TY - CONF A1 - Müller, Thoralf A1 - Seifert, Lando A1 - Ebell, Gino T1 - Abschlussvorstellung Wipano Vorhaben Spanntahlsicherheit N2 - In dem Vortrag werden die Highlights und Ergebnisse des abgeschlossenen Wipano Forschungsprojekts "Spannstahlsicherheit" berichtet. In dem Vorhaben wurde das Projektziel ein neues Prüfverfahren für die Prüfung von Spannstählen auf Spannungsrisskorrosionsempfindlichkeit zu entwickeln erfolgreich abgeschossen. Weiterhin wurden neue Erkenntnisse zu den Ursachen der Ergebnisstreuung der bisherigen Prüfung gemäß ISO 15630-3 gewonnen. Das neue Prüfverfahren soll bei der nächsten Überarbeitungsrunde der ISO 15630-3 als Verfahren zunächst in den informativen Anhang aufgenommen werden. T2 - Arbeitskreissitzung des GfKorr-Arbeitskreises Eisen und Stahl CY - Online meeting DA - 08.12.2022 KW - Korrosion KW - Spannstahl KW - Spannbetonbauwerke KW - Spannungsrisskorrosion KW - Wasserstoffversprödung PY - 2022 AN - OPUS4-56510 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spitzer, Stefan A1 - Askar, Enis A1 - Benke, Alexander A1 - Cloney, C. A1 - D’Hyon, S. A1 - Dufaud, O. A1 - Dyduch, Z. A1 - Gabel, D. A1 - Geoerg, P. A1 - Heilmann, V. A1 - Jankuj, V. A1 - Jian, W. A1 - Krause, U. A1 - Krietsch, Arne A1 - Mynarz, M. A1 - Norman, F. A1 - Skrinsky, J. A1 - Taveau, J. A1 - Vignes, A. A1 - Zakel, S. A1 - Zhong, S. T1 - 1st international round robin test on safety characteristics of hybrid mixtures N2 - There is no applicable existing standard for the determination of safety characteristics for hybrid mixtures. While developing a new standard in a joint research project in Germany first results from parameter studies led to a standard procedure that can be adopted by laboratories that are already testing dusts in the so called 20L-sphere with as little additional effort as necessary. In fact, one of the main objectives of this research project was to keep modifications and adjustments from the generally accepted dust testing procedures as easy and minimal as possible so as to limit potential deviations from one laboratory to another. In this first round robin test on hybrid mixtures ever, with methane as gas component and a specific corn starch as dust sample, the practicality of the whole procedure, the scattering of the results and the deviation between the testing apparatuses is investigated. This paper summarizes the experimental procedure adopted and objectives of the first round-robin phase involving three of the four original German companies, plus volunteering laboratories from Australia, Belgium, Czech Republic, France, Poland and P.R. China. The results will have an impact on the new standard and may lead to robust data for later simulation purposes. KW - Hybrid mixtures KW - 20L-sphere KW - Round robin test KW - Turbulent combustion PY - 2022 DO - https://doi.org/10.1016/j.jlp.2022.104947 SN - 0950-4230 VL - 81 SP - 1 EP - 8 PB - Elsevier CY - Amsterdam AN - OPUS4-56516 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Die Einfügedämmung bei Schienenfahrwegen Definition, Messung und Berechnung N2 - Die Definition und Beschreibung der Einfügedämmung im Normentwurf DIN 45673-4 ist noch nicht richtig. Es wird die Beschreibung aus DIN 45673-3 herangezogen, die für Messungen gilt. Für die drei Rechenverfahren gibt es jeweils eine passende Beschreibung. Mit diesen Vorlagen ist eine vernünftige Definition der Einfügungsdämmung zu finden. Es bedarf einer Abgrenzung gegenüber anderen (falschen) Möglichkeiten. Des Weiteren ist der Anhang 2 erweitert und der Parametersatz im Anhang 1 auf das Wesentliche reduziert worden. T2 - Norm-Arbeitsausschuss Schwingungsminderung in der Umgebung von Verkehrswegen CY - Online meeting DA - 14.12.2022 KW - Einfügungsdämmung KW - Schienenfahrwege KW - Kraft auf den Boden KW - Erschütterungen im Fernfeld PY - 2022 AN - OPUS4-56601 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz A1 - Said, Samir A1 - Rohrmann, R. T1 - Measurement and evaluation tools for ground and building vibrations from industrial pro-cesses, construction work, traffic and other sources N2 - Vibration measurements have many causes and many technical and natural sources. Problems can sometimes be solved by short-term measurements, but in many cases, a long-term measurement is necessary. In long-term measurements of days, weeks, months and even years, it is easy to collect a huge quantity of raw data, but at the end, the post-processing of these data can be exhausting (for example one-year vibration data of a wind energy tower). A software has been developed which con-sists of measuring and evaluation routines where the measuring routines can operate different meas-uring systems and different measuring cards. The main advantage of this software is the fact that the interesting evaluations can be integrated in the measuring process so that the characteristics of the vibration can be extracted without storing all the raw data. Only important time segments are stored, for example train passages. The overall concept of the software and the main evaluation routines will be described in some details. Examples of our measurement experience will illustrate the capabilities of the software. 1) Surveying construction work in nearby sensitive buildings (for example an old wind tunnel), including a stable alarm system and meaningful vibration limits. 2) Prediction of train-induced vibration for a planned building to prevent annoyance and to improve the building design. 3) Modal analysis and long term measurements of several single- or multi-span, concrete or steel bridges 4) Modal and wave analysis of coupled floors in a historical building (“Neues Palais” at Potsdam). 5) Soil properties of various measurement sites (different routines to evaluate the dispersion). Moreover, from many projects, amplitudes, frequencies, and attenuation laws have been collected and analysed for the different sources such as vibratory or impact pile driving and ground compaction, demolition work with different machines, blasting in quarries and in tunnel works, bomb and mine clearing. T2 - 28th International Congress on Sound and Vibration CY - Online meeting DA - 24.07.2022 KW - Ground vibration KW - Building vibration KW - Measurement KW - Evaluation KW - Modes KW - Waves PY - 2022 SP - 1 EP - 8 AN - OPUS4-56602 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Railway-induced ground and building vibrations – Analysis in frequency-wavenumber domain and fast prediction with approximate models N2 - A simple and fast prediction scheme is presented for train-induced ground and building vibrations. For the emission, finite-element boundary-element or multiple-beam-on-continuous-soil models of the track have been analysed and approximated by faster track-on-Winkler-soil models. The vehicle-track interaction due to irregularities yields the excitation forces. For the transmission of waves in the soil, the wavenumber integral of the compliance of layered soils has been evaluated. The calculation time is reduced for the prediction by using the solution of a homogeneous half-space with a frequency-dependent wave velocity (the dispersion) of the soil. For the immision, many 2 and 3-dimenisonal finite-element building models have been investigated, and a good approximation has been established by a 1-dimensional soil-wall-floor model. In addition, the axle sequence of the train, the quasi-static and the “scattered” response of the soil, and the wave propagation from a tunnel to a pile foundation of a building have been included. T2 - ISMA-Conference 2022 CY - Leuven, Belgium DA - 12.09.2022 KW - Ground vibration KW - Simple prediction KW - Vehicle-track interaction KW - Layered soil KW - Soil-building interaction KW - Soil-wall-floor model KW - Propagation from a tunnel KW - Tunnel-pile transfer PY - 2022 SP - 1 EP - 13 PB - KU Leuven CY - Leuven AN - OPUS4-56603 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Effects of a varying track and soil stiffness on ground vibrations near railway lines N2 - Usually, geometric irregularities are considered as the main cause of ground vibrations from trains. A varying stiffness of the track, the track support and the soil can also generate ground vibrations. The regular stiffness variation of the track on and between the sleepers results in a deterministic dynamic axle load. The random stiffness variation of the track support yields also dynamic axle loads which are generated by the acceleration of the unsprung mass (from the varying wheel displacements under the static axle load). The random stiffness variation has a second effect. The pulses from the passage of the static axle loads are superposed regularly to the quasi-static response, but also irregularly to yield a “scattered” part of the axle pulses. The same holds for a random variation of the soil stiffness. All these effects of stiffness variations have been calculated by wavenumber-domain multi-beam track models, a random finite-element soil model and the superposition of axle impulses in a stochastic simulation. The results are confronted with many measurements at different sites. It is concluded that the stiffness variation of the track and the soil generate an important ground vibration component near railway lines. T2 - International Conference Railways 2022 CY - Montpellier, France DA - 22.08.2022 KW - Ground vibration KW - Axle loads KW - Irregularities KW - Varying stiffness PY - 2022 SP - 1 EP - 11 AN - OPUS4-56605 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Königsbauer, Korbinian A1 - Schaller, M.-B. A1 - Nöther, N. A1 - Wosniok, Aleksander T1 - Entwicklung eines praxistauglichen auf POF basierenden Messsystems mittels digitaler I-OFDR zur Dehnungsdetektion N2 - Es wird ein faseroptisches Messsystem vorgestellt, welches auf Basis der Rayleigh-Rückstreumessung eine ortsauflösende Detektion von signifikant großen Dehnungen bei Bauvorhaben im von Anwendern geforderten Größenordnungsbereich von 3 % bis 10 % ermöglicht. Mit dem Verfahren der digitalen inkohärenten optischen Frequenzbereichsreflek-tometrie (I-OFDR) werden materialspezifische Vorteile robuster perfluorierter polymeroptischer Fasern (PF-POF) erschlossen. Für den angestrebten industriellen Einsatz für die Zustandsüberwachung im Bereich des Tunnel- und Spezialtiefbaus soll die spezifische Rückstreuzunahme in der PF-POF hochauflösend gemessen werden. In diesem Vortrag wird gezeigt, dass sich in ersten Projektergebnissen das digitale I-OFDR für eine Dehnungsdetektion von bis zu 10% eignet. T2 - 21. ITG/GMA-Fachtagung CY - Nuremberg, Germany DA - 10.05.2022 KW - I-OFDR KW - Structure health monitoring KW - Dehnungsdetektion KW - Reyleigh-Rückstreumessung PY - 2022 AN - OPUS4-56717 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Königsbauer, Korbinian A1 - Schaller, M.-B. A1 - Nöther, N. A1 - Wosniok, Aleksander T1 - Distributed POF sensors for structural health monitoring in civil construction applications N2 - In this presentation, a cost-efficient distributed fiber optic measurement system based on Rayleigh scattering is shown. The distributed digital incoherent optical frequency domain reflectometry (I-OFDR) method is devel-oped for detection of significantly large strain in the range from 3 % up to 10 % as required by end users. For this purpose, a vector network analyzer used in the I-OFDR is replaced by a compact and costeffective digital data acquisition system. This digital emitting/receiving unit enables the recording of the complex transfer function carrying information about the local deformations along the entire sensing fiber. T2 - POF 2022 The 30th International Conference on Plastic Optical Fibers CY - Bilbao, Spain DA - 26.09.2022 KW - I-OFDR KW - Perfluorinated polymer optical fiber (PF-POF) KW - Strain detection KW - Structural health monitoring. PY - 2022 AN - OPUS4-56714 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neumann, Patrick P. A1 - Hirschberger, Paul A1 - Bartholmai, Matthias ED - Holl, H. T1 - Flying ant robot for chemical trail detection and localization N2 - This paper presents first advances in the area of aerial chemical trail following. For that purpose, we equipped a palm-size aerial robot, based on the Crazyflie 2.0 quadrocopter, with a small lightweight metal oxide gas sensor for measuring evaporated ethanol from chemical trails. To detect and localize a 5 cm wide chemical trail, a detection criterion was developed that uses only relative changes in the transient phase of the sensor response. The reduction in signal strength dependence improves the robustness of its application. We tested our setup in first crossing-trail experiments showing that our flying ant robot can correlate an odor hit with the chemical trail within 0.14 m. Principally, this could enable aerial chemical trail following in the future. T2 - 37th Danubia - Adria Symposium on Advances in Experimental Mechanics CY - Linz, Austria DA - 21.09.2021 KW - Aerial robot KW - Trail following KW - Trail detection KW - Localization PY - 2022 DO - https://doi.org/10.1016/j.matpr.2022.02.594 SN - 2214-7853 VL - 62 SP - 2462 EP - 2465 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-54507 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kosareva, E. A1 - Gainutdinov, R. A1 - Michalchuk, Adam A1 - Ananyev, I. A1 - Muravyev, N. T1 - Mechanical Stimulation of Energetic Materials at the Nanoscale N2 - The initiation of energetic materials by mechanical stimuli is a critical stage of their functioning, but remains poorly understood. Using atomic force microscopy (AFM) we explore the microscopic initiation behavior of four prototypical energetic materials: 3,4-dinitropyrazole, 𝜖-CL-20, 𝛼-PETN and picric acid. Along with the various chemical structures, these energetic compounds cover a range of application types: a promising melt-cast explosive, the most powerful energetic compound in use, a widespread primary explosive, and a well-established nitroaromatic explosive from the early development of energetics. For the softest materials (picric acid and 3,4-dinitropyrazole), the surfaces were found to behave dynamically, quickly rearranging in response to mechanical deformation. The pit created by nanoscale friction stimulation on the surface of 3,4-dinitropyrazole doubled in volume upon aging for half an hour. Over the same time frame, a similar pit on picric acid surface increased in volume by more than seven-fold. Remarkably, increased humidity was found to reduce the rate of surface rearrangement, potentially offering an origin for the desensitization of energetic materials when wetted. Finally, we identify an inverse correlation between the surface dynamics and mechanical sensitivity of our test energetic compounds. This strongly suggests that surface dynamics influence a material’s ability to dissipate excess energy, acting as a buffer towards mechanical initiation. KW - Energetic materials KW - Mechanical Properties KW - Mechanical Sensitivity PY - 2022 DO - https://doi.org/10.1039/D2CP00832G VL - 24 IS - 15 SP - 8890 EP - 8900 PB - Royal Society of Chemistry AN - OPUS4-54562 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rhode, Michael A1 - Kannengießer, Thomas T1 - Fügetechnik für die neue Wasserstoffökonomie N2 - Die Herausforderungen für die Fügetechnikbranche, die sich durch die neuen Wasserstoff-Technologiefelder „Erzeugung“, „Speicherung“, „Transport“ und „Nutzung“ ergeben, sind sehr vielfältig. Der DVS-Bericht 373 gibt dazu einen tieferen Einblick. Der hier vorliegende Kurzbericht stellt dazu ausgewählte Praxisbeispiele, zugehörige Herausforderungen und sich ergebende Chancen vor. Fügetechnologien haben dabei wesentliche Bedeutung für das erfolgreiche Umsetzen und Herstellen der benötigten technischen Komponenten, wie anhand der Themenkomplexe „Wasserstoff-Pipelines“ und „additive Fertigung“ betrachtet wird. Zudem ergeben sich Herausforderungen für die notwendigen Regelwerke und Normen, die nahezu vollständig angepasst oder geschaffen werden müssen. KW - Wasserstoff KW - Fügetechnik KW - Studie KW - Werkstoffe KW - Schweißen PY - 2022 UR - https://www.schweissenundschneiden.de/artikel/fuegetechnik-fuer-die-neue-wasserstoffoekonomie SN - 0036-7184 VL - 74 IS - 3 SP - 142 EP - 144 PB - DVS Media GmbH CY - Düsseldorf AN - OPUS4-54563 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Burkert, Andreas T1 - Korrosion metallener Werkstoffe-Grundlagen N2 - Im Vortrag werden die wesentlichen Grundlagen zum Verständnis der Korrosion metallener Werkstoffe in komprimierter Form vorgestellt. Der Schwerpunkt liegt auf der Betrachtung der atmosphärischen Korrosion und den sich daraus ergebenden Anforderungen an den Korrosionsschutz. T2 - CORPAC Seminar: Wie lassen sich VCI-Korrosionsschutz und Nachhaltigkeit vereinbaren? CY - Weidhausen b. Coburg, Germany DA - 30.03.2022 KW - Einflussgrößen KW - Atmosphärische Korrosion KW - Befeuchtungsdauer PY - 2022 AN - OPUS4-54594 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wilrich, Cordula A1 - Wilrich, T. T1 - Kittelverbrennung auf der Abschlussfeier der Pharmaziestudierenden – Klage auf Anerkennung als Arbeitsunfall und Strafverfahren wegen fahrlässiger Körperverletzung N2 - Auf der Abschlussfeier von Pharmaziestudierenden wurden traditionellerweise (in einem „Ritual mit Risiko“) die Laborkittel in einer Metalltonne verbrannt. Nachdem ein Student Ethanol in die Tonne gegossen hatte, kam es zu einer Verpuffung und mehrere Studierende erlitten zum Teil schwerste Verbrennungen. Der Aufsatz bereitet die beiden Gerichtsverfahren zu dem Unfall auf – der Verletzten auf Anerkennung als Arbeitsunfall und das Strafverfahren gegen den Unfallverursacher. KW - CLP-Verordnung KW - Brand KW - Entzündbare Flüssigkeit KW - Ethanol KW - Gefahrstoff PY - 2022 DO - https://doi.org/10.37307/j.2199-7349.2022.04.09 SN - 2199-7330 SN - 2199-7349 (eJournal) IS - 4 SP - 186 EP - 188 PB - Erich Schmidt Verlag (ESV) CY - Berlin AN - OPUS4-54620 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Johann, Sergej A1 - Baensch, Franziska A1 - Sturm, Patrick A1 - Tiebe, Carlo A1 - Pötschke, Samuel A1 - Lay, Vera ED - Holl, H. T1 - HF RFID-based measurement comparison for method optimization in M2 concrete and alkali-activated mortars N2 - Monitoring of repositories for radioactive waste requires techniques which can be applied long-term under harsh conditions. In this work, the reliability and suitability of materials and a capacitive sensor for measuring relative humidity are investigated, which are to be embedded in the special concrete components for the closure structures of underground repository. Preliminary tests with accelerated aging of the materials used, validation of the sensors under difficult conditions, investigations of the surfaces after aging by pH 14 solution, defined exposure of the sensors in a climatic chamber and the microscope images are discussed. The results will be used for further development and optimization of the RFID based sensor systems which can be applied to monitor the condition of different building structures without cabling. T2 - 37th Danubia - Adria Symposium on Advances in Experimental Mechanics CY - Linz, Austria DA - 21.09.2021 KW - Alkali-activated mortars KW - Passive sensor interface KW - RFID KW - Structural health monitoring KW - Smart structures PY - 2022 DO - https://doi.org/10.1016/j.matpr.2022.03.465 SN - 2214-7853 VL - 62 IS - 5 SP - 2571 EP - 2576 PB - Elsevier CY - Amsterdam AN - OPUS4-54697 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grunert, Wiebke A1 - Walter, Astrid A1 - Schwarz, Silke A1 - Lohrer, Christian T1 - Odysseus - preventing, countering, and investigating terrorist attacks through prognostic, detection, and forensic mechanisms for explosive precursors N2 - Die Bekämpfung des Terrorismus erfordert ein ganzes Arsenal an Instrumenten. Unter anderem ist das Wissen über die Ausgangsstoffe für Explosivstoffe – chemische Substanzen, die für legale Zwecke verwendet, aber auch für die illegale Herstellung selbstgemachter Sprengstoffe missbraucht werden können – von entscheidender Bedeutung. In diesem Zusammenhang wird das EU-finanzierte Projekt ODYSSEUS effektive und effiziente prognostische, nachweisende und forensische Instrumente entwickeln, um die Prävention, Bekämpfung und Untersuchung von Terroranschlägen mit selbstgebauten Sprengstoffen zu verbessern. Die gewonnenen Erkenntnisse sollen zur Erarbeitung von Instrumenten zur Überwachung der chemischen Lieferkette und zur Erkennung von Ausgangsstoffen für Explosivstoffe in (nahezu) Echtzeit beitragen. Die Instrumente werden in drei Anwendungsfällen praktisch erprobt. T2 - 43. Informationstagung Sprengtechnik CY - Siegen, Germany DA - 22.04.2022 KW - Home made explosives KW - Explosiv- und Ausgangsstoffe KW - Sensor PY - 2022 AN - OPUS4-54687 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lu, Xin A1 - Krebber, Katerina T1 - Phase error analysis and unwrapping error suppression in phase-sensitive optical time domain reflectometry N2 - Phase-sensitive optical time domain reflectometry becomes an effective tool to realize distributed sensing, and the optical phase of the received light is usually used to quantify the strain for both dynamic and static measurement. The analysis on the overall phase error has been improved by considering the proportionality of the detection noise to the local optical power. The estimation accuracy is greatly improved by using the proposed theory, the probability density of the estimation accuracy over 99% is > 0.6, ∼39 times larger than the previously reported method. The phase unwrapping may malfunction due to the noisy signal, causing large phase errors. Point break detection algorithms are used to locate the incorrect phase unwrapping points, so the temporal evolution of the phase retrieved at each position can be divided into several sections with different offset. The phase unwrapping error is then suppressed by removing the offset. KW - Phase unwrapping KW - Distributed fiber sensing KW - Acoustic sensing PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543919 DO - https://doi.org/10.1364/OE.446517 VL - 30 IS - 5 SP - 6934 EP - 6948 PB - Optica Publishing Group AN - OPUS4-54391 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - Different types of continuous track irregularities as sources of train-induced ground vibration and the importance of the random variation of the track support N2 - Irregularities of the track are a main cause of train-induced ground vibration, and track maintenance is of great importance. Although geometric irregularities at the wheel-rail contact are widely used, other types of irregularities, such as stiffness irregularities, irregularities from different track positions and irregularities in the wave propagation, were analysed in the present study. The track behaviour was investigated by a multi-beam-on-soil model. This track model is coupled with a vehicle model to calculate the vehicle–track interaction. The track model was also used for the track filtering, which transfers a track support error to the equivalent rail irregularity or, conversely, the sharp axle pulse on the rail to a smoother pulse on the soil. In the case in which this filtering varies randomly along the track, the pulses of the moving static load induce a certain ground Vibration component (“the scatter of axle pulses”). This effect was calculated by the superposition of axle pulses in the frequency domain and by a stochastic simulation. Simultaneous vehicle, track and soil measurements at a certain site were used to evaluate the different excitation and ground Vibration components. The agreement between calculations and axle-box and soil measurements is good. The ground vibrations calculated from rail irregularities and corresponding dynamic loads, however, clearly underestimate the measured ground vibration amplitudes. Only the static load that is moving over a varying track support stiffness can produce the important mid-frequency ground Vibration component by the scatter of axle pulses. KW - Train-induced ground vibration KW - Geometric vehicle and track irregularities KW - Stiffness variation KW - Multi-beam track model KW - Track filtering KW - Dynamic axle loads KW - Static axle loads KW - layered soil PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543846 DO - https://doi.org/10.3390/app12031463 SN - 2076-3417 VL - 12 IS - 3 SP - 1 EP - 22 PB - MDPI CY - Basel AN - OPUS4-54384 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kaplan, F. A1 - Steinbock, O. A1 - Saloga, K. A1 - Ebell, Gino A1 - Schmidt, S. T1 - Überwachung der Brücke am Altstädter Bahnhof T1 - Monitoring of the bridge at the Altstadter Bahnhof in Brandenburg a. d. Havel N2 - Die B 1-Brücke am Altstädter Bahnhof war der wichtigste Verkehrsknotenpunkt in Brandenburg an der Havel. Im Dezember 2019 wurden die überführte Bundesstraße und die Straßenbahnlinie für den Verkehr gesperrt. Grund für die Sperrung war eine einsetzende Rissbildung in den Längsträgerstegen in Verbindung mit Hohlstellen, die letztlich auf gerissene Spanndrähte zurückgeführt werden. Um eine Sperrung der hoch frequentierten unterführten Verkehrswege zu verhindern, wurde ein umfangreiches Überwachungskonzept erforderlich. Wesentlicher Bestandteil dieses Konzepts war ein auf der Schallemissionsanalyse basierendes Monitoringsystem, mit dessen Hilfe Spanndrahtbrüche aufgezeichnet und lokalisiert werden konnten. Auf Grundlage der so gewonnenen Ergebnisse konnten Schwerpunkte für die Bauwerksprüfung abgeleitet werden. In diesem Bericht werden die gewonnenen Erkenntnisse zum messtechnisch erfassten Schadensfortschritt und den damit verbundenen visuell festgestellten Schäden beschrieben. Dabei werden die Besonderheit des verbauten konzentrierten Spannglieds (Spannblockverfahren nach TGL 173-33) und des Spannstahls in Bezug auf die Schadensbilder dargestellt. Die gewonnenen Erkenntnisse sollten bei der Beurteilung anderer Bauwerke mit vergleichbarer Bauart berücksichtigt werden. KW - Korrosion KW - Spannstahl KW - Spannungsrisskorrosion PY - 2022 DO - https://doi.org/10.1002/bate.202200008 SN - 0932-8351 VL - 99 IS - 3 SP - 222 EP - 230 PB - Ernst & Sohn AN - OPUS4-54485 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fulawka, K. A1 - Kwietniak, A. A1 - Lay, Vera A1 - Jaskiewicz-Proc, I. T1 - Importance of seismic wave frequency in FEM-based dynamic stress and displacement calculations of the earth slope N2 - Reliable assessment of earthen dams’ stability and tailing storage facilities widely used in the mining industry is challenging, particularly under seismic load conditions. In this paper, we propose to take into account the effect of the dominant frequency of seismic load on the stability assessment of tailing/earthen dams. The calculations are performed by finite element modelling (FEM) with the Mohr–Coulomb failure criteria. To separate the frequency content from other dynamic parameters describing the seismic wave, synthetic waveforms with identical amplitude and attenuation characteristics, but differing spectral characteristics have been used. The analysis has been performed for three different slope angles and two scenarios of seismic wave propagation. Consequently, the changes of total displacement and shear stresses depending on the frequencies have been determined and clearly show that lower frequencies cause higher stress levels and displacement. Finally, the response surface methodology has been applied to determine how different parameters affect the slope stability under dynamic load conditions. Overall, this study is a first step to improve the existing methods to assess slope stability when considering seismic load. KW - Slope stability KW - Numerical analysis KW - Seismic load KW - Frequency analysis PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-544047 DO - https://doi.org/10.2478/sgem-2022-0002 SN - 2083-831X VL - 44 IS - 1 SP - 82 EP - 96 PB - De Gruyter CY - Berlin AN - OPUS4-54404 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Corrosion of Steel in Concrete and Corrosion Behavior of Stainless Steel N2 - In order to obtain a statement on the corrosion resistance of stainless steel against pitting corrosion, a well-tested measuring arrangement is required. For this purpose, the so-called ECISS test can be used to determine the critical chloride content. This makes it possible to assess the corrosion resistance of various stainless steels that have different chromium contents. T2 - ISO-TC17-SC16-WG13 Expertensitzung CY - Online meeting DA - 11.01.2022 KW - Corrosion KW - Lochkorrosion KW - Chloride induced corrosion KW - Concrete KW - Stainless steel PY - 2022 AN - OPUS4-54239 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neumann, Patrick P. A1 - Hüllmann, Dino A1 - Winkler, Nicolas P. A1 - Kohlhoff, Harald A1 - Bartholmai, Matthias A1 - Hirschberger, Paul A1 - Bennetts, V. H. A1 - Lilienthal, A. J. T1 - Aerial Robot Olfaction - An Overview of Research @BAM N2 - This presentation gives an introduction to the gas-sensitive aerial robots developed at BAM, including various application examples in the field of mobile robot olfaction: gas source localization, gas distribution mapping, and trial following. T2 - The 6th Meeting of the Investigation Committee on Measurement of Odors and Applications of Their Psychological/Physiological Effects CY - Online meeting DA - 21.01.2022 KW - Mobile Robot Olfaction KW - Gas Tomography KW - Tunable Diode Laser Absorption Spectroscopy (TDLAS) KW - Gas Source Localization KW - Gas Distribution Mapping KW - Trial Following PY - 2022 AN - OPUS4-54241 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Die Berechnung der Einfügedämmung bei Schienenfahrwegen – die Impedanzmethode mit einem Freiheitsgrad N2 - Mit dieser Methode kann man die Einfügedämmung eines Schienenstützpunkts/einer Schwelle korrekt berechnen. Sie gilt in ihrer ursprünglichen Form für eine Unterschottermatte in einem Tunnel T2 - Norm-Arbeitsausschuss Schwingungsminderung in der Umgebung von Verkehrswegen CY - Online meeting DA - 20.1.2022 KW - Impedanzmethode KW - Elastische Elemente KW - Schienenfahrweg PY - 2022 AN - OPUS4-54243 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Babutzka, Martin A1 - Lehmann, Jens A1 - Burkert, Andreas T1 - Update nach 10 Jahren Bewitterung - Langzeitkorrosionsverhalten nichtrostender Stähle in maritimer Atmosphäre N2 - Durch Fortführung der Untersuchungen aus einem Forschungsvorhaben wurden neun verschiedene Stahllegierungen unter maritimen Umgebungsbedingungen über zehn Jahre ausgelagert und deren Korrosionsverhalten untereinander verglichen und bewertet. Anhand der Ergebnisse der Auslagerungsprüfungen konnten Rückschlüsse auf die Einflüsse der Legierungszusammensetzung, der Oberfächenausführung und der Auslagerungszeit unter maritimen Auslagerungsbedingungen gewonnen werden. Die Proben der drei untersuchten Duplexwerkstoffe zeigten über den Auslagerungszeitraum von zehn Jahren sowohl mit als auch ohne Spaltgeometrie die beste Korrosionsbeständigkeit. Ebenso konnte der molybdänlegierte Ferrit 1.4521 eine vergleichbar gute Korrosonsbeständigkeit erzielen, wie die klassischen austenitischen Werkstoffe 1.4301 und 1.4404. T2 - Korrosionsschutz in der maritimen Technik 2022 CY - Online meeting DA - 27.01.2022 KW - Auslagerungsversuche KW - Korrosionsschutz KW - Korrosion KW - Nichtrostende Stähle PY - 2022 AN - OPUS4-54276 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krankenhagen, Rainer A1 - Zirker, Stefan A1 - Joniertz, Florian T1 - Determination of thermal parameters of concrete by active thermographic measurements N2 - The knowledge of the thermal parameters of a particular concrete is essential for thermal design of a building, but also could help to identify and assess the state of a concrete structure. Active thermography has the potential to be applied onsite and to provide a fast investigation of thermal properties. In this work, three different concrete samples were investigated by active thermography in reflection and in transmission setup. It was found that this method yields the same results without direct contact as the Transient Plane Source (TPS) method as an established inspection tool. KW - Concrete KW - Effusivity KW - Thermal diffusivity KW - Photothermal KW - Thermography KW - Hot disc method KW - Parker method KW - Onsite inspection PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543781 DO - https://doi.org/10.1007/s10921-022-00861-6 SN - 0195-9298 SN - 1573-4862 VL - 41 IS - 1 SP - 1 EP - 20 PB - Springer AN - OPUS4-54378 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hicke, Konstantin T1 - Monitoring von Strukturverhalten mittels integrierter verteilter faseroptischer Sensorik - Verteilte akustische Sensorik (DAS) N2 - Die verteilte faseroptische akustische Sensorik (DAS) wird vorgestellt, hinsichtlich ihrer Leistungsfähigkeit beschrieben und verschiedenste Anwendungsfelder, z.B. für das Zustandsmonitoring oder für seismische Messungen, beispielhaft gezeigt. Zudem werden mögliche Anwendungsfelder von DAS für den Kontext Kerntechnische Entsorgung (KTE) und Rückbau aufgezeigt. T2 - Online-Workshop „Dauerhafte Verschlussbauwerke für Endlager“ CY - Online meeting DA - 14.02.2022 KW - Verteilte faseroptische Sensorik KW - Verteilte akustische Sensorik KW - DAS KW - KTE KW - Monitoring Endlager PY - 2022 AN - OPUS4-54348 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abbas, Z. A1 - Gabel, D. A1 - Krietsch, Arne A1 - Krause, U. T1 - Quasi-static dispersion of dusts for the determination of lower explosion limits of hybrid mixtures N2 - Knowledge of explosion limiting concentration of explosible materials is necessary forthe design of explosion protection measures. Currently employed methods of testing MEC of a dust cloud or LEL of a hybrid mixture are based on arbitrary assumptionsand possess technical limitations that often lead to values of MEC/LEL, which are unrealistically low or poorly reproducible. This contribution presents an improved method for experimental determination of MEC of a combustible dust cloud or LEL of a flammable gas or hybrid mixture. The new setup operates under laminar conditions and allows a uniform suspension of dust particles in an open top acrylic glass tube. Dust concentration is measured with the help of infrared sensors installed a few centimeters above and below the ignition source. In order to evaluate the dependence of MEC on flow front velocity, MEC of lycopodium was determined at four flow velocities. The results show that the flow field intensity does not significantly influence the MEC of lycopodium for the flow ranges tested in this work. Moreover, LEL of hybrid mixtures of lycopodium and methane was also tested at flow velocities of 4.7 cm/s, 5.8 cm/s, 7 cm/s and 11 cm/s and compared with the values obtained from other sources. The results suggest that the requirement of high energy pyrotechnical igniter may be relinquished, provided that a truly homogeneous suspension of dust particles could be achieved. Moreover, the effect of relative amount of dust and gas, on the course of ignition and flame propagation in hybrid mixtures at their LEL, was studied by the help of high speed videos. For hybrid mixtures of carbonaceous dusts (like lycopodium) at their LEL, ignition occurs in the gas phase, however, flame propagation is only possible through a two-way interaction of dust and gas during the course of combustion. KW - Dust explosions KW - Gas explosions KW - Lower explosion limit KW - Hybrid mixtures PY - 2022 DO - https://doi.org/10.1016/j.jlp.2021.104640 SN - 0950-4230 VL - 74 SP - 1 EP - 18 PB - Elsevier Ltd. AN - OPUS4-54077 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kasch, Thomas A1 - Thomas, Brock A1 - Hesse, Olaf T1 - Assessment Criteria to Evaluate Test Results on Compatibility of Nonmetallic Materials for Oxygen Service Based on BAM’s Safety Philosophy N2 - The general requirement, that nonmetallic materials for oxygen service must be tested and found suitable for their intended use in plants and components is the current state of technical safety. However, numerous requests of manufacturers, sales offices, and users show, that there is still a strong need for information on how these materials are tested and evaluated. Based on more than 60 years of expertise, this paper provides background information on BAM’s test approach. It explains why BAM applies additional assessment criteria on nonmetallic materials for certain use conditions. Hence, the test schedule as well as the final evaluation shall reflect the practical application in a more customer-related way in combination with a higher safety level. That is the demand of BAM’s safety philosophy. T2 - 15th international symposium on flammability and sensitivity of materials in oxygen-enriched atmospheres CY - Online meeting DA - 03.05.2022 KW - Oxygen compatibility KW - Background information on test approaches KW - Evaluation of test results KW - Assessment criteria KW - BAM’s safety philosophy PY - 2022 AN - OPUS4-54887 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Elastische Elemente in der Emission, Transmission und Immission von Bahnerschütterungen N2 - Dieser Vortrag präsentiert einige Prinzipien und einige Beispiele zur Minderung von Eisenbahnerschütterungen. Die Prinzipien unterscheiden sich für die Minderungsmaßnahmen im Gleis, im Boden und bei Gebäuden. Kraftübertragungsfunktionen isolierter und nicht isolierter Gleissysteme, reflektierte und durchgelassene Wellenamplituden bei gefüllten Bodenschlitzen und die Übertragung der Freifeldschwingungen ins Gebäude werden analysiert. Bei den einfachen Gleismodellen muss der richtige Anteil der unabgefederte Fahrzeugmasse zum eindimensionalen Gleismodell hinzugefügt werden. Der Minderungseffekt eines gefüllten Bodenschlitzes ist von der Steifigkeit und nicht von der Impedanz des Schichtmaterials bestimmt. Bei einer elastischen Gebäudelagerung muss die Minderungswirkung mit der richtigen Boden- (Fundament-) Steifigkeit berechnet werden, und das abgeminderte Gebäudeverhalten hängt wesentlich von der effektiven Gebäudemasse ab, die mit zunehmender Frequenz deutlich kleiner als die starre Gebäudemasse ist. T2 - Norm-Arbeitsausschuss Schwingungsminderung in der Umgebung von Verkehrswegen CY - Bludenz, Austria DA - 17.5.2022 KW - Erschütterungsminderung KW - Bahngleis KW - Bodenschlitz KW - Gebäudelagerung KW - Elastische Elemente PY - 2022 AN - OPUS4-54916 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liao, Chun-Man A1 - Bernauer, F. A1 - Hadziioannou, C. A1 - Fontoura Barroso, Daniel T1 - Passive and active bridge monitoring N2 - This research is to perform passive and active measurements on a large-scale prestressed concrete bridge model under the outdoor condition. Multi sensors were applied to this test structure – BLEIB, which is located at the BAM test site. The experimental evaluation of ultrasonic wave propagation and seismic noise recordings were considered for revealing the bridge damage condition, as a basic for developing a reliable bridge monitoring system. T2 - DGZfP-Jahrestagung 2022 CY - Kassel, Germany DA - 23.05.2022 KW - Bridge monitoring PY - 2022 AN - OPUS4-54918 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Boschmann Käthler, C. A1 - Ebell, Gino A1 - Keßler, S. A1 - Schiegg, Y, A1 - Dauberschmidt, C. A1 - Angst, U. M. T1 - A comparison of methods to assess the resistance of reinforcing steel against chloride‐induced corrosion in concrete - Particular consideration of 12% chromium steel N2 - The critical chloride content C(crit) is an indicator for the corrosion resistance of reinforcing steels in concrete. In this article, several experimental methods for determining the critical chloride content C(crit) of mild and an alloyed (12% Cr) steel in cementitious materials are compared. The methods used include accelerated polarization tests and tests using more natural (unpolarized) conditions in which chloride ingress occurs by diffusion and capillary uptake. The advantages and disadvantages of the methods are discussed, in particular, with the objective of reaching a compromise between applicability to practice and feasibility in laboratory testing. KW - Chloride‐induced corrosion KW - Critical chloride content KW - Reinforced concrete KW - Testing methods PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-529751 DO - https://doi.org/10.1002/maco.202112826 SN - 0947-5117 N1 - This article has been published in 2021 as an "Early View" version with the DOI 10.1002/maco.202112609. VL - 73 IS - 3 SP - 306 EP - 325 PB - Wiley-VCH CY - Weinheim AN - OPUS4-52975 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krentel, Daniel T1 - Wehrmedizinisches Sonderforschungsvorhaben 29K4 "Primäres Explosionstrauma": „Entwicklung und Validierung eines Körpermodells und eines Stoßwellengenerators zur Simulation der intrakorporalen Stoßwellenausbreitung nach Explosionen“ N2 - Im Rahmen dieses Vortrags wurden aktuelle Arbeiten im Rahmen der Forschungszusammenarbeit mit dem Bundeswehrkrankenhaus Berlin zum primären Explosionstrauma vorgestellt. T2 - 8. KSK Symposium Rüstung 2022 CY - Altensteig/Wart, Germany DA - 13.09.2022 KW - Blast KW - Primäres Explosionstrauma KW - Einsatzkräfte KW - Polizei KW - Körpermodell PY - 2022 AN - OPUS4-55841 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lengas, Nikolaos A1 - Müller, Karsten A1 - Schlick-Hasper, Eva A1 - Neitsch, Marcel A1 - Johann, Sergej A1 - Zehn, M. W. T1 - Bewertung von Fallfundamenten in der mechanischen Sicherheitsprüfung von Gefahrgutverpackungen N2 - Bericht über die Vorgehensweise der systematischen Untersuchungen zur Entwicklung angepasster Kriterien für die Bewertung von Aufprallfundamenten in der mechanischen Sicherheitsprüfung von Gefahrgutverpackungen T2 - AK Prüfstellen CY - Berlin, Germany DA - 21.09.2022 KW - Fallprüfung KW - Aufprallfundament KW - Gefahrgutverpackung KW - Fallfundament KW - Mechanische Sicherheitsprüfung PY - 2022 AN - OPUS4-55842 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lengas, Nikolaos A1 - Müller, Karsten A1 - Schlick-Hasper, Eva A1 - Neitsch, Marcel A1 - Johann, Sergej A1 - Zehn, M. W. T1 - Bewertung von Fallfundamenten in der mechanischen Sicherheitsprüfung von Gefahrgutverpackungen N2 - Bericht über die Vorgehensweise der systematischen Untersuchungen zur Entwicklung angepasster Kriterien für die Bewertung von Aufprallfundamenten in der mechanischen Sicherheitsprüfung von Gefahrgutverpackungen T2 - ERFA Verpackungen CY - Berlin, Germany DA - 22.09.2022 KW - Fallprüfung KW - Aufprallfundament KW - Gefahrgutverpackung KW - Fallfundament KW - Mchanische Sicherheitsprüfung PY - 2022 AN - OPUS4-55843 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lengas, Nikolaos A1 - Johann, Sergej A1 - Kadoke, Daniel A1 - Müller, Karsten A1 - Schlick-Hasper, Eva A1 - Neitsch, Marcel A1 - Zehn, M. W. T1 - Damage assessment of complete, filled fibreboard boxes in regulative vertical impact tests by dropping N2 - Due to the high damping mechanical properties of fibreboard materials, corrugated fibreboard boxes are widely used as transport packages of dangerous goods. Since there is a hazard of vertical impact within the distribution system, drop tests are performed as design type tests to assess the package’s ability to withstand damage. However, there is little information in this context regarding the mechanical response of a filled fibreboard box. This work aims to propose a concept utilizing experimental drop test results by means of finite-element (FE) analyses in order to predict the damage resistance of complete, filled corrugated fibreboard boxes which are ready for transportation. T2 - 38th Danubia Adria Symposium on Advances in Experimental Mechanics CY - Poros Island, Greece DA - 20.09.2022 KW - Drop test KW - Dangerous goods packagings KW - Corrugated fibreboard box KW - Finite-element-analysis KW - Explicit transient simulation KW - Crash simulation PY - 2022 AN - OPUS4-55845 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, Dejian A1 - Schmidt, Martin A1 - Krietsch, Arne A1 - Krause, U. T1 - Effect of oxygen concentration, inert gas and CH4/H2 addition on the minimum ignition energy of coal dusts N2 - MIKE III apparatus tests were conducted to investigate the minimum ignition energy (MIE) of coal dusts in air and O2/CO2 atmospheres with and without small amount of CH4/H2. The O2 mole fraction (XO2) in the gas mixtures varied from 21% to 50% with the CH4/H2 mole fraction from 0 to 2%. Experimental result showed that MIE of coal dusts significantly decreases even by three orders of magnitude in mJ with increasing XO2 and the addition of CH4/H2. Compared with CH4, H2 had a relatively strong promotion effect on the spark ignition of coal dusts. The inhibiting effect of CO2 was found to be much stronger than N2, but this inhibiting effect of CO2 could be eliminated by 9% increment of XO2. The effect on MIE of coal dusts thus followed by the order: 9% increment of XO2 > CO2 replacing N2 > 2% CH4 or H2 addition. Moreover, two empirical models were used to estimate the MIE of hybrid dust-gas mixture (HMIE), and the results showed that calculated data can well reflect the promoting effect of elevated XO2 and flammable gas addition, and the inhibiting effect of inert gas KW - Ignition energy KW - Hybrid mixture KW - Oxygen rich KW - Inerting effect KW - Empirical model PY - 2022 DO - https://doi.org/10.1016/j.jlp.2022.104772 SN - 0950-4230 VL - 77 SP - 1 EP - 10 PB - Elsevier Ltd. AN - OPUS4-55888 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, Dejian A1 - Zhu, Z. A1 - Bao, Z. T1 - Optimization of the content distribution of expanded natural graphite in a multilayer metal hydride bed for thermochemical heat storage N2 - The poor thermal conductivity of MH beds limits hydrogen absorption in metal hydride (MH) reactors for thermochemical heat storage. The compaction of MH powder with expanded natural graphite (ENG) is an efficient and cost-effective approach for the heat transfer enhancement of MH beds. However, the addition of ENG reduces the hydrogen storage density of the compacted composites. How to optimize the allocation of a limited amount of ENG in the MH bed has not been studied. In this study, a multilayer MH bed configuration with an ENG grade content was adopted to improve the heat transfer performance of an MH reactor for thermochemical heat storage. The effect of the ENG content gradient on the performance of the MH reactor was investigated using a mathematical model of the MH reactor. Furthermore, an optimization method based on the entransy dissipation extremum principle (EDEP) was proposed to optimize the ENG distribution in magnesium hydride (MgH2)-ENG compacts. The results showed that a larger ENG content gradient resulted in faster hydrogen absorption and better heat-discharge performance. Compared with a configuration with a uniform ENG content, the optimized configuration based on the EDEP exhibited a shorter reaction time, more uniform bed temperature distribution, and 15.33% higher gravimetric exergy-output rate. In addition, the number of optimization iterations had little effect on the optimal results, which could be obtained by implementing only one optimization iteration. The optimization results showed that more ENG should be allocated to the internal layer of the MgH2-ENG compact. The compacts were divided into three layers, and the ENG content of each layer was calculated according to the optimized configuration based on the EDEP. The optimization method proposed in this study can be applied to optimize KW - Metal hydride reactor KW - Expanded natural graphite KW - Multilayer bed KW - Entransy dissipation exremum principle KW - Thermochemical heat storage PY - 2022 DO - https://doi.org/10.1016/j.applthermaleng.2022.119115 SN - 1359-4311 VL - 216 SP - 1 EP - 10 PB - Elsevier Ltd. AN - OPUS4-55890 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klimek, André A1 - Stelzner, Ludwig A1 - Hothan, Sascha A1 - Rogge, Andreas T1 - Fire induced concrete spalling in combination with size effects N2 - The size effect has its origin in fracture mechanics and describes the formation as well as propagation of cracks in brittle and solid materials in dependence of the specimen size. However, the size effect in concrete spalling describes the damage behaviour on a macroscopic scale for different sized specimens in case of fire. Concrete spalling is a very complex and yet not fully understood phenomenon. To reduce the effort of fire tests to analyse the spalling behaviour of concrete mixtures, this study investigates the susceptibility to spalling for six different concrete mixtures and three specimen sizes. The sizes were divided in full scale slabs (1.8 m x 1.2 m x 0.3 m), intermediate scale cuboids (0.6 m x 0.6 m x 0.3 m) and small scale cylinders (Ø0.15 m x 0.3 m). For this purpose, a novel test set-up was built to test six intermediate scale or twelve small scale specimens simultaneously to ensure a similar heating regime for every specimen. All specimens were fire exposed on one side and remained unrestrained. A size effect occurred for four of the six concrete mixtures. Compared to the full scale specimens the spalling was reduced significantly for all smaller specimen sizes. Additionally, spalling did not occur for the small scale specimens. The results show that the specimen size is an essential parameter to investigate the susceptibility to spalling of a concrete mixture. For future investigations the testing conditions must be adjusted for the intermediate scale specimens to recreate the conditions of the slabs. KW - Concrete KW - Spalling KW - Size effect KW - Fire test PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559231 DO - https://doi.org/10.1617/s11527-022-02051-2 VL - 55 IS - 8 SP - 1 EP - 14 PB - Springer AN - OPUS4-55923 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Michalchuk, Adam T1 - The Mechanochemical Excitation of Crystalline LiN3 N2 - Mechanochemical reactions are driven by the direct absorption of mechanical energy by a solid (often crystalline) material. Understanding how this energy is absorbed and ultimately causes a chemical transformation is essential for understanding the elementary stages of mechanochemical transformations. Using as a model system the energetic material LiN3 we here consider how vibrational energy flows through the crystal structure. By considering the compression response of the crystalline material we identify the partitioning of energy into an initial vibrational excitation. Subsequent energy flow is based on concepts of phonon–phonon scattering, which we calculate within a quasi-equilibrium model facilitated by phonon scattering data obtained from Density Functional Theory (DFT). Using this model we demonstrate how the moments (picoseconds) immediately following mechanical impact lead to significant thermal excitation of crystalline LiN3, sufficient to drive marked changes in its electronic structure and hence chemical reactivity. This work paves the way towards an ab initio approach to studying elementary processes in mechanochemical reactions involving crystalline solids. KW - Energetic materials KW - Ab initio simulation KW - DFT KW - Mechanochemistry PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559310 DO - https://doi.org/10.1039/d2fd00112h SP - 1 EP - 20 PB - Royal Society of Chemistry AN - OPUS4-55931 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Henning, Ricky A1 - Sturm, Patrick A1 - Geddes, D.A. A1 - Keßler, S. A1 - Walkley, B. A1 - Gluth, Gregor T1 - The influence of curing temperature on the strength and phase assemblage of hybrid cements based on GGBFS/FA blends N2 - Hybrid cements are composites made of Portland cement or Portland clinker and one or more supplementary cementitious materials like slag, fly ash or metakaolin, activated with an alkali salt. To date, their hydration mechanism and the phase formation at various temperatures is insufficiently understood, partly due to the large variability of the raw materials used. In the present study, three hybrid cements based on ground granulated blast furnace slag, fly ash, Portland clinker and sodium sulfate, and an alkali-activated slag/fly ash blend were cured at 10 and 21.5°C, and subsequently analyzed by XRD, 27Al MAS NMR, and TGA. The compressive strength of the hybrid cements was higher by up to 27% after 91-day curing at 10°C, compared to curing at 21.5°C. The experimental results as well as thermodynamic modeling indicate that the differences in compressive strength were related to a different phase assemblage, mainly differing amounts of strätlingite and C-N-A-S-H, and the associated differences of the volume of hydration products. While the strätlingite was amorphous to X-rays, it could be identified by 27Al MAS NMR spectroscopy, TGA and thermodynamic modeling. The microstructural properties of the hybrid cements and the alkali-activated slag/fly ash blend as well as the compatibility between thermodynamic modeling results and experimental data as a function of curing temperature and time are discussed. KW - Hybrid cements KW - Strätlingite KW - Thermodynamic modelling KW - Hydration PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557767 DO - https://doi.org/10.3389/fmats.2022.982568 SN - 2296-8016 VL - 9 SP - 1 EP - 16 PB - Frontiers AN - OPUS4-55776 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Prestressed Concrete Structures with Concentrated Tendons - Structural Damage due to Hydrogen-Induced Stress Corrosion Cracking N2 - In the course of the deconstruction of the "Bridge of the 20th anniversary of the GDR" at the Altstädter Bahnhof in Brandenburg a. d. Havel, new information on the initiation of hydrogen-induced stress cracks was obtained. BAM was commissioned by the Brandenburg State Road Administration to participate in a corresponding joint project which is financed by the Federal Ministry for Digital and Transport. The added value of the new information gained in this project goes beyond the specific structure. It describes unexpected new damage patterns that can be transferred to other structures with concentrated tendons (tendon block method and Baur-Leonhardt method) and were previously unknown in this form. These should be made known to other developers to enable them to initiate any necessary actions. T2 - Eurocorr 2022 CY - Berlin, Gemany DA - 29.08.2022 KW - Korrosion KW - Corrosion KW - Hydrogen KW - Stress Cracking PY - 2022 AN - OPUS4-55613 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fürst, Richard A1 - Häßler, Dustin A1 - Hothan, Sascha T1 - Brandversuch eines Stahlzuggliedes mit reaktivem Brandschutzsystem N2 - Das Poster stellt den im Rahmen des Workshops "Feuerwiderstand von Stahlzuggliedern mit reaktiver Brandschutzbeschichtung" durchgeführten Brandversuch vor. T2 - Workshop - Feuerwiderstand von Stahlzuggliedern mit reaktiver Brandschutzbeschichtung CY - Berlin, Germany DA - 06.09.2022 KW - Brandschutz KW - Brandversuch KW - Feuerwiderstand KW - Reaktives Brandschutzsystem PY - 2022 AN - OPUS4-55699 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fürst, Richard A1 - Häßler, Dustin A1 - Hothan, Sascha T1 - Research Project FIRESTEMIC - Results and Recommendations N2 - The presentation summarizes the results of the research project. T2 - Workshop 2022 - Feuerwiderstand von Stahlzuggliedern mit reaktiver Brandschutzbeschichtung CY - Berlin, Germany DA - 06.09.2022 KW - Fire tests KW - Intumescent coating KW - Steel KW - Tension member PY - 2022 AN - OPUS4-55700 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Häßler, Dustin A1 - Hothan, Sascha A1 - Fürst, Richard T1 - Neue Prüfnorm für reaktive Brandschutzsysteme auf Stahlzuggliedern N2 - Der Vortrag stellt den Entwurf der neuentwickelten Prüfnorm vor. T2 - Workshop 2022 - Feuerwiderstand von Stahlzuggliedern mit reaktiver Brandschutzbeschichtung CY - Berlin, Germany DA - 06.09.2022 KW - Feuerwiderstand KW - Brandschutz KW - Stahlzugglieder KW - Reaktives Brandschutzsystem KW - Prüfnorm PY - 2022 AN - OPUS4-55701 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liao, Chun-Man A1 - Petryna, Y. T1 - Damage Assessment of Civil Structures Using Wave Propagation Analysis and Transmissibility Functions N2 - A common damage detection method in civil engineering is to monitor dynamic characteristics such as natural frequencies and modal shapes, which are directly related to the structural stiffness. However, the discrepancy in measured natural frequencies may result from environmental changes, the soil-structure interaction or effects caused by earthquakes. This makes it difficult to decide whether the local change in structural properties is caused by damage or other factors. To address this challenge and thus improve the current damage detection method, the wave propagation analysis method and the transmissibility relationship were considered. In our study, the wave propagation field in structures was reconstructed by applying the Normalized-Input-Output-Minimization (NIOM) method to vibration recordings. Wave velocities and transmissibility functions were considered as reference values for the damage indicators. This paper demonstrates the evaluation of local property changes in two examples of large-scale structures: a 14-story RC building and a 64 m long pedestrian bridge. The proposed damage indicators show a clear correspondence to structural changes. T2 - EVACES2021 9th International Conference on Experimental Vibration Analysis for Civil Engineering Structures CY - Online meeting DA - 14.09.2021 KW - Damage detection KW - Damage indices KW - Normalized-Input-Output-Minimization KW - Transmissibility function KW - Wave propagation PY - 2022 SN - 978-3-030-93235-0 SN - 978-3-030-93236-7 DO - https://doi.org/10.1007/978-3-030-93236-7_2 SP - 3 EP - 13 PB - Springer CY - Cham AN - OPUS4-55565 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jauregui-Correa, J. C. A1 - Otremba, Frank A1 - Hurtado-Hurtado, G. A1 - Romero-Navarrete, J. A. T1 - Experimental test rig for simulating dynamic loads on subway systems N2 - Degradation in substructures, Mexico’s City Subway. Improve predictions using vibration Measurements. Ability to test operating conditions at Laboratory. Improve previous laboratory rig. Control operating conditions. Produce enough data for evaluating actual conditions. T2 - Fifth International Conference on Railway Technology CY - Montpellier, France DA - 22.08.2022 KW - Test rig KW - Simulating KW - Dynamic loads KW - Subway PY - 2022 AN - OPUS4-55568 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Thoralf A1 - Wagner, Adrian A1 - Burkert, Andreas T1 - Field exposure studies of austenitic and duplex stainless steels in tunnel atmospheres N2 - Due to the high corrosivity that are present in road tunnel structures, cleaning and maintenance work on stainless steel components in the tunnels is carried out at regular intervals in the tunnels, which means that parts of the lanes or the whole tunnel have to be temporarily closed. To reduce these traffic disruptions and maintenance costs, it is important to reduce the work that is needed for cleaning and maintenance of stainless steel components in road tunnels. One possibility is the identification and utilization of better suited alternatives to the commonly used austenitic stainless steels AISI 316L and AISI 316Ti. Thus, a field exposure study was carried out in different road tunnels throughout Germany to qualify different duplex and lean duplex stainless steels for tunnel constructions. The proposed scientific poster gives an overview of results after the first three years of exposure in three different road tunnels. Samples of different stainless steels were placed in different areas of the tunnel – at lane height and at the ceiling. Some samples were exposed under sheltered conditions. Pit depths were evaluated on the free surface and in crevice areas after each year of exposure. The investigations show that duplex stainless steels have a comparable or even better corrosion resistance than austenitic steels in tunnel atmospheres. T2 - EUROCORR 2022 CY - Berlin, Germany DA - 28.08.2022 KW - Corrosion KW - Atmosphere KW - Tunnel KW - Stainless Steel PY - 2022 AN - OPUS4-55595 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Moye, Janis A1 - Sturm, Patrick A1 - Kühne, H.-C. A1 - Keßler, S. A1 - Pistol, K. T1 - Entwicklung und Charakterisierung von alkalisch aktivierten Mörteln für die Betoninstandsetzung - Robustheits- und Dauerhaftigkeitsbetrachtungen N2 - Für die flächige Instandsetzung von Stahlbetonkonstruktionen kommen nahezu ausschließlich zementgebundene Systeme mit hohem Zementgehalt zum Einsatz (1). Bereits 2008 war die Zementproduktion für 5% des weltweiten, anthropogenen CO2-Ausstoßes verantwortlich (2). Um die prozessbedingten CO2-Emissionen zu senken, wird der Zement bereits durch gewisse Mengen an Sekundärrohstoffen wie Flugasche, Silicastaub oder Hüttensandmehl (Hochofenschlacke) substituiert. Das Potenzial für weitere Modifikationen ist inzwischen begrenzt (3). Zudem ist eine hohe Lebensdauer der Konstruktionen in vielen Anwendungsbereichen nur bedingt realisierbar. Spätestens mit Erreichen der geplanten Nutzungsdauer müssen Stahlbetonkonstruktionen mit zementgebundenen Systemen instandgesetzt werden, was im ökonomischen und ökologischen Sinne keine nachhaltige Lösung darstellt. Die Verwendung neuer Baustoffe wie alkalisch aktivierte Mörtel hält sich bisher in Grenzen (4), sodass die Akzeptanz durch praxisnahe Forschung adressiert werden muss. Vorangegangene Forschungsergebnisse zeigen, dass alkalisch aktivierte Bindemittel vielversprechende technische Eigenschaften besitzen. So zeigen sich im Vergleich zu herkömmlichem Portlandzement ein ausgesprochen wirkungsvoller Verbund zu Stahl und Zementmörtel (5), (6), eine hohe chemische Beständigkeit sowie ein Erfolg versprechendes Abwitterungsverhalten bei Frost-Tau-Wechseln (7). Mit diesen Eigenschaften können alkalisch aktivierte Mörtel einen erheblichen Beitrag zur dauerhaften Betoninstandsetzung leisten und somit durch die verringerten CO2-Emmissionen dem Prinzip des nachhaltigen Bauens gerecht werden. Wichtig für die Produktion im größeren Maßstab ist die Verfügbarkeit der möglichen Reststoffe, um eine CO2-positivere Bilanz abzubilden. Im Zuge des Forschungsvorhabens sollen Rezepturen für Instandsetzungsprodukte entworfen werden, die auf alkalisch aktivierte industrielle Reststoffe zurückgreifen und die Anforderungen an konventionelle Instandsetzungsprodukte erfüllen. Hierzu wurden potenzielle Ausgangs-stoffe mit Natriumcarbonat aktiviert und die Verarbeitbarkeit der Leime sowie die Druckfestigkeiten nach sieben Tagen verglichen. Hüttensandmehl reagiert ausreichend mit diesem Aktivator, was sich mit Ergebnissen von (8) und (9) deckt. Es werden 〖CO〗_3^(2-)-Ionen in das System eingebaut, was zu einer anfänglichen Erstarrung des Gefüges durch die Bildung von Carbonaten (Calcit und Hydrotalcit) führt. Nach einer längeren dormanten Phase bilden sich zusätzlich Hydratphasen, die die Festigkeit weiter erhöhen. Weiterhin ist die chemische Zusammensetzung der Schlacken für die Erhärtung und die späteren Eigenschaften von großer Bedeutung (10), (11), was mit einer Parameterstudie im laufenden Jahr an natriumcarbonataktivierten Schlacken näher betrachtet werden soll. Erkenntnisse aus vergleichenden Versuchen durch (12) bestätigen die Einflussnahme der chemischen Zusammensetzung. Die übrigen Reststoffe konnten mit anderen Aktivatoren (z. B. Natriumsilicat und -hydroxid) zu einer Reaktion angeregt werden. Im Hinblick auf die Akzeptanz der alkalisch aktivierten Bindemittel stellen diese Aktivatoren jedoch bei der Herstellung höhere technische Anforderungen an das Personal und die verwendeten Geräte im Vergleich zur konventionellen Beton- und Mörteltechnik. Die Aktivierung mittels Alkalicarbonaten ermöglicht die Herstellung von Beton bzw. Mörtel nach dem üblichen „just add water“-Prinzip (13). Aktuell wird unter Einbindung einer studentischen Abschlussarbeit eine Rezeptur mit Hüttensandmehl hinsichtlich der Frisch- und Festeigenschaften charakterisiert und einer Referenzmischung – basierend auf Portlandzement – gegenübergestellt. Hieraus resultierende Ergebnisse sollen neben den Erkenntnissen aus den Vorversuchen zur Konferenz vorgestellt und ein Ausblick auf die weitere Forschungsarbeit gegeben werden. T2 - Nachwuchswissenschaftler*innenkonferenz 2022 CY - Brandenburg an der Havel, Germany DA - 11.05.2022 KW - Alternative Bindemittel KW - Alkalische Aktivierung KW - Instandsetzung KW - Realkalisierung PY - 2022 AN - OPUS4-55517 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rübner, Katrin A1 - Schumann, G. A1 - Hahn, A. A1 - Vöge, M. A1 - Bruch, I. A1 - Schnell, A. T1 - HYTEGRA - Hydrothermalgranulate - Rohstoffliches Recycling von Mauerwerkbruch N2 - Ziel des Projekts HYTEGRA ist die Herstellung leichter Gesteinskörnungen durch hydrothermale Behandlung quarz- und kalkreicher Reststoffe. Als Ausgangsstoffe dienen heterogener Mauerwerkbruch aus Bau- und Abbruchabfällen als SiO2-Träger und Papierasche aus dem Altpapierrecycling als CaO-Träger. Für beide Reststoffe besteht derzeit ein Verwertungsdefizit. Das Verfahren beruht auf der Idee des rohstofflichen Recyclings, d. h. die chemisch-mineralogischen Stoffeigenschaften werden für die hydrothermale Stoffumwandlung genutzt. Bei der Härtung der Hydrothermalgranulate bilden sich Calciumsilicathydrat-Phasen (CSH) aus der Reaktion zwischen Quarzpartikeln und Kalk im Autoklav bei 200 °C und 16 bar Sattdampf. T2 - Innovationstag Mittelstand des BMWK am 22. Juni 2022 CY - Berlin, Germany DA - 23.06.2022 KW - Mauerwerkbruch KW - Papierasche KW - Rohstoffliches Recycling KW - Leichte Gesteinskörnung KW - Bodenfilter PY - 2022 AN - OPUS4-55552 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Potential Mapping - What could we measure and what should we able to detect – guideline B03 of DGZfP N2 - “Electrochemical potential mapping according to guideline B3 of DGZfP (German Society for Non-Destructive Testing) is a recognized technique for the localization of corroding reinforcing steels. Areas of corroding reinforcement steel can be located in a non-destructive manner by means of this procedure. Half‐cell potential measurements are used in order to detect chloride‐induced corrosion. However, it is not recommended in order to assess the risk of carbonation‐induced corrosion. For this purpose, determining the carbonation depth and the concrete cover appears more appropriate. The content of this specification exclusively refers to the application of mobile, local variable reference electrodes, which are only placed on the concrete surface while measuring. The technique distinguishes itself thereby from the range of corrosion monitoring systems with stationary installed reference electrodes and sensor systems, respectively, whereby it is possible to continuously track measurements within the area of the installed electrodes. However, these methods are not dealt with in this specification.” T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Korrosion KW - Potentialfeldmessung KW - Corrosion KW - Half-cell potential KW - Potential mapping PY - 2022 AN - OPUS4-55524 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Feistkorn, S. A1 - Algernon, D. A1 - Arndt, R. A1 - Ebell, Gino A1 - Friese, M. A1 - Grosse, C. U. A1 - Holstein, R. A1 - Niederleithiger, Ernst A1 - Schickert, M. A1 - Schulze, S. A1 - Taffe, A. A1 - Walther, A. A1 - Wolf, J. A1 - Zoega, A. A1 - Zwanzig, M. T1 - Introduction to DIN 4871: Qualification of NDT Personnel in Civil Engineering (NDT‐CE) N2 - Recently, non-destructive testing in civil engineering (NDT-CE), in particular of concrete components, has successfully mastered the leap from research to practice. Several methods have been established for field inspections to determine the concrete cover of reinforcement or to estimate the compressive strength as well as other parameters related to the concrete material. In addition, the application of non-destructive testing is indispensable, if information about the inner structure - such as the location of rebars and tendon ducts or the damage-related condition assessment to detect grouting defects, honeycombs, delamination, or corrosion - is required. Besides the selection of a suitable NDT method and an appropriate inspection system, the reliability of the results depends largely on the person who applies the non-destructive inspection technique and evaluates the inspection results. To ensure a high quality of non-destructive concrete evaluation as well as to keep the uncertainty caused by the inspection personnel to a minimum, structured, consistent, and regulated theoretical as well as practical training of inspection personnel is essential. To close this gap, the subcommittee of education and training (UA-A) within the committee for NDT-CE of the German Society for Non-Destructive Testing (DGZfP) has been reactivated in 2018 to establish uniform training standards for non-destructive concrete inspections in the long term. The subcommittee consists of scientists, practitioners, authorities, and clients. So far, the national standard DIN 4871 “Non-destructive testing - Qualification of NDT personnel in Civil Engineering (NDT-CE)” was developed. This standard considers the civil-industry-specifics, for example, that standards for NDT of concrete, as well as related product standards with a few exceptions, still do not exist at the moment. Within this presentation, the concept, the connection to ISO 9712 and other standards as well as an overview of the recently developed German standard DIN 4871 will be presented. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Non-destrucive testing KW - Civil engineering PY - 2022 AN - OPUS4-55526 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -