TY - JOUR A1 - Bos, Freek A1 - Menna, Constantino A1 - Robens-Radermacher, Annika A1 - Wolfs, Rob A1 - Roussel, Nicolas A1 - Lombois-Burger, Hélène A1 - Baz, Bilal A1 - Weger, Daniel A1 - Nematollahi, Behzad A1 - Santhanam, Manu A1 - Zhang, Yamei A1 - Bhattacherjee, Shantanu A1 - Jia, Zijian A1 - Chen, Yu A1 - Mechtcherine, Viktor T1 - Mechanical properties of 3D printed concrete: a RILEM TC 304-ADC interlaboratory study — approach and main results N2 - To show compliance to structural engineering codes and implement quality control measures, it is critical to obtain reliable mechanical properties of the materials in question. For conventional cast and precast concrete, the experimental procedures and relationships between mechanical properties, the material composition, and the production methods are globally known, but for 3D concrete printing (3DCP), these relations have not yet been established. Previous studies have shown little consistency in results, and the underlying experimental methods have not been established broadly. There is an urgent need to address these issues as the application of 3DCP in practice projects is growing rapidly. Therefore, RILEM TC 304-ADC: Assessment of Additively Manufactured Concrete Materials and Structures has set up a large interlaboratory study into the mechanical properties of 3D printed concrete. This paper presents key elements of the experimental approach detailed in the Study Plan and the supporting considerations. Furthermore, it reports on the response, consisting of 34 contributions from 30 laboratories, detailing global coverage, properties of the applied mixture designs and characteristics of the printing facilities that have been used. Subsequently, some fundamental results from compression, flexural, and E-modulus testing are presented and—considering cast specimens as a reference—discussed. On average, a reduction in strength was found in compression and E-modulus (all tested orientations). For flexure, on the other hand, an increase was found in two testing orientations, while a decrease was observed in the third orientation. Importantly, even though the applied experimental methods were found to be reasonably appropriate to obtain the required data, the differences found between individual contributions are significant and sometimes non-consistent, suggesting that testing on specific material-facility combinations is necessary to reliably determine the mechanical properties of objects produced from them. Furthermore, a theoretical framework needs to be developed to further explain the variations that were observed. Extensive analyses of all acquired data are out of the scope of this contribution, but presented in two associated papers, whereas a third presents the data management approach used to process the approximately 5,000 test results. KW - 3D printed concrete KW - 3DCP KW - Mechanical properties KW - Interlaboratory study PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634631 DO - https://doi.org/10.1617/s11527-025-02686-x VL - 58 IS - 5 SP - 1 EP - 29 PB - Springer Nature AN - OPUS4-63463 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael A1 - Kannengießer, Thomas T1 - Fügetechnik in Wasserstofftechnologien - Forschungsbedarf für die Branche (Kurzversion) N2 - Die Studie gibt einen kurzen Überblick über die jetzige Bedeutung der Fügetechnik in Wasserstofftechnologien und über zukünftige Forschungsbedarfe für die Branche in den einzelnen Technologiefeldern Wasserstofferzeugung, -speicherung, -transport und -nutzung. Fügetechnologien haben dabei wesentliche Bedeutung für die erfolgreiche Umsetzung von technischen Komponenten der Wasserstofftechnologien. Die Schwerpunkte bzw. Forschungsbedarfe ergeben sich bspw. durch die Erstellung neuer Infrastruktur für Wasserstoffspeicherung und -transport sowie durch Umnutzung der bestehenden Erdgasinfrastruktur. Bei der Wasserstofferzeugung und -anwendung wird z.B. die Entwicklung effiziente Massenproduktionsmethoden von Elektrolyseuren und Brennstoffzellen einen wichtigen Meilenstein bilden und laserbasierte Fügetechnologien sind hier zum Teil schon etabliert. Die additive Fertigung nimmt dabei eine Querschnittsposition ein und besitzt hohes Anwendungspotential für die Zukunft z.B. für die Fertigung von Komponenten in Gasturbinen. Aus den technischen Fragestellungen und Forschungsbedarfen ergeben sich zudem Herausforderungen für die notwendige Neu- und Weiterentwicklung von technischen Regelwerken und Normen und den Eingang in die Aus- und Weiterbildung von fügetechnischem Fachpersonal. T2 - DVS Congress 2021 CY - Online meeting DA - 14.09.2021 KW - Wasserstoff KW - Fügetechnik KW - Forschung KW - Werkstoff KW - Bedarf PY - 2021 SN - 978-3-96144-146-4 VL - 371 SP - 612 EP - 624 PB - DVS Media GmbH CY - Düsseldorf AN - OPUS4-53370 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Seifert, Lando A1 - Grunewald, Andreas A1 - Müller, Thoralf A1 - Ebell, Gino T1 - Stress corrosion tests for prestressing steels—Part 1: The influence of surface condition and test solution composition on hydrogen charging N2 - Tests for assessing prestressing steels' susceptibility to hydrogen‐induced stress corrosion cracking are essential for approvals, in‐house monitoring, and third‐party material testing. According to ISO 15630‐3, the time to brittle fracture by constant load under corrosive conditions in thiocyanate test solutions (A or B) at 50°C is measured. In the literature, a high scattering in stress corrosion tests is reported, which questions the integrity of the test procedure. This paper shows the results of studies about the influence of solution composition on hydrogen charging in electrochemical and permeation measurements. Electrochemical experiments show that polished steel surfaces without common drawing layers have more consistent free corrosion currents, polarization resistances, and B‐values in solution A with low scattering compared to the solution B experiments. The influence of temperature at 50°C and an ambient temperature of 22°C was also tested. KW - Drawing layers KW - Hydrogen‐induced stress corrosion cracking KW - Permeation measurements KW - Prestressing steels KW - Stress corrosion tests KW - Surface conditions KW - Test solutions PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598738 DO - https://doi.org/10.1002/maco.202313948 VL - 75 SP - 1506 EP - 1518 PB - Wiley‐VCH GmbH AN - OPUS4-59873 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Rübner, Katrin A1 - Seher, Julia A1 - Müller, Constanze A1 - Müller, Anette A1 - Liebezeit, Steffen A1 - Schnell, Alexander A1 - Martin, Falk ED - Schermer, Detleff ED - Brehm, Eric T1 - REALight - Leichtgranulate und REA-Gips aus feinkörnigen sulfatbelasteten Bau- und Abbruchabfällen und industriellen Nebenprodukten N2 - Die Zielstellung des Forschungsprojekts REALight ist die Entwicklung eines Verfahrens zur Herstellung von Leichtgranulaten auf der Grundlage der Ergebnisse des BMBF-Projekts „Aufbaukörnungen“ unter Erweiterung der Technologie, um Gips zurückzugewinnen und weitere mineralische Einsatzstoffe zu nutzen. In einem thermischen Verfahren werden mineralische Bau- und Abbruchabfälle über ein rohstoffliches Recycling, d. h. einen thermisch-chemischen Stoffumwandlungsprozess, zu leichten Gesteinskörnungen verarbeitet. Dabei werden im Bauschutt vorhandene Sulfate zersetzt. In einer anschließenden Rauchgaswäsche werden die Sulfate abgetrennt. Sie können als Ersatz für REA-Gips verwendet werden. Dies ist Voraussetzung für die Übertragung der Produkt- und Verfahrensidee in die Praxis und für den Nachweis der Sulfatabtrennung und -rückgewinnung aus gipshaltigem Inputmaterial. Es werden Untersuchungen zur Verbreiterung der Rohstoffbasis durch Einkopplung spezifischer mineralischer Stoffströme durchgeführt, die im Ergebnis zu einer Reduktion des Blähmittelbedarfs und einer Absenkung der Brenntemperatur führen sollen. Die Herstellung ausreichender Mengen Leichtgranulate für eine umfassende Charakterisierung nach Norm und die Praxiserprobung in bekannten Anwendungen und neuen Einsatzfeldern ist ein weiteres Projektziel. KW - Bau- und Abbruchabfälle KW - Bauschutt KW - Leichtgranulat KW - Leichte Gesteinskörnung KW - Gipsrückgewinnung PY - 2024 UR - https://www.ernst-und-sohn.de/mauerwerk-kalender-2024-schwerpunkte-klimagerechtes-und-nachhaltiges-bauen-befestigungen-bauen-im?tab=inhalt#rs SN - 978-3-433-03408-8 SP - 515 EP - 518 PB - Ernst & Sohn CY - Berlin AN - OPUS4-60356 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Thoralf 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 - Stainless Steel World Conference & Expo 2023 CY - Maastricht, Netherlands DA - 26.09.2023 KW - Corrosion KW - Atmosphere KW - Tunnel KW - Stainless Steel PY - 2023 AN - OPUS4-58487 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seifert, Lando T1 - Nichtrostender Stahl im Kontakt mit anderen Werkstoffen N2 - Der Beitrag zeigt die Mechanismen, Voraussetzungen und Einflussgrößen der Bimetallkorrosion wichtiger Werkstoffe im Kontakt mit nichtrostenden Stahl anhand von verschiedenen Beispielen. Darüber hinaus wird das Korrosionsverhalten von nichtrostenden Stahl im Kontakt mit Holz als saurer Baustoff und mit Beton als alkalischer Baustoff beschrieben. T2 - VDEh Seminar Korrosionsverhalten nichtrostender Stähle CY - Düsseldorf, Germany DA - 30.01.2024 KW - Bimetallkorrosion KW - Nichtrostender Stahl KW - Saure und alkalische Baustoffe KW - Potentialbeeinflussung der Kontaktpartner PY - 2024 AN - OPUS4-59456 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Constanze A1 - Seher, Julia A1 - Martin, Falk A1 - Schnell, Alexander A1 - Rübner, Katrin T1 - Leichtgranulate aus gemischtem Mauerwerkbruch für die Anwendung in Infraleichtbeton T1 - Lightweight granular materials made from mixed masonry rubble for use in infra-lightweight concrete N2 - Infraleichtbeton zeichnet sich durch eine äußerst geringe Trockenrohdichte von maximal 800 kg/m³ aus, bei gleichzeitig ausreichender Festigkeit. Daraus resultieren geringe Wärme- und Schallleitfähigkeiten. Dies ermöglicht den Einsatz als Sichtbeton in Wandelementen ohne die Notwendigkeit einer zusätzlichen Dämmschicht. Vielversprechend erscheint der Einsatz von Leichtgranulaten in Infraleichtbeton, um seinen ökologischen Fußabdruck zu reduzieren und somit ein energieeffizientes und zugleich nachhaltiges Bauen zu ermöglichen. Die Leichtgranulate werden in einem thermo-chemischen Prozess aus gemischtem Mauerwerkbruch hergestellt. Ihre Verwendung bietet neben der Alternative zu herkömmlichen leichten Gesteinskörnungen auch die Möglichkeit, Abfallprodukte sinnvoll zu nutzen. In diesem Artikel werden die Leichtgranulate vorgestellt, ihre Anwendung in Infraleichtbeton geprüft und mit konventionellem Blähton verglichen. N2 - Infra-lightweight concrete exhibits an extremely low dry bulk density of up to 800 kg/m³ while also providing sufficient strength, resulting in low thermal and acoustic conductivity. This allows it to be used as exposed concrete in wall panels without requiring an additional insulating layer. Using lightweight granular materials in infra-lightweight concrete appears to be promising for reducing its environmental footprint and thus enabling energy-efficient and sustainable construction. Lightweight granules are produced from mixed masonry rubble in a thermo-chemical process. In addition to being an alternative to conventional lightweight aggregates, their use also provides the opportunity to put waste products to good use. This article reports on lightweight granules, their use in infra-lightweight concrete, and related tests in comparison to conventional expanded clay. KW - Infraleichtbeton KW - Leichtgranulat KW - Mauerwerkbruch KW - Recycling KW - Leichte Gesteinskörnungen PY - 2024 VL - 90 IS - 7 SP - 52 EP - 59 PB - Bauverlag CY - Gütersloh AN - OPUS4-60557 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Thoralf T1 - Bericht aus dem ISO-Gremium ISO TC 156 WG4 N2 - Der Vortrag gibt einen Überblick über die Tätigkeiten der Working Group 4 "Atmospheric Corrosion" des ISO Gremiums ISO TC 156 . Es werden neuste Informationen zum Stand verschiedener Normen aus dem Ausschuss wiedergegeben. T2 - GfKorr Gemeinschaftssitzung der AKs "Atmosphärische Korrosion" und "Korrosionsschutz in der Elektronik und Mikrosystemtechnik" CY - Online meeting DA - 05.12.2024 KW - Corrosion KW - Standards KW - Atmospheric Corrosion PY - 2024 AN - OPUS4-62305 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seifert, Lando T1 - Influence of Prestress Level on Susceptibility to HiSCC of Prestressed Steels N2 - The BAM developed a new test method for assessing susceptibility to hydrogen-induced stress corrosion cracking (HiSCC) of prestressed steel, especially for wires. The setup contains polished specimens pre-stressed to a constant 80% Rm stress level. The specimens are constantly charged with hydrogen during the test by an electrochemically applied cathodic current density. The time to brittle fracture is measured. The new test method can provide a sensitive separation between different kinds of susceptible prestressed steel wires by fracture times. This enables further parameter studies with load level and cathodic current density variation. Therefore, known as high-susceptible quenched and tempered prestressing wires of “old-type” (without alloying Cr and manufactured before 1965), Hennigsdorfer and Neptun and currently approved cold-drawn wires were tested. A design of experiments (DOE) statistical model of time to fracture was calculated for the three wires. A significant susceptibility change appears in specific load level ranges, this is the contribution of this EUROCORR lecture. T2 - Conference EUROCORR 2024 CY - Paris, France DA - 01.09.2024 KW - Prestressing Steels KW - ISO 15630-3 KW - Hydrogen-induced Stress Corrosion Cracking KW - Brittle Fracture KW - Hydrogen Charging PY - 2024 AN - OPUS4-60988 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino A1 - Müller, Thoralf A1 - Burkert, Andreas ED - G. Pillai, R. T1 - Stress Corrosion Cracking in Prestressed Concrete Bridge – A Case Study N2 - Bridge structures built using the prestressing block method can exhibit hydrogen-induced stress cracks across the entire cross-section of a prestressing channel due to their design. Crack growth can progress over the service life as a result of dynamic loading and lead to prestressing wire fractures. T2 - Consec 2024 CY - Chennai, India DA - 25.09.2024 KW - Corrosion KW - Spannungsrisskorrosion KW - Stress corrosion cracking KW - Hydrogen KW - Spannstahl PY - 2024 SP - 72 EP - 78 CY - Chennai AN - OPUS4-61330 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Characteristic Frequencies of Train-Induced Bridge, Track, Ground and Building Vibrations – Excitation and Mitigation N2 - The characteristic frequencies of train-induced vibrations are discussed in theory and experiment following the propagation of vibrations from the source to the receiver: 1. Out-of-roundness frequencies of the wheels, 2. sleeper-passage frequency, 3. the vehicle-track eigenfrequency, 4. band frequency of the impulses of the passing static axle loads, 5. car-length frequency and multiples, 6. axle-distance frequencies with two characteristic zeros, 7. bridge eigenfrequencies, 8. the cut-on frequency due to the layering, and 9. the cut-off frequency due to the material damping of the soil, 10. the building-soil eigenfrequency, 11. as a rigid building or flexible wall/column mode, 12. floor eigenfrequencies, 13. acoustic room resonances, 14. the „resonance“ frequency or cut-off frequency of a base isolation. Coincidences of some of these characteristic frequencies or frequency ranges can be typically problematic and mitigation measures at the track or at the building can be necessary. The bridge response to the passing static loads is deter¬mined by the axle-sequence spectrum, the eigenfrequency (transfer function) of the bridge, and the modal force or mode shape spectrum. The ground vibration has typically high frequencies for a stiff soil and low frequencies for a soft soil. The high amplitudes between the zeros of the axle-sequence spectrum are often measured in the ground vibrations, and they can be mitigated by soft support elements or a higher bending stiffness of the track. T2 - EVACES 2025 CY - Porto, Portugal DA - 02.07.2025 KW - Train-induced vibration KW - Axle-sequence spectrum KW - Vehicle-track eigenfrequency KW - Axle impulses PY - 2025 AN - OPUS4-63654 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Burkert, Andreas A1 - Müller, Thoralf A1 - Lehmann, Jens T1 - Langzeitkorrosionsverhalten nichtrostender Stähle in maritimer Atmosphäre N2 - Durch Fortführung der Untersuchungen aus einem Forschungsvorhaben wurden neun verschiedene Stahllegierungen unter maritimen Umgebungsbedingungen über fünf Jahre ausgelagert und deren Korrosionsverhalten untereinander verglichen und bewertet. Die parallele Untersuchung von vier verschiedenen 0berflächenausführungen der jeweiligen Legierungen ermöglichte zudem branchenspezifische Besonderheiten der Oberflächenausführung beim Werkstoffvergleich zu berücksichtigen. Anhand der Ergebnisse der Auslagerungsprüfungen konnten Rückschlüsse auf die Einflüsse der Legierungszusammensetzung, der 0berfächenausführung und der Auslagerungszeit unter maritimen Auslagerungsbedingungen gewonnen werden. Die Proben der drei untersuchten Duplexwerkstoffe zeigten über den Auslagerungszeitraum von fünf 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 CY - Hamburg, Germany DA - 25.01.2017 KW - Korrosionsschutz KW - Nichtrostende Stähle KW - Auslagerungsversuche PY - 2017 SN - 978-3-935406-64-2 SP - 7 EP - 20 AN - OPUS4-39054 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Burkert, Andreas T1 - Nichtrostende Stähle - Werkstoffauswahl entsprechend aktueller Regelwerke N2 - Bei richtiger Werkstoffauswahl ist die Sicherstellung des Korrosionsschutzes über 100 Jahre kein Problem. Regelungen zur Werkstoffauswahl sind in der DIN EN 1993-1-4:10-2015 enthalten. Korrosionsprobleme an nichtrostenden Stählen im Bauwesen sind überwiegend optische Probleme. Ursachen sind unsachgemäße Verarbeitung, ungeeignete Oberflächenausführung, fehlende Grund- und Unterhaltsreinigung. Kontakt von NIRO zu anderen Baustoffen oder mit anderen Werkstoffen ist im Bauwesen meist unproblematisch. In besonders korrosiven Atmosphären bei der Planung einen Fachmann hinzuziehen. T2 - BWM Thementage CY - Leinfelden, Germany DA - 17.11.2016 KW - Dauerhaftigkeit KW - Korrosion KW - Verarbeitung PY - 2016 AN - OPUS4-38413 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Burkert, Andreas T1 - Bedingungen für den schadensfreien Einsatz von nichtrostenden Stählen N2 - Unter Passivität versteht man den Korrosionsschutz durch dünne, festhaftende Schichten aus Korrosionsprodukten. Für den schadensfreien Einsatz nichtrostender Stähle ergeben sich daraus zwei grundsätzliche Anforderungen, die stets erfüllt sein müssen. Erstens muss sich die Passivschicht vollständig ausbilden können. Dabei sind die Oberflächenausführung,die mechanische Bearbeitung,die Elementverteilung, Ausscheidungen, die Wärmeeinbringung z.B. bei der schweißtechnischen Verarbeitung, Anlauffarben, sowie die chemische Nachbehandlung bzw. Konditionierung der Oberflächen von großer Bedeutung. Zweitens muss die Repassivierung von möglichen Defektstellen unter den Einsatzbedingungen möglich sein. Für das Repassi-vierungsvermögen sind die Legierungszusammensetzung, mögliche kritische Betriebszustände, prozessbedingte Besonderheiten wie etwa Stagnationsbedingungen und Reinigungsprozesse von Bedeutung. T2 - Nichrostende Stähle - Eigenschaften und Anwendungen CY - Düsseldorf, Germany DA - 05.06.2018 KW - Dauerhaftigkeit KW - Korrosionsverhalten KW - Passivität KW - Werkstoffauswahl PY - 2018 AN - OPUS4-45136 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Burkert, Andreas T1 - Korrosion von Edelstahl Rostfrei N2 - Zu Sicherstellung der dauer-haften Korrosionsbeständigkeit nichtrostender Stähle im Bereich von Abwasseranlagen sind komplexe Einflussfaktoren zu Berücksichtigen. Dazu gehören eine geeignete Werkstoffauswahl und Legierungszusammensetzung, fehlerfreie und ggf. speziell zertifizierte Halbzeuge, eine gleichmäßige Elementverteilung insbesondere die Vermeidung chromreicher Ausscheidungen, eine geeignete Umformung, möglichst wenig Wärme-einbringung; eine glatte Oberflächenausführung, eine gute schweißtechnische Verarbeitung und die nachträgliche Entfernung von Anlauffarben, eine geeignete mechanische Bearbeitung (Schleifen, Strahlen) und chemische Nachbehandlung (Beizen, Passivieren) sowie eine ausreichende Grundreinigung und eine angepasste Unterhaltsreinigung. T2 - DWA Seminar Korrosion in Abwasseranlagen CY - Soltau, Germany DA - 22.08.2017 KW - Abwasser KW - Werkstoffauswahl KW - Korrosion PY - 2017 AN - OPUS4-41591 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Thoralf T1 - Grundlagen der Korrosion N2 - Darstellung der Grundlagen der elektochemischen Korrosion von metallischen Werkstoffen im Bauwesen T2 - Schulung von Masterstudenten der BHT Berlin CY - BAM TTS, Horstwalde, Germany DA - 26.10.2017 KW - Korrosion PY - 2017 AN - OPUS4-42711 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Thoralf A1 - Ebell, Gino ED - Ebell, Gino T1 - Grundlagen der Korrosion N2 - Darstellung der Grundlagen der elektochemischen Korrosion von metallischen Werkstoffen im Bauwesen T2 - Lehrgang zum Erwerb des Sachkundenachweises zur Durchführung von Potentialfeldmessungen CY - Berlin, Germany DA - 11.06.2018 KW - Korrosion KW - Potentialfeldmessung PY - 2018 AN - OPUS4-45183 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Thoralf T1 - Grundlage der Korrosion N2 - Darstellung der Grundlagen der elektochemischen Korrosion von metallischen Werkstoffen im Bauwesen T2 - Lehrgang zum Erwerb des Sachkundenachweises zur Durchführung von Potentialfeldmessungen CY - Berlin, Germany DA - 11.06.2018 KW - Korrosion KW - Potentialfeldmessung PY - 2018 AN - OPUS4-45189 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hofmann, Detlef A1 - Basedau, Frank A1 - Pötschke, Samuel A1 - Breithaupt, Mathias T1 - Funktionsprinzip faseroptischer Sensoren N2 - Das Poster präsentiert die Grundlagen zur Funktionsweise optischer Fasern bzw. faseroptischer Sensoren, die im Rahmen eines Feldversuchs zum Einsatz kommen. T2 - Tag der offenen Tür auf dem Testgelände der BAM (BAM TTS) CY - Horstwalde, Germany DA - 29.09.2018 KW - Faseroptische Sensorik KW - Verteilte Messverfahren KW - Quasi-verteilte Messverfahren PY - 2018 AN - OPUS4-46333 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Thoralf 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 - JOUR A1 - Auersch, Lutz T1 - Mitigation of railway-induced ground vibration by soft support elements and a higher bending stiffness of the track N2 - The mitigation of train-induced ground vibrations by track solutions is investigated by calculations and measurements. The calculation by a wavenumber domain method includes the correct vehicle–track interaction and the correct track–soil interaction. Some theoretical results for elastic elements and an increased bending stiffness of the track are presented where the force transfer of the track and the vehicle–track interaction are calculated for the high-frequency dynamic mitigation, and the force distribution along the track is calculated for the low-frequency mitigation which is due to the smoother impulses from the passing static loads. Measurement results for the ground vibration near isolated and un-isolated tracks are given for several under-sleeper pads, for under-ballast mats, and for several under-ballast plates and ballast troughs. The elastic elements yield a resonance frequency of the vehicle–track–soil system and a high-frequency reduction of the dynamic axle loads which depends mainly on the softness of the pads or mats and which can be improved by a higher sleeper mass. In addition, all troughs and most of the soft elements show a low-frequency reduction which is attributed to the scattered impulses of the static axle loads. Besides this main contribution of the article, the problem of a soft reference section on a different soil is discussed and recommendations for better ground vibration measurements of mitigation effects are given. KW - Railway track KW - Elastic elements KW - Bending stiffness KW - Ground vibration KW - Mitigation KW - Lowfrequency reduction KW - Axle impulses PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612568 DO - https://doi.org/10.3390/app14031244 VL - 14 IS - 3 SP - 1 EP - 14 PB - MDPI CY - Basel AN - OPUS4-61256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - Some resonance effects of non-typical trains and railway bridges investigated by a frequency-domain method N2 - The resonances of railway bridges have often been analysed for short bridges under periodical high-speed trains, for simply supported one-span bridges, for the fundamental bridge mode, and by time-domain analyses. Many time-consuming calculations have been performed to establish simplified rules for standards. In this contribution, the passage of different (existing, new and hypothetic) trains over different (simply supported, integral, multi-span, continuous) bridges will be analysed in frequency domain by using three separated spectra with the purpose to get a better physical insight in the phenomena. At first, the excitation spectrum of the modal forces is built by the mode shape and the passage time of the train over the bridge. The second spectrum is the frequency response function of the bridge which include the modal frequency, damping and mass. The third part is the spectrum of the axle sequence of an arbitrary train which is not limited to periodical or specific (conventional, articulated, regular or standard) trains and which does not include any bridge parameters. The final solution in frequency domain is obtained as the product of these three complex, strongly varying spectra for the dominating bridge mode or in general as the sum of these products over all relevant bridge modes. The time domain solution is obtained via the inverse Fourier transform, and the resulting time histories have been successfully compared with some measurement results. The method is applied to the vertical and torsional modes of a mid-long single-span bridge on elastomeric bearings under standard train speeds, to a short two-span bridge under high-speed traffic, and to a long three-span integral bridge under long periodical freight trains. Different resonance and cancellation effects have been found for systematically varied train speeds according to the axle sequence of the whole train which is dominated by the two locomotives in that case. To be more specific, the first torsional mode of the mid-span bridge is excited for a train speed of 100 km/h whereas the second bending mode is excited for a train speed of 160 km/h. In both cases, the other mode is suppressed by the minima of the axle-distance spectra. In addition, the case of the German high-speed train ICE4, a Maglev train on a viaduct, and the very high-speed hyperloop case will be discussed briefly. In general, it is shown that resonance effects are also worth to be studied for freight and passenger trains with lower speeds. KW - Rail bridge KW - Resonance KW - ICE4 KW - MAGLEV KW - Hyperloop KW - Continuous bridge KW - Multi-span bridge PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612595 DO - https://doi.org/10.1088/1742-6596/2647/25/252014 VL - 2647 SP - 1 EP - 11 PB - IOP Publishing AN - OPUS4-61259 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Railway vibration – fast physics-based models for the prediction of ground vibration and the identification of track damage N2 - The following applications of machine learning will be discussed: 1. The prediction of the wave propagation from a railway line (completely physics based for surface lines, physics-based machine learning for tunnel lines) 2. The track behaviour for the emission of train-induced ground vibration (physics based for homogeneous soil, machine learning for layered soil) 3. Track damage detection and quantification from frequency response functions and moving load responses 4. Bridge damage detection and localisation from modal analysis and moving load 5. The use of axle-box acceleration for the identification of track/sub-soil condition and bridge resonances. The prediction of railway vibration usually needs time-consuming finite element, boundary element and wavenumber domain calculations. For a user-friendly prediction software however, fast calculations are needed. Several time-consuming detailed calculations have been used to develop simpler and fast models for the surface railway lines. The more challenging prediction from tunnel lines will be attacked by purely mathematical and by physics-informed machine learning. The dynamic stiffnesses of isolated or un-isolated railway tracks from detailed calculations with a continuous soil have been approximated with the simpler Winkler soil. The vehicle-track resonance (P2 resonance) rules the effect of the mitigation measures, and it can also be used for the on-board monitoring of the track and sub-soil condition. For the identification of track damage such as gaps between sleepers, track slabs and layers, detailed models with a continuous soil have been updated to get the best fit to the measured frequency response functions from hammer tests and the deformation pattern from the moving load response. Whereas the track damage can be locally identified, this is more difficult for bridges where the modal analysis gives mainly global information. The influence lines of the inclination for statically passing vehicles (locomotive, truck, compaction roller) have been used to localise bridge damage (stiffness variations). The on-board monitoring of rail bridges needs special conditions (regular trains with special speeds) to excite and measure the bridge resonance. T2 - 11th European Workshop on Structural Health Monitoring (EWSHM 2024) CY - Potsdam, Germany DA - 10.06.2024 KW - Vibration prediction KW - Track damage detection KW - Human and machine learning KW - Wave propagation KW - Surface line KW - Tunnel KW - Bridge resonance PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612462 DO - https://doi.org/10.58286/29865 SN - 1435-4934 SP - 1 EP - 9 PB - NDT.net CY - Kirchwald AN - OPUS4-61246 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hering, Marcus A1 - Agasty, Amit A1 - Costard, René A1 - Hüsken, Götz A1 - Chruscicki, Sebastian A1 - Hicke, Konstantin T1 - Explosion effects on reinforced concrete structures – A preliminary study of scaling laws N2 - Blast tests are required to investigate accidental or intentional blast events and to assess the level of protection for people and facilities in critical infrastructures. Conducting large-scale field tests for complex scenarios is very resource intensive. Reliable small-scale experiments are a promising alternative. However, the scaling laws for the design of reinforced concrete structures under blast loads are not sufficiently established. In our research work, a consortium made up of three BAM departments, focuses on reinforced concrete structures that are suitable for the standardization of scaled blast tests. As part of the feasibility study, blast tests were carried out on test specimens of different sizes on the BAM Test Site for Technical Safety (TTS). Various reinforced concrete plates were tested and subjected to different blast loads. The blast tests included various measurement techniques to quantify the blast load and the behavior of the reinforced concrete plate. The blast load was measured with flush-mounted piezoelectric pressure gauges, while accelerometers and embedded fiber optic sensor cables were used to characterize the dynamic behavior of the plate under blast loading. In addition, damage characteristics were also determined using distributed fiber optic sensing. The application of these measurement techniques as well as the use of different numerical software tools offer the possibility to verify or adapt the scaling laws. T2 - 19th International Symposium on Interaction of the Effects of Munitions with Structures (19th ISIEMS) CY - Bonn, Germany DA - 09.12.2024 KW - Scaling KW - Blast KW - Fiber optic sensing PY - 2024 SP - 1 EP - 9 AN - OPUS4-62258 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agasty, Amit T1 - Replica scaling of RC slabs under blast loading: a preliminary assessment N2 - Blast testing is undoubtedly the most straightforward and direct method of evaluating the blast resistance of a structure. For the calibration and validation of numerical models as well, blast tests must be carried out. However, true-scale prototype testing under different blast loading scenarios is not always feasible. Reliable small-scale experiments are a promising alternative. Application of dimensional analysis and similarity principals can be found in different engineering fields. For applications to the phenomenon of shock wave propagation, Hopkinson-Cranz or cube-root scaling is a well-established concept. When it comes to the scaling the structural response, research has predominantly focused on structures made of metallic materials. Scaled investigations with concrete or reinforced concrete (RC) structures remain limited, specifically under blast loading. In a preliminary study, we tested RC slabs at two different scales under near-field blast loading. Replica scaling, which is geometrical scaling while using the same materials at different scales, was implemented in the construction of the test specimens. The assessment of scaling and the discrepancy in its application was investigated by characterizing the blast loads, dynamic response, and damage. The experiments were supplemented by numerical simulations of these scenarios. The quantification of scenario-and-response-specific discrepancy can be used to modify the scaling laws, so that a blast assessment can be performed based on resource efficient small-scale tests. T2 - 25th International Physical Security Forum CY - Schwarzenburg, Switzerland DA - 11.05.2025 KW - Blast KW - RC slabs KW - Scaling PY - 2025 AN - OPUS4-63184 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agasty, Amit A1 - Hering, Marcus T1 - Experimental and Numerical Analysis of Reinforced Concrete Structures Under Blast Loading: Scopes and Challenges N2 - Protection against terrorist or accidental scenarios in industrial settings requires suitable designs of structures to resist blast loads. Field testing as well as finite element simulations are among the techniques available to engineers in the understanding of the structural behavior against blast loading. As blast testing of complex scenarios can be very resource intensive, tests are generally performed for simplified scenarios. Numerical tools can be used to model these scenarios in order to get a better insight into blast loading, structural response and the resulting damage to the structure. In the next steps, the simplified scenario is successively modified in numerical simulations to incorporate complexities that cannot be covered in blast testing experiments. One of the conditions for this approach to work is that the original simplified numerical simulation is valid. The scopes and challenges encountered in such a validation are the focus of this presentation. A relatively ‘simple’ field test of a horizontal reinforced concrete (RC) slab subjected to blast loading is taken as an example for validation of the performance of numerical tools. The blast test incorporated various measurement techniques to quantify the blast load as well as the behavior of the RC slab. Blast load was measured using flush-mounted piezoelectric pressure gauges, whereas acceleration sensors and fiber-optic sensor cables were used to characterize the dynamic behavior of the slab under blast loading. Additionally, damage characteristics were ascertained also using fiber-optic sensing. The application of such measurement techniques, along with different numerical software available for the analysis of the scenario in question, demonstrate the scope of our contribution. T2 - 24th International Physical Security Forum Brussels CY - Brussels, Belgium DA - 15.04.2024 KW - Blast KW - Reinforced Concrete Structures KW - Numerical simulations PY - 2024 AN - OPUS4-60880 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hering, Marcus T1 - Explosion effects on reinforced concrete structures: A preliminary study of scaling laws N2 - Blast tests are required to investigate accidental or intentional blast events and to assess the level of protection for people and facilities in critical infrastructures. Conducting large-scale field tests for complex scenarios is very resource intensive. Reliable small-scale experiments are a promising alternative. However, the scaling laws for the design of reinforced concrete structures under blast loads are not sufficiently established. In our research work, a consortium made up of three BAM departments, focuses on reinforced concrete structures that are suitable for the standardization of scaled blast tests. As part of the feasibility study, blast tests were carried out on test specimens of different sizes on the BAM Test Site for Technical Safety (TTS). Various reinforced concrete plates were tested and subjected to different blast loads. The blast tests included various measurement techniques to quantify the blast load and the behavior of the reinforced concrete plate. The blast load was measured with flush-mounted piezoelectric pressure gauges, while accelerometers and embedded fiber optic sensor cables were used to characterize the dynamic behavior of the plate under blast loading. In addition, damage characteristics were also determined using distributed fiber optic sensing. The application of these measurement techniques as well as the use of different numerical software tools offer the possibility to verify or adapt the scaling laws. T2 - 19th International Symposium on Interaction of the Effects of Munitions with Structures (19th ISIEMS) CY - Bonn, Germany DA - 09.12.2024 KW - Blast KW - Fiber optic sensing KW - Scaling PY - 2024 AN - OPUS4-62260 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Costard, René T1 - Auswirkungsbetrachtungen auf Strukturen T1 - Scaling of Blast Effects on Reinforced Concrete Structures N2 - Protection against terroristic or accidental scenarios in industrial settings requires suitable designs of structures to resist blast loads. Field testing as well as finite element simulations are among the techniques available to engineers in the understanding of the structural behavior against blast loading. As blast testing of complex scenarios can be very resource intensive, tests are generally performed for simplified scenarios. Numerical tools can be used to model these scenarios to get better insight into blast loading, structural response, and the resulting damage to the structure. During the next steps, the simplified scenario is successively modified in numerical simulations to incorporate complexities that cannot be covered in blast testing experiments. One of the conditions for this approach to work is that the original simplified numerical simulation is valid. The scopes and challenges encountered in such a validation are the focus of this presentation/article. A relatively ‘simple’ field test of a horizontal reinforced concrete (RC) slab subjected to blast loading is taken as an example for validation of the performance of numerical tools. The blast test incorporated various measurement techniques to quantify the blast load as well as the behavior of the RC slab. Blast load was measured using flush mounted piezoelectric pressure gauges, whereas acceleration sensors and fiber-optic sensor cables were used to characterize the dynamic behavior of the slab under blast loading. Additionally, damage characteristics were ascertained also using fiber optic sensing. The application of such measurement techniques, along with different numerical software available for the analysis of the scenario in question, demonstrate the scope of our contribution. When it comes to the challenges, it begins with proper instrumentation of the test specimen followed by the data processing. For numerical modelling, geometric conditions with appropriate boundary constraints, physical conditions such as the configuration of the rebars, as well as material parameters add to this challenge. The issues of choosing appropriate material models and comparison of results with multiple software tools will be discussed. This discussion forms the basis for a coherent approach to technical-safety assessment of blast effects on structures in its broader sense. T2 - Beiratssitzung Infrastruktur CY - Berlin, Germany DA - 11.04.2024 KW - Blast KW - Scaling KW - Fiber optic sensing KW - CFD KW - FEM PY - 2024 AN - OPUS4-59849 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agasty, Amit T1 - Numerical simulations and field validation tests for shock waves’ propagation N2 - At the BAM test range in Horstwalde a number of field trials were conducted with a HE to investigate the free field propagation of shock waves and that resulting from reflection at structure surfaces. In addition, the behavior of the structure under the effect of the dynamic pressure waves after explosion was studied. For both the tests, (a) with a 30 cm thick reinforced-concrete wall and (b) in free field, pressure was measured over the entire test duration with piezoelectric sensors at distances of 5, 10 and 15 m from the detonation center for a range of HE quantities. Apart from this, high speed footage of the tests was recorded as well. Corresponding to the field tests, numerical simulations of HE detonation were performed using APOLLO BLASTSIMULATOR, a CFD tool developed by Fraunhofer Institute for High-Speed Dynamics, Ernst-Mach-Institute. The accuracy of the simulation results as well as the computing times depend on the spatial grid resolution. The outputs of grid-independence study demonstrated that the peak pressure is higher and the pressure-rise is steeper for simulation runs with a finer grid. Remarkably however, the exponential pressure decline is independent of the grid resolution. Advantage was taken of this feature to obtain improved peak pressure values from comparatively coarser grids, in that curve-fitting was performed using the Friedlander Equation, which is well documented in literature. The simulation results for pressure-time histories were compared with the field-test results at the corresponding measurement positions. The two data sets showed good correlation in case of scaled distances greater than 5 [m/kg1/3] for both peak pressure and impulse values. This conclusion could be drawn for both trial-types: free-field and with reflection wall. The near field region, on the other hand, necessitates further investigation for the validation of numerical simulation. T2 - New Trends in Research of Energetic Materials CY - Pardubice, Czech Republic DA - 18.04.2018 KW - Numerical simulation KW - Field-tests KW - Shock waves KW - Friedlander curve PY - 2018 AN - OPUS4-46301 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maack, Jürgen A1 - Eidenmüller, Moritz A1 - Auersch, Lutz T1 - Prognose von Erschütterungs- und Sekundärschall- Immissionen an Bahnlinien unter Verwendung von FEM Gebäudemodellen N2 - Die Errichtung von Wohngebäuden an Bahnstrecken erfordert Betrachtungen zur Begrenzung der Erschütterungs- und Sekundärschallimmissionen. Hierzu werden spektrale Prognoseverfahren ausgehend von Freifeldmessungen eingesetzt. Im rechnerischen Modell werden die Teilaspekte der Körperschallübertragung mit Hilfe von spektralen Übertragungsfunktionen beschrieben. Kenntnis über die Zusammenhänge dieser spektralen Übertragungsfunktionen erhält man im Wechselspiel von: - Messergebnissen von Körperschall- und Luftschallmessungen für einzelne Übertragungssysteme - Modellberechnungen mit der Finite-Elemente-Methode, Parameterstudien, Abgleich mit Messergebnissen - Modellberechnung mit der Finite-Elemente-Methode zur Wechselwirkung des schwimmenden Estrichs mit dem Gebäude T2 - VDI-Tagung Baudynamik CY - Würzburg, Germany DA - 02.04.2025 KW - Bahnerschütterungen KW - Gebäudemodelle KW - Schwimmender Estrich KW - Sekundärschall PY - 2025 SN - 978-3-18-092447-2 SN - 0083-5560 VL - 2447 SP - 301 EP - 314 PB - VDI-Verlag CY - Düsseldorf AN - OPUS4-62887 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Erschütterungsprognose mit KI? Schnelle Ersatzmodelle und physikbasiertes maschinelles Lernen in der Bauwerk-Boden-Dynamik N2 - Erschütterungsprognosen können mit sehr detaillierten Modellen durchgeführt werden. Dies ist sowohl bei der Erstellung des Modells (zum Beispiel für ein Finite-Element-Modell für Boden und Bauwerk), als auch bei der Berechnung zeitaufwändig, von einigen Minuten für die Wellenausbreitung in geschichteten Böden mit Wellenzahlintegralen bis zu mehreren Stunden für Randelementlösungen für die korrekte Bauwerk-Boden-Wechselwirkung. Hier sind einfache und schnelle Ersatzmodelle von Vorteil, die die Ergebnisse der detaillierten Berechnungen gut wiedergeben. Diese Ersatzmodelle können vollständig auf physikalischen Überlegungen beruhen (white-box Modelle) oder mit Hilfe von maschinellem Lernen aus einer Vielzahl von detaillierten Rechenergebnissen erzeugt werden (black-box Modelle). Erfahrungen mit black-box Modellen zeigen, dass es sinnvoll ist das maschinelle Lernen mit physikalischen Informationen anzureichern (grey-box Modelle). Es werden Anwendungsmöglichkeiten für physikbasiertes maschinelles Lernen im Bereich von Bahnerschütterungen aufgezeigt, die Erschütterungsemission durch die Fahrzeug-Fahrweg-Wechselwirkung, die Wellenausbreitung im Boden, die Erschütterungsimmission in Gebäude, Gleisschäden und das Monitoring von Eisenbahnbrücken. T2 - VDI-Tagung Baudynamik CY - Würzburg, Germany DA - 02.04.2025 KW - Bahnerschütterungen KW - Emissionsmodell KW - Immissionsmodell KW - Transmissionsmodell KW - Tunnelausbreitung KW - Gleisüberwachung PY - 2025 SN - 978-3-18-092447-2 SN - 0083-5560 VL - 2447 SP - 53 EP - 64 PB - VDI-Verlag CY - Düsseldorf AN - OPUS4-62886 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Erschütterungsprognose mit KI? Schnelle Ersatzmodelle und physikbasiertes maschinelles Lernen in der Bauwerk-Boden-Dynamik N2 - Erschütterungsprognosen können mit sehr detaillierten Modellen durchgeführt werden. Dies ist sowohl bei der Erstellung des Modells (zum Beispiel für ein Finite-Element-Modell für Boden und Bauwerk), als auch bei der Berechnung zeitaufwändig, von einigen Minuten für die Wellenausbreitung in geschichteten Böden mit Wellenzahlintegralen bis zu mehreren Stunden für Randelementlösungen für die korrekte Bauwerk-Boden-Wechselwirkung. Hier sind einfache und schnelle Ersatzmodelle von Vorteil, die die Ergebnisse der detaillierten Berechnungen gut wiedergeben. Diese Ersatzmodelle können vollständig auf physikalischen Überlegungen beruhen (white-box Modelle) oder mit Hilfe von maschinellem Lernen aus einer Vielzahl von detaillierten Rechenergebnissen erzeugt werden (black-box Modelle). Erfahrungen mit black-box Modellen zeigen, dass es sinnvoll ist das maschinelle Lernen mit physikalischen Informationen anzureichern (grey-box Modelle). Es werden Anwendungsmöglichkeiten für physikbasiertes maschinelles Lernen im Bereich von Bahnerschütterungen aufgezeigt, die Erschütterungsemission durch die Fahrzeug-Fahrweg-Wechselwirkung, die Wellenausbreitung im Boden, die Erschütterungsimmission in Gebäude, Gleisschäden und das Monitoring von Eisenbahnbrücken. T2 - VDI-Tagung Baudynamik CY - Würzburg, Germany DA - 02.04.2025 KW - Bahnerschütterungen KW - Emissionsmodell KW - Immissionsmodell KW - Transmissionsmodell KW - Tunnelausbreitung KW - Gleisüberwachung PY - 2025 AN - OPUS4-62889 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Skłodowska, Anna T1 - Basics in acoustic emission N2 - A lecture on the basics of Acoustic Emission testing. The lecture provides a general overview of the method, its history, and its applications, followed by an explanation of instruments, measurement processes, and signal characteristics. In the second part, the presentation focuses on different types of data analysis - parameter- and signal-based approaches. At the end of the lecture, a brief overview of the source localization methods is given, focusing on Geiger's method. T2 - USES2 - MSCA Doctoral Network CY - Online meeting DA - 18.11.2024 KW - Acoustic Emission KW - NDT KW - Source localization PY - 2024 UR - https://www.youtube.com/watch?v=BmJt6qhRfV4 AN - OPUS4-63288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Skłodowska, Anna T1 - Acoustic Emission in Research and Practice: Basics, Tools, and Applications N2 - A lecture on the basics of Acoustic Emission (AE) testing in research and practice. The lecture provides a general overview of the basics of AE: what is it? What are the AE sources? How and using which equipment it can be detected? The second part of the presentation focuses on different types of data analysis: parameter- and signal-based approaches and gives a brief overview of the source localization methods, focusing on Geiger's method. The last part of the presentation shows application examples in research and in real-structures monitoring. T2 - CoDA Winter School 2025 and the 12th CoDA Plenary meeting CY - Garmisch-Partenkirchen, Germany DA - 03.03.2025 KW - Acoustic Emission KW - Source localization KW - SHM KW - Concrete PY - 2025 AN - OPUS4-63289 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Skłodowska, Anna T1 - First Characterization of MEMS Acoustic Emission Sensors for Concrete Monitoring N2 - Acoustic emission (AE) monitoring in concrete structures typically relies on bulky and expensive piezoelectric (PZT) sensors. In this study, we present an initial characterization of compact, low-cost MEMS AE sensors, comparing them with commercially available AE sensors and custom-built high-sensitivity low-cost (HSLC) resonant PZT disc sensors. This study evaluates whether MEMS sensors, traditionally used in metal applications, can be effectively adapted for concrete monitoring. Initial testing involves the evaluation of MEMS sensors mounted on a concrete specimen, using AE events simulated by pencil lead breaks (PLB) on the surface and by actuators embedded within the concrete medium. Despite their lower sensitivity, the MEMS sensors successfully detect AE signals even at frequencies away from their resonance, demonstrating potential for use beyond their originally intended applications in metals. Their narrowband, repeatable response resembles that of resonant PZT sensors commonly used for detecting damage initiation and locating sources. These preliminary results highlight the potential of MEMS sensors in AE monitoring of concrete, especially in applications where size, cost, and sensor-to-sensor consistency are important, and where signal characteristics fall within their tunable frequency range. T2 - Acoustic Emission Working Group meeting AEWG-65 CY - Chicago, IL, USA DA - 13.05.2025 KW - Acoustic Emission KW - MEMS KW - HSLC sensor KW - HSLC KW - concrete KW - SHM PY - 2025 AN - OPUS4-63287 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz ED - Papadrakakis, Manolis T1 - Frequency-wavenumber method for the wave propagation through the soil and the soil-structure interaction of railway tracks and building foundations near railway lines N2 - In soil-structure interaction, the soil and the (flexible) structures are modelled as elastic continua. The partial differential equations of elasticity can be transformed to algebraic equations in frequency-wavenumber domain where they can be solved by matrix methods. The results for the soil and a structure can be coupled in frequency-wavenumber domain, and the solution in space domain is obtained by an infinite wavenumber integral (the back-transformation). This method has several applications for the prediction of the emission, transmission and immission of railway-induced vibrations. The wave propagation in homogeneous or layered soils is calculated for surface and tunnel lines by a single wavenumber integration (transmission). The response of ballast or slab tracks (for the emission problem) and the foundation stiffness (for the immission problem) need an additional integration across the track or foundation width. In wavenumber domain, tracks and foundations of infinite length are analysed. Finite structures can be calculated by finite element models where the soil is calculated by the boundary element method. The Green’s functions for the boundary element method are calculated by a wavenumber integration as for the transmission problem. Some example results for all these tasks will be shown. The immission into buildings will be analysed in detail, and the effect of stiff slab foundations and (basement) walls on the incoming wavefield is quantified in a parameter study. The transfer function (the amplitude ratio) structure to free field usually starts with 1 at 0 Hz and decreases continuously with frequency. The reduction is due to the structural stiffness against wave deformation which turns to be higher than the stiffness of the soil, for example above the structure-soil coincidence frequency of the slab foundation. The reduction is better for a high structural stiffness and for a low soil stiffness. Walls are stiffer than plates for the relevant frequency range, but even walls and especially low basement walls are not infinitely rigid and can follow the wave deformation to a certain extent. These basic rules from frequency-wavenumber analysis can well be used for real building projects near railway lines where stiff foundations can be an alternative reduction method to the commonly used base isolation by elastic elements. T2 - COMPDYN 2025 CY - Rhodos, Greece DA - 15.06.2025 KW - Frequency-wavenumber method KW - Wave propagation KW - Soil-structure interaction KW - Building foundations KW - Mitigation measures PY - 2025 SP - 1 EP - 15 PB - NTUA CY - Athen AN - OPUS4-63470 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Frequency-wavenumber method for the wave propagation through the soil and the soil-structure interaction of railway tracks and building foundations near railway lines N2 - In soil-structure interaction, the soil and the (flexible) structures are modelled as elastic continua. The partial differential equations of elasticity can be transformed to algebraic equations in frequency-wavenumber domain where they can be solved by matrix methods. The results for the soil and a structure can be coupled in frequency-wavenumber domain, and the solution in space domain is obtained by an infinite wavenumber integral (the back-transformation). This method has several applications for the prediction of the emission, transmission and immission of railway-induced vibrations. The wave propagation in homogeneous or layered soils is calculated for surface and tunnel lines by a single wavenumber integration (transmission). The response of ballast or slab tracks (for the emission problem) and the foundation stiffness (for the immission problem) need an additional integration across the track or foundation width. In wavenumber domain, tracks and foundations of infinite length are analysed. Finite structures can be calculated by finite element models where the soil is calculated by the boundary element method. The Green’s functions for the boundary element method are calculated by a wavenumber integration as for the transmission problem. Some example results for all these tasks will be shown. The immission into buildings will be analysed in detail, and the effect of stiff slab foundations and (basement) walls on the incoming wavefield is quantified in a parameter study. The transfer function (the amplitude ratio) structure to free field usually starts with 1 at 0 Hz and decreases continuously with frequency. The reduction is due to the structural stiffness against wave deformation which turns to be higher than the stiffness of the soil, for example above the structure-soil coincidence frequency of the slab foundation. The reduction is better for a high structural stiffness and for a low soil stiffness. Walls are stiffer than plates for the relevant frequency range, but even walls and especially low basement walls are not infinitely rigid and can follow the wave deformation to a certain extent. These basic rules from frequency-wavenumber analysis can well be used for real building projects near railway lines where stiff foundations can be an alternative reduction method to the commonly used base isolation by elastic elements. T2 - COMPDYN 2025 CY - Rhodos, Greece DA - 15.06.2025 KW - Frequency-wavenumber method KW - Wave propagation KW - Soil-structure interaction KW - Building foundations KW - Mitigation measures PY - 2025 AN - OPUS4-63468 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agasty, Amit T1 - Structural behavior and damage assessment of a reinforced concrete wall by various NDT methods and embedded sensors under blast-loading N2 - A safety or security related assessment of explosions, accidental and intentional scenarios alike, often necessitate performance of replication-tests. Such test results are necessary to clarify the causes within the scope of forensic investigations. To gain important insights into the behavior of structures and materials under such loading, field tests may also be performed in accordance with different test standards. To determine the resistance of building-structures after explosions, estimation of the residual load-bearing capacity in addition to the assessment of dynamic structural response and damage to the building components is important. In most cases an evaluation of structural integrity is based only on the visual damage, resulting in an overestimation of the residual capacity. The Bundesanstalt für Materialforschung und -prüfung (BAM) operates the Test site for Technical Safety (TTS) on an area measuring about 12 km2 in the Federal State of Brandenburg for execution of true-to-scale explosion tests. At the TTS, building component testing was performed to assess the suitability of different non-destructive testing methods to characterize the dynamic structural response and damage resulting from the detonation of high explosives. Different blast-loading scenarios were realized by varying the net explosive mass and the standoff distance with all scenarios representing a near-field detonation. The test object was a reinforced concrete wall 2 m high, 2.5 m wide and 20 cm thick, fixed at both vertical edges. The dynamic loading of the wall was characterized with 8 piezoelectric pressure sensors flush-mounted on the front surface, thus measuring the reflected pressures from the shock wave. The tests were conducted with the aim of characterizing the global behavior of the wall under dynamic shock loading and the resulting local damage pattern, respectively. High speed digital image correlation was implemented in combination with multiple acceleration sensors to observe the rear surface of the wall to chart the dynamic deflection during the loading and to determine the residual deformation after the loading had ceased. In addition, one test specimen was instrumented with fiber optic sensor cables, both fixed to the rebars and embedded in the concrete-matrix, respectively. Firstly, these sensors were interrogated during the blast test by a distributed acoustic sensing (DAS) device using a particularly high sampling rate to measure the shock-induced vibrations in the structure with high temporal resolution. This delivers information on dynamics of compression and tension cycles from within the structure. Secondly, the local damage-pattern emerging during the series of blasts was determined via distributed fiber optic strain sensing (DSS) by interrogating the embedded fiber optic sensors with a high spatial resolution DSS device after each blast. This enabled the characterization of non-visual damage to the structure, in particular with regard to the formation of localized cracks in the concrete matrix. The DSS was further complimented by a structure-scanner based on ultrasonic measurements. Our contribution describes this new test approach in detail. Results of the three datasets, namely dynamic shock loading, global behavior of the test object and the local damage pattern will be presented. The suitability of the implemented measurement methods will be discussed in combination with the challenges in their application for technical safety evaluation of building components under explosive loading. T2 - 26th International Symposium on Military Aspects of Blast and Shock (MABS26) CY - Wollongong, Australia DA - 03.12.2023 KW - Blast tests KW - Reflected pressure KW - Embedded sensors KW - Distributed fiber optic sensors KW - Acceleration sensors KW - Digital image correlation KW - Ultrasonic structure-scanner PY - 2023 AN - OPUS4-58927 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Prediction of ground vibrations from rail tunnels finite element, boundary element and wavenumber calculations N2 - The prediction of ground and building vibrations has been established for surface lines and has now been extended to tunnel lines. The wave propagation in homogeneous or layered soils (the transmission) is calculated by an integration in wavenumber domain. The wave amplitudes at different distances and for different frequencies will be analysed for the following situations. 1. The horizontal propagation from a surface point to a surface point constitutes the basic rules. 2. The horizontal propagation from a source point at depth to a receiver point at depth which is related to a building with a deep basement or on a pile foundation. 3. The propagation from depth to the surface, which is the normal case for free-field measurements, has some different characteristics, for example a weaker attenuation with the horizontal distance from the source, which can be approximated by the full-space solution and the reflection rules for incident waves. The emission from a tunnel structure has been calculated by a finite-element model of the tunnel combined with a boundary-element model of the soil giving the reduction compared to a point-load excitation. The immission has been analysed by finite-element models of tunnel-soil-building systems for examples of research and consultancy work. Measurement results from a high-speed and a metro line confirm some of the established rules. T2 - Recent Advance in Structural Dynamics (RASD) CY - Southampton, UK DA - 01.07.2024 KW - Ground vibration KW - Building vibration KW - Railway tunnel KW - Wavenumber method KW - Finite element method KW - Boundary element method PY - 2024 AN - OPUS4-61230 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Auersch, Lutz T1 - Berechnungen und Messungen zum Schwingungsverhalten von Decken N2 - Es wurden Elemente zusammengetragen, die für die Prognose der Deckenschwingungen von Bedeutung sind. Das umfasst Formeln für die Deckeneigenfrequenzen, Rechenergebnisse zu einfachen und mehrfeldrigen Decken sowie vielfältige Messerfahrungen. Die Berechnungen zeigen die verschiedenen Einflüsse auf die Deckeneigenfrequenzen. Die Eigenfrequenzen berechnen sich aus den Abmessungen, dem Material und den Auflagerbedingungen der Decken. Es wurde auch der Einfluss von Unterzügen und von auskragenden Rändern untersucht. Bei Mehrfelddecken stellt man eine Häufung von Eigenfrequenzen in Frequenzbändern fest. Solche Fälle sollten sinnvollerweise nur mit Mittelwertaussagen erfasst werden. Die Berechnung einiger Gesamtgebäudemodelle führt zu vielfältigen Schwingantworten der verschiedenen Gebäudeteile, die ebenfalls Mittelungsgesetze notwendig erscheinen lassen. Die Nachgiebigkeit der Wände und Stützen führt zu einer Verringerung der rotatorischen und vertikalen Auflagersteifigkeit und damit der Deckeneigenfrequenzen. Die Festlegung der Eigenfrequenzen allein aus den Eigenschaften eines Deckenfeldes erscheint deshalb als nicht vernünftig. Es werden Mittelungsgesetze genannt und entwickelt, neben Mittelungsgesetzen für das Gesamtgebäude insbesondere eine Mittelung für die Berücksichtigung verschiedener Decken in einem Gebäude. Wesentliche Erkenntnisse werden aus den Messergebnissen gewonnen. Es wurden 18 Gebäude und insgesamt 55 Decken untersucht. Die Deckeneigenfrequenzen liegen zwischen 5 und 50 Hz. Es wurden empirische Formeln für die Eigenfrequenzen in Abhängigkeit von der Deckenfläche getrennt für Holz- und Stein/Betondecken aufgestellt. Ein weiterer wichtiger experimenteller Befund ist die Dämpfung der Decken, die im Bereich 1 % < D < 5 % ermittelt wurde. Dieser Dämpfungsbereich sollte für die Erschütterungsprognosen verwendet werden, wobei für eine konservative Prognose ein geringer Dämpfungswert einzusetzen wäre. Schließlich wurden Resonanzüberhöhungen der Decken gegenüber den Freifeldamplituden des Bodens gemessen. Mit diesen Messergebnissen kann dann das fertige Prognosemodell abgeglichen werden. Somit sind ausreichend Erkenntnisse über das Deckenverhalten zusammengetragen, die in das Prognosemodell für das gesamte Gebäude eingebaut werden können. KW - Deckenschwingungen KW - Deckeneigenfrequenz KW - Deckendämpfung KW - Boden-Bauwerk-Übertragung KW - Deckenmessungen KW - Auflagerbedingungen KW - Mehrfeld-Decken PY - 2005 SP - 1 EP - 69 AN - OPUS4-58512 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Costard, Rene A1 - Hering, Marcus T1 - Explosionsauswirkungen auf Strukturen N2 - Wir berichten über die Entwicklungen des AP2 im Hinblick auf Explosionsauswirkungen auf Strukturen und den Weg zur systematischen messtechnischen Erfassung zur ganzheitlichen Bewertung der Bauwerksicherheit unter Detonationsbelastung. Zusätzlich werden die Vorführungen zu Kontaktdetonationen während der 16. Informationsveanstaltung Sprengstoffe und Pyrotechnik vorgeführt. T2 - 16. Informationsveranstaltung Sprengstoffe und Pyrotechnik CY - Berlin, Germany DA - 20.05.2025 KW - Explosion KW - Kontaktdetonation KW - Blast PY - 2025 AN - OPUS4-63192 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Auersch, Lutz T1 - Mitigation measures for ballasted tracks - sleepers, sleeper pads and substructure - Results from the finite element boundary element method N2 - The ground vibrations, which are generated by trains on different tracks, have been calculated by finite-element boundary-element models. The ballasted track is modelled in detail by the finite element method. The infinite soil is modelled by the boundary element method as a homogeneous or layered half-space. The track-soil system is coupled with a simple rigid mass model of the vehicle so that the vehicle-track interaction is completely included. Transfer functions are calculated in frequency domain without and with vehicle-track interaction, the compliance of the track and the mobilities of the soil at different distances from the track. Finally, the ratios between the ground vibration amplitudes with and without mitigation measure are calculated to quantify the effectiveness of the mitigation measure. Tracks with under sleeper pads have been investigated in a wide parameter study. The main parameters that influence the reduction of ground vibration are the stiffness of the under sleeper pad, the mass and the width of the sleeper. The softest sleeper pad yields the best reduction of the ground vibration. The influence of the sleeper mass is not as strong as the characteristic frequency is ruled by the mass of the sleeper and the mass of the wheelset as well. The influence of other parameters has been examined. The stiffness of the rail pads, the bending stiffness of the track, the stiffness of the ballast, the sub-soil, and the soil, and the layering of the soil. All these parameters show no or only a minor influence on the mitigation effect. As the standard isolated track, a track with an under sleeper pad of a stiffness of kS = 5 107 N/m has been chosen, which can also be expressed as a stiffness per area of kS ’’ = 7.4 107 N/m3 = 0.074 N/mm3. The resonance frequency for this pad stiffness is observed between 32 and 40 Hz. The reduction of the ground vibration is about vi,I /vi,U = 0.2 and 0.1 at 100 Hz. The reduction can be improved by softer sleeper pads. But the compliance of the track gets higher than tolerable. A possibility to use softer sleeper pads without increasing the static compliance of the track is their combination with wide sleepers. The softer sleeper pads under wider sleepers yield the same compliance of the track and a better reduction of the ground vibration. KW - Heavy sleeper KW - Under sleeper pad KW - Finite-element boundary-element method KW - Mitigation KW - Ground vibration KW - Ballasted track PY - 2011 SP - 1 EP - 81 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-56607 LA - deu 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 - RPRT A1 - Auersch, Lutz T1 - Mitigation measures for slab tracks - wide sleepers on soft pads and different slabs - Results from the finite element boundary element method N2 - The ground vibrations, which are generated by trains on different slab tracks, have been calculated by finite-element boundary-element models. The slab track is modelled in detail by the finite element method. The infinite soil is modelled by the boundary element method as a homogeneous half-space. The track-soil system is coupled with a simple rigid mass model of the vehicle so that the vehicle-track interaction is completely included. Transfer functions are calculated in frequency domain without and with vehicle-track interaction, the compliance of the track and the mobilities of the soil at different distances from the track. Finally, the ratios between the ground vibration amplitudes with and without mitigation measure are calculated to quantify the effectiveness of the mitigation measure. Tracks with under sleeper pads have been investigated in a parameter study. The main parameter that influences the reduction of ground vibration is the stiffness of the under sleeper pad. The softest sleeper pad yields the best reduction of the ground vibration. The influence of other parameters has been examined. The stiffness of the rail pads, the stiffness of the slab material, the stiffness of the sleeper material, and the distance of the sleepers. All these parameters show no or only a minor influence on the mitigation effect. As the standard isolated track, a track with an under sleeper pad of a stiffness of kS = 5 107 N/m has been chosen, which can also be expressed as a stiffness per area of kS ’’ = 3.7 107 N/m3 = 0.037 N/mm3. The resonance frequency for this pad stiffness is observed between 32 and 40 Hz. The reduction of the ground vibration is about vi,I /vi,U = 0.1 at 100 Hz. KW - Wide sleeper KW - Under sleeper pad KW - Finite-element boudnary-element method KW - Slab track KW - Mitigation KW - Ground vibration PY - 2012 SP - 1 EP - 50 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-56608 LA - eng 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 - 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 - 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 T1 - Prognoseverfahren für Bahnerschütterungen – DIN 45672-3, VDI 3837, HighSpeed2 und die Fahrzeug-Fahrweg-Boden Wechselwirkung N2 - Die VDI Richtlinie 3837 enthält detaillierte Angaben zur Erschütterungsemission. Die DIN 45672-3 enthält nur den Tunnel- oder einen Bodenmesspunkt als Ausgangspunkt der Prognose. Die Erschütterungsanregung durch die Fahrzeug-Fahrweg-Wechselwirkung wird beschrieben. Die ERgebnisse der BAM stimmen sehr gut mit dem Prognosekonzept von Highspeed 2 überein. Dies wird an den Punkten 1. Störgrößen, 2. Achsimpulse, 3. Tunnelstrecken aufgezeigt. T2 - Norm-Arbeitsausschuss Schwingungsminderung in der Umgebung von Verkehrswegen CY - Frankfurt/M., Germany DA - 08.02.2023 KW - Normung KW - Bahnerschütterungen KW - Emission KW - Fahrzeug-Fahrweg-Boden-Wechselwirkung KW - Störgrößen KW - Achsimpulse KW - Tunnelstrecke PY - 2023 AN - OPUS4-56978 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - The dynamic train-track interaction on a bridge and in a tunnel compared with the simultaneous vehicle, track, and ground vibration measurements at a surface line N2 - The vehicle–track interaction generates forces and consequently vibrations in the environment. The interaction has been analysed by the simultaneous measurements of vehicle, track and ground vibrations during test runs with varied train speeds. The special effects of the passage over a bridge and through a tunnel are studied and compared with the measurements on a conventional ballasted surface line. The maximum amplitudes, narrow band and one-third octave band spectra are presented for the axle-box accelerations and for the track, bridge and ground vibrations. The different frequencies and frequency bands are related to wheel out-of-roundness, track alignment errors, the sleeper passage and the wheelset–track resonance. An axle impulse component has been observed at the track, at the near-field soil and as a scattered version in the far field. Specific results can be found for the bridge track, where clearly speed-dependent bridge resonances occur due to the axle sequence of the train, and for the tunnel track where soft rail pads are responsible for a strong amplification around the wheelset–track resonance. On the other hand, the axle impulses are strongly reduced by the tunnel track, and the scattered axle impulse component is not as relevant as for the surface track. As a consequence, a strong mid-frequency amplitude reduction of the tunnel compared to the surface line has been measured for low and high train speeds by the Federal Institute of Material Research and Testing (BAM) and by other institutes. KW - Vehicle–track interaction KW - Ground vibration KW - Tunnel-to-surface reduction KW - Bridge resonance KW - Axle sequence PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-585139 DO - https://doi.org/10.3390/app131910992 VL - 13 IS - 19 SP - 1 EP - 23 PB - MDPI CY - Basel, Schweiz AN - OPUS4-58513 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - Soil–structure interaction and damping by the soil - effects of foundation groups, foundation flexibility, soil stiffness and layers N2 - In many tasks of railway vibration, the structure, that is, the track, a bridge, and a nearby building and its floors, is coupled to the soil, and the soil–structure interaction and the damping by the soil should be included in the analysis to obtain realistic resonance frequencies and amplitudes. The stiffness and damping of a variety of foundations is calculated by an indirect boundary element method which uses fundamental solutions, is meshless, uses collocation points on the boundary, and solves the singularity by an appropriate averaging over a part of the surface. The boundary element method is coupled with the finite element method in the case of flexible foundations such as beams, plates, piles, and railway tracks. The results, the frequency-dependent stiffness and damping of single and groups of rigid foundations on homogeneous and layered soil and the amplitude and phase of the dynamic compliance of flexible foundations, show that the simple constant stiffness and damping values of a rigid footing on homogeneous soil are often misleading and do not represent well the reality. The damping may be higher in some special cases, but, in most cases, the damping is lower than expected fromthe simple theory. Some applications and measurements demonstrate the importance of the correct damping by the soil. KW - Soil–structure interaction KW - Soil dynamics KW - Radiation damping of the soil KW - Rigid foundation KW - Flexible foundation KW - Foundation groups KW - Boundary element method KW - Vibration measurement PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-627007 DO - https://doi.org/10.3390/vibration8010005 SN - 2571-631X VL - 8 IS - 5 SP - 1 EP - 28 PB - MDPI CY - Basel, Schweiz AN - OPUS4-62700 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fedoroff, Alexis A1 - Calonius, Kim A1 - Skłodowska, Anna T1 - Measuring damage anisotropy in concrete from ultrasound velocity data N2 - The uniaxial compression of an initially isotropic concrete specimen induces a damage pattern that is anisotropic: in the direction of loading, the concrete undergoes compaction, while in the directions orthogonal to the loading direction, concrete cracking can be observed. In order to quantify such damage patterns, one possibility is to observe the changes in the stiffness tensor of a compressed specimen with respect to the stiffness tensor of the corresponding virgin state specimen. The eigensolutions of the Kelvin–Christoffel matrix for anisotropic media provide the relation between ultrasound wave velocities in given wavefront and polarization directions and the stiffness matrix components. In this study, it is shown how using the through transmission method for the determination of first-time arrival, one can evaluate the sound wave velocities in different directions and compute the stiffness tensor components for a damaged concrete specimen. Plots of stiffness tensor components as a function of non-recoverable strain give a qualitative measure of the anisotropic strain degradation process. KW - Damage anisotropy in concrete KW - Kelvin–Christoffel eigenproblem KW - Ultrasound wavefront velocity KW - Through transmission measurement of time-of-flight PY - 2025 DO - https://doi.org/10.1177/10567895251357962 SN - 1530-7921 SP - 1 EP - 31 PB - Sage CY - Thousand Oaks, Calif. AN - OPUS4-63754 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -