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 - Costard, René T1 - Explosionsauswirkungen auf Strukturen Versuche und Simulationen N2 - Vorstellung der Versuche von Explosionsversuchen auf dem TTS. Diese werden ergänzt durch die Ergebnisse durchgeführter Simulationen und zeigen die Wirkung von zivilen Explosivstoffen auf Gebäudestrukturen und die aufgetretenen Schädigungen. T2 - 46. Informationstagung Sprengtechnik CY - Siegen, Germany DA - 25.04.2025 KW - Explosivstoff KW - Skalierung KW - Strukturauswirkung KW - Numerische Simulation PY - 2025 AN - OPUS4-62998 LA - deu 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 - 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 - THES A1 - Wiehle, Philipp T1 - Einfluss der Feuchtigkeit auf das Tragverhalten von Lehmmauerwerk N2 - Im Mittelpunkt der vorliegenden Arbeit steht der Einfluss der Feuchte auf die mechanischen Eigenschaften von Lehmmauerwerk. Der Wissensstand zum feuchteabhängigen Tragverhalten von Lehm(mauerwerk) ist bisher lückenhaft, sodass keine explizite Berücksichtigung der Bauteilfeuchte bei der Bemessung tragender Konstruktionen erfolgt. Aktuelle und verlässliche Daten zum Einfluss der Feuchte auf die mechanischen Kenngrößen moderner Lehmbaustoffe fehlen bisher ebenso wie Messwerte in Bezug auf die Bauteilfeuchte unter natürlichen Klimabedingungen. Deswegen wurden im Rahmen dieser Arbeit umfangreiche Untersuchungen zum mechanischen und hygrothermischen Verhalten von Lehmmauerwerk durchgeführt. Die experimentellen Untersuchungen bestehen im Wesentlichen aus Druckversuchen an Lehmsteinen, -mörteln, kleinformatigen Lehmmauerwerksprobekörpern und geschosshohen Lehmmauerwerkswänden. Um das Feuchteverhalten beschreiben zu können, fanden außerdem erstmalig magnetresonanzspektroskopische Messungen an Lehmsteinen statt und es wurden die tatsächlich auftretenden Feuchtegehalte an einer Lehmmauerwerkswand unter natürlichen Klimabedingungen in Form von Langezeitmessungen ermittelt. Es konnte festgestellt werden, dass ein linearer Zusammenhang zwischen Druckfestigkeit und relativer Luftfeuchte besteht, wobei sich die Druckfestigkeit umgekehrt proportional zur relativen Luftfeuchte verhält. Je Prozent Steigerung der relativen Luftfeuchte kommt es zur Abnahme von einem Prozent der Druckfestigkeit. Gleiches gilt für das Elastizitätsmodul. Weiterhin konnte auf Basis der feuchtetechnischen Untersuchungen ein numerisches Modell zur Berechnung des instationären hygrothermischen Verhaltens für Lehmbaustoffe kalibriert werden. Anhand dieses Modells gelang es die bemessungsrelevanten Feuchtegehalte unter Berücksichtigung des instationären hygrothermischen Verhaltens realitätsnah zu berechnen. Die maximalen Feuchtegehalte im Lehmmauerwerk konnten somit in Form einer Parameterstudie in Abhängigkeit des Anwendungsfalls ermittelt werden, wodurch eine explizite Berücksichtigung des Feuchtegehaltes bei der Bemessung ermöglicht wurde. Die Verknüpfung der Erkenntnisse aus den mechanischen und hygrothermischen Untersuchungen dieser Arbeit bildet die Grundlage für das Bemessungskonzept der im Juni 2023 veröffentlichten DIN 18940: Tagendes Lehmsteinmauerwerk. KW - NMR KW - Lehm KW - Mauerwerk KW - Druckfestigkeit KW - Feuchtigkeit PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-637794 DO - https://doi.org/10.14279/depositonce-20800 SP - 1 EP - 114 CY - Berlin AN - OPUS4-63779 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wiehle, Philipp A1 - Baier, Johanna A1 - Thiele, Marc T1 - Structural Design of Earth Masonry in Accordance with Eurocode 6 – Considering Moisture Content and E/fk Ratio N2 - The load‐bearing behaviour of earth masonry is similar to conventional masonry, with two key differences: compressive strength and Young's modulus are dependent on moisture content, and the ratio between Young's modulus and characteristic compressive strength (E/fk) is significantly lower. The current design concept according to the Lehmbau Regeln does not explicitly address these factors, relying instead on a general safety margin, leading to an underestimation of the load‐bearing capacity of modern earth masonry.Compression tests on small‐scale masonry specimens and storey‐high walls revealed that compressive strength and Young's modulus decrease inversely proportional to the increase in relative humidity. Additionally, it was found that conventional masonry design guidelines overestimate the buckling resistance of earth masonry due to its low E/fk ratio of ∼440. However, this ratio remains independent of moisture content, simplifying structural design, as the load‐bearing capacity is only influenced by wall slenderness.The study's findings form the foundation for the newly published German design standard DIN 18940, which explicitly considers moisture content through service classes with moisture factors and addresses the low E/fk ratio with a bilinear adaptation of the reduction factor considering the slenderness. Along with the introduction of the semi‐probabilistic design concept and rigid‐plastic determination of cross‐sectional load‐bearing capacity, modern earth masonry can now be applied in buildings up to four storeys. T2 - Earth Builder Summit CY - Biberach, Germany DA - 06.03.2025 KW - Service class KW - Earth masonry KW - Structural design KW - Moisture PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-637803 DO - https://doi.org/10.1002/cepa.3287 SN - 2509-7075 VL - 8 IS - 1 SP - 9 EP - 21 PB - Ernst & Sohn GmbH AN - OPUS4-63780 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 - CONF A1 - Artinov, Antoni T1 - Fracture Mechanics-Based Approach for Fatigue Life Assessment of Welded Structures: The Role of Real Weld Geometries and Welding Residual Stresses N2 - Fatigue failure is a critical concern in offshore wind structures, where welded joints are subjected to cyclic loading over extended service lifetimes. The combined effects of weld geometry [1, 2] and welding residual stresses (WRS) significantly influence the fatigue strength of welds [3-5]. In offshore wind applications, fatigue behavior is further complicated by cyclic loading conditions, where externally applied loads from wind, waves, and ocean currents interact with WRS, causing localized plastic deformation due to high-stress concentrations. Additionally, under prolonged cyclic loading, the redistribution of WRS can result in a shift of the fatigue-prone regions over time, meaning that locations identified as high-risk may not remain the dominant failure sites throughout the structure’s service life [6]. This presents a significant challenge for inspection and maintenance strategies, as conventional monitoring approaches may fail to detect the most vulnerable zones at later stages of operation. Early experimental studies on low-carbon steel plates and butt joints have shown that tensile WRS can reduce fatigue limits by up to 50% compared to stress-relieved specimens [7]. This effect is particularly pronounced in regions with welding defects, such as porosity, lack of fusion, and undercuts, as well as at geometric discontinuities, including weld toes and sharp notches, which induce localized stress gradients. The combined effect of tensile WRS and stress concentrations amplifies the local stress fields, promoting crack initiation and accelerating crack propagation, ultimately reducing the service life of offshore wind structures. Despite the critical role of weld geometry and WRS in fatigue performance, conventional fatigue assessment methods frequently neglect or oversimplify their effects, leading to overly conservative predictions and suboptimal structural designs. Current engineering standards, including BS 7910 (2019), BS 7608 (1993), EN 13001-3-1 (2020), and EN 1993-1-9 (2013), assume high tensile WRS in welded joints and apply simplified fatigue life prediction approaches that eliminate the need for explicit mean stress considerations. While some standards introduce correction factors for different WRS states, these remain highly generalized and lack accuracy. More sophisticated approaches, such as the Integrated Approach to Fatigue Strength Determination of Welded Structures (IBESS) [8], attempt to incorporate WRS into fatigue life assessments but rely on effective load ratios rather than explicitly modeling and considering real WRS distributions in the analysis. Additionally, IBESS does not fully integrate real weld geometries, limiting its predictive accuracy. These limitations result in significant scatter in fatigue life predictions, excessive conservatism, and inefficiencies in structural design. Although existing fatigue models improve on traditional methodologies, to the best of the authors' knowledge a unified framework that fully captures the combined effects of real weld geometries, WRS, and cyclic loading does not exist yet. The present research aims to develop an advanced fracture mechanics-based numerical framework for fatigue life assessment that explicitly accounts for these influencing factors at the specimen level, establishing the foundation for future scaling to component-level applications. T2 - Wind Energy Science Conference CY - Nantes, France DA - 23.06.2025 KW - Fatigue Assessment KW - Wind Offshore Structures KW - Fracture Mechanics KW - Digital Weld Geometries KW - Welding Residual Stresses KW - Numerical Modeling PY - 2025 AN - OPUS4-63591 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kemmler, Samuel T1 - Fully-resolved LBM-DEM simulations of piping erosion during a suction bucket installation N2 - Suction bucket foundations are a cost-efficient and environmentally sustainable solution to install offshore wind turbines, achieved through the application of growing suction pressure inside the bucket until its full embedment into the seabed. A key challenge for the installation process is the occurrence of piping erosion, a phenomenon where fluidization of particles beneath the bucket wall tip causes a drop in suction pressure, potentially leading to installation failure. Despite its significance, the complex physical mechanisms driving piping erosion remain insufficiently understood. To address this knowledge gap, a three-dimensional, fully-resolved coupled LBM-DEM simulation is employed to conduct an in-depth analysis of piping erosion, aiming to identify key influencing parameters, thus enhancing understanding and optimizing the installation process. The simulation of physically relevant problem sizes - comprising hundreds of thousands of grains - is equivalent to computational intensities which demand for extensive computational resources. Results from simulations executed on hundreds of GPUs on the LUMI supercomputer are presented, illustrating the method's capability to tackle this complex challenge. T2 - 10th International Conference on Discrete Element Methods CY - Himeji, Japan DA - 01.07.2025 KW - Offshore wind support structure KW - Suction bucket foundation KW - Piping erosion KW - Micromechanical simulation PY - 2025 AN - OPUS4-63691 LA - eng 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 - 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 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 - 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. KW - Railway tunnel KW - Ground vibration KW - Building vibration KW - Wavenumber integral KW - Full-space solution KW - Reflection at the surface PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-627015 DO - https://doi.org/10.1088/1742-6596/2909/1/012013 SN - 1742-6596 VL - 2909 SP - 1 EP - 12 PB - IOP Publishing CY - London AN - OPUS4-62701 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Modal analysis of road and rail bridges for damage detection and resonance prediction N2 - In the 1980s, the Federal Institute of Material Research and Testing started with modal analysis measurements of some bridges before and after repair. For one of the bridges, a structural health monitoring was installed 1994 which is still working up to now. It has been modified and extended several times. The monitoring was extended from the critical span to three neighbouring spans. A modal analysis of the whole bridge with seven spans have been done three times, twice together with EMPA of Switzerland. Additional calibration measurements have been done and additional evaluation procedures have been implemented for the monitoring of the steadily increasing loads from the road traffic. Additional sensors were installed such as strain gauges, crack-width, and temperature sensors. The strong influence of the temperature on the natural frequencies has been studied over the years. Later, a temperature compensation has been established and a weak aging trend has been found in the monitoring data. Now, the bridge will be demolished and replaced by a new bridge. Some results of this long-term monitoring will be shown and possible damages (changes of the pre-stress or the support structure) will be discussed. A second application of modal analysis will be demonstrated: the prediction of the resonances due to passing trains. The response of a bridge to passing trains can be calculated in frequency domain as the multiplication of three spectra, the axle sequence spectrum of the train, the transfer function of the bridge, and the modal force spectrum of a single passing load. A resonance occurs if a maximum of the train spectrum coincides with the maximum of the bridge spectrum. The amplitude at this resonance is strongly influenced by the modal force spectrum which is identical to the frequency or wavenumber spectrum of the corresponding mode shape. Therefore, modal analysis from calculation, impact measurements, wind and train measurements are necessary for the prediction of the resonance occurrence and amplification. Examples of mode shape spectra for single or multi-span bridges with simply supported or continuous spans will be shown, and some relations between mode shapes and resonance amplifications will be concluded. T2 - 11th International Operational Modal Analysis Conference (IOMAC) CY - Rennes, France DA - 20.05.2025 KW - Bridge monitoring KW - Multi-span bridges KW - Damage detection KW - Resonance PY - 2025 AN - OPUS4-63472 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rogge, Andreas T1 - Large scale impact tests with reinforced concrete plates for impact safety N2 - As part of a nuclear safety research project, large-scale impact tests were conducted on reinforced concrete slabs to investigate the structural integrity of containment structures under aircraft crash scenarios. The aim was to experimentally validate numerical models for both hard and soft impact conditions. Using a drop tower, concrete slabs were subjected to controlled impacts with a 404 kg impactor dropped from a height of 9.5 meters. The tests included force measurements, photogrammetric evaluations, and 3D scans to analyze deformations and damage. A total of six impact experiments were performed (2x hard impact, 2x combined hard/soft impact). The results provide a robust basis for advancing safety assessments of nuclear facilities. T2 - SMiRT28 - 28th International Conference on Structural Mechanics In Reactor Technology CY - Toronto, Canada DA - 10.08.2025 KW - Experimental mechanics KW - Aircraft crash scenario KW - Coupled impact loading PY - 2025 AN - OPUS4-64126 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schepers, Winfried T1 - Die Courant-Friedrichs-Lewy-Bedingung als Genauigkeits- und Stabilitätsbedingung bei FEM-Berechnungen zur Wellenausbreitung N2 - Bei numerischen Berechnungen zur Wellenausbreitung im Zeitbereich mit der FE-Methode wird sehr häufig die Courant-Friedrichs-Lewy-Bedingung als zwingend einzuhaltende Bedingung für das Zeitschrittintegrationsverfahren genannt. Darin wird gefordert, dass eine sich ausbreitende Welle innerhalb eines Zeitschritts nicht mehr als die Distanz zum nächstgelegenen Knotenpunkt zurücklegen dürfe. Dies lässt erwarten, dass es sich um eine physikalisch begründbare Bedingung handelt. Es ist jedoch in der Literatur zu beobachten, dass nicht weiter ausgeführt wird, ob es sich um eine Genauigkeits- oder um eine Stabilitätsbedingung handelt, und ob sie für alle Zeitschrittverfahren einzuhalten ist oder nur für einige spezielle. Auch werden entsprechende Aussagen ohne weiteren Quellennachweis gemacht. Dieser Beitrag erläutert zunächst die Fragestellung, der Courant et al. in der Originalveröffentlichung von 1928 nachgegangen sind, und zeigt auf, welche Bedeutung die von ihnen gefundene Beziehung für die dort untersuchte Fragestellung hat. Anschließend wird der Frage nachgegangen, inwieweit die dort gewonnenen Erkenntnisse auf FEM-Berechnungen übertragen werden können. Die Betrachtung der Stabilitätsbedingungen verschiedener Zeitschrittintegrationsverfahren im Kontext von FEM-Berechnungen in der Strukturdynamik zeigt anschließend, dass es sich bei der CFL-Bedingung nicht um eine physikalisch begründbare Beziehung, sondern um eine rein numerische Bedingung ohne physikalischen Hintergrund handelt. T2 - 19. D-A-CH Tagung Erdbebeningenieurwesen und Baudynamik CY - Vienna, Germany DA - 18.09.2025 KW - Numerische Methoden KW - Zeitschrittintegration KW - Verkehrserschütterungen PY - 2025 SN - 978-3-200-10710-6 DO - https://doi.org/10.34726/10599 SP - 259 EP - 264 PB - Österreichische Gesellschaft für Erdbebeningenieurwesen und Baudynamik (OGE) CY - Wien AN - OPUS4-64191 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schepers, Winfried T1 - Kritische Betrachtung der Impedanzfunktionen harmonisch angeregter Fundamente N2 - In den aktuellen Entwürfen des Eurocode 8 Teil 5 (FprEN 1998-5:2024) und auch des Euro-codes 7 Teil 3 (E DIN EN 1997-3:2022-10) werden Formeln für die Steifigkeiten eines Hal-braums mit einem darin eingebetteten starren masselosen Rechteckfundament gegenüber einer harmonischen Anregung angegeben. Die Formeln sind im Wesentlichen eine Kombination der Ergebnisse der Veröffentlichungen von Gazetas (1991) und Pais et al. (1988) über Forschungs-arbeiten, die in den 1980er Jahren durchgeführt wurden. Sie basieren auf numerischen Berech-nungen, deren Ergebnisse durch Ausgleichskurven approximiert wurden. Eine genauere Analyse der den Formeln zugrunde liegenden Veröffentlichungen zeigt einige Inkonsistenzen zwischen Eurocodes und den ursprünglichen Veröffentlichungen, deren Ursache nicht ohne weiteres er-kennbar ist. Darüber hinaus werden in den Eurocodes nur frequenzunabhängige Steifigkeiten angegeben. Das führt zu der Frage, wie verlässlich die Formeln sind. An zwei Beispielen wird nachfolgend die Notwendigkeit einer kritischen Verwendung der Impedanzfunktionen gezeigt. T2 - 19. D-A-CH Tagung Erdbebeningenieurwesen und Baudynamik CY - Vienna, Austria DA - 18.09.2025 KW - Impedanzen KW - Wellenausbreitung KW - Erschütterungen PY - 2025 SN - 978-3-200-10710-6 DO - https://doi.org/10.34726/10599 SP - 245 EP - 246 PB - Österreichische Gesellschaft für Erdbebeningenieurwesen und Baudynamik (OGE) CY - Wien AN - OPUS4-64187 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schepers, Winfried T1 - Kritische Betrachtung der Impedanzfunktionen harmonisch angeregter Fundamente N2 - In den aktuellen Entwürfen des Eurocode 8 Teil 5 (FprEN 1998-5:2024) und auch des Euro-codes 7 Teil 3 (E DIN EN 1997-3:2022-10) werden Formeln für die Steifigkeiten eines Hal-braums mit einem darin eingebetteten starren masselosen Rechteckfundament gegenüber einer harmonischen Anregung angegeben. Die Formeln sind im Wesentlichen eine Kombination der Ergebnisse der Veröffentlichungen von Gazetas (1991) und Pais et al. (1988) über Forschungs-arbeiten, die in den 1980er Jahren durchgeführt wurden. Sie basieren auf numerischen Berech-nungen, deren Ergebnisse durch Ausgleichskurven approximiert wurden. Eine genauere Analyse der den Formeln zugrunde liegenden Veröffentlichungen zeigt einige Inkonsistenzen zwischen Eurocodes und den ursprünglichen Veröffentlichungen, deren Ursache nicht ohne weiteres er-kennbar ist. Darüber hinaus werden in den Eurocodes nur frequenzunabhängige Steifigkeiten angegeben. Das führt zu der Frage, wie verlässlich die Formeln sind. An zwei Beispielen wird nachfolgend die Notwendigkeit einer kritischen Verwendung der Impedanzfunktionen gezeigt. T2 - 19. D-A-CH Tagung Erdbebeningenieurwesen und Baudynamik CY - Vienna, Germany DA - 18.9.2025 KW - Impedanzen KW - Wellenausbreitung KW - Erschütterungen PY - 2025 AN - OPUS4-64188 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias T1 - Anwendungsszenarien und Referenzanwendungen sensorbasiertes Monitoring N2 - Präsentiert wird eine Kategorisierung von Anwendungsszenarien für sensorbasiertes Monitoring und die Planung für die Referenzbauwerke mit SHM-Anwendungen. Im Rahmen des Forschungsvorhabens Aistec Pro werden Anwendungsszenarien für sensorbasiertes Monitoring kategorisiert und in Referenzanwendungen umgesetzt. Der Vortrag gibt einen Überblick über die abgeschlossene Planung. T2 - Jahrestreffen Verbund Aistec-Pro CY - Bonn, Germany DA - 17.09.2025 KW - SHM KW - Monitoring KW - Brückensicherheit KW - Aistec Pro PY - 2025 AN - OPUS4-64124 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Farhat, Abbas A1 - Luu, Li-Hua A1 - Doghmane, Alexis A1 - Cuéllar, Pablo A1 - Benahmed, Nadia A1 - Wichtmann, Torsten A1 - Philippe, Pierre T1 - Micro and macro mechanical characterization of artificial cemented granular materials N2 - The focus of this study is the experimental characterization of cemented granular materials, with the aim of identifying the microscopic properties of the solid bonds and describing the extension to macroscopic mechanical strength of cemented samples.We chose to use artificially bonded granular materials, made of glass beads connected by solid paraffin bridges. The results of several sets of laboratory tests at different scales are presented and discussed. Micromechanical tests investigate the yield strength of single solid bonds between particles under traction, shearing, bending and torsion loading, as a function of variations in particle size, surface texture and binder content. Macro-scale tensile tests on cemented samples explore then the scale transition, including influence of confining walls through homothetic variations of the sample size. Despite the large statistical dispersion of the results, it was possible to derive and validate experimentally an analytical expression for micro tensile yield force as a function of the binder content, coordination number and grain diameter. In view of the data, an adhesive bond strength at the contact between bead and solid bond is deduced with very good accuracy and it is even reasonable to assume that the other threshold values (shear force, bending and torsion moments) are simply proportional to the tensile yield, thus providing a comprehensive 3D model of cemented bond. However, the considerable dispersion of the data at the sample scale prevents validation of the extended model for macroscopic yield stress. A final discussion examines the various factors that may explain intrinsic variability. By comparison with other more realistic systems studied in the literature in the context of bio-cementation, our artificial material nevertheless appears suitable for representing a cemented granular material. Being easy to implement, it could thus enable the calibration of discrete cohesion models for simulation of practical applications. KW - Cemented granular material KW - Micro-mechanical characterisation KW - Artificial soils KW - Yield tensile stress PY - 2024 DO - https://doi.org/10.1007/s10035-024-01426-2 SN - 1434-5021 VL - 26 IS - 3 SP - 1 EP - 20 PB - Springer CY - Berlin AN - OPUS4-63507 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kemmler, Samuel A1 - Rettinger, Christoph A1 - Rüde, Ulrich A1 - Cuéllar, Pablo A1 - Köstler, Harald T1 - Efficiency and scalability of fully-resolved fluid-particle simulations on heterogeneous CPU-GPU architectures N2 - Current supercomputers often have a heterogeneous architecture using both conventional Central Processing Units (CPUs) and Graphics Processing Units (GPUs). At the same time, numerical simulation tasks frequently involve multiphysics scenarios whose components run on different hardware due to multiple reasons, e.g., architectural requirements, pragmatism, etc. This leads naturally to a software design where different simulation modules are mapped to different subsystems of the heterogeneous architecture. We present a detailed performance analysis for such a hybrid four-way coupled simulation of a fully resolved particle-laden flow. The Eulerian representation of the flow utilizes GPUs, while the Lagrangian model for the particles runs on conventional CPUs. Two characteristic model situations involving dense and dilute particle systems are used as benchmark scenarios. First, a roofline model is employed to predict the node level performance and to show that the lattice-Boltzmann-based Eulerian fluid simulation reaches very good performance on a single GPU. Furthermore, the GPU-GPU communication for a large-scale Eulerian flow simulation results in only moderate slowdowns. This is due to the efficiency of the CUDA-aware MPI communication, combined with the use of communication hiding techniques. On 1024 A100 GPUs, an overall parallel efficiency of up to 71% is achieved. While the flow simulation has good performance characteristics, the integration of the stiff Lagrangian particle system requires frequent CPU-CPU communications that can become a bottleneck, especially when simulating the dense particle system. Additionally, special attention is paid to the CPU-GPU communication overhead since this is essential for coupling the particles to the flow simulation. However, thanks to our problem-aware co-partitioning, the CPU-GPU communication overhead is found to be negligible. As a lesson learned from this development, four criteria are postulated that a hybrid implementation must meet for the efficient use of heterogeneous supercomputers. KW - Discrete element method KW - Hybrid implementation KW - High-performance computing KW - Particulate flow KW - Lattice Boltzmann method PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-623958 DO - https://doi.org/10.1177/10943420241313385 SN - 1741-2846 SP - 1 EP - 19 PB - SAGE Publications AN - OPUS4-62395 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zinas, Orestis A1 - Papaioannou, Iason A1 - Schneider, Ronald A1 - Cuéllar, Pablo T1 - Multivariate Gaussian Process Regression for 3D site characterization from CPT and categorical borehole data N2 - Accurate prediction of subsurface stratigraphy and geotechnical properties, along with quantification of associated uncertainties, is essential for improving the design and assessment of geotechnical structures. Several studies have utilized indirect data from Cone Penetration Tests (CPTs) and employed statistical and Machine Learning methods to quantify the geological and geotechnical uncertainty. Incorporating direct borehole data can reduce uncertainties. This study proposes a computationally efficient multivariate Gaussian Process model that utilizes site-specific data and: (i) jointly models multiple categorical (USCS labels) and continuous CPT variables, (ii) learns a non-separable covariance structure leveraging the Linear Model of Coregionalization, and (iii) predicts a USCS based stratigraphy and CPT parameters at any location within the 3D domain. The results demonstrate that integrating geotechnical and geological data into a unified model yields more reliable predictions of subsurface stratification, enabling the parallel interpretation of both USCS classification and CPT profiles. Importantly, the model demonstrates its potential to integrate multiple variables from different sources and data types, contributing to the advancement of methodologies for the joint modeling of geotechnical, geological, and geophysical data. KW - Geotechnical site-characterization KW - Cone Penetration Tests KW - Stratigraphy prediction KW - Multivariate Gaussian process KW - Variational inference KW - Linear Model of Coregionalization PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-629456 DO - https://doi.org/10.1016/j.enggeo.2025.108052 SN - 1872-6917 VL - 352 SP - 1 EP - 19 PB - Elsevier B.V. AN - OPUS4-62945 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herrmann, Ralf A1 - Schneider, Ronald A1 - Simon, Patrick A1 - Hille, Falk A1 - Said, Samir A1 - Baeßler, Matthias ED - Curbach, M. ED - Marx, S. ED - Scheerer, S. ED - Hampel, T. T1 - Structural Health Monitoring der Maintalbrücke Gemünden zur Unterstützung einer prädiktiven Instandhaltung N2 - Nach den bisherigen Regeln werden Bauwerksprüfungen von Brücken in starr definierten Intervallen durchgeführt. Diese starre, periodische, zustandsbasierte Instandhaltungsstrategie soll zukünftig durch eine flexible und prädiktive Instandhaltung ersetzt werden. Hierbei sollen Inspektionen und Instandhaltungsmaßnahmen unterstützt durch autonome Systeme auf der Grundlage von Monitoringdaten geplant und zusätzlich bei unvorhergesehenen Ereignissen ausgelöst werden. Im Rahmen des Verbundforschungsvorhabens AISTEC wird ein Vorgehen für Großbauwerke und kleinere Regelbauwerke zur Umsetzung eines kombinierten globalen, schwingungsbasierten und quasistatischen Monitorings entworfen. An der Maintalbrücke Gemünden – einer semiintegralen Rahmenbrücke aus Spannbeton auf der Schnellfahrstrecke Hannover–Würzburg – wurde als Demonstrator ein Dauermonitoring realisiert. T2 - 11. Symposium Experimentelle Untersuchungen von Baukonstruktionen (SEUB) CY - Online meeting DA - 08.03.2021 KW - Structural Health Monitoring KW - Umwelteinflüsse KW - Prädiktive Instandhaltung PY - 2021 UR - https://tu-dresden.de/bu/bauingenieurwesen/imb/ressourcen/dateien/veranstaltungen/seub/11-seub-2021/2021_SEUB11_06_Herrmann_et_al.pdf?lang=de VL - 55 SP - 66 EP - 76 PB - Technische Universität Dresden CY - Dresden AN - OPUS4-52810 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Haake, Gerrit T1 - ReNEW - Entscheidungstools für die Nutzungsverlängerung und das Repowering von Windenergieanlagen N2 - Der Vortrag gibt einen Überblick über gängige Nachnutzungskonzepte, die im Rahmen des Forschungsvorhabens ReNEW untersucht werden. Hierzu wir eine probabilistisches Entscheidungsmodell eingeführt. Die Möglichkeiten von Bauwerksertüchtigungen werden erörtert. T2 - RAVE ROWD Workshop 2024 CY - Hannover, Germany DA - 10.12.2024 KW - Windenergieanlagen KW - Bauwerksertüchtigung KW - Offshore-Windparks KW - Repowering PY - 2024 AN - OPUS4-62237 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eichner, Lukas A1 - Gerards-Wünsche, Paul A1 - Happel, Karina A1 - Weise, Sigurd A1 - Haake, Gerrit A1 - Sieber, Lars A1 - Flederer, Holger A1 - Schneider, Ronald A1 - Herrmann, Ralf A1 - Hille, Falk A1 - Baeßler, Matthias A1 - Huhn, Holger A1 - Küchler, Andreas T1 - Digitales Datenmanagement für die Instandhaltung von Offshore-Windparks T1 - Digital data management for maintenance in offshore wind farms N2 - Im Forschungsprojekt DiMoWind-Inspect wurde untersucht, welche Grundvoraussetzungen geschaffen werden müssen, um digitale Methoden für die Instandhaltung von Offshore-Windenergieanlagen einsetzen zu können. Daten aus allen Lebensphasen der Anlagen werden derzeit nur selten effizient dafür genutzt, um die sinnvollsten Instandhaltungsmaßnahmen am richtigen Ort, zum richtigen Zeitpunkt und mit den geringsten Kosten durchzuführen. Eine im Vorhaben entwickelte einheitliche Strukturierung der bisher häufig unstrukturierten Bau- und Instandhaltungsdaten ermöglicht ihre übergreifende, anwenderspezifische Verfügbarkeit. Hierfür werden Prinzipien des Referenzkennzeichnungssystems RDS-PP adaptiert. Es wird aufgezeigt, wie neben Bauteilen auch zusätzliche Informationen wie Instandhaltungsmaßnahmen oder Mängel strukturiert werden können. Dem Ansatz des Building Information Modeling folgend werden die Bauwerkskomponenten direkt mit den Informationen aus Inspektionen und weiteren Instandhaltungsmaßnahmen verknüpft. So können Informationen aus dem Betrieb über den Zustand der Struktur verarbeitet und für die maßgebenden Berechnungen und Nachweise zur Verfügung gestellt werden. Als Anwendungsfall wird ein zweistufiges Konzept vorgestellt, das zur Bewertung der Ermüdungslebensdauer eines korrosionsgeschädigten Konstruktionsdetails der Gründungsstruktur einer Offshore-Windenergieanlage mit Informationen aus der Instandhaltung eingesetzt wird. N2 - The DiMoWind-Inspect research project explored the essential requirements for implementing digital methods in the maintenance of offshore wind turbines. Currently, data from all stages of the turbines' lifecycles are underutilized, leading to suboptimal maintenance actions being taken in terms of location, timing, and cost. A consistent structuring of previously often unstructured construction and maintenance data developed in the project enables their cross-disciplinary, user-specific availability. To accomplish this, the principles of the Reference Designation System for Power Plants RDS-PP are applied. In this way, additional information, such as maintenance measures or defects, can be structured alongside components. The components of the structures are directly linked with information from inspections and other maintenance activities, following the Building Information Modeling approach. This allows for processing operational information about the condition of the structure and providing it for relevant calculations and assessments. As a use case, a two-stage concept is presented, utilizing maintenance information to assess the fatigue life of a corrosion-damaged structural detail in the support structure of an offshore wind turbine. KW - Building Information Modeling KW - Datenmanagement KW - Instandhaltung KW - Offshore-Windenergie KW - Referenzkennzeichnungssystem PY - 2024 DO - https://doi.org/10.1002/bate.202400026 VL - 101 IS - 10 SP - 558 EP - 567 PB - Ernst & Sohn CY - Berlin AN - OPUS4-60765 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph T1 - Moisture diffusion affected by the Knudsen effect in temporal changing pore networks N2 - Almost all building materials in civil engineering have an open porosity and interact with or are affected by the environmental conditions. Structures might suffer from effects such as moisture adsorption, carbonation, corrosion, penetration of salt ions and chemical substances, etc. In the hygroscopic range, these processes are mostly driven by diffusion. Due to the confinement of small pores ( 1 m), the Knudsen effect reduces the molecular diffusion. This reduction can become more significant in case of temporal changing pore systems because of physisorption of water vapor, carbonation, or chemisorption. In this study, unstabilised earth blocks and earth masonry are investigated. In a first step, the pore size distribution of the blocks is measured and sorption isotherms are recorded in experiments. Besides the ordinary physisorption, the involved clay minerals undergo swelling or shrinking due to chemisorption. The following two effects must be considered: first, the reduction of the available pore space by the adsorbed water layer. For this, the Hillerborg sorption theory is used, which is a combination of the well-known Brunauer-Emmett-Teller sorption theory and the Kelvin equation. This allows the computation of adsorbed water layers even in curved pore geometries. Second, the variation of the initial pore size distribution due to chemisorption needs to be modelled. Based on these two models, the effective diffusion coefficient can be predicted. For validation, arrays of relative humidity sensors were embedded into a free-standing earth masonry wall. This monitoring was carried out over more than a year to have a broad variety of environmental conditions and was located in Berlin, Germany. The prediction of the effective diffusion coefficient can also be transferred to other processes and allows the investigation of materials having temporarily changing pore systems. Examples are the carbonation of cementitious materials, alkali silica reaction, calcium leaching of long-lasting structures, etc. This effect becomes most prominent in the meso-pore range and might alter the effective diffusion coefficient by more than 100 %. T2 - 4th International Congress on Materials & Structural Stability CY - Rabat, Morocco DA - 08.03.2023 KW - Earth masonry KW - Material moisture KW - Molecular diffusion KW - Chemisoprtion KW - Knudsen effect KW - Physisorption PY - 2023 AN - OPUS4-57140 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Ronald T1 - Vibration-based system identification of a large steel box girder bridge N2 - The Bundesanstalt für Materialforschung und -prüfung (BAM) collaborates with TNO to develop a software framework for automated calibration of structural models based on monitoring data. The ultimate goal is to include such models in the asset management process of engineering structures. As a basis for developing the framework, a multi-span road bridge consisting of ten simply supported steel box girders was selected as a test case. Our group measured output-only vibration data from one box girder under ambient conditions. From the data, we determined eigenfrequencies and mode shapes. In parallel, we developed a preliminary structural model of the box girder for the purpose of predicting its modal properties. In this contribution, we provide an overview of the measurement campaign, the operational modal analysis, the structural modeling and qualitatively compare the identified with the predicted modes. As an outlook, we discuss the further steps in the calibration process and future applications of the calibrated model. T2 - XII International Conference on Structural Dynamics (EURODYN 2023) CY - Delft, Netherlands DA - 02.07.2023 KW - Bridge KW - Safety KW - Fatigue KW - Modal system identification KW - Model updating PY - 2023 AN - OPUS4-57863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gerards-Wünsche, Paul A1 - Ratkovac, Mirjana A1 - Schneider, Ronald A1 - Hille, Falk A1 - Baeßler, Matthias T1 - A framework for assessing the reliability of crack luminescence – an automated fatigue crack detection system N2 - The new crack luminescence method offers the possibility of making fatigue surface cracks in metallic materials more visible during inspections through a special coating system. This coating system consists of two layers, whereby the first layer has fluorescent properties and emits visible light as soon as it is irradiated by UV light. The top layer is black and is designed to prevent the fluorescent layer from emitting if no crack develops in the underlying material. The technique proved particularly useful in a wide variety of fatigue tests of steel components under laboratory conditions. Moreover, it has the potential to be used in various industrial applications. To enable industrial deployment and integration into maintenance strategies, a concept study is developed in this contribution, resulting in a qualification framework that can serve as a foundation for determining the reliability of the crack luminescence system in terms of a probability of detection curve. Within this study, factors causing measurement variability and uncertainty are being determined and their influences assessed. Due to the extension of the system by a moving computer vision system for automated crack detection using artificial intelligence, additional long-term effects associated with structural health monitoring systems need to be incorporated into an extended probability of detection study as part of the technical justification. Finally, important aspects and findings related to design of experiments are discussed, and a framework for reliability assessment of a new optical crack monitoring method is presented, emphasizing the influence of various uncertainty parameters, including long-term effects such as system ageing. T2 - SPIE Conference Smart Structures + Nondestructive Evaluation 2023 CY - Long Beach, CA, USA DA - 24.03.2023 KW - Structural Health Monitoring KW - Non-Destructive Evaluation KW - Probability of Detection KW - Reliability KW - Artificial Intelligence KW - Computer Vision KW - Crack Luminescence KW - Wind PY - 2023 SN - 978-1-5106-6086-1 DO - https://doi.org/10.1117/12.2658390 SP - 1 EP - 15 AN - OPUS4-57244 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Balscheit, Hagen A1 - Schepers, Winfried A1 - Victor, Albrecht A1 - Daryaei, Reza A1 - Bianco, Marcelo A1 - Starost, Christina T1 - Close-out Webinar OWA VERBATIM N2 - The risk of pile base buckling is a major reason for high pile wall thicknesses in monopiles. The VERBATIM project - Verification of the buckling detection and behaviour of large monopiles - aimed to investigate buckling phenomena related to both the plastic deformation of the pile tip during installation and the buckling of the embedded pile near the seabed. Numerical models were developed and validated on the basis of extensive tests. This enables a better understanding of the buckling behaviour in order to reduce the wall thickness, which allows cost savings in the amount of steel and the development of safer and optimised structures. The previous design procedures were able to ensure the successful installation of the monopiles. However, as the size of monopiles continues to increase, the development of improved design methods for safe and cost-effective foundations is becoming increasingly important. The presentation provides an overview of the investigations carried out and the results. T2 - Webinar Carbon Trust Offshore Wind Accelerator CY - Online meeting DA - 22.05.2024 KW - Offshore Windenergy Pile Buckling PY - 2024 AN - OPUS4-60348 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichner, Lukas A1 - Thiele, Marc A1 - Hille, Falk A1 - Baeßler, Matthias T1 - Digitale Modellierungsprozesse in der wiederkehrenden Prüfung von Windenergieanlagen - DiMoWind-Inspect - Abschlusstreffen N2 - Dieses Dokument enthält die Präsentationsfolien des BAM-Teams beim Abschlusstreffen des Forschungsprojekts DiMoWind-Inspect. Es wurden die Arbeitspakete Datenmanagement, Referenzkennzeichnungssystem, Grundlagen der Schadensbewertung, Risikobasierte Inspektions- und Instandhaltungsplanung und Schadensdetektion mittels Risslumineszenz sowie eine abschließende Bewertung des Projekts vorgestellt. T2 - DiMoWind-Inspect - Abschlusstreffen CY - Berlin, Germany DA - 12.09.2024 KW - Building Information Modeling (BIM) KW - Referenzkennzeichnungssystem KW - Risslumineszenz (Riluminati) KW - Risikobasierte Inspektionsplanung (RBI) PY - 2024 AN - OPUS4-61054 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Balscheit, Hagen T1 - Evaluation of pile tip buckling based on large scale tests N2 - Der Vortrag zum zugehörigen Konferenzbeitrag beschreibt eine groß angelegte Feldtestkampagne mit 16 Rammversuchen, um das Risiko des plastischen Versagens der Pfahlspitzen besser zu verstehen Ein numerisches Modell mit transientem Bodenkontakt zeigt eine gute Übereinstimmung mit den Testergebnissen. Parametervariationen verdeutlichen, wie empfindlich die Pfahlreaktion auf Imperfektionen und Randbedingungen ist. T2 - 5th International Symposium on Frontiers in Offshore Geotechnics (ISFOG) CY - Nantes, France DA - 09.06.2025 KW - Pile Tip Buckling KW - Monopile KW - Offshore Windenergy KW - Driving Refusal KW - Large Scale Test PY - 2025 AN - OPUS4-63391 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Ronald T1 - Probabilistic approaches to the design and assessment of offshore foundations considering spatially varying site conditions N2 - In this presentation, we discuss the potential of probabilistic approaches to the design and assessment of offshore foundations. The potential is demonstrated in a numerical example considering a laterally loaded monopile. As an outlook, we present a concept for managing the risk associated with installing large monopiles. T2 - 3rd International Conference on Structural Integrity for Offshore Energy Industry (SI 2021) CY - Online meeting DA - 15.11.2021 KW - Offhore KW - Foundations KW - Probabilistic KW - Design KW - Assessment PY - 2021 AN - OPUS4-53748 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Simon, Patrick A1 - Schneider, Ronald A1 - Baeßler, Matthias A1 - Morgenthal, Guido T1 - Parallelized adaptive Bayesian updating with structural reliability methods for inference of large engineering models N2 - The reassessment of engineering structures, such as bridges, now increasingly involve the integration of models with realworld data. This integration aims to achieve accurate ‘as-is’ analysis within a digital twin framework. Bayesian model updating combines prior knowledge and data with models to enhance the modelling accuracy while consistently handling uncertainties. When updating large engineering models, numerical methods for Bayesian analysis present significant computational challenges due to the need for a substantial number of likelihood evaluations. The novelty of this contribution is to parallelize adaptive Bayesian Updating with Structural reliability methods combined with subset simulation (aBUS) to improve its computational efficiency. To demonstrate the efficiency and practical applicability of the proposed approach, we present a case study on the Maintalbrücke Gemünden, a large railway bridge. We leverage modal property data to update a linear-elastic dynamic structural model of the bridge. The parallelized aBUS approach significantly reduces computational time, making Bayesian updating of large engineering models feasible within reasonable timeframes. The improved efficiency allows for a wider implementation of Bayesian model updating in structural health monitoring and maintenance decision support systems. KW - Bayesian model updating KW - Bayesian updating with structural reliability methods KW - Structural health monitoring KW - Parallelization KW - Modal analysis KW - Railway bridge PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-633686 DO - https://doi.org/10.1177/13694332251346848 SN - 1369-4332 SN - 2048-4011 SP - 1 EP - 26 PB - Sage AN - OPUS4-63368 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Benseghier, Z. A1 - Cuéllar, Pablo A1 - Luu, L.-H. A1 - Bonelli, S. A1 - Philippe, P. T1 - A parallel GPU-based computational framework for the micromechanical analysis of geotechnical and erosion problems N2 - This article deals with the relevance and practical feasibility of micromechanical simulations for their application to general geomechanical problems involving fluid-saturated granular assemblies, whether frictional or cohesive. A set of conceptual and numerical tools is here presented, advocating for a parallel computation using graphical processing units (GPUs) to treat large numbers of degrees of freedom with conventional Desktop computers. The fluid phase is here simulated with a particle-resolved approach in the frame of the Lattice Botzmann Method (LBM) while the granular solid phase is modelled as a collection of discrete particles from a Molecular Dynamics DEM perspective. The range of possible material behaviours for the solid granular phase is intended here to cover a broad spectrum from purely frictional to viscous cohesive materials with either brittle or transient debonding features. Specific details of the implementation and some validation cases are put forward. Finally, some exemplary applications in the fields of soil erosion and geotechnical profile installation are provided along with a discussion on the parallel performance of the presented models. The results show that a micromechanical approach can be feasible and useful in practice, providing meaningful insights into complex engineering problems like the erosion kinetics of a soil under an impinging jet or the penetration resistance of a deep foundation in a layered soil profile. KW - Offshore geomechanics KW - Erosion KW - Micromechanical modelling KW - LBM-DEM KW - GPU Parallel computing PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-502309 DO - https://doi.org/10.1016/j.compgeo.2019.103404 VL - 120 SP - Paper 103404, 1 PB - Elsevier Ltd. AN - OPUS4-50230 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Balscheit, Hagen A1 - Geißler, Peter A1 - Cuéllar, Pablo A1 - Basedau, Frank A1 - Baeßler, Matthias T1 - Large-scale field tests on plastic pile tip failure upon monopile installation N2 - Large-diameter monopiles are the most common foundation structures for offshore wind turbines. One relevant failure mode during installation is plastic failure of the pile tip which may increase progressively during further driving (pile tip buckling; extrusion buckling). This paper presents the details and results of a large-scale field-test campaign with dynamic pile installation for the validation and calibration of different numerical approaches concerning pile-tip buckling phenomena. The phenomenology of observed pile-tip failures is here described in detail and a first quantitative approach is evaluated based on the field-test data. As the number of new projects continues to grow and the necessity to construct wind farms in challenging terrain increases, such field data-sets will become increasingly relevant. KW - Monopile KW - Offshore Windenergy KW - Pfahlfußbeulen KW - Pile Tip Buckling KW - Reference Tests PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611651 DO - https://doi.org/10.1016/j.oceaneng.2024.119322 VL - 313 SP - 1 EP - 14 PB - Elsevier B.V. AN - OPUS4-61165 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -