TY - CONF A1 - Baar, C A1 - Laar von, C A1 - Plarre, Rudy A1 - McMahon, Dino T1 - Insektenmonitoring und genetisches Barcoding N2 - Die aus der Kirche in Greven entnommenen A. punctatum wiesen größere genetische Unterschiede auf als die aus der isolierten Zucht der BAM. Dies lässt vermuten, dass ein Austausch von zufliegenden oder eingeschleppten Individuen zu einer erhöhten genetischen Variabilität beiträgt. Die Ergebnisse der Sequenzanalysen vom Standort Greven zeigten, dass vier Variationen vorhanden waren. Die DNA-Barcodes aus der Datenbank NCBI (Frankreich, Finnland und Deutschland) besaßen nur SNPs, die bereits aus den Insekten der Kirche in Greven bekannt waren. Nach aktueller Datenlage für den betrachteten Genabschnitt sind diese Varianten (V2 bis V22) als repräsentativ für den mitteleuropäischen Raum anzunehmen. Potenzielle weitere Varianten lassen sich nur über eine größere Stichprobenanzahl entdecken/finden. Die Ergebnisse der Käferproben aus der isolierten Zucht der BAM sind deutlich homogener und entsprachen der Variante 1 aus Greven. Die Variante 1 wurde ebenfalls in vier französischen und einer deutschen Probe aus der NCBI-Datenbank nachgewiesen. Die Ergebnisse deuten auf zwei Hauptvariationen (Vx und V20) hin, wobei die eine (VJ homogener als die andere (V20) zu sein scheint. Da für den Räuber K. caeruleus keine Unterschiede in der COI gefunden wurden, gilt zu prüfen, ob der gewählte Genabschnitt für die Untersuchung repräsentativ ist. Dies ist mit einer höheren Probenzahl zu validieren. T2 - 32. Deutsche Holzschutztagung CY - Dresden, Germany DA - 25.04.2024 KW - Korynaetes caeruleus KW - Insektenmonitoring KW - Genetisches Barcoding KW - Anobium punctatum PY - 2024 SP - 244 EP - 252 AN - OPUS4-60027 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gook, Sergej A1 - El-Sari, Bassel A1 - Üstündag, Ömer A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael A1 - Biegler, Max T1 - Kombination des Laserhybridschweißens und UP-Engspaltschweißens für dickwandige Bauteile zur Erhöhung der Wirtschaftlichkeit N2 - Dieser Beitrag befasst sich mit der Entwicklung eines wirtschaftlichen und robusten Verfahrens zum Schweißen dicker Stahlbleche. Es werden Ergebnisse für das Fügen von Blechen im Dickenbereich von 25 mm bis 80 mm vorgestellt. Die 30 mm dicken Schweißnähte konnten im Stumpfstoß in zwei Durchgängen unter Verwendung des Laserhybridschweißens und des Unterpulverschweißens (UP) geschweißt werden. Das Laserhybridschweißen wird als Einschweißung mit einer Tiefe von ca. 25 mm ausgeführt. Die UP-Lagen werden auf der gegenüberliegenden Seite des Blechs aufgebracht. Bei richtiger Wahl der Schweißparameter wird der Nahtquerschnitt durch eine sichere Überlappung beider Lagen geschlossen. Bei Blechdicken über 30 mm ist eine Kantenvorbereitung erforderlich, die eine Ausführung der UP-Fülllagen in Engspalttechnik ermöglicht. Die Vorteile der vorgeschlagenen Prozesskombination liegen darin, dass die Nahtwurzel der Laserhybridnaht nicht geformt werden muss. Defekte in der Wurzel der Laserhybrideinschweißung können durch die UP-Lagen effektiv beseitigt werden. Das Verfahren bietet eine hohe Stabilität des Schweißprozesses in Bezug auf die Qualität der Blechkanten. Plasmageschnittene Kanten konnten ohne Bindefehler geschweißt werden. Die erreichte Nahtqualität wurde durch zerstörende und zerstörungsfreie Prüfungen bestätigt. T2 - Innovationstag 2024 CY - Düsseldorf, Germany DA - 10.04.2024 KW - Laserhybridschweißen KW - Windturm KW - Dickblech KW - Unterpulverschweißen PY - 2024 SN - 978-3-96144-253-9 VL - 391 SP - 186 EP - 194 PB - DVS Media GmbH CY - Düsseldorf AN - OPUS4-60031 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Holzwarth, Marcel A1 - Mayer, Uwe A1 - Baer, Wolfram T1 - Investigating the Applicability of the Master Curve Concept for Ductile Cast Iron – Early Results for 2 Different Test Temperatures 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 between MPA Stuttgart and BAM Berlin. This paper outlines the research approach, the planned investigations and first results of the experimental program. T2 - 8th SEDS Workshop: Safety of Extended Dry Storage CY - Garching, Germany DA - 15.05.2024 KW - Dynamic fracture KW - Brittle fracture KW - Ductile cast iron KW - Master Curve PY - 2024 SP - 1 EP - 4 AN - OPUS4-60013 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 - TY - CONF A1 - Ratkovac, Mirjana A1 - Gerards-Wünsche, Paul A1 - Thiele, Marc A1 - Brackrock, Daniel A1 - Stamm, Michael T1 - Detection and monitoring of the fatigue crack growth on welds – Application-oriented use of NDT methods N2 - Early detection of fatigue cracks and accurate measurements of the crack growth play an important role in the maintenance and repair strategies of steel structures exposed to cyclic loads during their service life. Observation of welded connections is especially of high relevance due to their higher susceptibility to fatigue damage. The aim of this contribution was to monitor fatigue crack growth in thick welded specimens during fatigue tests as holistically as possible, by implementing multiple NDT methods simultaneously in order to record the crack initiation and propagation until the final fracture. In addition to well-known methods such as strain gauges, thermography, and ultrasound, the crack luminescence method developed at the Bundesanstalt für Materialforschung und -prüfung (BAM), which makes cracks on the surface particularly visible, was also used. For data acquisition, a first data fusion concept was developed and applied in order to synchronize the data of the different methods and to evaluate them to a large extent automatically. The resulting database can ultimately also be used to access, view, and analyze the experimental data for various NDT methods. During the conducted fatigue tests, the simultaneous measurements of the same cracking process enabled a comprehensive comparison of the methods, highlighting their individual strengths and limitations. More importantly, they showed how a synergetic combination of different NDT methods can be beneficial for implementation in large-scale fatigue testing but also in monitoring and inspection programs of in-service structures - such as the support structures of offshore wind turbines. T2 - Fatigue Design 2023 (FatDes 2023) CY - Senlis, France DA - 29.11.2023 KW - Fatigue KW - Welded KW - NDT KW - Crack growth PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600238 DO - https://doi.org/10.1016/j.prostr.2024.03.062 VL - 57 SP - 560 EP - 568 PB - Elsevier B.V. AN - OPUS4-60023 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Holzwarth, Marcel A1 - Mayer, Uwe A1 - Baer, Wolfram A1 - Weihe, Stefan T1 - Investigation of the Master Curve Concept for Ferritic Ductile Cast Iron N2 - Within fracture mechanics safety assessment for steels in nuclear technology, the probabilistic master curve (MC) concept according to ASTM E1921 is currently used for quasi-static loading conditions as a supplement to the established deterministic ASME reference curve concept. However, for ductile cast iron (DCI), a systematic review of potential modifications to the assumptions and the procedure according to ASTM E1921 and an associated validation are still lacking. For this reason, the application of the fracture mechanics MC concept to ferritic ductile cast iron is being investigated in a joint research project between MPA Stuttgart and BAM Berlin. According to Hojo et al. (2008) the MC concept is already in use for the brittle fracture safety assessment of ferritic forged steel containers, which would suggest an extension to ductile cast iron containers. In compliance with IAEA SSG-26, the safety assessment of DCI containers for transport as well as storage of radioactive materials is based on the fracture mechanics criterion of general exclusion of crack initiation. Within this context, the focus of the current research project is on the further development of brittle fracture safety assessment methods. Therefore, a methodology shall be established to determine and assess dynamic fracture toughness values of DCI in the ductile-to-brittle transition regime, using only a low number of small fracture mechanics test specimens extracted from a component. For the experimental program, a DCI material of grade GJS-400 (GGG-40) has been produced as it is generally used for transport and storage containers for nuclear material. A basic mechanical-technological material characterization consisting of tensile, Charpy, and Pellini tests has been planned and a comprehensive fracture mechanics test program was compiled covering dynamic testing of DC(T)9, C(T)25, C(T)50, SE(B)10, SE(B)25, and SE(B)140 specimens at various loading rates and temperatures. The specimen testing is divided between the project partners based on specimen geometry. MPA Stuttgart has been tasked with the testing of the C(T), DC(T) and Pellini specimens, while BAM Berlin was assigned the SE(B), Charpy and tensile tests. These tests allow for the determination of the loading rate relevant for brittle fracture via C(T)25 specimens and an assessment of size effects by transferring the relevant loading rate to other specimen geometries and sizes. Numerical analyses of different specimen geometries and test setups are planned to investigate the influence of stress triaxiality and loading rate. Furthermore, the time-dependent course of the Weibull stress is assessed via these numerical analyses. Throughout the experimental program, the microstructure-property relationship will also be investigated based on quantitative metallographic and fractographic analyses like scanning electron microscope images and metallographic sections. With the acquired experimental database fundamental assumptions of the MC concept, like the weakest link model and the Weibull distribution, will be assessed for the application to DCI. In the end, the applicability of the MC concept will be evaluated and if necessary, modifications to the MC concept for DCI will be proposed. This paper will present the preliminary results of the GJS400 material characterization and the related selection of test specimen extraction points. First results of the C(T)25 and SE(B)140 specimen testing will also be discussed supported by first metallographic analyses. T2 - SMiRT27 Conference CY - Yokohama, Japan DA - 03.03.2024 KW - Ductile Cast iron KW - Dynamic Fracture Toughness KW - Safety Assessment KW - Master Curve Concept PY - 2024 SP - 1 EP - 10 AN - OPUS4-59302 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Barretto, T. A1 - Gentes, S. A1 - Braun, J. A1 - Averin, Anton A1 - Lecompagnon, Julien A1 - Stroncik, N. T1 - Automated non-destructive internal corrosion detection on radioactive drums (ZIKA) N2 - The aim of the ZIKA research project, funded by the BMBF funding program FORKA (FKZ:15S9446 A-C), is the automated detection of internal corrosion of radioactive drums using non-destructive testing (NDT). The newly gained findings will be combined with research results from the previous project EMOS (FKZ:15S9420), which dealt with the external damage of drums. Using NDT, internal corrosion and possible internal sources of damage can be identified before they become a safety-relevant issue. However, if internally sourced damages can be seen externally, the integrity of the damaged drum is no longer guaranteed, which has significant consequences. Therefore, early detection before integrity failure is of particular importance for interim storage facilities with low- and medium-level radioactive waste drums. T2 - Kerntechnik 2024 CY - Leipzig, Germany DA - 11.06.2024 KW - Corrosion detection KW - Non-destructive testing KW - Automated inspection system PY - 2024 SP - 1 EP - 5 AN - OPUS4-60322 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Völzke, Holger T1 - Brittle Failure Limits of Spent Fuel Claddings Subjected to Long-Term Dry Interim Storage Conditions N2 - The mechanical properties of spent fuel claddings can be adversely affected under the conditions of long-term dry interim storage, so that the failure limits may be reached in case of mechanical loads during handling or transport after storage. Pre-storage drying and the early stage of interim storage can expose the cladding to higher temperatures and higher tensile hoop stresses than those associated with in-reactor operation and pool storage. During slow cooling of a cladding tube under internal pressure, radial hydrides may precipitate in zirconium-based cladding alloys. This can lead to embrittlement of the material and sudden failure of the cladding integrity under mechanical stress. In order to prevent brittle failure, numerical methods are being developed to predict the mechanical behaviour and identify limiting conditions. Experimental investigations, numerical analyses and evaluation methods are discussed. An established experimental method for characterising cladding materials is the Ring Compression Test (RCT). Some test results on irradiated cladding tubes after operation in pressure water reactors are publicly available. However, it is helpful to carry out studies on unirradiated surrogate claddings with similar material properties to reduce the effort associated with irradiated samples in hot cells and to perform material tests with a wider range of parameters. On the basis of such experimental data, load-displacement curves have been numerically analysed for a selection of cladding materials. Radial hydrides can cause a sample to break suddenly due to fracture even at low deformation. Noticeable load drops in the RCT are caused by unstable crack propagation through the radial hydride network. The failure mechanism is quasi-cleavage in the hydrides and micro-void nucleation, growth, and coalescence in the zirconium matrix, with ductile tearing patches connecting adjacent hydrides. The cohesive zone approach was used to simulate the failure process taking into account the radial hydride morphology. The developed method can adequately describe both the deformation and failure behaviour of irradiated as well as unirradiated claddings of zirconium-based alloys with radial hydrides under RCT conditions. Limiting conditions can be expressed in terms of fracture energy and cohesive strength. T2 - IAEA International Conference on the Management of Spent Fuel from Nuclear Power Plants - Meeting the Moment CY - Vienna, Austria DA - 10.06.2024 KW - Ageing Management KW - Cladding Embrittlement KW - Extended Storage KW - Ring Compression Test KW - Spent Nuclear Fuel PY - 2024 SP - 1 EP - 10 AN - OPUS4-60323 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ronen, A. A1 - Vogel, Christian A1 - Leube, Peter A1 - Ben Efraim, R. A1 - Nir, O. A1 - Chaudhary, M. A1 - Futterlieb, M. A1 - Panglisch, S. T1 - DEFEAT-PFAS: Detection, Quantification, and Treatment of Per- and Polyfluoroalkyl Substances (PFAS) in Groundwater N2 - The research project focuses on tackling the detection, measurement, and elimination of per- and polyfluoroalkyl substances (PFAS) from polluted groundwater, with a particular emphasis on addressing short (C4-C7) and ultrashort (C1-C3) chain PFAS. Given the widespread use of PFAS in various products, they are commonly found in groundwater near industrial and military sites in Germany and Israel. Moreover, recent regulations limiting the use of long chain PFAS have led industries to shift towards shorter chain alternatives. Hence, our efforts are geared towards refining detection, quantification, and removal methods for short and ultrashort chain PFAS. In terms of detection, ww are developing passive sampling devices capable of collecting and tracking the temporal distribution of PFAS species in groundwater. This will enable us to analyze contaminations in German and Israeli groundwater using cutting-edge analytical techniques. Additionally, contaminated groundwater will undergo a two-stage treatment process aimed at concentrating the relatively low PFAS concentrations using innovative membrane technologies such as closed-circuit reverse osmosis and mixed matrix composite nanofiltration membrane adsorbers. Subsequently, the streams containing higher PFAS concentrations will be treated through coagulation, with the remaining PFAS being adsorbed onto carbonaceous nanomaterials. The outcome of this research will include the creation of advanced tools for detecting, measuring, and eliminating PFAS from polluted groundwater, while also enhancing our understanding of the scope of these contaminations. T2 - German Israeli Water Technology Status Seminar CY - Koblenz, Germany DA - 18.06.2024 KW - Ground water KW - Per- and Polyfluoroalkyl substances (PFAS) KW - Remediation PY - 2024 UR - https://indico.scc.kit.edu/event/4029/attachments/7552/12045/Proceedings_Ger-Isr-Coop_Status-Seminar-2024.pdf SP - 33 EP - 36 AN - OPUS4-60331 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lohrke, Heiko A1 - Kohlhoff, Harald A1 - Neumann, Patrick P. ED - Lee, J. B. T1 - Robotic Scanning Absorption Spectroscopy for Methane Leak Detection: the Virtual Gas Camera N2 - This paper explores combining a gimbal-mounted tunable diode laser absorption spectroscopy (TDLAS) sensor and a video camera to create a virtual gas camera for methane leak detection. This provides a low-to-zero-cost extension of typical TDLAS gas tomography systems. A prototype setup mounted on a ground robot is evaluated. Results acquired using a simulated methane leak show the feasibility of the virtual gas camera, accurately detecting methane leaks by overlaying concentrations onto a visual image. While the acquisition time is significantly longer than for traditional gas cameras, potential enhancements are discussed. The study concludes that the virtual gas camera is feasible and useful, despite its longer acquisition time. It serves as a valuable software-only addition to typical TDLAS gas tomography systems, offering quickly-available on-site data augmentation for visual leak assessment at low-to-zero cost. T2 - 20th International Symposium on Olfaction and Electronic Nose CY - Grapevine, Texas, USA DA - 12.05.2024 KW - Mobile Robotic Olfaction KW - TDLAS KW - Gas Tomography KW - Gas Camera KW - Plume PY - 2024 SN - 979-8-3503-4865-1 DO - https://doi.org/10.1109/isoen61239.2024.10556012 SP - 1 EP - 3 PB - IEEE CY - USA AN - OPUS4-60109 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wu, Hongyi A1 - Hofmann-Böllinghaus, Anja T1 - TREEADS - Experimente und numerische Simulation zur Brandausbreitung von Vegetationsbränden N2 - Um die Ausbreitungsmechanismen von Vegetationsbränden und besonders bei Bodenbränden besser zu verstehen, wurden die Einflussfaktoren auf die Brandausbreitung näher untersucht. Da die Brandausbreitung auch in starkem Maße von der lokalen Vegetation abhängt, war eine Charakterisierung der lokalen Vegetation und der Bodenverhältnisse wichtig. Die Wetterverhältnisse spielen einerseits im Vorfeld des Brandes durch längere Dürreperioden als auch während des Brandes, z.B. durch den Windeinfluss, zusätzlich eine große Rolle. Durch die numerische Simulation kann eine größere Variation der Einflussgrößen abgebildet werden als durch die zeitlich und finanziell begrenzten experimentellen Möglichkeiten. Für die Berechnungen wird der Fire Dynamic Simulators (FDS) mit dem Paket WFDS verwendet. Dadurch kann mit einem vereinfachten 3-Phasen-Reaktionskinetikmodell, bestehend aus Dehydrierung, Pyrolyse, Kohleoxidation, die Ausbreitung von Vegetationsbränden verschiedener Waldbodenarten untersucht werden. Es wurden dazu 6 typische Pflanzenarten und Bodenproben aus Kiefern-, Buchen und Eichenbeständen ausgewählt. Die gesammelten Waldbodenproben wurden alle hinsichtlich des Wassergehalts, des organischen Gehalts, der Packungsdichte, der Dichte und der statistisch ermittelten Pflanzenartenverteilung charakterisiert. Das kinetische Abbrandverhalten wurde durch Thermogravimetrische Analyse (TGA) untersucht. Alle diese Daten wurden als Eingabeparameter für die Simulation verwendet. Die numerischen Simulationen werden mit Experimenten im kleinen, mittleren und Real-Maßstab validiert. T2 - 70. Jahresfachtagung der Vereinigung zur Förderung des Deutschen Brandschutzes CY - Magdeburg, Germany DA - 06.05.2024 KW - Waldbrand KW - Simulation KW - FDS PY - 2024 SN - 978-3-936050-38-7 SP - 321 EP - 336 PB - VdS CY - Köln ET - 2 AN - OPUS4-60258 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reuter, T. A1 - Wohlgemuth, F. A1 - Bellon, Carsten A1 - Hausotte, T. T1 - Measurement-based Detector Characteristics for Digital Twins in aRTist 2 N2 - Various software products for the simulation of industrial X-ray radiography have been developed in recent years (e.g., aRTist 2, CIVA CT, Scorpius XLab, SimCT, Wilcore) and their application potential has been shown in numerous works. However, full systematic approaches to characterise a specific CT system for these simulation software products to obtain a truthful digital twin are still missing. In this contribution, we want to present two approaches to obtain realistic grey values in X-ray projections in aRTist 2 simulations based on measured projections. In aRTist 2, the displayed grey value of a pixel is based on the energy density incident on that pixel. The energy density is calculated based on the X-ray tube spectrum, the attenuation between source and detector as well as an energy-dependent sensitivity curve of the detector. The first approach presented in this contribution uses the sensitivity curve as a free modelling parameter. We measured the signal response at different thicknesses of Al EN-AW6082 at different tube voltages (i.e., different tube spectra). We then regarded the grey values displayed by these projections as a data regression respectively an optimisation problem and obtained the sensitivity curve that is best able to reproduce the measured behaviour in aRTist 2. The resulting sensitivity curve does not necessarily hold physical meaning but is able to simulate the real system behaviour in the simulation software. The second approach presented in this contribution is to estimate the sensitivity curve based on assumptions about the characteristics of the scintillation detector (e.g., scintillator material, scintillator thickness and signal processing characteristics). For this approach, a linear response function (linear relationship between the deposited energy per pixel and the resulting grey value) is assumed. If the detector characteristics, which affect the simulated deposited energy, are properly modelled, the slope and offset of the response function to match the measured grey values should be the same for different tube spectra. As the offset is constant and given by the grey values measured at no incident radiation, the slope is the remaining parameter to evaluate the success of the detector modelling. We therefore adapted the detector characteristics by changing the detector setup until the slope was nearly the same for all measured tube spectra. We are aware that the resulting parameters of the scintillator material and thickness might not be the real ones, but with those modelling parameters we are able to simulate realistic grey values in aRTist 2. Both of those approaches could potentially be a step forward to a full systematic approach for a digital twin of a real CT system in aRTist 2. T2 - 20th World Conference on Non-Destructive Testing (WCNDT 2024) CY - Incheon, South Korea DA - 27.05.2024 KW - Digital Twin KW - Computed Tomography KW - Simulation PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602046 DO - https://doi.org/10.58286/29910 SP - 1 EP - 10 PB - NDT.net CY - Mayen, Germany AN - OPUS4-60204 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simon, Franz-Georg A1 - Scholz, Philipp ED - Thiel, Stephanie ED - Thome-Kozminesky, Elisabeth ED - Antrekowitsch, Helmut ED - Pomberger, Roland ED - Firsbach, Felix T1 - Einstufung von Aschen und Schlacken aus der Abfallverbrennung im Hinblick auf die weitere Verwertung – Handlungsempfehlungen N2 - Die Einstufung von Hausmüllverbrennungsasche (IBA) als gefährlich oder nicht gefährlich nach der Gefahreneigenschaft HP14 (ökotoxisch) ist nach wie vor umstritten, da es noch keine keine allgemein anerkannten Methoden zur Bewertung gibt. Wenn die Berechnungsregeln angewendet werden sollen angewendet werden sollen, sind Kenntnisse über die chemische Zusammensetzung von IBA erforderlich. Informationen über über die chemische Zusammensetzung von IBA können mit einem Ansatz gewonnen werden, der auf der Gruppierung von Substanzen. Für IBA können vier Stoffgruppen definiert werden: 1. elementare und legierte Metalle, 2. leicht wasserlösliche Stoffe, 3. schwer lösliche Stoffe und 4. Stoffe mit starken chemischen Bindungen. Elementares und legiertes Cu und Zn sind in der IBA vorhanden und werden in der Regel als Nichteisenmetallfraktion zurückgewonnen, zumindest die größeren Partikel. Zn-Partikel, die kleiner als 1 mm sind, werden als H410 eingestuft, feine Partikel von Cu nur als H411. Die wasserlösliche Fraktion kann mit Standardauslaugungsmethoden quantifiziert werden Auslaugungsmethoden quantifiziert werden, z. B. bei einem Flüssigkeits-Feststoff-Verhältnis (L/S) von 2 oder 10 l/kg. Sowohl die Sulfate von Zn als auch von Cu gehören zu dieser Gruppe. In einer neueren Veröffentlichung wurde gezeigt, dass bei den oben genannten Metalle die ausgelaugte Menge weit unter dem Grenzwert von 1.000 mg/kg liegt, selbst wenn stöchiometrische Faktoren angewendet werden. Stoffgruppe 3 sind potenzielle H410-Stoffe. Dabei handelt es sich um Carbonate, Hydroxide und Oxide der betreffenden Elemente, die löslich sind in schwachen organischen Säuren wie Essigsäure löslich sind. Die Worst-Case-Stoffe der Gruppe 3, d. h. die Verbindungen mit den höchsten stöchiometrischen Faktoren, sind CuCO3xCu(OH)2 und ZnO. Stoffe mit starken chemischen Bindungen wie Silikate oder Sulfide sind nur löslich in starken Säuren (z.B. Königswasser) löslich und haben keinen Ökotoxizitäts-Gefahrencode. Das Mobilisierungsverhalten der relevanten Schwermetalle und damit der Gruppe der schwer schwerlöslichen Verbindungen kann mit der 4-stufigen sequentiellen Extraktion untersucht werden. Für die HP14 Einstufung könnte auch eine einstufige Extraktion ausreichend sein. Nur die Elemente Zn und Cu sind für die HP14-Einstufung der IBA von Bedeutung, da die Feststoffgehalte aller anderen Schwermetalle unterhalb des Feststoffgehalte aller anderen Schwermetalle unter der Cut-Off-Grenze von 0,1 % liegen, selbst wenn man sie in chemischen Verbindungen mit stöchiometrischen Faktoren. Im Ergebnis wurde gezeigt, dass IBA in der Regel als nicht gefährlich einzustufen ist. T2 - Berliner Konferenz Mineralische Nebenprodukte und Abfälle CY - Berlin, Germany DA - 12.06.2024 KW - Rostasche KW - Ökotoxizität KW - Sequenzielle Extraktion PY - 2024 SN - 978-3-911006-80-4 VL - 11 SP - 176 EP - 190 PB - TK-Verlag CY - Neuruppin AN - OPUS4-60281 LA - deu 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 - Wosniok, Aleksander A1 - Königsbauer, Korbinian A1 - Nöther, Nils A1 - Färber, Jan A1 - Schaller, M.-Barbara A1 - Krebber, Katerina T1 - Distributed polymer optical fiber sensors using digital I-OFDR for geotechnical infrastructure health monitoring N2 - We present a distributed polymer optical fiber sensor system for deformation monitoring of geotechnical infrastructure. The sensor system is based on the digital incoherent optical frequency domain reflectometry (I-OFDR) for the detection of local strain events along a perfluorinated polymer optical fiber (PF-POF) used as a sensing fiber. For the best possible load transfer, the PF-POFs were integrated onto geosynthetics which pose a sensor carrier for the sensing fiber. By using elastic PF-POF instead of a standard glass fiber as a sensing fiber the strain range of geosynthetics-integrated fiber optic sensors could be extended up to 10 % in accordance with the end-user requirements. T2 - 11th European Workshop on Structural Health Monitoring CY - Potsdam, Germany DA - 10.06.2024 KW - Digital I-OFDR KW - Distributed polymer optical fiber sensor KW - Ddistributed strain sensing KW - Smart geosynthetics KW - Structural health monitoring PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603096 SP - 1 EP - 7 PB - NDT.net AN - OPUS4-60309 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Schukar, Marcus A1 - Woody, Paul A1 - Wang, Bin A1 - Breithaupt, Mathias A1 - Kriegsmann, Andreas T1 - Distributed fiber optic strain sensing for structural health monitoring of 70 MPa hydrogen vessels N2 - We report on the development and testing of 70 MPa hydrogen pressure vessels with integrated fiber optic sensing fibers for automotive use. The paper deals with the condition monitoring of such composite pressure vessels (CPVs) using the optical backscatter reflectometry (OBR) applied for a distributed fiber optic strain sensing along fully integrated polyimide-coated single-mode glass optical fiber (SM-GOF). The sensing fibers were embedded into the vessel structure by wrapping them over the polymer liner during the manufacturing process of the carbon fiber reinforced polymer (CFRP). Detecting local strain events by the integrated fiber optic sensors can be an opportunity for monitoring the material degradation of CPVs under static and cyclic loading. T2 - 11th European Workshop on Structural Health Monitoring CY - Potsdam, Germany DA - 10.06.2024 KW - Fiber optic sensor KW - Distributed strain sensing KW - Composite pressure vessel KW - Structural health monitoring KW - Fiber-reinforced plastics PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603105 SP - 1 EP - 8 PB - NDT.net AN - OPUS4-60310 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bulling, Jannis A1 - Jurgelucks, B. A1 - Prager, Jens A1 - Walther, A. T1 - Modellierung und Validierung eines inversen Verfahrens zur Schadensrekonstruktion mittels Lamb-Wellen im Ultraschallbereich N2 - Das Ausbreitungsverhalten geführter Ultraschallwellen ermöglicht die großflächige Prüfung von Platten und schalenförmigen Bauteilen wie Rohren und Laminaten auf Fehlstellen von wenigen Prüfpunkten aus. Während die beschränkte Divergenz der geführten Wellen die Ultraschallprüfung begünstigt, erschwert das dispersive und multimodale Verhalten der Lamb-Wellen die Auswertung der Ultraschallsignale. Die dispersive und multimodale Wellenausbreitung verkompliziert die Bestimmung der Fehlerposition bei der Auswertung der Geschwindigkeiten einzelner Wellenpakete. Zudem ist es herausfordernd, einen einfachen Zusammenhang zwischen den Reflexionen der Fehlstelle und deren Größe und Form herzustellen. Eine Möglichkeit zur genauen Bestimmung der Fehlerposition und -geometrie bietet der direkte Vergleich der Messsignale mit den Signalen aus einem Simulationsmodell. Die Nachbildung des Schadens im Simulationsmodell stellt ein inverses Problem dar, das iterativ gelöst werden kann, indem ein Vorwärtsmodell immer weiter optimiert wird. Klassische Ansätze wie die Finite Elemente Methode (FEM) sind für die Simulation von Ultraschallwellen aufgrund der kleinen Wellenlängen im Vergleich zur Bauteilgröße meist ineffizient. Aus diesem Grund basiert das vorgestellte Vorwärtsmodell auf der semi-analytischen Scaled Boundary Finite Element Method (SBFEM), die große Teile der Wellenausbreitung analytisch berechnet. In diesem Beitrag wird die Validierung des zweidimensionalen Modells an Platten mit einer rechteckigen Nut als Ersatzfehler präsentiert und es werden erste Schritte zur Validierung von 3D-Modellen vorgestellt. T2 - DAGA 2024 CY - Hannover, Germany DA - 18.03.2024 KW - Geführter Ultraschall KW - Inverse Verfahren KW - SBFEM PY - 2024 UR - https://www.dega-akustik.de/publikationen/online-proceedings SP - 644 EP - 647 AN - OPUS4-60212 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 - 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 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 - Johann, Sergej A1 - Stührenberg, Jan A1 - Tandon, Aditya A1 - Dragos, Kosmas A1 - Bartholmai, Matthias A1 - Strangfeld, Christoph A1 - Smarsly, Kay T1 - Implementation and validation of robot-enabled embedded sensors for structural health monitoring N2 - In the past decades, structural health monitoring (SHM) has matured into a viable supplement to regular inspections, facilitating the execution of repair and maintenance work in the early stages of structural damage. With the advent of wireless technologies and advancements in information and communication technologies, civil infrastructure has been increasingly instrumented with wireless sensor nodes to record, analyze, and communicate data relevant to SHM. A promising method for SHM is to embed sensors directly into concrete for recording SHM data from inside structural elements. In this paper, a sensor system for embedment into concrete is proposed, able to assess SHM data recorded from concrete. Power is supplied to the sensors on-demand by quadruped robots, which also collect the SHM data via radio-frequency identification (RFID), providing an automated and efficient SHM process. In laboratory experiments, the capability of the sensor system of automatically collecting the SHM data using quadruped robots is validated. In summary, the integration of RFID technology and robot-based inspection presented in this study demonstrates a vital approach to evolve current SHM practices towards more digitalized and automated SHM. T2 - 11th European Workshop On Structural Health Monitoring CY - Potsdam, Germany DA - 10.06.2024 KW - Structural health monitoring KW - RFID-based sensors KW - Smart sensors KW - Embedded sensors KW - Legged robots KW - Quadruped robots PY - 2024 SP - 1 EP - 8 AN - OPUS4-60335 LA - eng 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 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 - Nerger, Tino A1 - Neumann, Patrick P. A1 - Weller, Michael G. T1 - Drone-based Localization of Hazardous Chemicals by Passive Smart Dust N2 - We introduce a passive smart dust concept as a novel solution for environmental monitoring. Utilizing chemical reagents like colorimetric indicators and other chemosensors, these particles detect varying environmental conditions. We developed paper-based sensors that are both cost-effective and eco-friendly. In practical tests, these sensors, dispersed over a designated area, successfully identified hazardous substances by changing their color when exposed to acids or bases. This color change was remotely detectable using a drone-mounted color camera. The data thus obtained was processed through specialized software, accurately pinpointing areas of contamination. This method proves the efficacy and scalability of passive smart dust technology for real-time, environmentally sustainable remote sensing of hazardous materials T2 - 2024 IEEE International Symposium on Olfaction and Electronic Nose (ISOEN) CY - Grapevine, Texas, USA DA - 12.05.2024 KW - Indicator KW - Passive Smart Dust KW - Colorimetric Sensor KW - Drone KW - Cellulose KW - Environmental Monitoring KW - Confetti KW - Hazard Detection PY - 2024 SN - 979-8-3503-7053-9 VL - 1 SP - 1 EP - 3 PB - IEEE CY - Piscataway, NJ 08855-1331 USA AN - OPUS4-60176 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schumacher, T. A1 - Bertola, N. A1 - Epple, Niklas A1 - Bruehwiler, E. A1 - Niederleithinger, Ernst T1 - Combined Passive and Active Ultrasonic Stress Wave Monitoring of Concrete Structures: An Overview of Data Analysis Techniques and Their Applications and Limitations N2 - Combined passive ultrasonic (US) stress wave [better known as acoustic emission (AE)] and active US stress wave monitoring has been shown to provide a more holistic picture of ongoing fracture processes, damage progression, as well as slowly occurring aging and degradation mechanisms in concrete structures. Traditionally, different data analysis techniques have been used to analyze the data generated from these two monitoring techniques. For passive US stress wave monitoring, waveform amplitudes, hit rates, source localization, and b-value analysis, among others, have been used to detect and locate cracking. On the other hand, amplitude tracking, magnitude squared coherence (MSC), and coda wave interferometry (CWI) are examples of analyses that have been employed for active US stress wave monitoring. In this paper, we explore some of these data analysis techniques and show where their respective applications and limitations might be. After providing an overview of the monitoring approach and the different data analysis techniques, results and observations from selected laboratory experiments are discussed. Finally, suggestions for further work are proposed. T2 - 11th European Workshop on Structural Health Monitoring (EWSHM 2024) CY - Potsdam, Germany DA - 11.06.2024 KW - Ultrasound KW - Acoustic emission KW - Concrete KW - Stress PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604687 UR - https://www.ndt.net/article/ewshm2024/papers/824_manuscript.pdf DO - https://doi.org/10.58286/29863 SN - 1435-4934 SP - 1 EP - 8 PB - NDT.net AN - OPUS4-60468 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sklodowska, Anna A1 - Baensch, Franziska A1 - Lay, Vera A1 - Niederleithinger, Ernst A1 - Kühne, Hans-Casten T1 - Acoustic emission monitoring for engineered barriers in nuclear waste disposal N2 - To safely dispose of nuclear waste in underground facilities, engineered barrier systems are needed to seal shafts and galleries. The material used in these barriers must be adapted to the host rock parameters. Shrinking and cracking must be avoided to provide a barrier with almost zero permeability. For repositories in salt rock environments, several types of salt concrete (SC) are possible construction materials. Within the project SealWasteSafe, we compared the behavior of an innovative alkali-activated material (AAM) with standard SC in their hydration and hardening phase. To monitor the microstructural changes within the two materials SC and AAM, acoustic emission (AE) signals have been recorded for up to ~250 days on 340-litercubic specimens. The phenomenon of AE is defined as the emission of elastic waves in materials due to the release of localized internal energy. Such energy release can be caused by the nucleation of micro-fracture, e.g., in concrete while curing or when exposed to load. The occurrence of AE events gives first rough indications of microstructural changes and potentially occurring cracking and thus, provides insights for structural health monitoring (SHM). The results show, that for the first 28 days after casting, less AE activity was detected in the AAM compared to SC. After 61 days, in the AAM material, the number of AE events exceeded those observed in the SC. However, the majority of the AE detected and located in AAM was related to surface effects, and not to microstructural changes or occurring cracks within the bulk volume. Additionally, the source location analysis indicated, that despite lower activity in SC, we observed some clustering of the events. In contrast, in AAM, the activity inside the specimen is randomly distributed over the whole volume. The monitoring results help to estimate the material’s sealing properties which are crucial to assess their applicability as sealing material for engineered barriers. T2 - 11th European Workshop on Structural Health Monitoring (EWSHM 2024) CY - Potsdam, Germany DA - 11.06.2024 KW - Endlager KW - Barriere KW - AAM KW - Akustische Emission PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604699 UR - https://www.ndt.net/article/ewshm2024/papers/768_manuscript.pdf DO - https://doi.org/10.58286/29834 SN - 1435-4934 SP - 1 EP - 7 PB - NDT.net AN - OPUS4-60469 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertola, N. A1 - Schumacher, T. A1 - Niederleithinger, Ernst A1 - Bruehwiler, E. T1 - Early detection of structural damage in UHPFRC structures through the combination of acoustic emission and ultrasonic stress wave monitoring N2 - Ultra-High-Performance Fiber-Reinforced Cementitious Composite (UHPFRC) offers several advantages compared to concrete, notably due to the strain hardening behavior under tensile actions. Structures made of this composite material are lightweight and highly durable, thanks to the UHPFRC waterproofing quality. Nonetheless, the tensile behavior leads to a different cracking pattern than conventional concrete and is not fully understood yet. This paper presents a combined approach using both passive ultrasonic (US) stress wave (or acoustic emission) and active US stress wave monitoring to localize and quantify damage progression in a full-scale UHPFRC beam during experimental load testing. The proposed monitoring approach involves 24 US transducers that are embedded randomly throughout a 4.2- meter-long laboratory UHPFRC T-beam. Continuous monitoring enabled accurate localization of US stress sources caused by loading-induced cracking as well as from pulses generated by the embedded US transducers. This study shows that it is possible to predict the location and shape of the macro-crack that is linked to structural failure early on, i.e., just after the end of the elastic domain. This combined approach opens new possibilities to monitor the structural behavior and detect damage on UHPFRC structures before they affect the structural behavior in terms of deflection and strain. T2 - 11th European Workshop on Structural Health Monitoring (EWSHM 2024) CY - Potsdam, Germany DA - 11.6.2024 KW - UHPFRC KW - Acoustic emission KW - Damage detection PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604708 UR - https://www.ndt.net/article/ewshm2024/papers/477_manuscript.pdf DO - https://doi.org/10.58286/29698 SN - 1435-4934 SP - 1 EP - 8 PB - NDT.net AN - OPUS4-60470 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tiebe, Carlo A1 - Davenport, John A1 - Lorek, Andreas A1 - Garland, Stephen A1 - Schwanke, Volker A1 - Wernecke, Roland T1 - Gasfeuchtemessung in der Normung N2 - Schwefelhexafluorid (SF6) ist ein 22.800-mal stärkeres Treibhausgas als CO2, wird aber aufgrund seiner isolierenden Eigenschaften in Mittel- und Hochspannungssystemen wie Schaltanlagen eingesetzt. Voraussetzung für die Durchschlagfestigkeit ist ein geringer Wasserdampfgehalt. Viele aktuelle Feuchtigkeitssensoren zeigen jedoch eine Querempfindlichkeit gegenüber CO2. Diese Richtlinienarbeit zielt darauf ab, den aktuellen Stand der Technik zu erweitern und neue Erkenntnisse zu gewinnen. Abschließend erfolgt eine Erweiterung der Richtlinie zur Gasfeuchte-Messung VDI/VDE 3514. T2 - GMA/ITG – Fachtagung Sensoren und Messsysteme 2024 CY - Nuremberg, Germany DA - 11.06.2024 KW - Gassensorik KW - Industrienormen KW - SF6 PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604597 DO - https://doi.org/10.5162/sensoren2024/P32 SP - 547 EP - 549 PB - GMA/ITG – Fachtagung Sensoren und Messsysteme 2024 CY - Nürnberg AN - OPUS4-60459 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eberwein, Robert A1 - Hajhariri, Aliasghar A1 - Camplese, Davide A1 - Scarponi, Giordano Emrys A1 - Cozzani, Valerio A1 - Otremba, Frank ED - Di Benedetto, Almerinda T1 - Experimental Research Of A Tank For A Cryogenic Fluid With A Wall Rupture In A Fire Scenario N2 - In the course of decarbonizing the energy industry, cryogenic energy carriers as liquefied hydrogen (LH2) and liquefied natural gas (LNG) are seen as having great potential. In technical applications, the challenge is to keep these energy carriers cold for a long time. This is achieved in the road transport sector and also stationary applications by thermal super insulations (TSI) which based on double-walled tanks with vacuum and multilayer insulation (MLI) in the interspace. This study focuses on the behaviour of widely used combustible MLI in a fire scenario, at vacuum and atmospheric pressure conditions. The former corresponds to the typical design condition and the latter to the condition after an outer hull rapture of a tank. Furthermore, two fire scenarios were taken into account: a standard-oriented approach and a hydrocarbon fire-oriented approach. For the study, a test rig was applied that allows testing of TSI at industrial conditions and subsequent analysis of TSI samples. The test rig allows thermal loading and performance analysis of TSI samples at the same time. Comparing the tests, the samples degraded differently. However, no sudden failure of the entire MLI was observed in any test. These results are relevant for the evaluation of incidents with tanks for the storage of cryogenic fluids and can thus contribute to the improvement of TSI and the development of emergency measures for the protection of persons and infrastructures. T2 - 15th International Symposium on Hazards, Prevention and Mitigation of Industrial Explosions (ISHPMIE) CY - Neapel, Italy DA - 10.06.2024 KW - Liquefied hydrogen KW - Liquefied natural gas KW - Cryogenic storage tank KW - Fire KW - Thermal insulation KW - Multi-Layer Insulation PY - 2024 SP - 707 EP - 717 AN - OPUS4-60460 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hajhariri, Aliasghar ED - Eberwein, Robert ED - Perrone, Luca pakj ED - Cozzani, Valerio ED - Otremba, Frank ED - Seidlitz, Holger T1 - Study the Impact of Spacer at Thermal Degradation Process of MLI-based Insulation in Fire Condition N2 - To reduce carbon dioxide emissions, energy carries such as hydrogen consider to be a solution. Consumption of hydrogen as a fuel meets several restrictions such as its low volumetric energy density in gas phase. To tackle this problem, storage as well as transportation in liquid phase is recommended. To be able to handle this component in liquid phase, an efficient thermal insulation e.g., MLI insulation is required. Some studies have been revealed vulnerability of this type of insulation against high heat flux, for instance a fire accident. Some investigations have been depicted the importance of consideration of the MLI thermal degradation in terms of its reflective layer. However, limited number of studies have been focused on the thermal degradation of spacer material and its effect on the overall heat flux. In this study, through systematic experimental measurements, the effect of thermal loads on glass fleece, glass paper as well as polyester spacers are investigated. The results are reported in various temperature and heat flux profiles. Interpreting the temperature profiles revealed as the number of spacers in the medium increases, the peak temperature detectable by the temperature sensor on the measurement plate decreases. Moreover, the contribution of each individual spacer in all cases regarding the experimental temperature range is assessed to be around 8%. This value may increase to around 50% for glass paper and polyester spacers, and to around 25% for glass fleece spacers as the number of spacer layers increases up to six layers. To utilize the outcomes of the experiment later and integrate the results into numerical and CFD simulations, a model is proposed for the mentioned experimental temperature range up to 300°C to predict a heat flux attenuation factor. The model proposes a fitting factor that can reproduce the least square fitted line to the experimental data. T2 - 15th International Symposium on Hazards, Prevention, and Mitigation of Industrial Explosions Naples (ISHPMIE) CY - Naples, Italy DA - 10.06.2024 KW - Multi-Layer Insulation KW - Cryogenics KW - Liquid Hydrogen KW - Heat Transfer KW - Hydrogen Storage PY - 2024 SP - 744 EP - 755 AN - OPUS4-60461 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 - Di Benedetto, Almerinda ED - Portarapillo, Maria T1 - Investigation of the thermal radiation from hydrogen jet flames N2 - For industrial applications dealing with hydrogen, the definition of safety distances and the assessment of possible hazards emanating from releases is mandatory. Since hydrogen is usually stored and transported under pressure, one scenario to be considered is the momentum driven release of hydrogen from a leakage with subsequent ignition. In this scenario, the emitted heat radiation from the resulting jet flame to the surroundings has to be determined to define adequate safety distances. For hydrocarbon flames, different jet flame models are available to assess the hazards resulting from an ignited jet release. Since hydrogen flames differ from hydrocarbon flames in their combustion behavior, it has to be checked if these models are also applicable for hydrogen. To evaluate the accuracy of these models for hydrogen jet flames, tests at real-scale are carried out at the BAM Test Site for Technical Safety (BAM-TTS). Herein, the flame geometry and the heat radiation at defined locations in the surroundings are recorded for varying release parameters such as leakage diameter (currently up to 30 mm), release pressure (currently up to max. 250 bar) and mass flow (up to max. 0.5 kg/s). The challenge here is the characterization of the flame geometry in an open environment and its impact on the thermal radiation. Existing heat radiation data from the literature are mostly based on unsteady outflow conditions. For a better comparability with the steady state jet flame models, the experiments presented here are focused on ensuring a constant mass flow over the release duration to obtain a (quasi) stationary jet flame. In addition, stationary outflow tests with hydrocarbons (methane) were also carried out, which are intended to serve as reference tests for checking flame models based on hydrocarbon data. T2 - 15th International Symposium on Hazards, Prevention and Mitigation of Industrial Explosions (ISHPMIE) CY - Neaples, Italy DA - 10.06.2024 KW - Hydrogen KW - Release KW - Jet flame KW - Thermal radiation PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-605107 DO - https://doi.org/10.5281/zenodo.12515710 VL - 2024 SP - 1322 EP - 1333 PB - Zenodo CY - Geneva AN - OPUS4-60510 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 - Bahrami Eskandari, Ardalan A1 - Küttenbaum, Stefan T1 - NDT Data-Supported Structural Reassessments based on Regression Relations in Measuring Data Analysis N2 - Non-destructive Testing (NDT) provides valuable data about structural elements, supporting the assessment of existing infrastructures without incurring additional structural damage from inspections. Simultaneously, the uncertainty in measurement, which quantifies the quality of measurement results, plays a crucial role in decisions aimed at, e.g., optimizing maintenance strategies, rehabilitation works and Structural Health Monitoring (SHM) implementations. The Guide to the Expression of Uncertainty in Measurement (GUM) framework has already been considered for non-destructive concrete testing. Regarding that, extensive measurements with sophisticated scopes need to be conducted by experts as an obligatory process. This study illustrates how NDT results describing the inner structure of a concrete element can effectively support the reassessment of bridges in operation. To achieve this, the study considers the various measurable positions of the resisting longitudinal tendons of a bridge structure to investigate the displacement change under dynamic service loads. Furthermore, this study aims to simplify and optimize existing NDT data analysis procedures by employing regression analysis, enabling the detection of structural features. This regression analysis yields a modifier for determining the correct depth of an object within the structural element. The method is validated through laboratory experiments, including the use of an ultrasonic measurement system. As a result, it provides unbiased and accurately measured results, while ensuring that the measurement data can remain uncorrelated. Major advantages include efficient computation, a wider scope, and avoiding redundant information about the measuring process. The findings demonstrate that employing the proposed NDT analysis method, with its enhanced practicability, can significantly augment the efficiency of NDT data-supported structural reassessments across various scenarios. T2 - EWSHM 2024 CY - Potsdam, Germany DA - 10.06.2024 KW - Existing structures KW - Non-destructive testing KW - Practicality measurement KW - Bridge reassessment KW - Statistical analysis PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604825 DO - https://doi.org/10.58286/29714 SN - 1435-4934 SP - 1 EP - 9 PB - NDT.net AN - OPUS4-60482 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bahrami Eskandari, Ardalan A1 - Nikkhoo, Ali A1 - Hajirasouliha, Iman T1 - Analyzing Vertical Earthquake Vibrations and Moving Vehicle Loads for Structural Health Monitoring and Vibration Suppression in Bridges N2 - The design of bridges often overlooks the vertical component of earthquakes or considers it of secondary importance, despite compelling evidence indicating specific structural damage caused by primary earthquake waves. Conversely, during the operational phase, the combined influence of ground motion and moving loads from vehicles can significantly impact the structural health monitoring (SHM) of bridges. This study aims to evaluate the simultaneous effect of vertical earthquake vibrations and moving vehicle loads on simply supported bridges. The research employs a practical methodology based on the eigenfunction expansion method to analyze change of deflection due to the effect of these concurrent forces under seven different earthquake records. It is shown that within a realistic range of vehicle mass and velocity, the average of changing the maximum deflection at the mid-span of the main beam (denoted as M_n) reaches up to 163% under various scenarios. Subsequently, the seismic parameters influencing this phenomenon are identified through a statistical analysis of set of 100 different earthquake records with unique features. A linear regression equation is presented to predict the M_n based on the earthquake specific properties. Additionally, to control the vertical vibration of bridge systems, a novel vibration suppression system utilizing steel pipe dampers is introduced, and its reliability is examined across a broad spectrum of bridge flexural rigidity. The results indicate that the system's efficiency depends on M_n and the soil type of the bridge construction, enabling a reduction in structural sections (up to 27%) while achieving the same maximum target deflection in the initial state. This efficiency leads to a more economical design solution, emphasizing the potential benefits of the proposed system for practical application. T2 - 11th European Workshop on Structural Health Monitoring (EWSHM 2024) CY - Potsdam, Germany DA - 10.06.2024 KW - Bridge structures KW - Vertical earthquakes KW - Health monitoring KW - Moving vehicles KW - Suppressing vibrations PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604893 DO - https://doi.org/10.58286/29746 SP - 1 EP - 10 PB - NDT.net AN - OPUS4-60489 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schubert, Sven A1 - Komann, Steffen A1 - Neumann, Martin A1 - Reichardt, Adrian A1 - Müller, Lars A1 - Wille, Frank T1 - Ageing management measures of transport packages for radioactive materials N2 - The consideration of ageing mechanisms is with integration into the IAEA-requirements now obligatory for the design of transport packages. For packages intended to be used for shipment after storage the consideration of the effects of ageing mechanisms during storage in safety analyses and the implementation of corresponding instructions for operation and maintenance are required. Therefore, these packages have been maintained during storage in a manner that all requirements specified in the IAEA-requirements and in the applicable certificates of approval have been fulfilled. BAM is the competent authority in Germany for evaluating the thermal and mechanical design of packages for the transport of radioactive materials. In this context, BAM also evaluates the aging mechanisms and aging effects occurring during the long-term storage period of such transport packages. BAM has developed a guideline for the implementation of ageing assessment and of the measures for ageing management into the approval procedure based on IAEA-requirements. The goal of the presented paper is to introduce this guideline and the general approach for ageing management requirements and to describe the application to a specific package design. The type and amount of the ageing management not only depend on the use of the packaging, but also on the accessibility of the components that are considered in the ageing assessment. The different operating phases of a packaging are considered for the ageing assessment, such as loading, interim storage or transport. The implementation of measures for ageing management is divided into three levels – systemic measures, package design related measures and documentation. The systemic measures are attributed to the general management system and define the whole activities for organization of ageing management like structure, responsibilities, documentation, reports and evaluation. The package design related measures are defined in an ageing management plan. These measures shall ensure that the anticipated changes of the package design under consideration of ageing effects still complies with the design approval specification. Therefore, an ageing surveillance program and, if necessary, a gap analysis program shall be developed. The ageing management documentation ensures the continuous documentation of the compliance of a specific package to the approved package design, comprising mainly records resulting from operation and surveillance. T2 - RAMTRANS 2024 CY - London, United Kingdom DA - 15.05.2024 KW - Radioactive Materials KW - Ageing Management KW - Transport Packages KW - Dual Purpose Casks PY - 2024 VL - 2024 SP - 1 EP - 8 PB - Nuclear Institute CY - London AN - OPUS4-60186 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Karapanagiotis, Christos A1 - Schukar, Marcus A1 - Breithaupt, Mathias A1 - Duffner, Eric A1 - Ulbricht, Alexander A1 - Prager, Jens A1 - Krebber, Katerina T1 - Structural health monitoring of hydrogen pressure vessels using distributed fiber optic sensing N2 - We report on distributed fiber optic sensing-based monitoring of hydrogen composite overwrapped pressure vessels (COPV) to simultaneously increase the operational lifespan and mitigate maintenance costs. Our approach represents, to the best of our knowledge, the first application of distributed fiber optic sensing for COPV Type IV monitoring, where the sensing fibers are attached to the surface, rather than integrated into the composite material. Specifically, we attach an optical fiber of 50 m to the pressure vessel's surface, covering both the cylindrical and dome sections. We note that our fiber optic sensing technique relies on swept wavelength interferometry providing strain information along the entire length of the optical fiber with high spatial resolution even at the millimeter scale. When the vessel is pressurized, the sensing optical fiber shows a linear strain response to pressure at every position along the fiber. After thousands of load cycles, the vessel finally fails with the optical fiber detecting and precisely localizing the damage in the vessel’s blind dome area. Furthermore, we discuss the potential of state-of-the-art signal processing methods and machine learning for advancing predictive maintenance. This could reduce the number of regular inspections, mitigate premature maintenance costs, and simultaneously increase the vessel’s remaining safe service life. We believe that the structural health monitoring of hydrogen pressure vessels with fiber optic sensors can enhance trust in hydrogen technology contributing to the energy transition in the future. T2 - 11th European Workshop on Structural Health Monitoring CY - Potsdam, Germany DA - 10.06.2024 KW - Hydrogen KW - Fiber optic sensors KW - Composites KW - Machine learning KW - Structural health monitoring PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602731 UR - https://www.ndt.net/search/docs.php3?id=29701 SP - 1 EP - 7 PB - NDT.net AN - OPUS4-60273 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Karapanagiotis, Christos A1 - Heimann, Jan A1 - Duffner, Eric A1 - Charmi, Amir A1 - Schukar, Marcus A1 - Hashemi, Seyedreza A1 - Prager, Jens T1 - Towards predictive maintenance of hydrogen pressure vessels based on multi-sensor data fusion and digital twin modeling N2 - Hydrogen pressure vessels are among the most essential components for reliable hydrogen technology. Under current regulations, a mostly conservative strategy is employed, restricting the usage time of hydrogen pressure vessels without providing information on the real remaining lifetime. During the service life, pressure vessels are inspected periodically. However, no established method that can provide continuous monitoring or information on the remaining safe service life of the vessel. In this paper, we propose a sensor network for Structural Health Monitoring (SHM) of hydrogen pressure vessels where data from all sensors are collected and centrally evaluated. Specifically, we integrate three different SHM sensing technologies namely Guided Wave ultrasonics (GW), Acoustic Emission testing (AT), and distributed Fiber Optic Sensing (FOS). This integrated approach offers significantly more information and could therefore enable a transition from costly and time-consuming periodic inspections to more efficient and modern predictive maintenance strategies, including Artificial Intelligence (AI)-based evaluation. This does not only have a positive effect on the operational costs but enhances safety through early identification of critical conditions in the overall system in real-time. We demonstrate an experimental set-up of a lifetime test where a Type IV Composite Overwrapped Pressure Vessel (COPV) is investigated under cyclic loading instrumented with AT, FOS, and GW methods. We acquired data from the sensor network until the pressure vessel failed due to material degradation. The data collected using the three different SHM sensor technologies is planned to be evaluated individually, using data fusion, and AI. In the future, we aim to integrate the measurement setup into a hydrogen refueling station with the data stream implemented into a digital signal processing chain and a digital twin. T2 - 11th European Workshop on Structural Health Monitoring CY - Potsdam, Germany DA - 10.06.2024 KW - Acoustic emission KW - Ultrasonic guided waves KW - Fiber optic sensors KW - Hydrogen KW - Pressure vessels KW - Structural health monitoring KW - Machine learning PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602764 UR - https://www.ndt.net/search/docs.php3?id=29702 SP - 1 EP - 8 PB - NDT.net AN - OPUS4-60276 LA - eng 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 - ISBN 978-3-00-079329-5 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 - 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 - ISBN 978-3-00-079329-5 SP - 87 EP - 97 AN - OPUS4-60400 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja A1 - Wachtendorf, Volker A1 - Falkenhagen, Jana T1 - Combined impact of UV radiation and nitric acid (HNO3) on HDPE jerrycans – comparison of outdoor and lab test N2 - A damaging action of HNO3-55% only occurs in combination with its decomposition into nitrous gases, which can be caused by UV radiation. In a laboratory test, transparent HDPE jerrycans have been exposed to both UV radiation and 55 wt-% nitric acid solution at (41 ± 2)°C, for up to 20 days. For comparison, UV radiant exposure (21 days) and nitric acid exposure (up to 6 weeks) were performed separately, at nearly equal temperatures. The respective damages are compared with FTIR spectroscopy in ATR and HT-gel permeation chromatography (GPC) on a molecular level and with hydraulic internal pressure testing as a component test. For the used jerrycans, relevant oxidation can only be found after the combined exposure. The gradual increase in oxidative damage shows the good reproducibility of the lab exposure. The decomposition of nitric acid into nitrous gases by UV radiation – as well as the jerrycan oxidation – is also observed at lower HNO3 concentration (28 wt- %). Similar results are obtained after outdoor tests. Again, the damage occurs only after combined exposure, in contrast to the exposures to UV only and to HNO3 only, which were conducted in parallel. Outdoor exposures are most readily accepted as they represent possible end-use conditions. However, the reproducibility of these exposures is poor due to the large temporal variations in weather. There are also several safety risks, which is why the number of replicates remains limited. Since the outdoor and lab exposure tests show the same qualitative results, it is appropriate to conduct systematic studies in the laboratory. After 6 days of lab exposure, the oxidation damage is rated as critical, which corresponds to about 1/10 year in Central Europe, according to the UV radiant exposure. It should be noted that this amount can also occur in two sunny weeks. T2 - 24th iapri World Packaging Conference CY - Valencia, Spain DA - 17.06.2024 KW - Ppolyethylene KW - UV exposure KW - Nitric acid KW - Oxidation PY - 2024 VL - 2 SP - 30 EP - 37 PB - ITENE AN - OPUS4-60414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Gaddampally, Mohan Reddy A1 - Völzke, Holger T1 - Failure Analysis on Irradiated Claddings Subjected to Long-Term Dry Interim Storage N2 - Long-term dry interim storage may adversely affect the mechanical properties of spent fuel rods, possibly resulting in a reduced resilience during handling or transport after storage. The cladding is the first barrier for the spent fuel pellets. An established method for characterising the cladding material is the ring compression test (RCT), in which a small, cylindrical sample of the cladding tube is subjected to a compressive load. Radial hydrides may precipitate in zirconium-based alloys (Zircaloy) under pre-storage drying and during slow cooling, which result in embrittlement of the cladding material and eventually a possible sudden failure of cladding integrity under additional mechanical loads. The focus of the presented research is on the development of appropriate nu-merical methods for predicting the mechanical behaviour and identification of limiting conditions to prevent brittle fracture of Zircaloy claddings. A modelling approach based on cohesive zones is ex-plained which is able to reproduce the propagation of cracks initiated at radial hydrides in the zir-conium matrix. The developed methods are applied to defueled samples of cladding alloy ZIRLO®, which were subjected to a thermo-mechanical treatment to reorient existing circumferential hy-drides to radial hydrides. A selected sample showing sudden load drops during a quasi-static ring compression test is analysed by means of fracture mechanics for illustrative purposes. Based on the developed fracture mechanics approach, not only the deformation behaviour but also the fail-ure behaviour of irradiated as well as unirradiated Zircaloy claddings with radial hydrides under RCT loading conditions can be adequately described. T2 - 27th International Conference on Structural Mechanics in Reactor Technology - SMiRT 27 CY - Yokohama, Japan DA - 03.03.2024 KW - Cladding Embrittlement KW - Cohesive Zone Modelling KW - Ring Compression Test KW - Spent Nuclear Fuel PY - 2024 SP - 1 EP - 8 AN - OPUS4-60671 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bhadeliya, Ashok A1 - Rehmer, Birgit A1 - Fedelich, Bernard A1 - Jokisch, Torsten A1 - Skrotzki, Birgit A1 - Olbricht, Jürgen T1 - High Temperature Fatigue Crack Growth in Nickel-Based Alloys Refurbished by Additive Manufacturing N2 - Hybrid additive manufacturing plays a crucial role in the restoration of gas turbine blades, where, e.g., the damaged blade tip is reconstructed by the additive manufacturing process on the existing blade made of a parent nickel-based alloy. However, inherent process-related defects in additively manufactured material, along with the interface created between the additively manufactured and the cast base material, impact the fatigue crack growth behavior in bi-material components. This study investigates the fatigue crack growth behavior in bi-material specimens of nickel-based alloys, specifically, additively manufactured STAL15 and cast alloy 247DS. The tests were conducted at 950 °C with stress ratios of 0.1 and −1. Metallographic and fractographic investigations were carried out to understand crack growth mechanisms. The results revealed significant retardation in crack growth at the interface. This study highlights the potential contributions of residual stresses and microstructural differences to the observed crack growth retardation phenomenon, along with the conclusion from an earlier study on the effect of yield strength mismatch on crack growth behavior at a perpendicular interface in bi-material specimens. T2 - Superalloys 2024 Conference CY - Champion, Pennsylvania, USA DA - 08.09.2024 KW - Fatigue crack growth KW - Bi-material structure KW - Additive manufacturing KW - Nickel-based alloys PY - 2024 SN - 978-3-031-63937-1 DO - https://doi.org/10.1007/978-3-031-63937-1_92 SN - 2367-1181 SN - 2367-1696 VL - 15th SP - 994 EP - 1001 PB - Springer CY - Cham AN - OPUS4-60907 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gleim, Tobias A1 - Feldkamp, Martin A1 - Quercetti, Thomas A1 - Wille, Frank T1 - Experimental and Numerical Analyses for the Evaluation of Heat Fluxes of a Fire Reference Test N2 - Packages for the transport of high-level radioactive material are designed to endure severe accidents. To obtain approval, these transport packages must adhere to the specification-based criteria of the IAEA SSR-6. To ensure compliance with these requirements, specific mechanical and thermal tests need to be appointed with respect to the package type. Typically, IAEA SSR-6 prescribes mechanical tests followed by a thermal fire test as part of a cumulative test sequence. To approve the fire test, BAM uses a reference package representing the original package in its outer geometry for characterizing the actual fire and its impact on the package. This serves a dual purpose: it allows the precise adjustment of experimental parameters for the package design to be approved, and it provides input parameters for thermomechanical simulations, cf. With the help of this methodology for characterizing boundary conditions of the package, temperature evolutions within the reference package can be studied in a Finite-Element Analyses (FEA). This helps to compare the experiments with the numerical simulations on the case of the reference package, but also serves at the same time for preliminary simulations with the package design to be approved. The thermal test consists of a 30-minute fully engulfing 800°C pool fire or an equally severe fire, e.g. a propane gas fire. The fire reference test is performed prior to the regulatory fire test with the package design to be approved. The fire reference package in the described case is a closed sheet 316L steel 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 insulating material. T2 - ASME PVP 2024 CY - Bellevue, WA, USA DA - 28.07.2024 KW - Reference Test KW - Experimental KW - Numerical KW - Heat Flux PY - 2024 SP - 1 EP - 8 AN - OPUS4-60848 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Naster, Maximilian A1 - Gleim, Tobias A1 - Wille, Frank T1 - Experimental and Numerical Analyses for the Evaluation of Hydrogen as an Energy Source for Thermal Testing of Transport Packages of Radioactive Material N2 - In this paper we present a new hydrogen-based test rig for an ongoing feasibility study of using hydrogen as an energy source for the thermal testing of transport packages containing radioactive materials. The test rig will be capable of combusting hydrogen for a wide range of different burner geometries, mass flows and if necessary hydrogen blends. As this type of fire test according to the IAEA boundary conditions does not yet exist, a large number of preliminary investigations, safety assessments and calculations must be carried out in order to develop a viable concept for hydrogen fires. In the first step of the feasibility study, the temperature, structure, and radiation of various hydrogen flames are surveyed. In future works, the results will make it possible to design burner frames that are suitable for fire reference tests in order to make comparisons with pool and propane fires used in assessment procedures today. In parallel comparative numerical simulations are conducted to model the thermal behaviour of hydrogen flames using the software package Ansys®. On the one hand, the numerical simulations support the experiments by providing an overview of numerous parameters and the measuring range; on the other hand, they will help with the design of the burner frame in future work. This paper gives an overview in the design and capabilities of the test rig. Furthermore, the results of the parameter studies show that burner geometry and mass flow provide a significant design margin for the thermal shape of the hydrogen flames. In addition, the results of the initial numerical calculations will be used to determine the necessary sensors, the positions, and their operating range. Only the optimal interaction allows a controlled system that permits user-defined hydrogen fires. T2 - PVP2024, Pressure Vessels & Piping Conference CY - Bellevue, Washington USA DA - 29.07.2024 KW - Hydrogen KW - Fire KW - Computational Fluid Dynamics (CFD) KW - IAEA fire test KW - Burner PY - 2024 SP - 1 EP - 9 AN - OPUS4-60852 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 - Karapanagiotis, Christos A1 - Schukar, Marcus A1 - Breithaupt, Mathias A1 - Krebber, Katerina T1 - Monitoring of composite pressure vessels using surface applied distributed fiber optic sensors N2 - In this paper, we report on surface-applied distributed fibre optic sensors for monitoring composite pressure vessels designed for hydrogen storage. Previous reports have revealed that integrating optical fibres within vessel composite structures effectively enables the monitoring of structural behavior throughout their lifetime. However, integrating optical fibres during the manufacturing process is complex and time-consuming. Therefore, we aim to simplify this process by attaching the optical fibres to the vessel’s surface. This method is significantly more timeefficient than the integration process and can be applied to any vessel. Our results demonstrate that surface-applied fibre optic sensors can detect and precisely localise damage. Additionally, signs of damage can be recognised even before the damage occurs. Predictive maintenance using fibre optic sensors could reduce premature maintenance costs and periodic inspections while increasing safety and extending the vessel’s useful service life. The role of machine learning in predictive maintenance is also discussed. T2 - 20th Sensors & their Applications Conference CY - Limerick, Ireland DA - 11.08.2024 KW - Hydrogen KW - Fiber optic sensors KW - Composites KW - Machine learning KW - Structural health monitoring PY - 2024 SP - 1 EP - 4 AN - OPUS4-60911 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Yang, Fan A1 - Meng, Xiangmeng A1 - Putra, Stephen Nugraha A1 - Bachmann, Marcel A1 - Rethmeier, Michael T1 - Experimental and numerical investigations of suppression mechanisms by an oscillating magnetic field on process porosity during laser beam welding N2 - The magnetohydrodynamic (MHD) technology is recognized as a promising approach for improving the quality of deep penetration laser beam welding. This study employs experimental and numerical methods to investigate the effects of an auxiliary oscillating magnetic field on reducing porosity in the laser beam welding of 5754 aluminum alloy. The experimental results clearly demonstrate a significant reduction of 97% in the porosity ratio of the welded joints applied with an oscillating magnetic field compared to those without magnetic field, thereby validating the efficiency of applying MHD technology in mitigating porosity during the laser beam welding process. In addition, a transient 3D multi-physical model has been developed, integrating the MHD model and metal vapor plume, to gain a more comprehensive understanding of the porosity suppression mechanism. The weld pool shape is significantly widened and enlarged because of the Lorentz force, which facilitates the escape of gas bubbles. Meanwhile, the introduction of an oscillating magnetic field generates a time-averaged downward Lorentz force. This averaged downward Lorentz force, in turn, enhances and stables the downward fluid flow, which hinders the bubble backward movement. Meanwhile, this averaged downward Lorentz force induces an upward electromagnetic expulsive force on the bubble, which effectively increases the upward escape velocity of bubbles in the weld pool. The simulation results agree well with the experimental results. T2 - 44. Assistentenseminar Füge- und Schweißtechnik CY - Päwesin, Germany DA - 20.09.2023 KW - Laser beam welding KW - Numerical simulation KW - Magnetohydrodynamic technology KW - Porosity defect KW - Keyhole PY - 2024 UR - https://www.dvs-media.eu/de/neuerscheinungen/4671/44.-assistentenseminar-fuegetechnik SN - 978-3-96144-267-6 VL - 394 SP - 77 EP - 86 PB - DVS Media GmbH CY - Düsseldorf AN - OPUS4-60784 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 - 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 - Marquardt, R. A1 - Osayi, J. A1 - Kmieciak, S. A1 - Biegler, M. A1 - Rethmeier, Michael T1 - Verschleißschutz einer Schneckengeometrie durch funktional gradierte Materialien N2 - Hochbelastete Stahlbauteile lassen sich durch Auftragen von Kobalt-Chrom Legierungen vor Verschleiß schützen. Die plötzliche Änderung der Materialeigenschaften führt jedoch zu Spannungen und Rissen im Anbindungsbereich. Daraus resultierende Abplatzungen stellen eine Gefahr für die Funktionsfähigkeit der Maschine und damit für Mensch und Umwelt dar. Um die Belastbarkeit der Schutzschicht zu verbessern, kann die Anbindung durch einen gradierten Materialübergang optimiert werden. Diese funktional gradierten Materialien können mittels pulverbasiertem Directed Energy Deposition aufgetragen werden. Die Methodik zum Aufbau und zur Qualitätssicherung solcher Materialien wurde in vorangegangenen Arbeiten für dickwandige Geometrien gezeigt. Für dünnwandige Geometrien ist die Anwendbarkeit bisher unzureichend untersucht worden. Diese Arbeit zeigt am Beispiel einer dünnwandigen gradierten Schneckengeometrie die Einsatzfähigkeit der Methodik. Dafür wird die Gefügestruktur der Gradierung auf Fehler untersucht und der Härteverlauf gemessen. Außerdem wird die relative Dichte anhand eines bereits trainierten neuronalen Netzes vorhergesagt und mit einer Porositätsuntersuchung verglichen. T2 - 14. Tagung Verschleiß- und Korrosionsschutz von Bauteilen durch Auftragschweißen CY - Halle a. d. Saale, Germany DA - 12.06.2024 KW - Directed Enery Deposition KW - Funktionally Graded Material KW - Additive Manufacturing KW - DED KW - FGM KW - AM PY - 2024 SP - 1 EP - 7 PB - SLV Halle AN - OPUS4-60721 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lemke, J. A1 - Biegler, M. A1 - Rethmeier, Michael T1 - Fließfähigkeitsanalyse zweier Pulverfraktionen aus AISI 316L und resultierende Bauteildichte DED-LB aufgebauter Quader N2 - Die Fließfähigkeit von Metallpulvern gilt als wichtige Pulvereigenschaft für den additiven Aufbau mittels Laser, wobei bisher wenige Arbeiten die Auswirkungen im Laserpulverauftragschweißen (Engl.: Directed Energy Deposition DED-LB) untersuchen. Arbeiten, die sich mit den Pulvereigenschaften für Pulverbettverfahren beschäftigen, zeigen Korrelationen zwischen Partikelgrößenverteilung und Fließeigenschaften mit der Bauteildichte und den mechanischen Eigenschaften. Sie bewerten insbesondere Pulverbettdichte und -stabilität. In der vorliegenden Arbeit werden daher die Eigenschaften zweier Pulverfraktionen (20 µm – 63 µm und 63 µm – 150 µm) des austenitischen Stahls AISI 316L und deren freien Ausfluss im Vergleich zur Pulverdichte untersucht. Die Untersuchungen zeigen, dass die feinere Pulverfraktion eine um 14,5 % höhere Durchflussrate erzielt als die gröbere Fraktion. korreliert die Ergebnisse zur inneren Porosität und Partikelgrößenverteilung. Die Analyse der Bauteilqualität zeigt einen geringen Einfluss der Korngrößenverteilung auf die Porosiät der DED-LB aufgebauten Quader. T2 - 44. Assistentenseminar Fügetechnik der WGF CY - Päwesin, Germany DA - 20.09.2023 KW - 316L KW - Fließfähigkeit KW - DED-LB KW - Hall-Flow KW - Metallpulver PY - 2024 SP - 131 EP - 140 AN - OPUS4-60723 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gaal, Mate A1 - Wernicke, Pascal A1 - Hufschläger, D. T1 - Pulse compression for air-coupled ferroelectret and thermoacoustic transducers N2 - The main advantage of air-coupled ultrasonic testing is the absence of a liquid couplant, which can damage some materials. However, most air-coupled testing scenarios have the challenge of low signals and a signal-to-noise ratio (SNR) several orders of magnitude lower than with couplant-assisted tech-niques. Since this challenge of small SNR also exists in radar technology, the pulse compression used there was adapted and applied to the physical conditions of air-coupled ultrasonic testing. This paper presents ultrasonic transmission measurements on a carbon-fibre-reinforced polymer plate using two experimental setups: 1) a thermoacoustic transmitter and an optical microphone and 2) a pair of ferroe-lectret transducers as transmitter and receiver. Thermoacoustic transmitters convert electrical energy to heat, which causes the air to expand thus producing acoustic waves. The optical microphone is based on a Fabry-Perot interferometer. Ferroelectrets are charged cellular polymers, having piezoelectric proper-ties and excellent acoustic matching to air. Both thermoacoustic transmitters and ferroelectrets are non-linear regarding the relationship between the excited sound pressure and the excitation voltage. Due to these physical boundary conditions, unipolar coding was used to modulate the excitation signals. Vari-ous codes were tested, and parameters of the excitation pulses were varied to find the optimal combina-tion for each experimental setup. The application of pulse compression to the combination of thermo-acoustic transmitter and optical microphone increased the signal-to-noise ratio by up to 16 dB and for the ferroelectret transducers by up to 23 dB. T2 - 30th International Congress on Sound and Vibration CY - Amsterdam, The Netherlands DA - 08.07.2024 KW - Pulse compression KW - Air-coupled ultrasonic transducers KW - Ferroelectret KW - Thermoacoustics PY - 2024 SP - 1 EP - 7 AN - OPUS4-60725 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -