithinger, Ernst T1 - Application of Elastic Reverse Time Migration to Ultrasonic Echo Data from Concrete Structures N2 - To enhance ultrasonic imaging of concrete structures, we adapted the geophysical migration method, Reverse Time Migration (RTM), for non-destructive testing (NDT) in civil engineering. First, two 2D elastic RTM algorithms, each considering different wave types, were implemented and evaluated with synthetic ultrasonic data. The algorithm that best resolved numerical concrete structures was subsequently applied to real ultrasonic data from a concrete specimen. Compared with conventional synthetic aperture focusing technique (SAFT) imaging, elastic RTM reproduced a greater number of structural features in both the numerical model and the concrete specimen. In particular, elastic RTM reconstructed vertical interfaces as well as hidden lower edges of modeled cavities and tendon ducts. Notably, imaging the full cross-sections of tendon ducts, which enables direct diameter estimation, represents a novel achievement for ultrasonic NDT. T2 - NDT-CE 2025 - The International Symposium on Nondestructive Testing in Civil Engineering CY - Izmir, Turkey DA - 24.09.2025 KW - Concrete Structures KW - Ultrasonic Echo Technique KW - Ultrasonic Imaging KW - Elastic Reverse Time Migration KW - Synthetic Aperture Focusing Technique PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-650350 DO - https://doi.org/10.58286/31680 SN - 1435-4934 SP - 1 EP - 3 PB - e-Journal of Nondestructive Testing CY - www.ndt.net AN - OPUS4-65035 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mair, Georg W. A1 - Günzel, Stephan A1 - Bock, Robert T1 - Risk management and consequence control in hydrogen transport - volume dependent pressure limitation as a scientific approach for consequence control N2 - With technological development, the transport units for compressed gases are becoming larger and their number is increasing. Simultaneously, the filling pressure for hydrogen in transport has increased far beyond the 200 bar, which has been the common European standard for decades. In total, this increases the potential consequences of an incident, which needs to get limited for ensuring acceptance in current practice with pressure vessels from large serial production. Consequently, the measures for new developments of extremely large and highly pressurised pressure vessels should meet a risk based higher level of requirements. For this purpose, the so-called pressure-volume product was proposed as a safety related criteria to the relevant regulatory bodies in 2020. The approach was accepted, and a working group was set up at the United Nations for developing a broadly accepted limitation of today's established pressure vessels compared to future units with even more gas content. The path to the finally decided limit value of 1.5 million bar litres is presented here for hydrogen with its individual steps: ‘Boundary between major accident and disaster’, ‘The effect of pressure waves on the human body’, ‘The propagation of pressure waves’, ‘The reference value for population density’ and ‘Impact of pressure waves’. This result of the UN working group has been accepted in December 2023 and will lead to a binding limitation of the pressure volume product for the so called pressure receptacles by 2027. The work on units larger than this pV-limit is going on at ISO level. T2 - 11th International Conference on Hydrogen Safety ICHS 2025 CY - Seoul, South Korea DA - 22.09.2025 KW - Safety KW - Hydrogen transport KW - Major accident KW - Pressure wave KW - Population density KW - UN Model Regulations PY - 2025 SP - 1 EP - 14 AN - OPUS4-64199 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nattuveettil, Keerthana A1 - Liebner, Christian A1 - Tiebe, Carlo T1 - Hydrogen safety- Dealing with Closed Spaces N2 - Hydrogen is under discussion as a potentially clean energy source, but its safe usage and handling in enclosed environments remains a critical challenge due to the properties of hydrogen. This work focuses on detecting and monitoring hydrogen concentration in closed spaces to improve safety by developing a sensor network-based leak detection system to prevent of the accumulation of hazardous mixtures. Furthermore, the study details the implementation of a hydrogen sensor network within a container, analysing sensor placement, data collection, and safety improvements. The findings contribute to better risk assessment and enhanced safety protocols in hydrogen storage and usage facilities. T2 - SMSI 2025 CY - Nuremberg, Germany DA - 06.05.2025 KW - Sensor Network KW - Hydrogen safety KW - QI-Digital PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-640630 SN - 978-3-910600-06-5 DO - https://doi.org/10.5162/SMSI2025/C6.2 SP - 167 EP - 168 PB - AMA Verband für Sensorik und Messtechnik e.V. CY - Berlin AN - OPUS4-64063 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klippel, Andrea A1 - Hofmann-Böllinghaus, Anja A1 - Heydick, Lukas A1 - Piechnik, Kira A1 - Wu, Hongyi A1 - Köhler, Florian T1 - Experimental Analysis of Fire Behaviour in Pine Forests and Agricultural Fields Large Scale Tests conducted within the TREEADS Project N2 - In two large-scale tests fire spread mechanisms in vegetation ground fires were studied in a pine forest and a crop field. Both fires were ignited with a drip torch using a gasoline-diesel mix. The tests were part of the European TREEADS project, specifically in the research work from the German Pilot focusing on Saxony-Anhalt and Brandenburg. These regions are known for dry, sandy soil, with pine trees covering approximately 73% of forested areas in Brandenburg and 48% in Saxony-Anhalt. The results of both experiments make a substantial contribution to optimizing extinguishing methods and strategies and enhancing a continued wildfire research in Germany. The test areas included a 16 x 22 m plot in a Saxony-Anhalt pine forest and a 20 x 100 m plot on a crop field, with fires ignited along a line using a drip torch at both locations. Fire spread was monitored with video and IR cameras mounted on a drone. In the pine forest, 96 thermocouples and gas sensors were attached to trees and a mobile FTIR spectrometer was used for real-time gas measurements. A protective strip was created around the test area using a soil tiller and fire-retardant foam to prevent uncontrolled fire spread. The experiment showed a consistent temperature rise as the fire was ignited and spread. Thermocouple data captured detailed thermal dynamics, while tree-mounted gas sensors recorded significant fluctuations in combustible gases. Real-time gas spectra from the FTIR spectrometer enabled precise smoke analysis. Conducted in stable weather - 23°C, light wind, low soil moisture—this setup improved reproducibility, with a weather station monitoring temperature, humidity and wind conditions to assess fire-environment interactions. After ignition process the fire showed a slow spread and distinct combustion phases. Smouldering was more pronounced in areas with grasses and deadwood, highlighting vegetation-specific burn patterns critical to wildfire research. The experiment showed numerous smouldering and burning spots, with flames igniting and extinguishing repeatedly. However, flame height did not exceed half a meter. Due to substantial smoke production, visibility in the test field was limited and team members wore respirators to collect specific smoke gases such as benzene and formaldehyde for analysis. Field measurements showed flame temperatures exceeding 500°C. Toxic smoke gas concentrations of up to 238 ppm CO were measured, although precise gas capture appeared challenging due to wind turbulence. The second large-scale area in Nauen, a cut wheat field (stubble height approx. 30 cm) was burned, with fire spreading across approximately 700 m². A 20 m ignition line directed flames with the wind. Fire spread was observed using drones equipped with IR cameras. Experiments demonstrated how unpredictable and challenging it is to measure large outdoor fires. To enable a comprehensive theoretical and numerical description of fire dynamics in wildfires, it is essential to conduct further large-scale experiments. T2 - Interflam 2025, 16th International Fire Science and Engineering Conference CY - London, United Kingdom DA - 30.06.2025 KW - Wildfire PY - 2025 SP - 1435 EP - 1444 PB - Interscience CY - London AN - OPUS4-63926 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hofmann-Böllinghaus, Anja A1 - Klippel, Andrea A1 - Piechnik, Kira T1 - Vehicle fires: significant fire hazard in transportation infrastructure N2 - The zeolitic imidazole framework-8 (ZIF-8) is a crystalline porous material that has been widely employed as template to fabricate porous nitrogen-doped carbons with high microporosity via thermal treatment at high temperatures. The properties of the carbon scaffold are influenced by the pore structure and chemical composition of the parent ZIF. However, the narrow pore size distribution and microporous nature from ZIF-8 often results in low mesopore volume, which is crucial for applications such as energy storage and conversion. Here we show that insertion of N-heterocyclic amines can disrupt the structure of ZIF-8 and dramatically impact the chemical composition and pore structure of the nitrogen-doped carbon frameworks obtained after high-temperature pyrolysis. Melamine and 2,4,6-triaminopyrimidine were chosen to modify the ZIF-8 structure owing to their capability to both coordinate metal ions and establish supramolecular interactions. Employing a wide variety of physical characterization techniques we observed that melamine results in the formation of a mixed-phase material comprising ZIF-8, Zn(Ac)6(Mel)2 and crystallized melamine, while 2,4,6-triaminopyrimidine induces the formation of defects, altering the pore structure. Furthermore, the absence of heterocyclic amine in the ZIF-8 synthesis leads to a new crystalline phase, unreported to date. The thermal conversion of the modified ZIFs at 1000 °C leads to nitrogen-doped carbons bearing Zn moieties with increased surface area, mesopore volume and varying degree of defects compared to ZIF-8 derived carbon. This work therefore highlights both the versatility of heterocyclic amines to modify the structure of framework materials as well as their role in tuning pore structure in nitrogen-doped carbons, paving the way to targeted design of high-performance electrodes for energy storage and conversion. T2 - Interflam 2025, 16th International Fire Science and Engineering Conference CY - London, United Kingdom DA - 30.06.2025 KW - Vehicle fires PY - 2025 SP - 1291 EP - 1298 PB - Interscience CY - London AN - OPUS4-63924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Piechnik, Kira A1 - Hofmann-Böllinghaus, Anja A1 - Klippel, Andrea T1 - Characterization and assessment of smoke emissions from smouldering forest fires: a combined experimental and numerical approach N2 - This article builds upon the publication "Comprehensive Laboratory Study on Smoke Gases During the Thermal Oxidative Decomposition of Forest and Vegetation Fuels"1 in Fire and Materials, 2024, summarizing the experimental methodology and highlighting key findings. The study investigates the gas-phase composition of smoke emissions from forest and vegetation fuels. The study focuses on pine-dominated ecosystems in Eastern Germany, with the objective of improving the understanding of wildfire-related gaseous emissions, as a contribution to the German pilot activities within the EU Project TREEADS. Using a modified DIN tube furnace in a bench-scale setup, the investigation centers on gaseous emissions from five trees and two ground cover species, explicitly excluding particulate matter. T2 - Interflam 2025, 16th International Fire Science and Engineering Conference CY - London, UK DA - 30.06.2025 KW - Wildfire PY - 2025 SP - 288 EP - 294 PB - Interscience CY - London AN - OPUS4-63999 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mente, Tobias A1 - Grimault de Freitas, Tomás A1 - Nietzke, Jonathan A1 - Konert, Florian A1 - Sobol, Oded A1 - Wackermann, Ken A1 - Ruchti, Peter A1 - Elsen-Humberg, Stefan A1 - Systermans, Thomas ED - Zimmermann, Martina T1 - Hohlzugprüfung als kostengünstige Methode zur Werkstoffcharakterisierung für die Wasserstoffwirtschaft N2 - Wasserstoff ist ein notwendiger Baustein zur Erreichung zukünftiger Klimaziele. Für eine schnell hochlaufende Wasserstoffwirtschaft ist es daher notwendig sowohl bestehende Infrastruktur als auch neue Werkstoffe für den sicheren und nachhaltigen Einsatz in Wasserstofftechnologien zu qualifizieren. Die akzeptierten und standardisierten Prüfverfahren zur Ermittlung des Einflusses gasförmigen Wasserstoffs auf die mechanischen Eigenschaften metallischer Werkstoffe sind meist sehr komplex, mit hohem technologischem und finanziellem Aufwand verbunden und stehen nur Wenigen Instituten weltweit zur Verfügung. Die Hohlzugprüftechnik bietet hier eine kostengünstige und einfach zu realisierende Alternative. Mit der im Jahr 2024 erstmals veröffentlichten ISO 7039 wurde diese Prüftechnik auch für die Wirtschaft anwendbar gemacht. Der Standard gilt allgemein für die Prüfung mit gasförmigen Medien, weist jedoch in Bezug auf die Prüfung mit gasförmigem Wasserstoff noch einige Wissenslücken auf. Im Teilvorhaben H2HohlZug des Leitprojekt TransHyDE werden die Lücken zum Einfluss der Geometrie, Oberflächenqualität sowie Gasreinheit in einzelnen Arbeitspaketen geschlossen und die Erkenntnisse in einen Standard überführt. T2 - 43. Vortrags- und Diskussionstagung Werkstoffprüfung 2025 - Werkstoffe und Bauteile auf dem Prüfstand CY - Dresden, Germany DA - 27.11.2025 KW - Hohlzugprüfung KW - Druckwasserstoff KW - ISO 7039 KW - H2HohlZug - TransHyDE PY - 2025 SN - 978-3-88355-454-9 SP - 11 EP - 17 PB - Deutsche Gesellschaft für Materialkunde e.V. (DGM) CY - Dresden AN - OPUS4-64937 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Leo, Reinhold A1 - Sobol, Oded A1 - Hango, Silas Ithete A1 - Saliwan Neumann, Romeo A1 - Askar, Enis A1 - Boellinghaus, Thomas T1 - Ex-situ investigation of the compatibility of Duplex Stainless Steel for high-pressure hydrogen applications N2 - The key to a successful transition into clean energy carriers such as hydrogen requires the construction of safe transportation pipelines made of alloys which are not susceptible to hydrogen assisted cracking. Duplex Stainless Steels (DSS) are considered as a proper class for components because of their many distinctive qualities. As this consideration depends strongly on the susceptibility level to Hydrogen Assisted Cracking (HAC), the DSS class has been broadly investigated under electrochemical charging conditions. In this work, the interplay between several factors controlling the level of HAC, was examined using light microscopy, high-pressure gaseous hydrogen pre-charging, Electron Backscatter Diffraction (EBSD), tensile testing, fractography and hydrogen concentration measurements using Carrier Gas Hot Extraction (CGHE). The effect of gaseous hydrogen on the mechanical properties with the role of hydrogen induced phase transformation have been investigated both in unused material and in high pressure pipeline section. In contrary to the common electrochemical charging described broadly in the literature, no significant martensitic phase transformation of the austenitic phase was observed. On the other hand, the influence of hydrogen on parameters such as elongation at fracture and reduction of area was noticeable. It is concluded based on the performance of DSS in gaseous hydrogen, that this material has a better potential for utilization in hydrogen applications. As for future experiments, the intention is to analyse the impact of high-pressure gaseous hydrogen on the welded components of this grade, and under mechanical load using the hollow specimen technique. T2 - 5th International Conference on Metals and Hydrogen CY - Ghent, Belgium DA - 14.10.2025 KW - High-Pressure Hydrogen KW - Pipelines KW - Duplex Stainless Steels KW - Hydrogen Assisted Cracking KW - Hollow Specimen Technique PY - 2025 SN - 978-9-08179-424-4 SP - 1 EP - 19 AN - OPUS4-64426 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Askar, Enis A1 - Schmidt, Martin A1 - El Harrab, Hayat A1 - Pekalski, Andrzej T1 - Ignition Indices of Hydrogen Mixtures under Electrolysis Process Conditions N2 - The formation of hydrogen-oxygen mixtures for example due to cross-over, malfunction or start-up and shut-down processes is a hazard very specific to given electrolysis processes that must be properly addressed. In this work the explosion limits of hydrogen-oxygen-mixtures at conditions up to 30 bar and 300 °C were determined experimentally. It was found that the existing experimental data can be interpolated with good accuracy using empirical approaches. Moreover, explosion limits at atmospheric conditions were also determined with reduced ignition energy, down to 1 mJ. Although in the literature it can be found that the ignition energy of flammable gases increases strongly when the concentration changes from stoichiometric to near the explosion limits, no significant influence on the mixture concentration was found within tested ignition energy range for H2/O2 mixtures. Finally, hot surface ignition for mixtures with 6 mol% hydrogen in oxygen, thus slightly above the explosion limit, were experimentally studied at different pressures up to 30 bara. Similarly, only slight difference from the ignition temperatures determined for stoichiometric mixtures were found. A 0D adiabatic, constant-volume reactor model was used to calculate the ignition temperatures. The model was tested for its prediction of ignition temperatures of hydrogen mixtures at different pressures. T2 - 11th International Conference on Hydrogen Safety (ICHS) 2025 CY - Seoul, South Korea DA - 22.09.2025 KW - Explosion limits KW - Ignition temperature KW - Ignition energy KW - Electrolyzer PY - 2025 SN - 979-12-243-0274-2 VL - 11 SP - 1259 EP - 1271 AN - OPUS4-64525 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gluth, Gregor ED - Wittke, W. T1 - Alkalisch aktivierter Beton (Geopolymer-Beton) N2 - Alkalisch aktivierte Bindemittel (AAB) sind Zemente, deren Erhärtung auf der alkalischen Anregung von reaktiven Aluminiumsilicaten beruht. AAB sind nach gegenwärtigem Stand die vielversprechendste Option, die mit der Herstellung und dem Einsatz von Zementen verbundenen CO2-Emissionen mittel- bis langfristig signifikant zu senken. Die Erhärtungsreaktionen und die Einflüsse auf die Mikrostruktur von AAB sind durch jahrzehntelange Forschung gut verstanden, und zahlreiche Beispiele belegen, dass AAB grundsätzlich als Betonbindemittel geeignet sind. Offene Fragen bestehen aber immer noch hinsichtlich der Dauerhaftigkeit von mit AAB hergestellten Betonen. Der vorliegende Beitrag gibt eine kurze Einführung in die Nomenklatur und die Geschichte von AAB. Die wichtigsten Reaktionen und Reaktionsprodukte, die zur Bildung der Mikrostruktur von AAB führen, werden beschrieben. Der Hauptteil des Beitrags diskutiert aktuelle Forschungsergebnisse und offene Fragen zur Dauerhaftigkeit von Betonen auf Basis von AAB. Wichtige Fortschritte auf diesem Gebiet konnten in den letzten Jahren insbesondere zum Einfluss von Sulfiden auf die Bewehrungskorrosion, zum Carbonatisierungswiderstand und zum Säurewiderstand erzielt werden. T2 - 10. Felsmechanik- und Tunnelbautag CY - Weinheim, Germany DA - 22.05.2025 KW - Alkali-activated materials KW - Carbonation KW - Reinforcement corrosion KW - MIC KW - Microbially induced corrosion PY - 2025 SN - 978-3-00-083562-9 SP - 73 EP - 84 PB - WBI GmbH CY - Weinheim AN - OPUS4-64266 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nicolicea, Alberto A1 - Pelkner, Matthias A1 - Melzer, Michael A1 - Oliveros-Mata, E. S. A1 - Zabila, Y. A1 - Makarov, D. T1 - Flexible AMR sensors for novel non-destructive testing capabilities N2 - Reshapeable magnetic field sensors fabricated on flexible substrates by thin-film deposi-tion or printing have recently emerged with promising applications in different field. In this study, flexible anisotropic magneto-resistive (AMR) sensors were used for the scanning of a curved and flat sample with reference defects, to prove the capability of this method for curved surface scanning, and to benchmark the performance when compared to a more standard method using rigid giant magneto-resistive (GMR) sensors. Defects with depths ranging from 110 μm up to 2240 μm were detected with a signal-to-noise ratio (SNR) of 2.7 up to 27.9 employing flexible AMR sensors. T2 - XMR-Symposium CY - Wetzlar, Germany DA - 12.03.2025 KW - non-destructive testing KW - Flexible sensor KW - Magnetoresistance PY - 2025 SP - 1 EP - 6 AN - OPUS4-65045 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meng, Xiangmeng A1 - Bachmann, Marcel A1 - Kising, Pascal A1 - Yang, Fan A1 - Rethmeier, Michael T1 - Prediction of weld pool and keyhole geometries in high-power laser beam welding through a physics-informed generative artificial intelligence approach N2 - The weld pool and keyhole geometries are critical characteristics in evaluating the stability of the high-power laser beam welding (LBW) process and determining the resultant weld quality. However, obtaining these data through experimental or numerical methods remains challenging due to the difficulties in experimental measurements and the high computational demands of numerical modelling. This paper presents a physics-informed generative approach for predicting weld pool and keyhole geometries in the LBW process. With the help of a well experimentally validated numerical model considering the underlying physics in the LBW, the geometries of the weld pool and keyhole under various welding conditions are calculated, serving as the dataset of the generative model. A Conditional Variational Autoencoder (CVAE) model is employed to generate realistic 2D weld pool and keyhole geometries from the welding parameters. We utilize a β-VAE model with the Evidence Lower Bound (ELBO) loss function and include Kullback-Leibler divergence annealing to better optimize model performance and stability during training. The generated results show a good agreement with the ground truth from the numerical simulation. The proposed approach exhibits the potential of physics-informed generative models for a rapid and accurate prediction of the weld pool geometries across a diverse range of process parameters, offering a computationally efficient alternative to full numerical simulations for process optimization and control in laser beam welding processes. T2 - International Congress of Applications of Lasers & Electro-Optics 2025 CY - Orlando, USA DA - 12.10.2025 KW - Laser beam welding KW - Generative artificial intelligence KW - Machine learning KW - numerical simulation PY - 2025 SP - 1 EP - 10 AN - OPUS4-65075 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mair, Georg W. A1 - Hajhariri, Aliasghar A1 - Sklorz, Christian A1 - Kriegsmann, Andreas A1 - Müller, Karsten T1 - A modular concept for protection against debris flight - Design, properties and usage N2 - With advances in technological development, stationary and mobile storage units for compressed hydrogen are becoming larger and larger. Their number is also increasing. At the same time, their design has evolved from steel and aluminium to pressure vessels made of composite materials. For safety reasons the design approval of those composite cylinders requires fire engulfment tests, which are mainly organised as open-air tests always needs dedicated protection measures. Under some conditions those protections measures even reduce the effort for organisational safety measures if e.g. the emission of splinters can get totally prevented. Another aspect is the improved reproducibility of fire tests by reducing the influence of wind. Between 2017 and 2019, BAM developed a stackable protective frame made of steel to safely capture splinters for the safe execution of high-energy impact tests. However, this frame was not flexible enough for the follow-up project, which led to a completely new protection concept for (potentially) destructive tests on gas-filled pressure vessels. This concept is based on very robust building blocks made from welded steel. Despite their considerable weight of around 500 kg p.p., they can be combined and stacked very easily like ‘Lego bricks’. The presentation will show the flexibility of the concept, some results of tests on the robustness against pressure waves and the effectiveness in wind attenuation. Finally, the interaction with a new, also modular burner concept for localised fires and full engulfment fires will be presented. T2 - 11th International conference on hydrogen safety (ICHS 2025) CY - Seoul, Republic of Korea DA - 22.09.2025 KW - Splinter protection KW - Pressure vessel testing KW - Fire engulfment KW - Destructive tests KW - Rupture KW - Gaseous tests KW - Pressure wave KW - Test equipment KW - Precaution measures PY - 2025 SN - 979-1-2243-0274-2 VL - 2025 SP - 1428 EP - 1439 AN - OPUS4-65100 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Channammagari, Harichandana A1 - Sahr, Rabea A1 - Trappe, Volker T1 - Experimentelle, Analytisch-Numerische Untersuchung des thermischen Ausdehnungsverhaltens von Faser-Kunststoff-Verbunden N2 - Im Rahmen des Forschungsvorhabens PROVING wurde eine Methode zur rechnerischen Bestimmung thermomechanischer Eigenspannungen in CFK entwickelt. Ziel ist die Berücksichtigung des thermischen Ausdehnungsverhaltens bei der Bestimmung des dreidimensionalen in-situ-Spannungszustands der Matrix für den strukturellen Nachweis. Die Eigenspannungen werden über mikromechanische Modellierung und FEM berechnet; die zugrunde liegenden Ausdehnungsfunktionen wurden experimentell validiert. N2 - As part of the PROVING research project, a method for calculating thermomechanical residual stresses in CFRP was developed. The aim is to take thermal expansion behavior into account when determining the three-dimensional in-situ stress state of the matrix for structural verification. The residual stresses are calculated using micromechanical modeling and FEM; the underlying expansion functions have been experimentally validated. T2 - 43. Vortrags- und Diskussionstagung Werkstoffprüfung 2025 CY - Dresden, Germany DA - 27.11.2025 KW - Thermische Eigenspannungen KW - Mikromechanik KW - Faser-Kunststoff-Verbunde KW - FEM PY - 2025 SN - 978-3-88355-454-9 VL - 2025 SP - 154 EP - 159 PB - DGM CY - Sankt Augustin AN - OPUS4-65112 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Huo, Wenjie A1 - Schmies, Lennart A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael A1 - Wolter, Katinka T1 - An illumination based backdoor attack against crack detection systems in laser beam welding N2 - Deep neural networks (DNNs) have been wildly used in engineering and have achieved state-of-the-art performance in prediction and measurement tasks. A solidification crack is a serious fault during laser beam welding and it has been proven to be successfully detected using DNNs. Recently, research on the security of DNNs is receiving increasing attention because it is necessary to explore the reliability of DNNs to avoid potential security risks. The backdoor attack is a serious threat, where attackers aim to inject an inconspicuous pattern referred to as trigger into a small portion of training data, resulting in incorrect predictions in the reference phase whenever the input contains the trigger. In this work, we first generate experimental data containing actual cracks in the welding laboratory for training a crack detection model. Then, targeting this scenario, we design a new type of backdoor attack to induce the model to predict the crack as a normal state. Considering the stealthiness of the attack, a common phenomenon during the welding process, illumination, is used as the backdoor trigger. Experimental results demonstrate that the proposed method can successfully attack the crack detection system and achieve over 90% attack success rate on the test set. T2 - 8th ML4CPS 2025 – Machine Learning for Cyber-Physical Systems CY - Berlin, Germany DA - 06.03,2025 KW - System security KW - Welding crack detection KW - Backdoor attack KW - Deep neural networks PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651357 DO - https://doi.org/10.24405/20021 VL - 2025 SP - 12 EP - 21 PB - Universitätsbibliothek der HSU/UniBw H CY - Hamburg AN - OPUS4-65135 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wu, Hongyi A1 - Buhk, Frederik A1 - Christiani, Ricardo A1 - Hofmann-Böllinghaus, Anja T1 - Influence of local vegetation on ignition and fire spread of vegetation fires-Experimental and numerical approach N2 - Within the framework of the European TREEADS project, Brandenburg and Saxony-Anhalt were designated as model regions. This designation facilitated the investigation of vegetation types, soil structure, and soil dryness. Brandenburg and Saxony-Anhalt are identified as the driest regions in Germany according to the annual mean soil moisture data. In these regions, 48% to 73% of the forests are composed of pine species. The soil profile is characterized by a relatively thin organic layer, measuring between 0.2 and 0.3 meters, underlain by sandy substrates. Consequently, surface and ground fires are more prevalent in these areas compared to other types of fires, such as crown fires. To investigate the influence of local vegetation, it goes through two aspects. One is laboratory study, the local vegetation samples were collected and tested for the thermal properties, such as activation energy, heat content and reaction kinetic of pyrolysis and dehydration. At the same time, small and medium scale combustion experiments were conducted to investigate the burning behavior. The other aspect is using the thermal properties as the input parameters for the development of numerical simulation in the computational fluid dynamics (CFD) tool. These models were then be validated with the combustion experiments, as a baseline for the further scaling up of the models, in order to investigate how the parameters influencing the fire spread in a large-scale case numerically. T2 - Interflam 2025, 16th International Fire Science and Engineering Conference CY - London, United Kingdom DA - 30.06.2025 KW - Wildfire PY - 2025 SP - 2221 EP - 2225 PB - Interscience CY - London AN - OPUS4-63932 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Junias, Josua Kondja A1 - Holtappels, Kai A1 - Liebner, Christian A1 - Thewis, Max A1 - Askar, Enis A1 - Shaanika, Erasmus T1 - Hydrogen Mixtures Flammability Limits Prediction using Machine Learning Models N2 - Flammability characteristics of hydrogen mixtures have been extensively investigated at different initial conditions(temperature and pressure). Based on the available experimental datasets, empirical and semi-empirical models are commonly used to calculate flammability limits in dependance to initial conditions and mixture composition to reduce the experimental effort. However, unevenly distributed empirical data and the complex non-linear relationship characteristics of these data present significant challenges to empirical flammability limits prediction methods under various mixture initial conditions. Moreover, the empirical models and semi-empirical models only cover some influencing parameters, respectively. To address these issues, the present study adapts a machine learning (ML) approach for improving the hydrogen-air/oxygen-inert gas mixture flammability limits prediction at different conditions with a holistic approach. A Multi-Layer Perceptron (MLP) model was trained, validated, and tested using key input features such as flammability state, initial mixture temperature, equivalence ratio, inert gas concentration, adiabatic flame temperature, and Lewis numbers. Data augmentation techniques were conducted on experimental datasets to improve the predictive capability of the model. The models’ performance was compared with empirical flammability limit prediction methods. The goal is to deliver fast, reliable, and more accurate predictions across different scenarios with a single prediction model. Most importantly, the machine learning approach offers a cost-effective and robust alternative to existing empirical flammability limit prediction methods, thus also reducing the experimental effort for explosion limits determination. T2 - 11th International Conference on Hydrogen Safety (ICHS) 2025 CY - Seoul, South Korea DA - 22.09.2025 KW - Machine Learning KW - Flammability Limits PY - 2025 SN - 979 -12 -243 -0274 - 2 SP - 1389 EP - 1401 AN - OPUS4-64624 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Simon, Patrick ED - Cunha, Álvaro ED - Caetano, Elsa T1 - Review of Ballasted Track Destabilization on Shake Table Tests N2 - Shake table tests have been used for a long time to understand the densification and fluidization of granular materials. While purely vertical shaking is quite unlikely to be found in vibration analysis when it comes to granular materials as soils, it has been found that the vertical vibration of railway bridge support structures can affect the fabric of the ballasted track on top. Starting from the experience at French railway lines with destabilizing track conditions on short bridges in high speed lines in the 1990s, various shake table test configurations have been used to investigate the destabiliza-tion of ballast at high acceleration levels. This article describes the effects of the variously investigated dynamic excitations of railway bridges on the bal-lasted track itself. T2 - 11th International Conference on Experimental Vibration Analysis for Civil Engineering Structures (EVACES 2025) CY - Porto, Portugal DA - 02.07.2025 KW - Infrastructure KW - Ballasted track KW - Ballast KW - Railway bridge dynamics PY - 2025 SN - 978-3-031-96105-2 DO - https://doi.org/10.1007/978-3-031-96106-9_62 SP - 595 EP - 604 PB - Springer CY - Cham AN - OPUS4-64265 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Characteristic Frequencies of Train-Induced Bridge, Track, Ground and Building Vibrations – Excitation and Mitigation N2 - The characteristic frequencies of train-induced vibrations are discussed in theory and experiment following the propagation of vibrations from the source to the receiver: 1. Out-of-roundness frequencies of the wheels, 2. sleeper-passage frequency, 3. the vehicle-track eigenfrequency, 4. band frequency of the impulses of the passing static axle loads, 5. car-length frequency and multiples, 6. axle-distance frequencies with two characteristic zeros, 7. bridge eigenfrequencies, 8. the cut-on frequency due to the layering, and 9. the cut-off frequency due to the material damping of the soil, 10. the building-soil eigenfrequency, 11. as a rigid building or flexible wall/column mode, 12. floor eigenfrequencies, 13. acoustic room resonances, 14. the „resonance“ frequency or cut-off frequency of a base isolation. Coincidences of some of these characteristic frequencies or frequency ranges can be typically problematic and mitigation measures at the track or at the building can be necessary. The bridge response to the passing static loads is deter¬mined by the axle-sequence spectrum, the eigenfrequency (transfer function) of the bridge, and the modal force or mode shape spectrum. The ground vibration has typically high frequencies for a stiff soil and low frequencies for a soft soil. The high amplitudes between the zeros of the axle-sequence spectrum are often measured in the ground vibrations, and they can be mitigated by soft support elements or a higher bending stiffness of the track. T2 - EVACES 2025 CY - Porto, Portugal DA - 02.07.2025 KW - Train-induced vibration KW - Vehicle excitation KW - Track response KW - Bridge resonance KW - Ground vibration KW - Soil-building transfer KW - Floor resonance KW - Axle-sequence spectrum KW - Vehicle-track eigenfrequency KW - Axle impulses PY - 2025 SN - 978-3-031-96113-7 DO - https://doi.org/10.1007/978-3-031-96106-9_77 VL - 2025 SP - 1 EP - 8 PB - Springer CY - Cham, Schweiz AN - OPUS4-63655 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Popiela, Bartosz A1 - Günzel, Stephan A1 - Mair, Georg W. T1 - Discussion of creep phenomena during initial loading of type 4 composite pressure vessels N2 - To maintain the highest safety standards for compressed gas storage in composite pressure vessels, a deeper understanding of their ageing mechanism is required. In this study, two designs of type 4 cylinders were manufactured the only difference being the internal pressure function used during the filament winding process. Hence, their residual stress state and the quality of the composite layers varied. Ten pressure vessels were initially loaded under sustained pressure and increased temperature and later subjected to slow burst tests. Comparing the results with cylinders tested in a pristine state underlines a significant improvement in the performance of initially loaded cylinders of one of the designs. This phenomenon was caused by a significant decrease of the scattering of burst pressures within a sample. At the same time, a slight decrease of the burst pressures could be observed. An explanation of this behavior could be supported by strain measurements with fiber optic sensors, which were embedded in the composite material. The strains measured during the initial loading indicate a stress redistribution, which has an impact on the strength of the pressure vessel. Moreover, an increased stiffness during the slow burst tests after initial loading was observed that indicates a better exploitation of the individual layers of the composite structure. The study supports previous observations on the increased performance after initial loading and provides new insights into the strain development in creep effects in type 4 pressure vessels. T2 - Pressure Vessels & Piping Conference PVP2025 CY - Montreal, Quebec, Canada DA - 20.07.2025 KW - Type 4 pressure vessel KW - Creep KW - Fiber optic sensors KW - Slow burst test KW - Mechanics of composites PY - 2025 SN - 978-0-7918-8907-7 VL - 2025 SP - 1 EP - 7 PB - ASME AN - OPUS4-63897 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simon, Patrick A1 - Baeßler, Matthias ED - Cunha, Álvaro ED - Caetano, Elsa T1 - On the reassessment of bridge superstructure vibrations for high-speed traffic N2 - The acceleration thresholds of bridge superstructures remain critical for designing and reassessing railway bridges on high-speed lines, with ballasted track systems historically limited to 3.5 m/s2 vertical accelerations due to destabilization risks. As part of the European InBridge4EU project, this study addresses methodological uncertainties in linking vertical bridge vibrations to lateral track creep—a key focus area for modernizing assessment protocols. A comparative analysis of two acceleration postprocessing methods (peak identification vs. fatigue-derived rainflow counting) as part of a recently proposed framework was conducted using an example bridge and train combination. Results demonstrate that rainflow counting yields more conservative creep estimates with the bulk of cumulative vibration-induced creep attributable to accelerations exceeding 3 m/s2. However, discretizing acceleration ranges into 1 m/s2 bins introduced significant errors compared to continuous cycle data, highlighting sensitivity to analysis parameters. These findings underscore the complexity of reconciling laboratory-derived harmonic vibration models with real-world bridge dynamics, where non-uniform acceleration patterns dominate. The research directly informs ongoing efforts to refine standardized criteria for ballasted track stability, particularly through the InBridge4EU project’s systematic re-evaluation of vibration limits and their engineering implications. By quantifying discrepancies between computational approaches, this work advances the development of robust protocols for predicting track degradation under high-speed operational loads. T2 - 11th International Conference on Experimental Vibration Analysis for Civil Enginering Structures (EVACES 2025) CY - Porto, Portugal DA - 02.07.2025 KW - Infrastructure KW - Railway bridges KW - Ballast destabilization KW - Acceleration limit KW - Ballasted track KW - Rainflow counting PY - 2025 SN - 978-3-031-96105-2 DO - https://doi.org/10.1007/978-3-031-96106-9_53 VL - 675 SP - 506 EP - 515 PB - Springer CY - Cham AN - OPUS4-64267 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liao, Chun-Man A1 - Bernauer, F. A1 - Niederleithinger, Ernst A1 - Igel, H. A1 - Hadziioannou, C. T1 - Assessment of prestress loss in a large-scale concrete bridge model under outdoor condition N2 - Environmental conditions affect the accuracy of field measurements used to monitor civil structures. Previous studies have shown that measured dynamic responses often lack the sensitivity needed for effective localized damage detection. To address this issue, our study focuses on distinguishing environmental effects from damage related effects in measured data to enhance vibration-based damage identification methods. Experimentally, the problem of prestress loss in a prestressed concrete bridge model was examined. By adjusting the pre-stressing force in a large-scale concrete bridge model, cracking phenomena were observed. To demonstrate field monitoring of a large-scale prestressed structure, noise recording was performed and the measurement data was analyzed with operational modal analysis. Additionally, ultrasonic testing, known for its high sensitivity in damage localization, was used to cross-check the structural damage. Seismic and coda wave interferometry were also employed to estimate wave velocities, providing insights into the level of prestress loss and temperature sensitivity. Ultimately, these measurable wave properties help to overcome the uncertainties associated with traditional vibration-based damage detection methods. T2 - EVACES 2025 CY - Porto, Portugal DA - 02.07.2025 KW - Prestress Loss KW - NDT KW - Ambient Vibration KW - Ultrasonic Testing KW - Coda Wave Interferometry KW - Seismic Interferometry PY - 2025 SN - 978-3-031-96105-2 DO - https://doi.org/10.1007/978-3-031-96106-9_20 VL - 675 SP - 181 EP - 189 PB - Springer Nature CY - Cham AN - OPUS4-64212 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Anderson, Johan A1 - Chiva, Roman A1 - Dumont, Fabien A1 - Lalu, Octavian A1 - Hofmann-Böllinghaus, Anja T1 - Assessment of fire performance of facades in a round robin using the European approach N2 - In recent years, an experimental round robin of full-scale façade tests was conducted using the proposed new European approach for assessing the fire performance of façades. The initial results were used to develop a calibration scheme and to propose assessment criteria aligned with appropriate safety levels. During the project, a need emerged to evaluate the stability of the fire source and the Consistency of heat exposure. This paper addresses these concerns by comparing the mass loss rates across a series of tests and analysing averaged temperature readings at various locations on the façade. The findings indicate that the method demonstrates high stability in terms of mass loss rates and provides consistent and appropriate heat exposure. T2 - Interflam 2025, 16th International Fire Science and Engineering Conference CY - London, UK DA - 30.06.2025 KW - Facade systems KW - Testing PY - 2025 VL - 2025 SP - 562 EP - 572 PB - Interscience CY - London AN - OPUS4-63998 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baer, Wolfram A1 - Ohm, Katrin A1 - Holzwarth, Marcel A1 - Mayer, Uwe T1 - Master Curve-Auswertungen und fraktographische Analysen zum Bruchmechanismus – neue Ergebnisse zur Untersuchung des Master Curve Konzepts für ferritisches Gusseisen mit Kugelgraphit bei dynamischer Beanspruchung (Projekt MCGUSS) N2 - In diesem Beitrag werden erste Master Curve (MC)-Auswertungen und fraktographische Analysen zum Bruchmechanismus aus dem laufenden Kooperationsprojekt MCGUSS zwischen der BAM Berlin und der MPA Stuttgart diskutiert. Für zwei SE(B)140-Großprobenversuchsserien mit je 6-8 Versuchen bei -40 °C bzw. -60 °C und Belastungsraten von 5-8x10^4 MPa√m/s wurden Referenztemperaturen T0 bestimmt. Ergänzt wird dies für erste Versuchsreihen an SE(B)25-Kleinproben, die bei -60 °C und Belastungsraten von ca. 2x10^5 MPa√m/s geprüft wurden. An ausgewählten Bruchflächen dieser Versuche wurden detaillierte fraktographische REM-Analysen vorgenommen. Im Vordergrund stand die Charakterisierung des Bruchmechanismus in Abhängigkeit von den Einflussfaktoren Temperatur und Probengröße. In Richtung der Zähigkeitstieflage werden die Analysen komplettiert durch die Ergebnisse von zwei SE(B)140-Großprobenversuchen bei -100 °C bzw. -140 °C und Belastungsraten von ca. 5-8x10^4 MPa√m/s. T2 - 57. Tagung des DVM-Arbeitskreises Bruchmechanik und Bauteilsicherheit CY - Köln, Germany DA - 18.02.2025 KW - Dynamische Beanspruchung KW - Bruchmechanik KW - Master Curve-Konzept KW - Gusseisen mit Kugelgraphit PY - 2025 DO - https://doi.org/10.48447/BR-2025-467 SP - 113 EP - 122 PB - DVM-Verlag CY - Berlin AN - OPUS4-62554 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Holzwarth, Marcel A1 - Baer, Wolfram A1 - Mayer, Uwe A1 - Weihe, Stefan T1 - On the Applicability of the Master Curve Concept for Ductile Cast Iron based on experimental and microstructural results N2 - Based on the state-of-the-art research and regulations, the application of the fracture mechanics master curve (MC) concept to ferritic ductile cast iron (DCI) is being investigated in a joint research project (MCGUSS) between BAM Berlin and MPA Stuttgart. The experimental program included a basic mechanical-technological material characterization consisting of tensile, Charpy and Pellini tests. To determine the relevant loading rate for brittle fracture, instrumented C(T)25 fracture tests were performed at different loading rates at a temperature of -40°C. The relevant loading rates are 5x10^3 MPa√ms-1 and 5x10^4 MPa√ms-1. A series of dynamic fracture tests consisting of DC(T)9, C(T)25 and C(T)50 specimens were performed at MPA. BAM performed corresponding test series with SE(B)10 (pre-cracked Charpy), SE(B)25 and SE(B)140 specimens to cover the influence of specimen geometry. In total about 400 tests were performed during this project. The experimental program is complemented by extensive fractographic and metallographic studies using scanning electron microscopy and cross sectioning, as well as characterizations of the chemical composition of the material and of the morphology and distribution of the graphite particles. KJcd values were evaluated for all C(T)25 specimens and some C(T)50 and DC(T)9 specimens. First Master Curve analyses suggest that modifications on the Master Curve setup will be neccessary for instance changing the coefficient from 0.019 to 0.045. This modification requires further validation and is only one of many possible modifications. The SE(B) specimen results clearly show an inverse size effect. This does not correlate with the weakest link effect attributed to steels which dictates lower fracture toughness values for larger specimens. Due to the presence of graphite particles in the DCI material, it is currently assumed that these particles play a significant role in the failure behavior of DCI materials and the following fracture mechanism is proposed: “Specimen size-dependent arrest of local brittle fracures before global brittle failure by weakest link”. T2 - 9th SEDS Workshop: Safety of Extended Dry Storage, 20.-22. Mai 2025 CY - Garching, Germany DA - 20.05.2025 KW - Statistics KW - Dynamic fracture toughness KW - Ductile cast iron KW - Master curve KW - Safety assessment PY - 2025 SP - 1 EP - 3 AN - OPUS4-63566 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Unger, Jörg F. T1 - Methodological Prerequisites for Reliable Simulation Results in the Virtual Lab and Digital Twins N2 - Simulationen übernehmen zunehmend eine zentrale Rolle in sicherheitskritischen Entscheidungsprozessen, etwa im Bauwesen, bei digitalen Zwillingen oder in der prädiktiven Instandhaltung. Damit diese Entscheidungen auf zuverlässigen numerischen Modellen basieren können, müssen die zugrunde liegenden Teilmodelle eindeutig beschrieben, reproduzierbar und in der Community validiert sein. Dieses Manuskript skizziert die notwendigen Voraussetzungen für vertrauenswürdige, FAIR-konforme und entscheidungsfähige Simulationsprozesse. Zunächst wird die Notwendigkeit einer formalen, softwareunabhängigen Beschreibung mathematischer Modelle und numerischer Implementierungen diskutiert. Standards wie VMAP, Ontologien wie MathModDB sowie BIM- und STEP-Formate bieten erste Ansätze zur semantischen Modellbeschreibung und zur automatisierten Generierung simulationsfähiger Eingabedaten. Im zweiten Teil wird die Rolle experimenteller Daten für die Validierung von Modellen beleuchtet. Es wird gezeigt, dass hochwertige, strukturierte und maschinenlesbare Validierungsdatensätze essenziell sind, insbesondere für die Bewertung konstitutiver Modelle. Ein weiteres Kapitel widmet sich der Unsicherheitsquantifizierung. Neben klassischen Fehlermaßen werden aleatorische und epistemische Unsicherheiten sowie deren Einfluss auf die Modellbewertung behandelt. Besondere Aufmerksamkeit gilt der Bayes’schen Kalibrierung, der Trennung von Trainings und Testdaten und der Notwendigkeit, auch Begleitversuche aus Materialtests zu dokumentieren. Abschließend wird die Idee einer Benchmarking-Plattform vorgestellt, die auf reproduzierbaren Workflows, automatisierter Provenienzverfolgung und der Nutzung von Research Object (RO) Crates basiert. Diese Plattform erlaubt die dezentrale Veröffentlichung und zentrale Abfrage von Benchmark-Ergebnissen und fördert eine gemeinschaftliche Verifikation und Validierung. Ziel ist es, die Vergleichbarkeit von (Open-Source-)Simulationstools zu verbessern um dadurch komplexe experimentelle Setups zunehmend durch zuverlässige Simulationen ersetzen zu können. T2 - NAFEMS - Symbiose von Simulation und Test CY - Wiesbaden, Germany DA - 12.11.2025 KW - Verification and Validation, KW - Digital twins KW - Virtual lab KW - Uncertainty quantification PY - 2025 SN - 978-1-83979-242-7 SP - 23 EP - 28 PB - NAFEMS CY - Wiesbaden, Germany AN - OPUS4-65271 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Schukar, Marcus A1 - Breithaupt, Mathias A1 - Kriegsmann, Andreas T1 - Distributed Fibre Optic Monitoring of Hydrogen Storage Composite Pressure Vessels for Automotive Use N2 - We present our research work on the condition monitoring of hydrogen storage composite pressure vessels using distributed fibre optic sensors. The sensing fibres are integrated into the composite structure by wrapping them over the polymer liner in the helical and circumferential direction during the manufacturing process of the carbon fibre reinforced polymer. The following use of optical backscatter reflectometry allows for continuous condition monitoring and precise detection and localization of structural damages during the entire service life. To account for the time-dependent strength degradation of the composite pressure vessels, both slow burst and ambient hydraulic cycling tests, respectively, were conducted on five 70 MPa pressure vessels with integrated fibre optic sensors. The results achieved via distributed fibre optic strain sensing demonstrate a near linear strain response to pressure suitable for sensitive condition monitoring and confirm the required robustness of the selected sensor solution. T2 - DGZfP-Jahrestagung 2025 CY - Berlin, Germany DA - 26.05.2025 KW - Distributed fibre optic sensor (DFOS) KW - Composite pressure vessel KW - Optical backscatter reflectometry KW - Slow burst test KW - Ambient hydraulic cycling test PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653067 DO - https://doi.org/10.58286/32344 SP - 1 EP - 8 PB - NDT.net AN - OPUS4-65306 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kocherla, Amarteja A1 - Strangfeld, Christoph A1 - Hüsken, Götz T1 - Embedded Sensors for Quality Control and Structural Integrity Monitoring of Large-scale 3DCP Structures N2 - In extrusion-based 3D concrete printing (3DCP), addressing challenges related to safety, reliability, and quality control is crucial for widespread adoption. Yet current limitations in monitoring material properties during and after printing hinder the development of effective 3DCP guidelines. Therefore, the development of an inline sensing system capable of real-time monitoring and adjustment of process parameters is necessary to overcome these challenges. Building upon an existing inline sensing system developed by BAM, which currently monitors material properties during printing and the geometry of the print post-extrusion, this study extends its capabilities to post-extrusion monitoring using embedded piezoelectric (PZT) sensors. These PZT sensors provide localized measurements of material changes through electrical impedance (EI) measurements without disrupting the printing process. By embedding these sensors in 3D printed structures, continuous monitoring is achieved from layer deposition through 1-day of hydration. To achieve this, initially, PZT sensors were developed with multiple layers of protective coatings. Two different 3D printed mixtures, each with different hydration behaviors, were utilized, and PZT sensors were strategically placed between printed layers to maintain their integrity. EI measurements were collected continuously from printing through 1 day of hydration. Analysis of amplitude and frequency changes in the EI response spectrum provided insights into material behavior post-printing. The study highlights how continuous monitoring of frequency and conductance can track structural builtup and property development of the material. Rapid changes in conductance measurements, immediately post-printing indicate swift structural built-up, while key hydration phases are reflected in frequency measurements. T2 - 34th Annual Conference and Exhibition on Non Destructive Evaluation & Enabling Technologies CY - Chennai, India DA - 12.12.2024 KW - Embedded Sensors KW - 3D Concrete Printing KW - Quality Control KW - Inline Sensing KW - Structural Integrity PY - 2025 SP - 1 EP - 8 PB - Springer Nature CY - Heidelberg AN - OPUS4-65305 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sauer, Hannah A1 - Okpeke, Bright Ebikemefa A1 - Dzielendziak, Agnieszka Sylwia A1 - Batcke, Lars A1 - Eberwein, Robert A1 - Ehlers, Sören T1 - Comparative life cycle assessment of different vacuum insulation panel core materials for cryogenic storage tanks – with a focus on glass bubbles as a novel core material N2 - Developing a sustainable hydrogen supply chain is important in facilitating the energy transition towards climate neutrality. Hydrogen in its free form can be stored and transported either as a gas or a liquid. Due to gaseous hydrogen's comparatively low energy density, liquefied hydrogen (LH 2) is often preferred, especially with regard to long-distance transportation and storage in bulk. A notable challenge associated with LH2 is the inherent requirement to preserve it at a low temperature of -253°C. Consequently, the utilisation of thermally insulated tanks is necessary to minimise LH 2 evaporation. There is a lack of literature on the environmental impacts of insulation materials and concepts for cryogenic storage tank applications in the hydrogen supply chain. Hence, this study investigates a novel concept, namely vacuum insulation panels (VIPs), focusing on their core materials, with a view to assessing their environmental sustainability and circularity. A cradle-to-grave life cycle assessment (LCA) model is employed to investigate six distinct VIP core materials, namely, silica aerogel, rigid polyurethane foam, expanded perlite, glass fibre, fumed silica, and glass bubbles (hollow glass microspheres), with a special focus on the latter. The LCA results show that polyurethane foam and silica aerogel rank low in environmental performance, making them less suitable as primary choice. Expanded perlite is the most environmentally friendly material option, followed by glass fibre, glass bubbles, and fumed silica. Improvements to the environmental impact of glass bubbles can be achieved via the implementation of closed-loop recycling in their life cycle. T2 - The World Hydrogen Technologies Convention 2025 CY - Dublin, Ireland DA - 21.10.2025 KW - LH2 KW - Insulation KW - Life cycle assessment PY - 2025 UR - https://www.whtc2025.com/conference-proceedings SP - 65 EP - 67 AN - OPUS4-64668 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bernardy, Christopher A1 - Habib, Abdel Karim A1 - Kluge, Martin A1 - Schalau, Bernd A1 - Schulze, Marcel A1 - Kant, Hanjo A1 - Orchini, Alessandro ED - Ruggiero, Eric J. T1 - Experimental investigation of large-scale hydrogen diffusion jet flames N2 - Hydrogen is a promising alternative to natural gas in industrial energy applications which would serve the goal of limiting global warming. However, wide application of hydrogen requires specific safety considerations taking into account that hydrogen is stored and transported under much higher pressure than natural gas. Thus, one scenario to be considered for hazard assessment is a sudden release of hydrogen from a leakage or safety valve and its subsequent ignition. For hydrocarbon flames, various jet flame models are available. However, hydrogen flames significantly differ from hydrocarbon flames in their combustion behavior, so that the applicability of these models to hydrogen has to be investigated. For that purpose, reals scale tests were carried out at the BAM Test Site Technical Safety. In addition, hydrocarbon jet flames (methane) were investigated. In these tests, the flame geometry and the thermal heat radiation were investigated for a release angle of 90°, for different release pressures (up to 220 bar) and mass flows (up to 0.175 kg/s). While existing heat radiation data from the literature are mostly based on unsteady outflow conditions and/or releases in still air, the experiments presented here are focused on ensuring a constant mass flow over the release duration under realistic free field conditions (with wind influence). This allows a better comparability with the stationary jet flame models and assessment of wind influence on model predictions. A number of parameters such as the surface emissive power of the jet flame and the radiant heat fraction were determined. A detailed comparison of the obtained experimental results with literature radiation models was performed. Good agreement between experimental and literature data was found for hydrogen whereas significant differences were identified for methane. Based on the investigations, empirical equations for modelling jet flames could be derived. T2 - American Society of Mechanical Engineers - Turbomachinery Technical Conference & Exposition GT2025 CY - Memphis, TN, USA DA - 16.06.2025 KW - Hydrogen release KW - Jet flame KW - Radiant heat fraction KW - Thermal radiation PY - 2025 SN - 978-0-7918-8877-3 DO - https://doi.org/10.1115/GT2025-FM2 SP - 1 EP - 11 PB - The American Society of Mechanical Engineers CY - Livingston AN - OPUS4-64098 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sarif, Raduan A1 - Tiebe, Carlo A1 - Herglotz, Christian T1 - Early Response Prediction for H2 Sensors N2 - Green hydrogen (H2) is essential for the global transition to clean energy; it will significantly reduce emissions from heavy industry and the long-distance transport system. H2 can be used as fuel in fuel cells, storing surplus renewable energy, and as a feedstock in industrial processes. However, H2 faces significant safety challenges during storage and transportation. Accidents due to H2 leakage and explosions raise serious concerns due to its high flammability, rapid diffusion in air, and extremely low ignition energy. To mitigate risks associated with H2 leakages, reliable and automated H2 safety systems are essential for emergency repairs or shutdown. An early response from H2 sensors is crucial for early warning in accidents. The earlier response time of H2 sensors is often constrained by their sensor principle, which is heavily influenced by the sensor material’s properties. This study explores methods for earlier sensor response through predictive algorithms. Specifically, we investigate transient response predictions using a First-Order (FO) model and propose improvements through the First-Order with early response and the First-Order with adapted early response model. Both models can predict the stable value of the H2 sensor response from a small time window, which is 70.89% and 83.72% earlier, respectively, than the time required for the sensor hardware to reach it physically. The model’s performance is evaluated by calculating the fitting error with a 2 % threshold. Our current research lays the groundwork for future advancements in real-time sensor response predictions for hydrogen leakage. T2 - IARIA Congress 2025 : The 2025 IARIA Annual Congress on Frontiers in Science, Technology, Services, and Applications CY - Venice, Italy DA - 06.07.2025 KW - H2 Safety KW - H2 leakage detection KW - First-Order (FO) model KW - H2 Sensor data analysis KW - H2 sensor response predictions PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-640676 UR - https://www.thinkmind.org/articles/iaria_congress_2025_1_250_50159.pdf SN - 978-1-68558-284-5 SP - 1 EP - 8 PB - IARIA Press CY - Wilmington AN - OPUS4-64067 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sarif, Raduan A1 - Tiebe, Carlo A1 - Herglotz, Christian T1 - Analysis of Methods for Predicting H2 Sensor Responses N2 - Hydrogen (H2) is crucial for replacing fossil fuels and achieving net-zero emissions, but its flammability and explosiveness pose safety challenges. Rapid H2 leak detection is essential for triggering emergency accidents. However, H2 sensor response is constrained by material properties and gas flow dynamics, causing response and detection delays. Our current study explores various available algorithms for H2 sensor response prediction from early responses with a small time window, accelerating leakage detection. Our findings identify the most efficient algorithms for real-time implementation, enhancing H2 safety systems. T2 - SMSI 2025 2025-05-06 - 2025-05-08 Nürnberg CY - Nuremberg, Germany DA - 06.05.2025 KW - H2 safety KW - Early H2 leakage detection KW - Prediction algorithms KW - Stable H2 value prediction PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-640617 SN - 978-3-910600-06-5 DO - https://doi.org/10.5162/SMSI2025/C6.3 SP - 169 EP - 170 PB - AMA Verband für Sensorik und Messtechnik e.V. CY - Berlin AN - OPUS4-64061 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Theiler, Geraldine A1 - Cano Murillo, Natalia A1 - Sawae, Y. A1 - Shinmori, H. A1 - Hashimoto, H. A1 - Aoyagi, A. A1 - Dobbelaar, E. T1 - Towards sustainable and hydrogen compatible sealing materials N2 - Materialien auf PTFE-Basis werden in der Regel als Kolbenringe in Hochdruck- und/oder kryogenem Wasserstoff verwendet. In diesem Projekt werden neu formulierte und nachhaltigere Polymerwerkstoffe mit herkömmlichen Materialien verglichen. Auf Grundlage der tribologischen Ergebnisse werden vielversprechende Kandidaten zusammen mit Reibungsmechanismen sowohl bei Hochdruck- als auch bei Niedrigtemperatur-Wasserstoff vorgeschlagen. T2 - 66. GfT Tribologie-Fachtagung 2025 CY - Wernigerode, Germany DA - 29.09.2025 KW - Wasserstoff KW - Reibung KW - Verschleiß KW - Kolbenring KW - Dynamische Dichtung PY - 2025 VL - 09 SP - 1 EP - 4 AN - OPUS4-64314 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schaad, C. A1 - Tiebe, Carlo A1 - Groth, Katrina M. T1 - A Framework for Transforming Process Control System Data from a Hydrogen Fueling Station into HyCReD Data N2 - Reliability data for hydrogen infrastructure components is essential for developing Quantitative Risk Assessment (QRA) for these technologies, which in turn is necessary for a safer deployment and expansion of the hydrogen market. However, there is currently a lack of hydrogen component reliability data available for these systems, thus limiting the usefulness of insights obtained from these QRA. The Hydrogen Component Reliability Database (HyCReD) has been proposed as a tool for reliability data collection and as a source for future QRAs. In this paper, we develop a digital tool that automatically processes data coming from Process Control System (PCS) in a hydrogen fueling station, detects the relevant failure events for hydrogen systems during its operation, and then logs the event information into HyCReD. To build this tool, we first categorized the station components in hydrogen service, their specific failure modes, and the specific failure mechanisms that are relevant to a QRA. Then, we identified the data available in the station PCS and the methods available for diagnosing the relevant failure events. The resulting tool is divided into three steps: (1) PCS data collection through an API, (2) data analysis for the detection and diagnosis of new failure events, and (3) logging that event into HyCReD. Finally, we discuss the potential for expanding the detection and diagnosis to more complex failure modes present in a hydrogen fueling station. This digital tool is set for implementation and validation on an experimental hydrogen fueling site. The goal for this digital tool is to be applicable to every kind of hydrogen fueling station and to be extendable to similar hydrogen technologies. T2 - 35th European Safety and Reliability Conference (ESREL2025) and the 33rd Society for Risk Analysis Europe Conference (SRA-E 2025) CY - Stavanger, Norway DA - 15.06.2025 KW - Reliability data KW - Hydrogen safety KW - HyCReD KW - Hydrogen Component Reliability Database KW - Hydrogen fueling station KW - Hydrogen refuelling station KW - HRS PY - 2025 UR - https://rpsonline.com.sg/proceedings/esrel-sra-e2025/html/ESREL-SRA-E2025-P6264.html SN - 978-981-94-3281-3 DO - https://doi.org/10.3850/978-981-94-3281-3-procd SP - 2663 EP - 2670 PB - Research Publishing CY - Singapore AN - OPUS4-63532 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eberwein, Robert A1 - Hajhariri, Aliasghar A1 - Otremba, Frank A1 - Camplese, Davide A1 - Scarponi, Giordano E. A1 - Cozzani, Valerio A1 - Seidlitz, Holger T1 - Repeatable testing of a cryogenic storage tank with variable insulation material in fire like conditions N2 - For decarbonizing the energy industry and transport, cryogenic energy carriers have great potential. The storage takes place in tanks with thermal super-insulations, which are in application for decades, but there is only limited knowledge about its behaviour in a fire scenario. This represents a major incident that may generate extraordinary loads on the tank and its insulation system, and that eventually lead to a sudden tank failure. This paper presents a test rig called the Cryogenic High Temperature Thermal Vacuum Chamber (CHTTVC), which can be used to test typical thermal superinsulation’s under cryogenic and fire-like conditions in parallel. The test method makes it possible to measure the heat flow through the thermal superinsulation over time and to investigate the degradation behaviour of the insulation within a test. In the paper results from the first tests are presented. T2 - 18th Cryogenics 2025, IIR Conference CY - Prague, Czech Republic DA - 07.04.2025 KW - LH2 KW - LNG KW - Fire KW - Insulation KW - Safety PY - 2025 DO - https://doi.org/10.18462/iir.cryo.2025.0007 SP - 205 EP - 210 CY - Prag AN - OPUS4-63740 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Harwege, Finn A1 - Schmidt, Heiko A1 - Eberwein, Robert T1 - Testing of vacuum insulation panels for liquid hydrogen storage tanks N2 - Vacuum insulation panel (VIP) based insulation could present an alternative to the common double walled vacuum insulation for large liquefied Hydrogen (LH2) storage tanks. In this paper a brief introduction on VIPs and the envisioned design of VIP-based LH2-tank insulation is given. The design of a flat plate boil-off calorimeter for the testing of the insulation concept is shown, with regard to thermal design, mechanical design and instrumentation. Finally, an overview over the particular challenges for modelling VIP-based insulation and the proposed testing to be performed on the test rig is presented. T2 - 18th Cryogenics IIR International Conference CY - Prague, Czech Republic DA - 07.04.2025 KW - Liquefied Hydrogen KW - Insulation KW - Calorimeter KW - Vacuum Insulation Panel KW - LH2 PY - 2025 SN - 0151-1637 DO - https://doi.org/10.18462/iir.cryo.2025.0010 SN - 978-2-36215-053-1 VL - 2025 SP - 168 EP - 174 PB - ICCEX CY - Prag AN - OPUS4-62959 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Holzwarth, Marcel A1 - Baer, Wolfram A1 - Mayer, Uwe A1 - Weihe, Stefan T1 - Master Curve-Auswertungen und Untersuchung des Größeneffekts für c(t)-proben - Aktuelle Erkenntnisse zur Untersuchung des Master Curve Konzepts für ferritisches Gusseisen mit Kugelgraphit bei dynamischer Beanspruchung N2 - Ausgehend vom Stand des Regelwerkes und der Forschung wird in einem BMUV-Verbundprojekt zwischen der MPA Stuttgart und der BAM Berlin die Anwendung des Master Curve (MC)-Konzepts auf ferritisches Gusseisen mit Kugelgraphit (DCI) untersucht. Ziel des Verbundprojekts ist die Anwendbarkeit des MC-Konzepts näher zu untersuchen und ggf. Modifikationen vorzunehmen, um eine Bewertungsmethode für die dynamische Bruchzähigkeit von DCI im Übergangsbereich zu erarbeiten. Auf den Jahrestagungen 2023 und 2024 des DVM-AK Bruchmechanik und Bauteilsicherheit wurden bereits der Forschungsansatz sowie erste Ergebnisse des Projekts MCGUSS präsentiert. Der Beitrag für die diesjährige Tagung soll nun MC-Auswertungen und den Größeneffekt für C(T)-Proben aus DCI diskutieren. T2 - 57. Tagung des DVM-Arbeitskreises Bruchmechanik und Bauteilsicherheit CY - Köln, Germany DA - 18.02.2025 KW - Versuche KW - Master Curve KW - Bruchmechanik KW - Dynamische Beanspruchung KW - Gusseisen mit Kugelgraphit PY - 2025 DO - https://doi.org/10.48447/BR-2025-495 SP - 123 EP - 129 PB - DVM-Verlag CY - Berlin AN - OPUS4-62555 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weber, Mike A1 - Jaunich, Matthias A1 - Goral, Milan A1 - Völzke, Holger T1 - Reproducing and discussion of mechanisms in the contact area between metallic seals and flange during aging by finite element analysis (FEA) N2 - When the first site-specific interim storage licenses for DPCs (dual purpose casks), loaded with spent nuclear fuel or vitrified high-level waste from reprocessing were issued, a duration of 40 years was considered for interim storage license application and the long-term safety assessment of casks. In the meantime, the availability of a final repository is further delayed by several decades and thus interim storage for more than a century becomes a necessity. To assess the long-term performance of the typically used metal seals (e.g. Helicoflex), consisting of a helical spring (Nimonic), an inner stainless steel liner and an outer liner made from silver or aluminum, several experimental programs were conducted and are still ongoing. The investigated metal seals are typically mounted in mock-up flange systems and stored at increased temperatures to accelerate the aging process. In certain intervals the remaining seal force, the useable resilience and the corresponding leakage rate are determined. BAM has accompanied such programs for many years and started independent investigations in 2009. Although the remaining seal force is often used as “…one of the key parameters regarding sealing performances over time…” the presented results so far have shown that the courses of the leakage rate and the remaining seal force do not always correlate as expected. In 2016 BAM firstly published results of seals with aluminum liners where the measured leakage rate started to rise after a quite short time period (< 1 year) at 150 °C, although the seal force decreased only slightly compared to the previous measurement. After exceeding the required leakage rate of 10-8 Pa*m3/s it decreased again to acceptable values in the further course of aging. With reference to already published works, BAM has developed a new detailed ABAQUS finite-element (FE) model to represent the behavior of the seal mounted in the mock-up flange during aging, mainly characterized by the creeping of the outer liner. The main goal of the numerical simulation is to reproduce and understand the changing distribution of contact stresses (outer liner/flange) during aging and to discuss if and how it could be causative for the observed early breach of the leak tightness criteria and its later recovery. T2 - PATRAM 2025, 21st International Symposium on the Packaging and Transportation of Radioactive Materials CY - San Antonio, Texas, USA DA - 27.07.2025 KW - Finite element analysis KW - Metallic seals KW - Aging KW - Contact area PY - 2025 SP - 1 EP - 10 PB - INMM CY - Indianopolis, Indiana, USA AN - OPUS4-63882 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Kömmling, Anja A1 - Böhning, Martin A1 - Silbernagl, Dorothee T1 - Comparison of ageing behavior of O-ring seals under hydrogen and air N2 - Elastomeric seals are essential components in the infrastructure which prevent leakage of gas and ensure proper function of technical devices and are therefore highly safety relevant. For proper function a remaining resilience and tolerance to pressure changes is required. The ageing of elastomers is an undesirable but inevitable process leading to a limited lifetime of rubber products such as seals. Independent of the application, as e.g. automotive, piping or container applications, a long lifetime or at least a timely exchange of a seal before occurrence of critical failure is desired. Hydrogen is a key element for the energy turnaround and therefore the compatibility of seals with hydrogen is essential. In addition to the effect of hydrogen uptake and release, which might also cause destructive effects such as rapid gas decompression, ageing at high temperature under hydrogen atmosphere is of interest too. Most of the existing work is addressing the performance of new materials and comprises only very limited investigations concerning long-term use and the behaviour of aged materials in contact with hydrogen. As ageing can lead to substantial changes of material properties, it must be evaluated whether these changes are beneficial or deteriorating for the component function. In this work we present and compare results of the characterization of three sealing materials (EPDM, HNBR, FKM) after ageing at high temperature under hydrogen and air. Despite the common assumption that ageing under hydrogen atmosphere should be less severe for the material in comparison to air ageing, this is not the case for every material. T2 - ASME PVP2025, Pressure Vessels & Piping Conference CY - Montreal, Quebec, Canada DA - 20.07.2025 KW - Aging KW - Seal KW - Compression set KW - Atomic force microscopy PY - 2025 SP - 1 EP - 7 AN - OPUS4-63889 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Campos de Oliveira, Paula A1 - Markötter, Henning A1 - Zhang, Wen A1 - Eddah, Mustapha A1 - Widjaja, Martinus Putra A1 - Remacha, Clément A1 - Bruno, Giovanni T1 - Enhanced image segmentation of refractories using synchrotron X-ray computed tomography and machine learning techniques N2 - The microstructure of refractory materials is complex, featuring a variety of mineral phases, agglomerates, defects, and controlled porosity. The behavior of refractories at high temperatures adds another layer of complexity, as phase transitions and particle rearrangements can strongly affect their properties. To analyze such intricate microstructure, advanced imaging techniques such as Synchrotron X-ray Computed Tomography (SXCT) allow detailed 3D visualization and quantification of features up to 1 μm. However, the intricacy of these microstructures makes phase identification (known as image segmentation) in digital images a challenging process. X-ray images often contain noise and image artifacts, making the analysis more difficult. Therefore, this work describes image segmentation and artifact reduction methods to characterize refractories using X-ray imaging. We studied refractory ceramics used in the aerospace industry, primarily composed of fused silica. For image segmentation, the traditional approach of greyscale thresholding was compared with machine learning. Greyscale thresholding relies on predefined algorithms to assign phases based on intensity values. In contrast, machine learning extracts patterns from large datasets, enabling more adaptive and accurate segmentation. By combining high-resolution SXCT and machine learning analysis algorithms, we successfully segmented previously uncharacterized 3D microstructural key features of refractories, including agglomerates, grain boundaries, pore size distribution and interconnectivity. Compared to traditional methods, the machine learning-enhanced segmentation presented a more accurate quantification of porosity and defects. The integration of advanced imaging techniques with machine learning segmentation significantly improves the characterization of refractory materials, providing a more precise understanding of the relationship between microstructure and material performance, supporting the development of innovative industrial solutions. T2 - The 19th Biennial International Technical Conference on Refractories (UNITECR 2025) CY - Cancún, Mexiko DA - 27.10.2025 KW - Synchrotron X-ray Tomography KW - Machine learning KW - Image segmentation KW - Ceramics KW - Refractories PY - 2025 SP - 478 EP - 481 AN - OPUS4-64803 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bernardy, Christopher A1 - Habib, Abdel Karim A1 - zur Nedden, Philipp Maximilian A1 - von Saldern, Jakob Georg Raimund A1 - Beuth, Jan Paul A1 - Orchini, Alessandro ED - Carcassi, Marco T1 - Thermal radiation of inclined large scale hydrogen jet flames N2 - In order to assess the thermal radiation emanating from hydrogen jet flames, experiments under real scale conditions were carried out at the Test Site Technical Safety of BAM. Herein, the behavior of inclined hydrogen jet flames was investigated. The aim of the work is to determine the Surface Emissive Power and radiant heat fraction of these flames and to provide a reliable dataset for model evaluation purposes. Since the aforementioned values are not directly measurable, the incident heat radiation was measured at defined distances from the flame, as well as the flame's shape and size. The required values were then derived from these measurements. The hydrogen releases ranged from 0.005 kg/s to 0.175 kg/s with a 30 mm orifice. The mass flows were held constant during the releases, nevertheless a transient behavior of the flame could be observed since the experiments were carried out under open field conditions, with unsteady wind fields. In the literature, the flame lengths are often determined using visible light imaging, either by injecting coloring substances in the low light emitting hydrogen jet flame or by carrying out the measurements in darkness. In this work the jet flames were visualized using infrared (IR) and OH* imaging. The recorded flame shapes and resulting flame lengths are compared. Results from this showed that the flame lengths determined with OH* and IR recordings differ greatly. A flame length ratio l_(f OH*)/l_(f IR) in the range of 0.47-0.62 can be found. In addition, the SEP differ also in the range of 10 kW/m²-16 kW/m² (IR) and 40 kW/m²-80 kW/m² (OH*) for hydrogen jet flames due to differences in the determined flame surface. Conclusions regarding the determined x_(RAD )values for IR and OH* result in approximately the same range of 0.031-0.043. T2 - 11th International conference on hydrogen safety 2025 CY - Seoul, Republic of Korea DA - 22.09.2025 KW - IR and OH* measurement KW - Hydrogen release KW - Inclined jet flame KW - Thermal radiation KW - Radiant heat fraction PY - 2025 SN - 979-12-243-0274-2 SP - 837 EP - 849 AN - OPUS4-65362 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Averin, Anton T1 - Automated thermographic inspection of radioactive waste drums N2 - In Germany, more than 130,000 cubic meters of low- and medium-level radioactive waste, comprising approximately 90% of the nation’s total radioactive waste, are stored in 200-liter drums. These waste drums, housed in interim storage facilities, are subject to human visual inspections for outer corrosion, while the final disposal site, the Konrad mine, is scheduled for completion in 2030. Manual inspections introduce the risk of human error, making the process less reliable and less safe. The proposed study aims to automate these inspections by implementing remote and non-destructive testing (NDT) methods. The part of project specifically focuses on the application of infrared thermography to detect inner defects in the metallic drums, which could not have been detected so far using visual inspection alone. However, several challenges affect the accuracy of thermographic inspections, such as the presence of surface contaminants (scratches, dirt, stickers), multiple paint layers with low thermal conductivity, and barrel curvature, which disrupt heat distribution and obscure defect signals. This study explores the effectiveness of various thermographic heat sources—flash lamps and laser—as well as techniques including conventional pulse thermography (PT), lock-in thermography. It explores various thermal data processing methods as principal component thermography (PCT), pulse-phase thermography (PPT) and thermal signal reconstruction (TSR). Additionally, machine learning models were estimated to process thermographic images, effectively filtering artifacts (e.g. surface contaminants). The findings suggest that combining advanced thermography techniques with machine learning improves defect detection, ensuring more reliable and automated inspection processes for radioactive waste storage. T2 - SPIE Defense + Commercial Sensing - Thermosense: Thermal Infrared Applications XLVII CY - Orlando, FL, USA DA - 13.04.2025 KW - Automated inspection KW - Defect detection KW - Infrared thermography KW - Laser thermography KW - Machine Learning KW - Principal component thermography KW - Pulse-phase thermography KW - Thermal Data Processing PY - 2025 UR - https://www.spiedigitallibrary.org/conference-proceedings-of-spie/13470/3052732/Automated-thermographic-inspection-of-radioactive-waste-drums/10.1117/12.3052732.short DO - https://doi.org/10.1117/12.3052732 SP - 1 EP - 19 PB - SPIE AN - OPUS4-63285 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Genga, R. M. A1 - Conze, S. A1 - Berger, L.M. A1 - Pötschke, J. A1 - Witte, Julien A1 - Schröpfer, D. A1 - Cermak, A. A1 - Zeman, P. A1 - Ngongo, S. A1 - Janse van Vuuren, A. T1 - Enhanced Fe and Ni bonded NbC Laser Surface Engineered based Hardmetals: Alternative Cutter Materials for Electric Vehicle Applications N2 - The efforts to substitute both tungsten carbide (WC) and cobalt (Co) has gained prominence in recent years due to the classification of Co as a carcinogen and the classification of Co and W as critical raw materials in the EU as well as within regulations of the U.S. National Toxicology Program. In this study, substitution of both WC and Co with advanced hardmetals consisting of NbC with Ni and Fe-based metal binders are investigated for their use of machining of metals used electric vehicle manufacturing. The developed NbC-Ni/Fe based hardmetals employ a Machining Property Led Tailored Design (MPLTD) approach. This reverse engineering strategy uses data from machining performance to guide the development of microstructural, mechanical, and behavioral properties. Four advanced NbC-based hardmetals were produced, two with Ni-based binders and two with Fe-based binders, along with two reference materials for comparison (WC-Co and straight NbC-12Ni). Hardmetals were characterized using field emission scanning electron microscopy (FE-SEM), annular dark-field scanning transmission electron microscopy (ADF-STEM), Vickers hardness, fracture toughness, and elastic moduli. Cutting tool inserts were manufactured from the developed hardmetals and enhanced using femto-second laser surface engineering. The inserts’ performance was evaluated through face milling tests on AZ31 automotive magnesium alloy, providing insights into their suitability for high-demand industrial applications. T2 - 21. Plansee Seminar CY - Reutte, Österreich DA - 01.06.2025 KW - Niobium carbide KW - Alternative binders KW - Alternative hard phases KW - Face milling KW - AZ31 magnesium alloy PY - 2025 VL - 2025 SP - 1 EP - 10 AN - OPUS4-65382 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kunji Purayil, Sruthi Krishna A1 - Hirsch, Philipp Daniel A1 - Lecompagnon, Julien A1 - Ziegler, Mathias ED - Ferrarini, Giovanni ED - López, Fernando ED - Spaeth, Peter T1 - Multispectral fusion-based crack detection using automated laser thermography inspection N2 - Crack detection of complex components is critical for maintaining the integrity and safety of structures across industries such as energy production and aerospace. The integration of multispectral imaging and automatic robot-based non-destructive testing (NDT) marks a significant advancement in the inspection of complex geometries. Multispectral imaging leverages the utilization of image data from different wavelength ranges for enhanced feature extraction and analysis. This paper proposes a novel image fusion model by combining thermal and visual images for the detection of surface and sub-surface cracks of turbine blades in energy production. Our study uses 3D scanning of components using a robot-assisted flying laser line, which measures high-resolution thermal data and RGB images using visual cameras simultaneously. Laser thermography induces a localized heating on the sample, creating a thermal response that highlights cracks and defects that are often undetectable using conventional imaging techniques. Multispectral image fusion models are developed based on an unsupervised generative adversarial network (GAN) for precise crack detection. The model validation is done using experimental data and it demonstrated high crack detection accuracy compared to conventional single-band imaging methods. This research highlights the new potential for advancing NDT technologies by combining thermal inspection techniques with optical imaging to develop a multispectral inspection approach. T2 - Thermosense: Thermal Infrared Applications XLVII CY - Orlando, Florida, United States DA - 13.04.2025 KW - Infrared imaging KW - Laser KW - Multispectral imaging KW - NDE 4.0 KW - Non-destructive testing PY - 2025 DO - https://doi.org/10.1117/12.3052496 SP - 1 EP - 11 PB - SPIE AN - OPUS4-63253 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sagradov, Ilja T1 - Long-term tests on metal seals using continuous force measurement in compressed state N2 - In Germany, spent fuel and heat generating radioactive waste is stored in casks for transport and storage (DPCs). The storage licenses were granted for up to 40 years. Due to the delay in identifying a final repository site for such radioactive waste, the storage periods are to be extended significantly. The objective of our research work is to collect additional material data for metal seals in order to be able to better assess the long-term safety of the sealing system of the casks for a period of up to 100 years. A principal safety consideration for the DPCs is the long-term performance of bolted lid sealing systems utilizing metal seals to ensure the safe enclosure of the radioactive inventory during interim storage. To assess the sealing behavior, it is necessary to examine the aging-dependent residual restoring force for the metal seals and the usable resilience. By investigating the change in these values as a function of time and temperature, further insight can be gained into the assessment of long-term safety for extended interim storage. In the present study, the restoring force of metal seals with an outer aluminum jacket and a torus diameter of 9.9 mm was measured continuously. For this purpose, a specially designed device equipped with a load cell was used under isothermal conditions. As part of the investigation, the level and rate of decrease of the restoring seal force were recorded over test periods of one and two months. The seal temperature was set to 35 °C, 75 °C, 100 °C, 125 °C, and 150 °C, respectively. A direct correlation was observed between the temperature of the seal, the level of the restoring force after compressing and heating the seal, and the drop-off characteristics of the restoring force. It was found that in our test device the force level immediately after reaching the respective temperature is lower for higher seal temperatures, while the drop rate of the restoring force is higher. This paper describes the experimental setting and discusses first results in comparison with our long-term discontinuous measurements. T2 - 21st International Symposium on the Packaging and Transportation of Radioactive Materials - PATRAM 2025 CY - San Antonio, TX, USA DA - 27.07.2025 KW - Long-Term Safety Assessment KW - Extended Interim Storage KW - Metal Seal Aging KW - Restoring Force Degradation KW - Temperature-Dependent Performance PY - 2025 VL - 2025 SP - 1 EP - 10 CY - Indianapolis, IN, USA AN - OPUS4-63881 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Popiela, Bartosz A1 - Günzel, Stephan A1 - Oktaviany, Jennifer A1 - Widjaja, Martinus Putra A1 - Mair, Georg W. A1 - Seidlitz, Holger T1 - Influence of Internal Pressure Regulation During Filament Winding on Failure Mechnism in Type 4 Pressure Vessels: A Case Study N2 - Hydrogen storage is a crucial part of the hydrogen value chain, particularly in terms of safety and social acceptance of hydrogen technologies. For on-board and transportation applications, hydrogen is commonly stored as a compressed gas in pressure vessels. Full composite wrapped Type 4 pressure vessels are especially beneficial due to their high weight-saving potential and their capability to withstand high working pressures. To maintain an appropriate safety level, the mechanical behavior of the composite structure has been the subject of investigation in numerous studies. In this study, the failure mechanisms of two designs of Type 4 cylinders are investigated. The two designs differ solely in the manufacturing process parameters, particularly the internal pressure applied during the filament winding process. Variations in internal pressure result in different residual stress states and changes in the quality of the composite structure. The stacking sequence, materials used, and other manufacturing parameters remain unchanged. The cylinders show different failure mechanisms in slow burst tests: one design fails in hoop windings, while the other one fails in helical windings, despite no stress exaggeration in the fiber direction being observed with embedded optical fibers or in numerical simulations. To explain the failure mechanisms, the quality of the cylinders is investigated. The results of X-ray computed tomography and pulse-echo investigation, highlight the complexity of the interactions between manufacturing process parameters, residual stresses, manufacturing quality, and the mechanical behavior of composite pressure vessels. Resin-rich areas in the composite material are identified as a possible cause of the differing failure mechanisms. T2 - 11th International Conference on Hydrogen Safety ICHS 2025 CY - Seoul, South Korea DA - 22.09.2025 KW - Composite KW - Pressure vessel KW - Filament winding KW - Burst test PY - 2025 SP - 1 EP - 12 AN - OPUS4-64452 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hothan, Sascha A1 - Häßler, Dustin A1 - Stelzner, Ludwig A1 - Fürst, Richard A1 - Eiz Eddin, Ahmad T1 - Lösungsansätze für neue Herausforderungen im konstruktiven baulichen Brandschutz N2 - Der Klimawandel und die zunehmende Ressourcenknappheit stellen Herausforderungen dar, die in Zukunft grundlegende Anpassungen in der Art des Umgangs mit Rohstoffen, Energie und des Wirtschaftens an die Gesellschaft stellen werden. In der Leichtbaustrategie der Bundesregierung wird zusammenfassend festgestellt, dass der fortschreitende Klimawandel Technologien erfordert, die die Transformation der Wirtschaft, eine ressourcenschonende Wertschöpfung und eine nachhaltige und resiliente Rohstoffversorgung sicherstellen. Aus diesen für alle Wirtschaftszweige sehr allgemein formulierten Anforderungen und vor dem Hintergrund eines wachsenden Bedarfs schnell verfügbarer Bausubstanz, lassen sich konkrete Anforderungen für das Bauwesen ableiten. Es geht um die Reduktion des Ressourcenverbrauchs für die Errichtung und den Betrieb neuer Gebäude sowie die Nach- und Weiternutzung bestehender Bausubstanz. In der Bundesanstalt für Materialforschung und -prüfung (BAM) wurde im Themenfeld Infrastruktur das Aktivitätsfeld Leichtbau ins Leben gerufen, das die Forschungsaktivitäten zum Leichtbau bündelt. Im vorliegenden Beitrag werden ausgewählte Projekte in Bezug auf den konstruktiven baulichen Brandschutz vorgestellt und die besonderen Herausforderungen verdeutlicht sowie die daraus abgeleiteten technischen Lösungsmöglichkeiten aufgezeigt. Als Beispiel einer Bauweise mit höchstmöglicher Effizienz in der Materialausnutzung sowie exzellenter Recyclingfähigkeit des Werkstoffs wird im Abschnitt „Einsatz reaktiver Brandschutzsysteme auf Stahlzuggliedern mit Vollprofil“ gezeigt, wie der Feuerwiderstand von Stahlzuggliedern mit minimalem Materialaufwand sichergestellt werden kann. Anhand des Beispiels der „Alten Aktienspinnerei“ verdeutlicht sich die Relevanz der Methode für die Nachnutzung historischer Bausubstanz. Im Abschnitt „In situ Überprüfung des Feuerwiderstands von Stahltragwerken mit gealterten reaktiven Brandschutzsystemen“ wird gezeigt, wie in Zukunft die minimalinvasive Überprüfung der Wirksamkeit bereits über Jahrzehnte in Nutzung befindlicher reaktiver Brandschutzsysteme (RBS) ermöglicht wird. Dies bildet die Grundvoraussetzung für eine Weiternutzung sowie möglicherweise erforderliche Instandsetzung auch nach Überschreitung der ursprünglich vorgesehenen Nutzungsdauer des RBS anhand einer quantitativen Aussage zum noch vorhandenen Feuerwiderstand. Eine wichtige Strategie im Betonbau zur Verringerung des CO2-Ausstoßes wird im Abschnitt „Feuerwiderstand von Leichtbaukonstruktionen aus vorgespanntem Carbonbeton“ vorgestellt. Das Verbundforschungsvorhaben verfolgt die Entwicklung eines neuen Deckensystems aus vorgespanntem Carbonbeton. Die angestrebte Leichtbauweise verringert den Einsatz von Zement durch Minimierung des erforderlichen Betonvolumens. Um einen möglichst dünnen Deckenspiegel zu erzeugen ist eine Reduzierung der Betondeckung erforderlich, weshalb für den Brandfall Maßnahmen zu ergreifen sind, die die Erwärmung der Carbonbewehrung und die damit einhergehende Degradation des Materials begrenzen. In diesem Zusammenhang sind auch wirksame Strategien zur Eindämmung von Beton-abplatzungen zu entwickeln. Abschließend wird im Abschnitt „Gebäude in Stahl-Modulbauweise mit selbstaussteifenden Raumzellen“ herausgearbeitet, wie diese Bauweise zukünftig noch effizienter werden kann, indem eine Nachweismöglichkeit der aussteifenden Wände in Leichtbauweise für den Brandfall geschaffen wird. T2 - Bauphysikertreffen 2025 - Hochschule für Technik Stuttgart CY - Stuttgart, Germany DA - 28.11.2025 KW - Klimawandel KW - Ressourcenknappheit KW - Bausupstanz KW - Brandfall PY - 2025 VL - Bauphysikertagung 2025 SP - 1 EP - 12 AN - OPUS4-65371 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Narayanan, M.M. A1 - Nicolai, M. A1 - Prager, J. T1 - C9-a5 - Optimization of Low-Frequency Shear Wave Transducers for Guided Wave Applications N2 - Development of ultrasonic transducers for the excitation of a torsional mode T(0,1) mode in a large pipe of the material typical of actual oil/gas pipelines is discussed. Towards this,16 ultrasonic transducers are designed and fabricated using shear plates of PIC 255 material, backing mass of tungsten-epoxy composite and brass shims as wear plates. The transducers are qualified using Laser Doppler Vibrometry. Then, the transducers are embedded in a springloaded ring and tested on a pipe using a multi-channel ultrasonic system. The results show the successful excitation of T(0,1) mode and it is seen to propagate for distance of 60 m with a good SNR. T2 - 2025 ICU PADERBORN - 9th International Congress on Ultrasonics CY - Paderborn, Germany DA - 21.09.2025 KW - Ultrasonic guided waves KW - Torsional mode KW - Shear PZT plates KW - Ring array transducer design KW - Pipe testing PY - 2025 DO - https://doi.org/10.5162/Ultrasonic2025/C9-a5 SP - 223 EP - 226 PB - AMA Service GmbH AN - OPUS4-65356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zeipert, H. A1 - Nellius, T. A1 - Schönlau, N. A1 - Wippermann, M. A1 - Claes, L. A1 - Henning, B. A1 - Nicolai, Marcel A1 - Prager, J. T1 - C6-a3 - Monitoring the curing process of adhesive bonds using selective excitation of guided ultrasonic waves N2 - A measurement setup for the selective excitation of guided ultrasonic waves in adhesively bonded plates is introduced. Changes of the dispersive behaviour of the guided waves during the curing process is known to be accompanied by a change in the propagating waves group velocities. The proposed measurement setup is used to monitor that change during the curing process of an aluminium-epoxy-polycarbonate bond. T2 - 2025 ICU PADERBORN - 9th International Congress on Ultrasonics CY - Paderborn, Germany DA - 21.09.2025 KW - Ultrasonic guided waves KW - Selective excitation KW - Non-destructive testing KW - Adhesive bonding KW - Condition monitoring PY - 2025 DO - https://doi.org/10.5162/Ultrasonic2025/C6-a3 SP - 207 EP - 210 PB - AMA Service GmbH AN - OPUS4-65357 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mezhov, Alexander A1 - Bright, Asante A1 - Schmidt, Wolfram T1 - Increasing the Incorporation of CO2-Sequestering Materials in Concrete N2 - Concrete is the most widely used construction material accounting for approximately half of all human production throughout history. The production of one ton of cement emits around 600 kg of CO2. With a global cement production estimate of 4.2 billion tons, this results in about 2.5 billion tons of CO2 emissions. This accounts for roughly 7.2% of the total global carbon emissions in 2021. Strategies to decrease carbon emissions in the cement and concrete industry include carbon capture and storage (CCS), reduced binders like ordinary Portland cement (OPC) clinker and optimizing material use through improved processes and structural design. This also means changing architectural vision [6], avoiding concrete where its structural performance is not required and use alternative materials instead, and optimizing the communication among the entire production value chain. T2 - 1st International Conference on Net-Zero Built Environment: Innovations in Materials, Structures, and Management Practices (Net-Zero Future 2024) CY - Oslo, Norway DA - 19.06.2025 KW - Concrete KW - CO2-Sequestering PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-638531 DO - https://doi.org/10.1007/978-3-031-69626-8_4 VL - 237 SP - 39 EP - 48 PB - Springer Nature Switzerland AG CY - Schweiz AN - OPUS4-63853 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zekhnini, Khalid A1 - Babutzka, Martin A1 - Seifert, Lando A1 - Burkert, Andreas A1 - Ebell, Gino A1 - Bäßler, Ralph T1 - Investigation of corrosion behavior of S355 steel in artificial seawater and sediment N2 - The safe operation of offshore wind turbines places high demands on corrosion protection. This is particularly the case about the planned future extension of the service life beyond 25 years. The highly corrosive environment towards metallic materials leads to a loss of material thickness of the tower structure and thus to a deterioration of mechanical properties. This can be counteracted by corrosion protection measures adapted to the respective load case, such as organic coatings and cathodic corrosion protection (CCP). Much research has already been done in this area about inhibiting the corrosion process and there are regulations and guidelines that specify requirements for corrosion protection to achieve the required service lives. However, gaps exist regarding free corrosion. This plays a greater role especially for time intervals during the installation of the plants and their maintenance, during which often no CCP can be operated. This applies to the exposure areas in the underwater and sediment area. This problem is intensified by the difficult to estimate corrosion rates caused by the different zones, with their different amounts of dissolved oxygen and the various influencing factors. This paper deals with experiments conducted in a laboratory container with artificial seawater and sediment in basins. T2 - AMPP Annual Conference + Expo 2025 CY - Nashville, TN, USA DA - 06.04.2025 KW - Seawater KW - Sediment KW - Corrosion KW - Offshore KW - Foundation KW - Element current PY - 2025 DO - https://doi.org/10.5006/C2025-00002 SP - 1 EP - 16 PB - AMPP CY - Houston TX USA AN - OPUS4-62963 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pirskawetz, Stephan A1 - Zaripova, Gulshat A1 - Brinkman, Nienke A1 - Gebraad, Lars A1 - Boehm, Christian A1 - Trattnig, Horst T1 - Digital Twin for the Simulation of Acoustic Emission Wave Propagation in Prestressed Concrete Elements N2 - In the 1950s, the use of prestressed concrete construction for bridges became widespread. The lack of experience in the early days causes problems today regarding a combination of corrosion and fatigue of the tendons. Wire breaks can lead to structural failure without warning. Acoustic emission analysis is the only reliable monitoring method to prevent catastrophic damage. Through an acoustic simulation of the structure and its fusion with measurement data, the research project "Digital Twin for the Simulation of Acoustic Emission Wave Propagation in Prestressed Concrete Elements" lays the foundation for optimizing the monitoring systems. T2 - III AE 2025 Nagoya CY - Nagoya, Japan DA - 04.11.2025 KW - Acoustic emission monitoring KW - Digital acoustic twin KW - Prestressed concrete bridge KW - Wire break KW - Stress corrosion cracking PY - 2025 SP - 113 EP - 117 PB - Japanese Society for Non-Destructive Inspection (JSNDI) AN - OPUS4-65456 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epple, Niklas A1 - Sanchez Trujillo, Camila Andrea A1 - Hau, Julia A1 - Niederleithinger, Ernst A1 - Malm, F. T1 - Structural Monitoring in an Urban Underground Metro Station Using Cod N2 - Active ultrasonic monitoring with coda wave interferometry has demonstrated its potential for structural Health monitoring in concrete structures. This study investigates its application using ultrasonic transducers embedded in the ceiling of a subway station in Munich, Germany. We evaluate the impact of environmental conditions, specifically electromagnetic interference and temperature, on data quality, as well as the influence of regular loading from passing trams. Results indicate that electromagnetic interference significantly affects measurements, while temperature effects remain minimal due to the station’s stable thermal environment. Long-term measurements and a controlled load test show that both dynamic and static loading from trams induce ultrasonic velocity changes of only 0.01%–0.06%. Although the experiment demonstrates the capacity to detect structural responses and supports the feasibility of long-term monitoring, improved electromagnetic shielding and Hardware reliability are required for successful future applications. T2 - NDT-CE 2025 CY - Izmir, Turkey DA - 24.09.2025 KW - Coda Wave Interferometry (CWI) KW - Structural health monitoring (SHM) KW - Concrete KW - Ultrasonic testing KW - Urban infrastructure PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654619 DO - https://doi.org/10.58286/31706 SN - 1435-4934 SP - 1 EP - 10 PB - e-Journal of Nondestructive Testing (eJNDT) AN - OPUS4-65461 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baier, Johanna A1 - Wiehle, Philipp A1 - Thiele, Marc ED - Nille-Hauf, Konstantin T1 - Structural design of rammed earth – Influence of manufacturing parameters on the compressive strength N2 - At present, no structural design code for rammed earth exists that is based on the semiprobabilistic safety concept and adequately reflects the mechanical performance of modern rammed earth structures. This research aims to establish a scientifically grounded design framework for load-bearing rammed earth walls, incorporating the semi-probabilistic safety approach to ensure reliability and structural integrity. As a first step within the research project the influence of the manufacturing parameters of rammed earth on its mechanical properties are investigated. Compressive strength tests are carried out on cylinders produced with varying initial moisture contents and different compaction energies. Moreover, it is investigated whether the Proctor test according to DIN 18127 is suitable for determining the optimal moisture content (OMC) of rammed earth production. T2 - Earth Builder Summit EBS 2025 CY - Biberach, Germany DA - 06.03.2025 KW - Rammed earth KW - Structral design KW - Mechanical parameters PY - 2025 SP - 41 EP - 44 PB - Hochschule Biberach CY - Biberach AN - OPUS4-64343 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Keserović, A. A1 - Sobetzki, J. A1 - Sarmiento-Klapper, H. A1 - Boduch, A. A1 - Aristia, G. A1 - Faes, W. A1 - Stoljarova, A. A1 - Zimmer, S. T1 - Metallene Werkstoffe in Geothermieanlagen - nicht nur aus Sicht der Korrosion N2 - Um Konstrukteuren und Nutzern geothermischer Anlagen grundlegende Informationen über die Korrosionsbeständigkeit zur Verfügung zu stellen, wurden verschiedene metallene Werkstoffe, darunter nichtrostende Duplex- und austenitische Stähle sowie eine Nickellegierung, in künstlichen Geothermalwässern, die die Bedingungen an verschiedenen Standorten mit geothermischem Potenzial simulieren, mit Hilfe von elektrochemischen und Langzeittests hinsichtlich ihrer Eignung bewertet. In hochsalinaren Umgebungen erwies sich Spaltkorrosion als der entscheidende Mechanismus. Die Nickellegierung zeigt eine ausgezeichnete Beständigkeit gegenüber Lochkorrosion. Abgesehen von ihren hohen Kosten eignet sie sich sehr gut für den Bau von Geothermieanlagen mit stark salzhaltigen Fluiden. Rostfreie Stähle und Duplexstähle weisen eine begrenzte Korrosionsbeständigkeit gegen Loch- und Spaltkorrosion auf. Daher sind sie für stark salzhaltige Fluide nicht geeignet. Der Superaustenit zeigt ein temperaturabhängiges Verhalten. In nichtsalinaren Umgebungen könnten niedriglegierte Stähle (neben den höherlegierten Werkstoffen) als Konstruktionsmaterial für Geothermieanlagen eingesetzt werden, sofern eine ausreichende Wandstärke des Materials berücksichtigt wird. Neben Korrosionsaspekten erwies sich auch die Ausfällung von Fluidbestandteilen als interessantes Thema. Beim Betrieb der Forschungsanlage in Groß Schönebeck wurden Kupfer- und Bleieffekte im Bohrloch festgestellt. Die auftretenden Mechanismen und Maßnahmen zur Verhinderung von Ausfällungen und Abscheidungen wurden ebenso untersucht, wie deren mögliche Einflüsse auf die Korrosionsbeständigkeit metallener Werkstoffe für Anlagenkomponenten. Der Beitrag beschreibt die Wechselwirkungen zwischen Geothermalwässern und Ausrüstungskomponenten. T2 - 57. Kraftwerktechnisches Kolloquium CY - Dresden, Germany DA - 07.10.2025 KW - Örtliche Korrosion KW - Edelstahl KW - Ni-Legierungen KW - Geothermie KW - Abscheidung PY - 2025 SN - 978-3-00-082651-1 SN - 978-3-00-082652-8 SP - 551 EP - 568 PB - IKS-Verlag CY - Freiberg AN - OPUS4-64320 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, S. A1 - Herzel, Hannes A1 - Adam, Christian A1 - Montag, D. ED - Holm, O. ED - Thomé-Kozmiensky, E. ED - Quicker, P. ED - Kopp-Assenmacher, S. T1 - Langzeitlagerung von Klärschlammaschen ab 2029? Erste Erfahrungen zur Phosphorrückgewinnung aus deponierten Klärschlammverbrennungsaschen N2 - Das Institut für Siedlungswasserwirtschaft (ISA) der RWTH Aachen University sowie die Bundesanstalt für Materialforschung und -prüfung (BAM) untersuchen gemeinsam fünf deponierte KSA, die von drei Deponiebetreibern ausgebaut und zur Verfügung gestellt wurden sind. Im Fokus der Untersuchungen stehen die physikalische und chemische Charakterisierung der deponierten KSA sowie deren P-Rückgewinnungspotenzial bei der Behandlung in thermochemischen sowie nasschemischen Verfahren. Diese Ergebnisse werden im Vergleich mit „frischen“, also nicht deponierten KSA-Proben vergleichbarer Herkunft bewertet, um so den Einfluss der Lagerung auf die KSA zu erfassen. T2 - Berliner Klärschlamm Konferenz CY - Berlin, Germany DA - 11.11.2025 KW - Klärschlammasche KW - Recycling KW - Deponie KW - Monoverbrennung PY - 2025 SN - 978-3-911006-63-7 VL - 8 SP - 192 EP - 202 PB - Thomé-Kozmiensky Verlag GmbH CY - Neuruppin AN - OPUS4-65017 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Joachim A1 - Adamczyk, Burkart A1 - Ebert, Dominik A1 - Ehrenberg, Andreas A1 - Schraut, Katharina A1 - Algermissen, David A1 - Adam, Christian T1 - Usage of BOF slag and next generation EAF slag in the cement industry N2 - When the transformation of its production routes, which the European steel industry aims to complete within the next two decades, is accomplished, increased amounts of EAF slag will be generated. In most cases the BF/BOF production route is intended to be substituted by a DRI/EAF combination. But in some cases only the BF will be substituted by a DRI/SAF (smelter) combination and the BOF process remains. Then BOF slags will remain, too. BAM and FEhS cooperate together with further research and industry partners in two research projects dealing on the one hand with the utilisation of modified BOF slag as a cement clinker substitute ("SlagCEM") and on the other hand with the use of modified and granulated EAF slag as granulated blast furnace slag (GBS) substitute ("DRI-EOS"). T2 - 9th International Slag Valorisation Symposium CY - Leuven, Belgium DA - 08.04.2025 KW - Steel slags KW - Basic oxygen furnace (BOF) KW - Electric arc furnace (EAF) KW - Cement KW - Slag valorisation PY - 2025 SP - 187 EP - 191 AN - OPUS4-64713 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herzel, Hannes A1 - Leimkötter, D. A1 - Hermann, L. A1 - Emter, J. A1 - Brey, C. A1 - Künstler, J. A1 - Hartmann, S. A1 - Krannich, G. A1 - Moggert, N. A1 - Kurz, P. A1 - Eder, C. A1 - Grimm, B. A1 - Adam, Christian ED - Holm, O. ED - Thomé-Kozmiensky, E. ED - Quicker, P. ED - Kopp-Assenmacher, S. T1 - Success-Story CaNaPO4: Erfolgreiche REACH Registrierung und Inbetriebnahme großtechnischer Anlagen N2 - The Sewage Sludge Ordinance (AbfKlärV), which was amended in 2017, obligate the recovery of phosphorus from sewage sludge and sewage sludge ash from 2029 and 2032, respectively. Thermal disposal of sewage sludge has established itself as the preferred method of disposal, and the capacities of mono-incineration plants are being continuously expanded. Plants for phosphorus recovery, on the other hand, are currently still mainly in the construction, piloting, or commissioning phase. It is estimated that the plant capacities for P recovery planned today will not even be able to cover a quarter of the volume of these ashes in 2029. Therefore, temporary storage of the remaining ashes is currently being discussed to retrieve it later and process it in the P recovery plants, which will then be sufficiently available. It is currently unclear how such interim or long-term storage (> 1 year) should be organized. In addition to legal (fee) issues, the assessment of the technical feasibility of retrievability and the phosphorus recovery potential of landfilled ash remains open. The Institute of Environmental Engineering (ISA) at RWTH Aachen University and the Federal Institute for Materials Research and Testing (BAM) are jointly investigating five deposited ashes that have been dug out and were provided by three landfill operators. The investigations focus on the physical and chemical characterization of these landfilled ashes and its P recovery potential during treatment in thermochemical and wet chemical processes. These results are evaluated in comparison with “fresh,” i.e., non-landfilled sewage sludge ash samples of comparable origin in order to determine the influence of storage. T2 - Berliner Klärschlamm Konferenz CY - Berlin, Germany DA - 11.11.2025 KW - Phosphor KW - Recycling KW - Thermochemisch KW - Dünger KW - Großtechnik PY - 2025 SN - 978-3-911006-63-7 VL - 8 SP - 236 EP - 256 PB - Thomé-Kozmiensky Verlag GmbH CY - Neuruppin AN - OPUS4-64833 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wöhlecke, Andreas T1 - Aktuelle Themen aus dem Fachbeirat der BAM N2 - Die Anforderungen an Geokunststoffprodukte und deren Qualitätssicherung unterliegen einem stetigen Wandel, der sowohl durch technische Veränderungen als auch durch normative und organisatorische Entwicklungen geprägt ist. Insbesondere der Fachbeirat der BAM gemäß Deponieverordnung (DepV) spielt hier im Bereich der Deponietechnik eine wichtige Rolle. An dieser Stelle sollen aktuelle Themen aus dem Fachbeirat der BAM vorgestellt werden, die wesentliche Änderungen in der Zulassungs- und Anwendungspraxis betreffen. Der Beitrag beleuchtet unter anderem Veränderungen innerhalb der BAM, die Modernisierung der Publikationsformate sowie die fachliche Weiterentwicklung der Zulassungsrichtlinien. Besondere Aufmerksamkeit gilt der Diskussion um die Einbauhilfe im Schutzschichtsystem, der Einführung einer europäischen Zugversuchsnorm für Kunststoffdichtungsbahnen sowie der Fremdüberwachung der Produktion geosynthetischer Komponenten. Darüber hinaus werden neue Anforderungen an Edelstahlelektroden in Dichtungskontrollsystemen und die Spannungsrissbeständigkeit von PE-HD-Dichtungsbahnen thematisiert. T2 - 35. Karlsruher Deponie- und Altlastenseminar CY - Karlsruhe, Germany DA - 15.10.2025 KW - Deponie PY - 2025 VL - 48 SP - 26 EP - 35 PB - ICP AN - OPUS4-64408 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Martin T1 - Selbstentzündung von Biokohlen – Lager- und Transportsicherheit N2 - Mit der Abkehr von der Nutzung fossiler Rohstoffe rücken regenerative Energieträger immer weiter in den Focus. Neben klassischen Holzkohlen werden verstärkt so genannte Biokohlen produziert. Dieser Begriff findet Verwendung für mit Hilfe verschiedener Verfahren karbonisierte pflanzliche, tierische oder mikrobielle Ausgangsstoffe. Diese Kohlen werden zum Teil über weite Strecken zum Bestimmungsort transportiert (Überseetransporte) oder vor Verwendung für längere Zeit gelagert. Häufig zeigen diese Kohlen ein kritisches Selbstentzündungsverhalten, wobei Einstufungstests (UN N.4 Test) versagen können. Ein negatives Testergebnis des UN N.4 Tests führte dabei in der Vergangenheit zur Nichteinstufung als selbsterhitzungsfähiger Stoff; in der Praxis entzündeten sich aber bereits vergleichsweise kleine Schüttungen (einige m³), z. B. beim Seetransport in Containern. Der Artikel geht auf dieses Problem ein und stellt Prüfverfahren vor. Aus den Ergebnissen durchgeführter Untersuchungen werden Empfehlungen für sicheren Transport und Lagerung abgeleitet. T2 - Magdeburg-Köthener Brandschutz- und Sicherheitstagung CY - Magdeburg, Germany DA - 14.03.2024 KW - Biokohlen KW - Selbstentzündung KW - Gefahrguteinstufung PY - 2024 SN - 978-3-948749-41-5 SP - 68 EP - 77 PB - Otto-von-Guericke-Universität Magdeburg CY - Magdeburg AN - OPUS4-59717 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Feldkamp, Martin A1 - Quercetti, Thomas A1 - Gleim, Tobias A1 - Wille, Frank T1 - Evaluation of Heat Fluxes in Fire Reference Test Conducted in BAM Propane Gas Fire Test Facility N2 - Packages for the transport of intermediate- and high-level radioactive waste are designed to withstand severe accidents. The International Atomic Energy Agency (IAEA) has established specific mechanical and thermal tests. Packages for the transport of radioactive material must withstand these tests to comply with the Regulations for the Safe Transport of Radioactive Materials IAEA [IAEA (2018)]. A fire reference package was developed with the primary objective to demonstrate that the fire meets the regulatory requirements. Another aim is to characterise the boundary conditions of the actual fire as input parameters for thermo-mechanical simulations. A simple method to characterise the boundary conditions of a real steady state fire with a fire reference package is presented. The thermal test mainly consists of a 30 minute fully engulfing 800°C pool fire or an equally severe fire, such as a propane gas fire. The fire reference tests are performed prior to the actual fire test with the real package. The heat fluxes into the package depend substantially on the fire characteristics and the surface temperature of the package. To investigate local and overall heat fluxes over a wide range of surface temperatures in this test facility a fire reference package was designed for repeated use. The fire reference package presented in this paper represents the outer geometry of a small transport container for radioactive material and is used as a device in civil engineering. It is designed as a closed steel sheet cylinder with a wall thickness of 10 mm, a length of 182 mm and a diameter of 102 mm. The package was instrumented with thermocouples and filled with heat resistant insulation material. Open-air fire tests were performed in a BAM propane gas fire test facility with the fire reference package. The measured temperatures are used to determine the changes of heat fluxes into the fire reference package in relation to the package surface temperature. The calculated heat fluxes allow its fitting to express the thermal exposure as simple mathematical boundary condition. Therefore, in a first approach, fire properties such as adiabatic surface temperature (AST) as proposed by Wickström et al. (2007), convection coefficient and emissivity are determined mathematically fitting the heat flux development presented in this paper. The evaluated results provide an initial picture of local fire characteristics of the conducted propane gas fire and are a further development of previous works from Feldkamp et al. (2020). The results can be used in thermal and thermo-mechanical models to simulate the load on the real transport package in fire. The test shows that the examined propane gas fire covers the IAEA-fire over a wide range of surface temperatures with the chosen test stand parameters. T2 - SMiRT 27 (27th conference on Structural Mechanics in Reactor Technology) CY - Yokohama, Japan DA - 03.03.2024 KW - Fire KW - Propane KW - Heat Flux KW - Fire Reference PY - 2024 SP - 1 EP - 10 PB - IASMiRT AN - OPUS4-59679 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hashemi, Seyedreza A1 - Heimann, Jan A1 - Charmi, Amir A1 - Prager, Jens T1 - Guided Wave Behavior in Type IV Composite Overwrapped Pressure Vessels Under Fatigue Loading N2 - The digitalization of quality control processes and the use of digital data infrastructures is a novel idea that can be applied for ensuring the operational safety and reliability of pressure vessels, particularly in the context of hydrogen storage at high pressure. Despite the critical role these pressure vessels play, current safety regulations lack an established concept for Structural Health Monitoring (SHM). This research addresses this gap by presenting a study on the application of ultrasonic guided waves (GWs) for SHM of Type IV Composite Overwrapped Pressure Vessels (COPVs). The study focuses on the development of a reliable measurement system to transition from conventional periodic inspections to SHM and predictive maintenance, prolonging the remaining lifetime of the vessels. A sensor network is employed, consisting of fifteen piezoelectric wafers arranged in three rings, which are mounted on the outer surface of the COPV. Deploying GWs, known for their long-distance propagation and ability to cover complex structures, the study explores GW behavior under different environmental and operational conditions, including periodic pressure fluctuations and temperature loadings. Meticulous analysis of GW signals by utilizing various features and damage indices, underscores their suitability for an effective SHM under realistic working conditions. The project aims to localize defects by considering temperature, and internal pressure. Mimicking the continuous monitoring of Type IV COPVs in H2 refueling gas stations under authentic operational conditions, the COPV underwent thousands of pressure load cycles in our special test facility. The implemented methodology facilitates early damage detection, showcasing the efficacy of the designed method in effective safety assurance. T2 - 11th European Workshop on Structural Health Monitoring CY - Potsdam, Germany DA - 10.06.2024 KW - Predictive Maintenance KW - Industry 4.0 KW - Structural Health Monitoring KW - Ultrasonic Guided Waves KW - Hydrogen Storage KW - Type IV Composite Overwrapped Pressure Vessels PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608600 DO - https://doi.org/10.58286/29780 SN - 1435-4934 SP - 1 EP - 8 PB - NDT.net CY - Potsdam, Germany AN - OPUS4-60860 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ermilova, Elena A1 - Hertwig, Andreas A1 - Döhring, Thorsten A1 - Stanik, Eva A1 - Cotroneo, Vincenzo A1 - Gibertini, Eugenio T1 - Ellipsometrical characterization of poly-dopamine layers considered for technical applications N2 - Although the organic molecule dopamine (3,4-dihydroxyphenethylamine) is commonly known as the “hormone of happiness”, thin films of poly-dopamine also have interesting technical properties. When produced by dip coating, the self-organizing layers grow in a reproducible thickness of single or multiple molecule monolayers of a few nanometer thickness only. In this work, we introduce a method of determining the layer thickness of poly-dopamine on mirrors for astronomical X-ray telescopes. This work is based on spectroscopic ellipsometry measurements and involves the development of an optical model for the poly-dopamine layers including the dielectric function. Thereby the complex refractive index of the produced layers was determined, covering the range from the ultraviolet to the near infrared spectral region. These measurement results and the corresponding technical challenges are presented in this contribution. Furthermore, an outlook to potential technical applications of this interesting material is given and poly-dopamine layers will make scientist and engineers hopefully happy as an innovative and fascinating technical solution for the future. T2 - SPIE PHOTONICS EUROPE CY - Strasbourg. France DA - 08.04.2024 KW - Polydopamine KW - Thin Solid Layers KW - X-ray optics KW - Spectroscopic Ellipsometry PY - 2024 SN - 978-1-5106-7344-1 DO - https://doi.org/10.1117/12.3015281 VL - 13013 SP - 1 EP - 8 PB - SPIE digital library AN - OPUS4-60954 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brunner-Schwer, Christian A1 - Üstündağ, Ömer A1 - Bakir, Nasim A1 - Akyel, Fatma T1 - Auf dem Weg zum einlagigen Schweißen von dickwandigen Bauteilen – Prozesse, Potenziale, Beispiele N2 - Bislang kommt das Laserstrahlschweißen bzw. Laserhybridschweißen hauptsächlich bei Dickblechen mit einer Wandstärke von bis zu 15 mm zum Einsatz. Für Anwendungen über 20 mm war dieses Verfahren aufgrund einiger Herausforderungen bisher nur bedingt realisierbar. Die von der Ausgründung WeldNova GmbH der Bundesanstalt für Materialforschung und -prüfung (BAM) entwickelte Schweißbadsicherung ermöglicht nun ein einlagiges Schweißen von bis zu 40 mm Wandstärken mit einer Laserleistung von bis zu 20 kW. T2 - 52. Sondertagung Schweißen im Anlagen und Behälterbau 2024 CY - Munich, Germany DA - 12.03.2024 KW - Behälterbau KW - Schweißen KW - Laserschweißen PY - 2024 SN - 978-3-96144-256-0 VL - 392 SP - 101 EP - 105 PB - DVS Media CY - Düsseldorf AN - OPUS4-60602 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brunner-Schwer, Christian A1 - Üstündağ, Ömer A1 - Bakir, Nasim A1 - Akyel, Fatma T1 - Hochleistungslaserhybridschweißen von dickwandigen Stählen – potenzielle Anwendungen in der Windenergieindustrie N2 - Das Laserstrahl-Lichtbogen-Hybridschweißverfahren kombiniert Laserstrahl- und Lichtbogenschweißverfahren in einem gemeinsamen Schmelzbad. Das Verfahren wurde Ende der 70er Jahre entwickelt, um die Synergieeffekte der Schweißprozesse effektiv zu nutzen. Durch die hohe Strahlungsintensität des Laserstrahls werden hohe Einschweißtiefen erreicht. Es ist möglich, die Anzahl der Schweißlagen zu reduzieren und somit die thermische Belastung des Grundwerkstoffes zu senken, da der Wärmeeintrag verringert wird. Die Überbrückung von Spalten und Kantenversatz kann durch die Zufuhr eines geschmolzenen Zusatzdrahtes durch das MSG-Verfahren erreicht werden. Der Zusatzdraht kann zudem das metallurgische Gefüge positiv beeinflussen. Daher ist das Laser-Hybridschweißverfahren ideal für das einlagige Schweißen von Dickblechen und wird bereits erfolgreich in der Schiffbauindustrie zum Schweißen von Blechen mit einer Dicke von bis zu 15 mm verwendet. Obwohl Hochleistungslaser heutzutage bereits im Multi-Kilowatt-Bereich verfügbar sind, sind sie für den industriellen Einsatz nur auf Stahlbleche mit einer Dicke von max. 15 mm geeignet. Hohe Abkühlgeschwindigkeiten, gravitationsbedingtes Austropfen beim einlagigen Schweißen von Dickblechen, Prozessinstabilitäten bei höheren Laserleistungen und Schweißnahtimperfektionen wie Rissbildung sind einige Faktoren, die den Einsatz von Laser-Hybridschweißtechnologien aktuell begrenzen. Ohne eine Badstütze ist eine Verringerung der Schweißgeschwindigkeit und somit der Abkühlgeschwindigkeit aufgrund unzulässiger Wurzelüberhöhungen oder gravitationsbedingtem Austropfen nicht möglich. Bei herkömmlichen Badstützen ist es allerdings erforderlich, dass sie mechanisch befestigt und die Wurzel entfernt oder nachbearbeitet werden muss. In dieser Arbeit wird als Alternative das innovative Konzept der elektromagnetischen Schweißbadsicherung vorgestellt und die Fähigkeiten dieses Verfahrens erläutert. T2 - 21. Tagung Schweißen in der maritimen Technik und im Ingenieurbau CY - Hamburg, Germany DA - 24.04.2024 KW - Behälterbau KW - Schweißen KW - Laserschweißen PY - 2024 VL - 21 SP - 26 EP - 35 PB - DVS-Bezirksverband Hamburg CY - Hamburg AN - OPUS4-60603 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmitt, M. A1 - Casperson, Ralf A1 - Baensch, F. A1 - Müller, D. T1 - Nationale, europäische und internationale Normung in der zerstörungsfreien Prüfung N2 - Normung und Standardisierung in der zerstörungsfreien Prüfung finden auf nationaler, europäischer und internationaler Ebene statt. Die Übernahme von Leitungsfunktionen in diesen Gremien erzeugt die Möglichkeit der Steuerung von Themen und Inhalten der relevanten Normen. Das persönliche Engagement der Fachexpert*innen in den nationalen Gremien und den europäischen und internationalen Arbeitsgruppen ist ein zusätzlicher Faktor für die inhaltliche Korrektheit und die inhaltliche Ausrichtung der Norm. Denn wer nicht normt, wird genormt und muss letztlich Normen anwenden, die andere entsprechend ihrer eigenen Interessen gestaltet haben. Voraussetzung für die Teilnahme in europäischen und internationalen Normungsgremien ist die Mitwirkung in den entsprechenden DINSpiegelgremien, welche die europäischen (CEN) und internationalen (ISO) Aktivitäten spiegeln und die Fachexpert*innen für die Mitarbeit autorisieren. Auf internationaler Ebene findet die Normungsarbeit in den technischen Komitees ISO/TC 135 “Non-destructive testing” und ISO/TC 44/SC 5 “Testing and inspection of welds” und ihren Arbeitsgruppen statt. Das europäische Pendant ist das CEN/TC 138 “Zerstörungsfreie Prüfverfahren” mit seinen Arbeitsgremien. Die DINSpiegelgremien sind für die deutsche Mitarbeit in diesen Gremien und die inhaltliche Bewertung der Norm-Entwürfe zuständig. T2 - DGZfP Jahrestagung 2024 CY - Osnabrück, Germany DA - 05.05.2024 KW - Normung KW - Zerstörungsfreie Prüfung KW - Qualifizierung KW - Qualitätssicherung PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600726 DO - https://doi.org/10.58286/29496 IS - 5 SP - 1 EP - 6 AN - OPUS4-60072 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Krebber, Katerina T1 - Configuration simplification and data reduction in a DAS system for monitoring large infrastructures N2 - The distributed acoustic sensor based on an imbalanced Mach-Zehnder interferometer with a 3×3 coupler is simplified by using a balanced detector instead of three identical photodetectors. The obtained data is reduced by two third accordingly. T2 - Optica Sensing Congress 2024 CY - Toulouse, France DA - 15.07.2024 KW - Data reduction KW - Distributed fiber optic sensing KW - System simplification PY - 2024 SP - 1 EP - 2 PB - Optica CY - Washington D.C., USA AN - OPUS4-60840 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sunder, Sruthi A1 - Jauregui Rozo, Maria A1 - Ruckdäschel, Holger A1 - Schartel, Bernhard T1 - Investigating the trade-off effects of inorganic phosphate/silicate flame retardant content on the fire performance and post-fire flexural mechanics of epoxy/glass fiber composites N2 - Considering the existing challenges involved in the transfer of flame retardant (FR) formulations from epoxy (EP) resins to glass fiber reinforced composites (GFRCs), obtaining data on the post-fire flexural properties of such composites is even more challenging as this involves balancing test parameters with potential composite delamination. In this study, solvent-free FR additives: ammonium polyphosphate (APP), and inorganic silicate (InSi) were added at 10, 30% and 50% w/w loading to a Bisphenol A diglycidyl ether (DGEBA)-dicyandiamide (DICY)-Urone resin matrix. These resin formulations were transferred to bidirectional (BD) glass fiber composites via prepregs. A novel, but facile approach was developed to prepare the composite samples for furnace tests at 400 oC. The composites were also subjected to fire exposure at different heat fluxes and times via a bench-scale test and subsequently tested via three-point bending. At approximately 3.5% P content, the FRs significantly improve the fire performance of both the resins and composites. However, they also degrade the systems’ pre- and postfire flexural modulus and strength. Therefore, improving the flame-retardant mode of action of the FRs in the composites, contrastingly reduces their structural integrity post-fire leading to a trade-off effect. T2 - ECCM21 – 21st European Conference on Composite Materials CY - Nantes, France DA - 02.07.2024 KW - Flame retardants KW - Post-fire KW - Epoxy KW - Glass fiber composites KW - Prepregs PY - 2024 SP - 1 EP - 7 AN - OPUS4-60788 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - El Moutaouakil, H. A1 - Fuchs, C. A1 - Savli, E. A1 - Heimann, Jan A1 - Prager, Jens A1 - Moll, J. A1 - Tschöke, K. A1 - Márquez Reyes, O. A1 - Schackmann, O. A1 - Memmolo, V. A1 - Schneider, T. T1 - Acquiring a Machine Learning Data Set for Structural Health Monitoring of Hydrogen Pressure Vessels at Operating Conditions using Guided Ultrasonic Waves N2 - Hydrogen is an energy source of increasing importance. As hydrogen is very reactive to air and needs to be stored under high pressure, it is crucial to provide safe transportation and storage. Therefore, structural health monitoring, based on guided ultrasonic waves and machine learning methods, is used for Composite Overwrapped Pressure Vessels (COPVs) containing hydrogen. To acquire data that allows robust detection of COPV defects, there are two main process parameters to consider. These are the pressurization of the vessel and the temperature conditions at the vessel. This paper will focus on the derivation of a design of experiment (DoE) from the needs of various validation scenarios (e.g. concerning pressure, temperature or excitation frequency). Practical limitations must be considered as well. We designed experiments with multiple reversible damages at different positions. A network of 25 transducers, structured as five rings with five sensors in one line, is installed on a vessel. Guided ultrasonic waves are used via the pitch-catch procedure, which means that the transducers act pairwise as transmitter and receiver in order to measure all transmitterreceiver combinations. This leads to 600 signal paths, recorded by a Verasonics Vantage 64 LF data acquisition system. Finally, the influences of temperature and pressure within the acquired data set are going to be visualized. T2 - 11th European Workshop on Structural Health Monitoring CY - Potsdam, Germany DA - 10.06.2024 KW - Composite Overwrapped Pressure Vessel KW - Hydrogen KW - Guided Ultrasonic Waves KW - Data Acquisition KW - Pressurization KW - Machine Learning PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-607472 DO - https://doi.org/10.58286/29754 SN - 1435-4934 SP - 1 EP - 8 AN - OPUS4-60747 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Häßler, Dustin A1 - Becker, Andreas A1 - Fürst, Richard A1 - Hothan, Sascha ED - Simões da Silva, Luís ED - Vila Real, Paulo ED - Santiago, Aldina ED - Craveiro, Hélder ED - Laim, Luís T1 - Fire resistance testing of steel tension members with hollow section protected by intumescent coating N2 - This book presents the proceedings of the Thirteenth International Conference Structures in Fire. The conference took place at the Department of Civil Engineering, University of Coimbra, Portugal, from 19 to 21 June 2024, under the auspices of the SIF movement. Structural fire safety is a crucial aspect of the design of buildings and infrastructures. Significant advances in research have increased the knowledge on this topic. However, until the 1990s, there were few forums for structural fire engineers to exchange ideas and share research findings. SIF (Structures in Fire) specialised workshop series was conceived in the late 1990s and the “First International SIF Workshop” was held in Copenhagen, Denmark in 2000, followed by workshops in Christchurch, New Zealand (2002), Ottawa, Canada (2004) and Aveiro, Portugal (2006). The series of workshops evolved into conferences and the 2008 event in Singapore was the fifth International Conference on Structures in Fire. This was followed by events in East Lansing, USA (2010), Zurich, Switzerland (2012), Shanghai, China (2014), New Jersey, USA (2016), Belfast, UK (2018), Brisbane, Australia (2020) and Hong Kong, China (2022). Information about previous conferences, including complete proceedings, can be found at www.structuresinfire.com. The main mission of SIF conferences is to provide an opportunity for researchers and engineers from the global structural fire engineering community to participate, share and discuss the recent findings, innovations and developments with their peers in an open and international forum. Following the great success of the previous International Conferences, the University of Coimbra was selected to host the 13th International Conference on Structures in Fire. As with most of the recent conferences, the number of papers submitted far exceeds the number of papers that can be accommodated in the three-day programme, even with two parallel sessions. SIF 2024 received 249 abstracts before the deadline and accepted 172 abstracts after the review process by at least three reviewers from the scientific committee. These proceedings represent 132 full papers, collectively representing the state of the art in fundamental knowledge and practical application of structures in fire. Forty-two countries from around the globe have contributed to them. The papers are grouped into the following research topics: Applications of Structural Fire Engineering, Composite Structures in Fire, Concrete Structures in Fire, Timber Structures in Fire, Masonry Structures in Fire, Steel Structures in Fire, Experimental Research of Structures in Fire, Numerical Modelling of Structures in Fire, Other Topics Related to Structures in Fire. Finally, the Organizing Committee would like to thank the continuous support from the SIF Steering Committee chaired by Prof Jean-Marc Franssen. We also would like to thank to the Scientific Committee chaired by Prof Paulo Vila Real, the authors and all the supporting staff (and volunteer team) from the Institute for Sustainability and Innovation in Structural Engineering (ISISE) in Coimbra, for making SIF 2024 a successful conference. DA - 19.06.2024 KW - Fire resistance KW - Fire test KW - Intumescent coating KW - Steel KW - Tension member PY - 2024 DO - https://doi.org/10.30779/cmm_SIF24 SP - 1173 EP - 1183 PB - CMM – Portuguese Steelwork Association AN - OPUS4-60815 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin A1 - Lu, Xin A1 - Chruscicki, Sebastian A1 - Krebber, Katerina T1 - Measurement of Slowly Changing and Quasi-Static Strain Signals for Ground Motion Monitoring Applications using Distributed Acoustic Sensing N2 - The suitability of wavelength-scanning COTDR for distributed dynamic strain sensing (DAS) along buried fiber cables for long-term geotechnical monitoring applications is demonstrated by experiments showing the method’s capability to demodulate slowly varying and quasi-static signals. T2 - Optica Sensing Congress 2024 CY - Toulouse, France DA - 15.07.2024 KW - Ground motion KW - Ground movement monitoring KW - Distributed fiber optic sensing KW - Quasi-static signals KW - Geomonitoring PY - 2024 SP - 1 EP - 2 PB - Optica CY - Washington D.C., USA AN - OPUS4-60816 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Singh, R. A1 - Vigelahn, L. A1 - Vogel, Christian A1 - Roesch, Philipp A1 - Simon, Franz-Georg A1 - Egloffstein, T. A1 - Birke, V. T1 - Rapid and Virtually Complete Mechanochemical Reductive Defluorination of Per- and Polyfluoro Alkyl Substances (PFAS) In Contaminated Soil Using Sodium and Amines as Co-milling Agents: A Promising First Approach for the Development of Novel Non-Combustion PFAS Remediation Processes for Soils N2 - PFAS contamination poses significant challenges due to their persistence, bioaccumulation, and potential adverse effects on ecosystems and human health. In recent years, conventional treatment methods, such as incineration, photolysis, and chemical oxidation, have been applied for PFAS treatment. However, these technologies have limitations in terms of their efficacy and cost-effectiveness for efficient PFAS degradation. Consequently, researchers have explored alternative approaches such as photocatalysis, sonochemical degradation, oxidation, electrochemical degradation, and mechanochemical degradation also known as DMCR (Dehalogenation by Mechanochemical Reaction) to address the remediation challenge posed by PFAS contaminated environments. Lab scale experiments were conducted using a planetary ball mill, procured from Retsch GmbH Germany, equipped with 50 mL steel grinding jars under controlled conditions to investigate the degradation of perfluorooctanoic sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in contaminated model sand. The experiments were carried out in two stages: initially, with sand alone (15 g), and subsequently, with the addition of co-milling agents, that is, sodium metal (Na), Na with butylamine (BA), and Na with ethylenediamine (EDA) in different proportions. T2 - International CleanUp conference CY - Adelaide, Australia DA - 15.09.2024 KW - Mechanochemical treatment KW - Per- und Polyfluoroierte Alkylsubstanzen (PFAS) KW - Remediation PY - 2024 SP - 177 AN - OPUS4-61119 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schultheiß, Annika L. A1 - Kruschwitz, Sabine A1 - Wilsch, Gerd A1 - Bogner, Andreas A1 - Patel, Ravi T1 - Lessons learnt on quantiative spatial chloride analysis using libs and µXRF N2 - Understanding chloride ingress is crucial in the context of the durability of concrete structures against corrosion. Techniques such as Laser-Induced Breakdown Spectroscopy (LIBS) and Micro X‑ray Fluorescence (µXRF) can provide a 2D representation of chloride ingress. However, obtaining quantitative data from such techniques is not a trivial task. In this study, we focus on factors such as sample preparation, measurement settings, calibration strategy, and post-processing of results which directly affect the outcome of the experiments but are rarely discussed in the literature. T2 - Rilem Annual Week 2024 CY - Toulouse, Frankreich DA - 25.08.2024 KW - Durability KW - Chloride ingress KW - LIBS KW - µXRF KW - Nondestructive testing KW - Imaging PY - 2024 SP - 1 EP - 9 AN - OPUS4-61664 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Sarah-K. A1 - Tschirschwitz, Rico A1 - Amano, Kofi Owusu Ansah A1 - Gimadieva, Elena A1 - Krause, Ulrich T1 - A Study on Thermal Runaway Propagation in Battery Modules Assembled from Pouch Cells N2 - Thermal runaway reactions were studied in arrangements from single battery cells with energy capacities of 2.5 Ah (9.25 Wh) to battery modules up to 6.85 kWh. All cells were pouch cells of the Li-ion NMC type and the modules were composed of such. Abuse was triggered either by overcharging or thermally by attaching a heat source (heating plate or glow plug) to the cells. Experiments with single cells or assemblies of two to four cells were undertaken in closed autoclaves. Samples of the gas released from the cells during the runaway were extracted and analysed using a Fourier-transformed infrared spectrometer (FTIR). In some experiments pressure peaks up to 7 bar (g) were observed which could not be explained by the gas release alone. Obviously, secondary explosions took place. Thermal runaway propagation was studied with and without an insulation layer between the battery cells. Several materials and combinations of them were tested as insulations: hollow glass spheres (Pyrobubbles®), phase change materials (PCM) and intumescent materials. Experiments showed that already layers of 10 to 20 mm of insulation effectively prevented the propagation of a thermal runaway. In addition to the experiments, a mathematical model was developed for studying numerically the heat transfer through arrangements of multiple battery cells and also the effect of insulation layers. This model was implemented into the commercial finite-element software package COMSOL Multiphysics®. The simulations confirmed the experimental findings that already quite thin insulation layers between cells or modules effectively delay or even suppress the propagation of the thermal runaway. T2 - EUSAS conference "Addressing the Fire Risks of Electromobility" CY - Frankfurt am Main, Germany DA - 10.05.2023 KW - Thermal Runaway KW - Consequences KW - Electrical Energy Storage KW - Gas release KW - Lithium-ion battery PY - 2024 UR - https://eusas.eu/publications/eusas-journals VL - 15 SP - 43 EP - 50 PB - EUSAS e.V. (European Society for Automatic Alarm Systems e.V.), Universität Duisburg-Essen, Dept. Nachrichtentechnische Systeme CY - Duisburg AN - OPUS4-61598 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weichert, Dorina A1 - Kister, Alexander A1 - Houben, Sebastian A1 - Link, Patrick A1 - Ernis, Gunar ED - Kiyavash, Negar ED - Mooij, Joris M. T1 - Robust Entropy Search for Safe Efficient Bayesian Optimization N2 - The practical use of Bayesian Optimization (BO) in engineering applications imposes special requirements: high sampling efficiency on the one hand and finding a robust solution on the other hand. We address the case of adversarial robustness, where all parameters are controllable during the optimization process, but a subset of them is uncontrollable or even adversely perturbed at the time of application. To this end, we develop an efficient information-based acquisition function that we call Robust Entropy Search (RES). We empirically demonstrate its benefits in experiments on synthetic and real-life data. The results show that RES reliably finds robust optima, outperforming state-of-the-art algorithms. T2 - UAI 2024 CY - Barcelona, Spain DA - 15.07.2024 KW - Bayesian Optimization KW - Gaussian process KW - Active learning PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-613523 UR - https://proceedings.mlr.press/v244/weichert24a.html SN - 2640-3498 VL - 244 SP - 3711 EP - 3729 PB - Proceedings of Machine Learning Research AN - OPUS4-61352 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Melzer, Michael ED - Deschermeier, Regina ED - Bünger, Lars ED - Schüür, Jens T1 - Good practice für digitale Kalibrierscheine von Temperatur- und Feuchtemessgrößen N2 - Der digitale Kalibrierschein (DCC) enthält alle Informationen eines herkömmlichen Kalibrierscheins in maschinenlesbarer und möglichst auch -interpretierbarer Form, um eine Automatisierung des Qualitätsmanagements und der metrologischen Rückführbarkeit in den Laboren und im industriellen Messwesen zu ermöglichen. Neben den allgemeinen Anforderungen, z.B. aus ISO/IEC 17025, gibt es spezifische Anforderungen bezüglich der Messgrößen und der Kalibrierverfahren, die auch in digitalen Ergebnisberichten erfüllt sein müssen. Innerhalb des DKD Fachausschusses für Temperatur und Feuchte werden derzeit good practice Empfehlungen erarbeitet, um zu definieren, wie genau diese Anforderungen im Rahmen des DCC erfüllt werden sollten. Anhand der Temperaturskala und des Kalibriermediums werden zwei dieser good practices hier beispielhaft erläutert. Außerdem wird eine Übersicht über die bereits definierten spezifischen refType-Attribute für Temperatur- und Feuchtemessgrößen gegeben. T2 - TEMPERATUR 2024 CY - Berlin, Germany DA - 05.06.2024 KW - Digital Calibration Certificate KW - Digital certificates KW - Digital Metrology KW - QI-Digital KW - Calibration PY - 2024 UR - https://www.temperatur.ptb.de/startseite SP - 145 EP - 151 AN - OPUS4-61923 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Sarah-K. A1 - Saupe, Alexander A1 - Tschirschwitz, Rico A1 - Bernardy, Christopher A1 - Janßen, Marvin A1 - Amano, Kofi Owusu Ansah A1 - Krause, Ulrich T1 - Sicherheit elektrochemischer Energiespeicher – Ergebnisse aus dem Projekt SEE-2L N2 - Die Transformation der Energienutzung von konventionellen zu erneuerbaren Quellen führt dazu, dass zukünftig mehr Energie effizient zwischengespeichert werden muss. Eine Möglichkeit der elektrochemischen Zwischenspeicherung bieten Lithium-Ionen-Batterien. Hierfür können ausgemusterte Automobilantriebsbatterien verwendet werden. Erfüllen sie die hohen Anforderungen des mobilen Bereichs nicht mehr, haben sie oftmals noch eine ausreichende Kapazität und Leistungsfähigkeit für die stationäre Zwischenspeicherung. Neben der Verwendung der Batterien im größeren Maßstab, z.B. bei Energieversorgern, werden durch den vermehrten Einsatz von Photovoltaik-Anlagen in Ein- und Mehrfamilienhäusern verstärkt Zwischenspeicher für Privathaushalte nachgefragt. Dies birgt auch für Einsatzkräfte neue Herausforderungen in der Gefahrenabwehr. Im vom Bundesministerium für Bildung und Forschung (BMBF) geförderten Verbundprojekt „SEE-2L – Sicherheit elektrochemischer Energiespeicher in Second Life Anwendungen“ wurden Versuche mit Second Life Modulen durchgeführt. Verbundpartner im Projekt waren neben der vfdb die Otto-von-Guericke-Universität Magdeburg und die Bundesanstalt für Materialforschung und -prüfung. Zudem war das Institut der Feuerwehr Nordrhein-Westfalen eingebunden. Die durchgeführten Versuche bilden eine Grundlage für die Einordnung der Batteriespeicher, z.B. aus Sicht des baulichen Brandschutzes, zur Methodik der Brandbekämpfung oder zur Risikobewertung hinsichtlich der Prozess- und Anlagensicherheit. Im Beitrag werden die Versuchsergebnisse vorgestellt und Ansätze für deren Anwendung gezeigt. Um die gewonnenen Erkenntnisse zu vermitteln, wurde im Projekt zudem ein Schulungskonzept für Einsätze mit Lithium-Ionen-Technologien erarbeitet, das im Beitrag präsentiert wird. Es besteht aus theoretischen und praktischen Anteilen, sodass bei den Feuerwehren praxisnah aus- bzw. fortgebildet werden kann. T2 - 70. Jahresfachtagung der vfdb CY - Magdeburg, Deutschland DA - 06.05.2024 KW - Auswirkungsbetrachtungen KW - Elektrische Energiespeicher KW - Lithium-Ionen-Batterie KW - Stationäre Energiespeicher KW - Thermisches Durchgehen PY - 2024 SN - 978-3-9360-5038-7 SP - 645 EP - 657 PB - vfdb, Vereinigung zur Förderung des Deutschen Brandschutzes e.V. CY - Münster AN - OPUS4-60068 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gaal, Mate A1 - Wernicke, Pascal A1 - Hufschläger, Daniel T1 - Pulskompression für luftgekoppelte Ultraschallprüfung mit Ferroelektret- und thermoakustischen Wandlern N2 - Die größten Vorteile der luftgekoppelten Ultraschallprüfung sind: die berührungslose Prüfung und der Verzicht auf ein flüssiges Koppelmittel. Allerdings weisen die meisten luftgekoppelten Prüfszenarien ein sehr geringes Signal-zu-Rausch-Verhältnis (SNR) auf und die Pegel, die von luftgekoppelten Ultraschallwandlern realisiert werden, sind um mehrere Größenordnungen kleiner. Da diese Herausforderung auch in anderen Disziplinen wie bspw. der Radartechnik existiert und dort ebenfalls eine entscheidende Rolle spielt, wurde die dort eingesetzte Pulskompression auf die physikalischen Gegebenheiten der luftgekoppelten Ultraschallprüfung angepasst und angewandt. Dieser Beitrag präsentiert die Ergebnisse von zwei Versuchsaufbauten: 1) ein thermoakustischer Sender und ein optisches Mikrofon und 2) ein Paar Ferroelektret-Wandler als Sender und Empfänger. Aufgrund der physikalischen Randbedingungen wurden unipolare Kodierungen verwendet. Die Verwendung von unipolaren Kodes zur Modulation der Anregungssignale stellt dabei eine neue Methode dar, die so die Pulskompression für Ferroelektret- und thermoakustische Wandler ermöglichen soll. Die Anwendung der Pulskompression auf die Kombination aus thermoakustischem Sender und optischem Mikrofon konnte das Signal-zu-Rausch-Verhältnis um bis zu 15 dB und für die Ferroelektret-Wandler um bis zu 23 dB erhöhen. T2 - DAGA CY - Hannover, Germany DA - 19.3.2024 KW - Pulskompression KW - Luftgekoppelter Ultraschall KW - Ferroelektrete KW - Thermoakustik PY - 2024 UR - https://pub.dega-akustik.de/DAGA_2024/ SP - 1580 EP - 1583 AN - OPUS4-60169 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kowalski, Kurt A1 - Hulshoff, S.J. A1 - Ströer, P. A1 - Withag, J. A1 - Genot, A. A1 - Morgans, A.S. A1 - Bake, Friedrich A1 - Venner, K. A1 - Sanders, M.P.J. A1 - Hirschberg, Lionel T1 - Entropy-patch choked-nozzle interaction: quasi-steady-modeling-regime limits probed N2 - Indirect combustion noise due to the interaction of flow inhomogeneities with a choked combustion-chamber exit is an important cause of combustion instability in solid rocket motors. Moreover, it is believed to be an issue in electrical-power generation turbines and aero-engines. If these flow inhomogeneities are essentially characterized by the fluid having a locally appreciablydifferent thermodynamic state, the acoustic response engendered by its interaction with the combustion-chamber exit is commonly referred to as entropy noise. In this paper, dedicated numerical-simulation results of entropy-patch choked-nozzle interactions are presented. Two types of entropy patches were considered: rectangular slugs and circular spots. Moreover, analytical-model-based analysis, of said simulation results, is presented. Based on said analysis, the authors posit the existence of three modeling regimes: the quasi-steady-modeling regime, the blended-physical-effects regime, and the inertial-modeling regime. T2 - 30th AIAA/CEAS Aeroacoustics Conference (2024) CY - Rome, Italy DA - 04.06.2024 KW - Entropy-Nozzle Interaction KW - Indirect Combustion Noise KW - Entropy Noise PY - 2024 SN - 978-1-62410-720-7 DO - https://doi.org/10.2514/6.2024-3113 SP - 1 EP - 23 AN - OPUS4-60174 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Quercetti, Thomas A1 - Feldkamp, Martin A1 - Gleim, Tobias A1 - Musolff, Andre A1 - Werner, Jan A1 - Wille, Frank T1 - Enhancement of the BAM Fire Test Stand for Testing a Large Transport Package for Radioactive Materials N2 - Packages for the transport of spent nuclear fuel are designed to endure severe accidents. To obtain approval, these transport packages must adhere to the specification-based criteria of the international transport regulations SSR-6 of the International Atomic Energy Agency (IAEA). To ensure compliance with these requirements, specific mechanical and thermal tests need to be addressed with respect to the package type. Typically, SSR-6 prescribes a mechanical test followed by a thermal fire test as part of different testing scenarios. To approve the latter test of the sequence, BAM performs calorimeter tests in advance with so-called fire reference packages for characterizing the actual fire and its impact on the package to be tested. Packages are designed with different geometry sizes depending on their purpose. For previous tests, the implemented test setups in the fire test stand were sufficiently dimensioned and could cover all requirements in this respect. However, to cover additional testing needs in the future, BAM is expanding the test setup for the purpose of testing significantly larger packages. In previous test setups one ring burner for propane surrounding the test specimen was sufficient. The limiting size in this configuration was the design height of the transport package to be tested. According to the thermal test of the IAEA-Regulations [1], a 30-minute fully engulfing 800°C pool fire or an equally severe fire, e.g., propane gas fire, must be applied to the transport package. Possible adjustments such as nozzle cross-section and propane mass flow can be adjusted to a certain extent. Further modifications, to cover significantly higher and larger packages all-around with a fully engulfing fire, must be accomplished with an additional, second burner ring. Both burner rings had the same dimensions and were mounted on top of each other at different heights to create a significantly larger volume of fire that completely engulfs the package including its impact limiter. To meet the IAEA regulatory boundary conditions, the enhanced fire test stand with the second burner ring is tested with a large fire reference package and will then be used for real-size transport packages after all parameters are successfully met. This fire reference package represents the external geometry of a generic transport cask for radioactive material and is equipped with numerous temperature sensors to record temperature curves at the interior wall surfaces. T2 - RAMTrans 2024 CY - London, United Kingdom DA - 14.05.2024 KW - Fire testing KW - Full-scale KW - Transport package PY - 2024 SP - 1 EP - 7 AN - OPUS4-60253 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lu, Xin A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Distributed fiber optic sensing for monitoring of underground facilities N2 - Distributed fiber optic sensing (DFOS) technique is a promising and robust non-destructive testing tool that can seamlessly acquire environmental conditions over large scales. Therefore, it has found extensive applications in structural health monitoring. Its appeal for monitoring underground facilities lies in the intrinsic properties of the optical fiber, such as immunity to magnetic interference, small size, chemical inertia, etc. This paper provides a concise overview of DFOS applications in underground facility monitoring. Following a brief introduction to the workingbnprinciple of the DFOS technique, various examples are provided to demonstrate how distributed fiber sensors contribute to monitoring underground facilities. The paper presents unpublished field test results with an emphasis in the energy sector, including monitoring gas storage facilities, geothermal reservoir exploration, and ground movement detection. Furthermore, the paper identifies several directions for enhancing the DFOS system. T2 - SPIE Photonics Europe CY - Strasbourg, France DA - 07.04.2024 KW - Structure health monitoring KW - Geothermal borehole KW - Distributed fiber optic sensing KW - Ground movement KW - Leakage detection PY - 2024 DO - https://doi.org/10.1117/12.3023571 SN - 0277-786X VL - 13001 SP - 1 EP - 10 PB - SPIE AN - OPUS4-60384 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hirsch, Philipp Daniel A1 - Kunji Purayil, Sruthi Krishna A1 - Lecompagnon, Julien A1 - Hassenstein, Christian A1 - Ziegler, Mathias T1 - Robotergestützte 3D-Scans und Laserthermografie zur Prüfung an komplexen Bauteilen auf Risse N2 - Die Integration von Automation und Robotik in die Prüfprozesse ermöglicht die Untersuchung komplexer Bauteile. Diese Studie präsentiert die robotergestützte Laserthermografie, um Risse in solchen Bauteilen zu identifizieren und analysieren. Diese Technik ermöglicht die automatisierte Rissprüfung welche im Vergleich zur Farbeindringprüfung auf viele, meist manuelle, Arbeitsschritte sowie die notwendigen Chemikalien verzichtet. Zusätzlich wird ein automatisiertes Einscannen der Bauteile mithilfe eines Linienscanners vorgestellt. Dieser Schritt ermöglicht eine detaillierte 3D-Rekonstruktion der Bauteilgeometrie und ermöglicht eine einfache Korrektur von Abweichungen in der Bauteilaufnahme und eröffnet Möglichkeiten zur adaptiven Bahnplanung bei Bauteilverformungen. Die Rückprojektion der gefundenen Risse auf die Oberfläche des Bauteils kann automatisiert erfolgen. Dieser Schritt erlaubt nicht nur die Identifikation der Risse, sondern auch eine genauere Analyse ihrer Geometrie und Lage am Bauteil. Die Kombination von robotergestützter Laserthermografie, automatisiertem 3DScanning und Rückprojektion der Risse auf die Bauteiloberfläche eröffnet neue Möglichkeiten in der zerstörungsfreien Prüfung von komplexen Bauteilen und erweitert damit mögliche Anwendungsfelder. T2 - Jahrestagung der Deutschen Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) 2024 CY - Osnabrück, Germany DA - 06.05.2024 KW - ZFP4.0 KW - Automatisierung KW - Thermografie KW - Laser KW - Roboter PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604811 UR - https://www.ndt.net/?id=29520 VL - 182 SP - 1 EP - 8 PB - NDT.net AN - OPUS4-60481 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schlegel, Moritz-Caspar A1 - McAlister, Catriona A1 - Rama, Mathieu T1 - Pioneering durability in electronics - The role of standardisation in policymaking and vice versa N2 - This paper highlights the role of standardisation in enabling greener electronics in the EU. It presents an analysis of the evolving landscape of material efficiency standardization, the majority of which has been undertaken in the framework of the European Ecodesign Directive, soon to be repealed by the Ecodesign for Sustainable Products Regulation. The impending policy shift will include a very broad extension of product scope, a strengthening of the way in which material efficiency aspects are addressed, and wider potential for product labelling. During the stakeholder consultation process, the European Commission announced that the durability of products would be one of the major topics in the new regulatory approach - hence the specific focus of this paper on durability scoring. The paper first examines the policy and standardization context, and then provides an overview of material efficiency indexes and scoring systems currently in place or being developed. It highlights where standardization is following policymaking, and where standardization is paving the way for more circular products. Scoring systems and indexes could potentially be used for both (i) setting minimum requirements for products entering the EU market, and (ii) consumer labels on material efficiency aspects such as product durability that could trigger environmentally sustainable purchase decisions. Subsequently, a methodological framework for a comprehensive durability scoring system that could be developed in standards is proposed, and the potential for these to be used as a basis for product legislation is explored. Potential durability criteria are listed, divided into technical, servicerelated and further aspects. Technical aspects include external factors that influence the durability of products such as drop/shock resistance. Service-related aspects include, for example, pre-purchase information provision on battery replaceability or availability of software updates. Other aspects include for example pro. T2 - EGG+ Electronics Goes Green 2024+ CY - Berlin, Germany DA - 18.06.2024 KW - Circular Economy KW - Durability KW - Material efficiency KW - Ecodesign KW - ESPR KW - Labelling KW - Consumer PY - 2024 SN - 979-8-3503-8822-0 SP - 56 EP - 62 AN - OPUS4-60399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tochtrop, Christoph A1 - von Geibler, Justus A1 - Rückschloss, Jana A1 - Schlegel, Moritz-Caspar T1 - Product features: Upgraded Functionality or Sustainability Problem? An environmental assessment approach for additional product functions and its application in the case of fridge-freezers N2 - Next to primary functions, energy-related products have an increasing number of additional functions. This affects the overall environmental footprint, but the question is how? A number of European policy strategies, initiatives and measures, such as the Green Deal, the Circular Economy Action Plan,the Ecodesign Directive and the EU Energy Labelling, aim to ensure that the environmental impact of the overall product is better determined, communicated and finally reduced. A core element of these efforts is the DIN EN 4555x series of standards. However, there is currently no comprehensive and systematic classification of the additional product functions or an approach to assess the associated positive and negative environmental impacts. Therefore, we present in this study an environmental assessment approach for additional product functions and illustrate its application in the case of fridge-freezers. A key element of the life-cycle-oriented methodology is an assessment matrix to categorize and evaluate the direct, indirect and systemic impacts of products’ functions. Based on semiquantitative assessments of experts, the matrix provides an indication of how the additional function affects the overall environmental product impact as well as specific product aspects such as durability or reparability. Based on the results experts can discuss and better understand how specific functions can influence various stages of the product life cycle and how intended systemic changes or rebound effects could occur. As part of the approach, a representative survey was conducted to analyze consumers’ knowledge and information needs. Based on the results, recommendations for purchasing decisions and the consumer information were developed. This paper presents the results from the assessment of the additional functions of fridge-freezers. T2 - EGG+ Electronics Goes Green 2024+ CY - Berlin, Germany DA - 18.06.2024 KW - Circular Economy KW - ESPR KW - Material efficiency KW - Ecodesign KW - Policy making KW - Standardization KW - Consumer PY - 2024 SN - 978-3-00-079329-5 DO - https://doi.org/10.23919/EGG62010.2024.10631252 SP - 87 EP - 97 AN - OPUS4-60400 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Casperson, Ralf A1 - Friedrich, Alexander A1 - Heckel, Thomas A1 - Zhang, Tianyun T1 - Verwendung von DICONDE bei der Eisenbahn-Schienenprüfung N2 - Bei der zerstörungsfreien Prüfung verlegter Eisenbahnschienen werden die Rohdaten derzeit in proprietären Datenformaten gespeichert und auf Datenträgern zwischen den Prüfzügen und den auswertenden Stellen versendet. Die proprietären Datenformate sind in der Regel nur den Herstellern der Prüfsysteme bekannt und deren Dokumentation nicht allgemein zugänglich. Die „Standard Practice for Digital Imaging and Communication in Nondestructive Evaluation“ (DICONDE), basierend auf dem medizinischen Standard „Digital Imaging and Communication in Medicine“ (DICOM), ermöglicht es, sowohl Prüfdaten als auch Prüfergebnisse und Streckeninformationen in einem standardisierten Format zu speichern und zwischen verschiedenen Endpunkten zu übertragen. Das Poster gibt zunächst einen kurzen Überblick über die hierarchische Struktur von DICONDE und zeigt dann, wie DICONDE bei der Prüfung verlegter Eisenbahnschienen verwendet werden kann. Die geometrischen Besonderheiten (mehrere Kilometer Länge pro Prüffahrt, kurviger Streckenverlauf) stellen dabei eine besondere Herausforderung dar. Im Rahmen des mFUND-geförderten Projektes „Arteficial Intelligence for Railway Inspection (AIFRI)“, Förderkennzeichen 19FS2014C, wurde ein Vorschlag für eine Erweiterung des DICONDE-Standards für die Schienenprüfung erarbeitet und bei der ASTM eingereicht. T2 - DGZfP Jahrestagung 2024 CY - Osnabrück, Germany DA - 05.05.2024 KW - DICONDE KW - Eisenbahn KW - Schienenprüfung PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600204 DO - https://doi.org/10.58286/29500 SP - 1 EP - 5 PB - NDT.net AN - OPUS4-60020 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -