TY - CONF A1 - Artinov, Antoni T1 - Modeling the Relationship between Weld Pool Dynamics and Centerline Solidification Cracking in High Power Laser Beam Welding N2 - The present work deals with the recently confirmed widening of the weld pool interface, known as a bulging effect, and its relevance in high power laser beam welding. A combined experimental and numerical approach is utilized to study the influence of the bulge on the hot cracking formation and the transport of alloying elements in the molten pool. A technique using a quartz glass, a direct-diode laser illumination, a high-speed camera, and two thermal imaging cameras is applied to visualize the weld pool geometry in the longitudinal section. The study examines the relevance of the bulging effect on both, partial and complete penetration, as well as for different sheet thicknesses ranging from 8 mm to 25 mm. The numerical analysis shows that the formation of a bulge region is highly dependent on the penetration depth and occurs above 10 mm penetration depth. The location of the bulge correlates strongly with the cracking location. The obtained experimental and numerical results reveal that the bulging effect increases the hot cracking susceptibility and limits the transfer of alloying elements from the top of the weld pool to the weld root. T2 - Gastvortrag an der Universität Innsbruck, Institut für Konstruktion und Materialwissenschaften CY - Innsbruck, Austria DA - 18.06.2023 KW - Laser beam welding KW - Centerline solidification cracking KW - Bulging KW - Numerical simulation PY - 2024 AN - OPUS4-60333 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simon, Patrick T1 - Bayesian system identification of a reinforced concrete beam subject to temperature variations based on static response data N2 - Changes in the measured response of structural systems can be an indication of structural damages. However, such changes can also be caused by the effect of varying environmental conditions. To detect, localize and quantify changes or damages in structural systems subject to varying environmental conditions, physics-based models of the structural systems have to be applied which explicitly account for the influence of ambient conditions on the structural behavior. Data obtained from the structural systems should be used to calibrate the models and update predictions. Bayesian system identification is an effective framework for this task. In this paper, we apply this framework to learn the parameters of two competing structural models of a reinforced concrete beam subject to varying temperatures based on static response data. The models describe the behavior of the beam in the uncracked and cracked condition. The data is collected in a series of load tests in a climate chamber. Bayesian model class selection is then applied to infer the most plausible condition of the beam conditional on the available data. T2 - Tenth International Conference on Bridge Maintenance, Safety and Management (IABMAS 2020) CY - Online meeting DA - 11.04.2021 KW - Bayesian system identification KW - Reinforced concrete KW - Damage identification KW - Environmental effects KW - Structural health monitoring KW - Structural systems PY - 2021 AN - OPUS4-52812 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias T1 - Recap: Main Results of the BUMP Study and Relevance for VERBATIM N2 - Zusammenfassung des Forschungsprojekts BUMP hinsichtlich der Relevanz für das Projekt VERBATIM N2 - BUMP had been a theoretical prestudy on open issues for the pile tip buckling of large monopiles. The presentation summarizes the main results and considers the impact for the ongoing VERBATIM project. VERBATIM is set up as a mainly experimental verification project for pile buckling. T2 - Kick-Off Projekt VERBATIM CY - BAM, Berlin, Germany DA - 23.01.2020 KW - Buckling piles circular shells PY - 2020 AN - OPUS4-50515 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hille, Falk A1 - Herrmann, Ralf T1 - Structural Health Monitoring am Großen Fallturm der BAM N2 - In diesem Beitrag wird die Structural Health Monitoring Kampagne am Großen Fallturm der BAM vorgestellt. T2 - Seminar "Zerstörungsfreie Prüfung" CY - Online meeting DA - 13.01.2022 KW - Belastungsversuch KW - Großer Fallturm Horstwalde KW - Schwingungsdynamik KW - Modalanalyse PY - 2022 AN - OPUS4-55478 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hille, Falk T1 - Discussion on data evaluation of tomographic and numerical results N2 - The contribution discusses the processing and analysis of data generated on two different ways of investigations for impact damage in reinforced concrete structures. Damage investigations are essential to determine type and characteristics of damage and thus the residual capacity. Damage describing data is generated using two different types of investigation, a non-destructive tomographic as well as numerical examination. Subsequently, data of both sources was merged and analysed. Within the research project “Behaviour of structural components during impact load conditions caused by aircraft fuel tank collision” reinforces concrete plates were damaged by impact loading, see Hering (2020). Afterwards the damaged specimens were investigated tomographically as well as numerically using several methods and models. Aim of the presented research work was to specify an objective comparability of numerical data with experimentally determined damage patterns and based on this, to establish a quantitative damage evaluation. T2 - 26th International Conference on Structural Mechanics in Reactor Technology CY - Potsdam, Germany DA - 10.07.2022 KW - Impact damage of reinforced concrete KW - Tomographic damage evaluation KW - Numerical simulation of impact damage PY - 2022 AN - OPUS4-55476 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simon, Patrick T1 - Research Data Management of Structural Health Monitoring Projects and Subsequent Applications of Artificial Intelligence Methods N2 - Structural health monitoring (SHM) intends to improve the management of engineering structures. The number of successful SHM projects – especially SHM research projects – is ever growing, yielding added value and more scientific insight into the management of infrastructure asset. With the advent of the data age, the value of accessible data becomes increasingly evident. In SHM, many new data-centric methods are currently being developed at a high pace. A consequent application of research data management (RDM) concepts in SHM projects enables a systematic management of raw and processed data, and thus facilitates the development and application of artificial intelligence (AI) and machine learning (ML) methods to the SHM data. In this contribution, a case study based on an institutional RDM framework is presented. Data and metadata from monitoring the structural health of the Maintalbrücke Gemünden for a period of 16 months are managed with the RDM system BAM Data Store, which makes use of the openBIS data management software. An ML procedure is used to classify the data. Feature engineering, feature training and resulting data are performed and modelled in the RDM system. T2 - 11th International Conference on Bridge Maintenance, Safety and Management (IABMAS2022) CY - Barcelona, Spain DA - 11.07.2022 KW - Research data management KW - Structural health monitoring KW - Artificial intelligence PY - 2022 AN - OPUS4-55494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichner, Lukas T1 - Optimal sensor placement for vibration-based structural health monitoring obtained via value of information analysis as part of a digital structural integrity management of offshore structures N2 - A digital structural integrity management of offshore structures enables an optimized planning of inspections and repairs with risk-based methods. In a risk-based approach, the inspection and repair strategy that minimizes the expected lifetime costs consisting of the expected inspection, repair and failure costs is determined. In addition to inspections, information on the structural condition can be continuously obtained by monitoring the vibration response of the structural system. Changes in the vibration characteristics quantified in terms of modal properties can be an indication of structural damage. In risk-based inspection and repair planning, the effect of monitoring results is determined via Bayesian updating of the structural condition and reliability. This information should be applied to inform decisions on inspections and may result in a reduced inspection effort. The benefit of continuously monitoring the structural health can be quantified in terms of the value of information, which corresponds to the difference between the expected lifetime costs with and without monitoring. In this work, we demonstrate in a numerical example how an optimized sensor placement for a vibration-based structural health monitoring system can be determined by maximizing the value of information. T2 - 3rd International Conference on Health Monitoring of Civil & Maritime Structures (HeaMES 2022) CY - Online meeting DA - 08.06.2022 KW - Bayesian System Identification KW - Offshore Wind Energy KW - Optimal Sensor Placement KW - Structural Health Monitoring KW - Value of Information PY - 2022 AN - OPUS4-55473 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simon, Patrick T1 - Sensorbasierte Systemidentifikation N2 - Die aktuelle Instandhaltungsstrategien von Ingenieurbauwerken arbeiten zustandsbasiert und stützen sich auf visuelle Inspektionen in kurzen, starren Intervallen. Beim Übergang zu Predicitive-Maintenance-Strategien können Sensordaten eigesetzt werden um Prognosemodelle der Bauwerke zu aktualisieren. Ein erster Schritt hierzu ist die sensorbasierte Systemidentifikation. T2 - Abschlussveranstaltung AISTEC CY - Berlin, Germany DA - 02.05.2022 KW - Systemidentifikation KW - Strukturmonitoring PY - 2022 AN - OPUS4-55495 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichner, Lukas T1 - A framework for data and structural integrity management for support structures in offshore wind farms based on building information modelling N2 - Support structures of wind turbines in German offshore wind farms are regularly inspected. Currently, inspection outcomes are generally not systematically recorded. This prevents their consistent handling and processing, which is a key requirement to enable an efficient structural integrity management. As part of the DiMoWind-Inspect project, a data model and reference designation system for such inspection results is developed to facilitate their identification, localization, quantification, tracing and linking throughout the lifetime of a wind farm and beyond. The inspection results together with structural health monitoring results and information on repairs form the basis for assessing and predicting the structural condition, estimating the remaining lifetime, and planning of future inspections, structural health monitoring, and repairs. As a basis for developing a digital structural integrity management, a generic framework is proposed in this paper, which describes the stakeholders, data, models, processes and workflows of the integrity management of support structures in offshore wind farms and their interrelations. The framework adopts a building information modelling approach to describe the information relevant to the structural integrity management. The central digital space of the framework is a common data environment. An implementation of the framework will enable a digital structural integrity management in which inspection, structural health monitoring, repair, assessment and planning outcomes generated throughout the life cycle of a wind farm can be consistently collected, managed, shared and processed by the relevant shareholders. T2 - 8th International Symposium on Reliability Engineering and Risk Management CY - Hannover, Germany DA - 04.09.2022 KW - Offshore wind energy KW - Support structures KW - Building information modelling KW - Structural health monitoring KW - Structural integrity maintenance PY - 2022 AN - OPUS4-55651 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Ronald T1 - Belastungsversuch und Methodenvalidierung an der Maintalbrücke Gemünden N2 - Im Projekt AISTEC wurden Methoden entwickelt, die der prädiktiven Instandhaltung von Ingenieurbauwerken dienen. Zur Validierung dieser Methoden wurden an einem Referenzbauwerk - der Maintalbrücke Gemünden - Belastungstests durchgeführt. T2 - Abschlussveranstaltung AISTEC CY - Berlin, Germany DA - 02.05.2022 KW - Belastungsfahrt KW - GNSS KW - Einflusslinien PY - 2022 AN - OPUS4-55496 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hille, Falk T1 - Structural Health Monitoring am Großen Fallturm der BAM N2 - Am Fallturm auf dem Testgelände Technische Sicherheit (TTS) der BAM wurden bei Inspektionen Vorspannungsverluste in den Bolzen der Stahlverbindungen festgestellt. Um ein Verständnis für die zugrundeliegenden Trag- und Schädigungsmechanismen zu erlangen und um den Zustand der vorgespannten Schraubverbindungen langzeitlich zu überwachen, wurde am Fallturm ein Structural Health Monitoring (SHM) System installiert. Für die Auslegung des Monitoringsystems sowie zur Unterstützung der Untersuchung des Schädigungsprozesses wurde ein numerisches Modell erstellt und in Bezug auf die gemessenen Antworten des Tragwerks kalibriert. Im Vortrag werden die experimentellen und numerischen Untersuchungen zur Systemidentifikation des Stahlrohrgitterturms als auch die Überwachungskampagne mit dem eingesetzten Monitoringsystem sowie die Messergebnisse und deren Bewertung vorgestellt. T2 - Seminar "Zerstörungsfreie Prüfung" am Lehrstuhl für Zerstörungsfreie Prüfung ,Technische Universität München CY - Online meeting DA - 13.01.2022 KW - Structural Health Monitoring KW - Schadensüberwachung KW - Schwingungsmonitoring PY - 2022 AN - OPUS4-56667 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ramasetti, Eshwar Kumar A1 - Herrmann, Ralf A1 - Degener, Sebastian A1 - Baeßler, Matthias T1 - Development of generic AI models to predict the movement of vehicles on bridges N2 - For civil, mechanical, and aerospace structures to extend operation times and to remain in service, structural health monitoring (SHM) is vital. SHM is a method to examining and monitoring the dynamic behavior of essential constructions. Because of its versatility in detecting unfavorable structural changes and enhancing structural dependability and life cycle management, it has been extensively used in many engineering domains, especially in civil bridges. Due to the recent technical developments in sensors, high-speed internet, and cloud computing, data-driven approaches to structural health monitoring are gaining appeal. Since artificial intelligence (AI), especially in SHM, was introduced into civil engineering, these modern and promising methods have attracted significant research attention. In this work, a large dataset of acceleration time series using digital sensors was collected by installing a structural health monitoring (SHM) system on Nibelungen Bridge located in Worms, Germany. In this paper, a deep learning model is developed for accurate classification of different types of vehicle movement on the bridge from the data obtained from accelerometers. The neural network is trained with key features extracted from the acceleration dataset and classification accuracy of 98 % was achieved. T2 - SMAR 2024 - 7th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures CY - Salerno, Italy DA - 04.09.2024 KW - Machine learning KW - Structural Health Monitoring (SHM) PY - 2024 AN - OPUS4-61375 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herrmann, Ralf T1 - A Living Lab for Structural Health Monitoring at the Nibelungen Bridge Worms for Transfer Learning of Structural Dynamics N2 - The Nibelungen Bridge in Worms, Germany has been selected as a national demonstration structure for advanced non-destructive testing (NDT) and structural health monitoring concepts to extend the lifetime of civil structures and to optimize O&M actions. Parts of the research that involves this bridge as a demonstrator belong to the focus area program SPP100+. In this program, the bridges SHM System has been extended and combined with an additional setup of vibration sensors. The used digital smart sensor with pre-processing functions, the arrangement of the sensors at the structure and additional edge computing capability allows the investigation of transfer learning and other methods directly into the real structure. The living lab with seven triaxial accelerometers can be reconfigured in real-time and adjusted to the needs of AI models for classification. The comparison with the existing conventional SHM sensors has been made possible by hardware synchronization to the existing SHM System and collocating sensors at similar positions, so that a hardware exchange can be an investigated use-case for the transfer learning. During idle times, the system collects vibration data like a conventional SHM system. T2 - 10th European Workshop on Structural Health Monitoring (EWSHM 2024) CY - Potsdam, Germany DA - 10.06.2024 KW - Structural Health Monitoring (SHM) KW - SPP100+ KW - Nibelungen Bridge KW - Sensor technology PY - 2024 AN - OPUS4-61284 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hille, Falk T1 - Leitfaden für den strategischen Einsatz von Monitoring an Straßenbrücken N2 - Für die Anwendung von Structural Health Monitoring (SHM) im Rahmen des Managements von Straßenbrücken wurde zur Unterstützung von Straßenbauverwaltungen, Ingenieurbüros, Bauunternehmen und weiteren Akteuren die Erstellung eines Leitfadens initiiert. Dieser Leitfaden stellt typische Anwendungsfälle für Monitoring vor und schlägt für diese bewährte Herangehensweisen vor. Darüber hinaus bietet der Leitfaden Empfehlungen für Ausschreibung und Vergabe von Monitoringleistungen, eine Anleitung zur Bewertung des wirtschaftlichen Nutzens von SHM, Hinweise zur optimal einsetzbaren Messtechnik sowie einen Ansatz für das Datenmanagement zur Integration der Monitoringdaten in das Brückenmanagement. T2 - 11. Jahrestagung des DAfStb mit 63. Forschungskolloquium der BAM CY - Berlin, Germany DA - 16.10.2024 KW - Bauwerksmonitoring KW - Straßenbrücken KW - Leitfaden PY - 2024 AN - OPUS4-61400 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herrmann, Ralf T1 - Föderiertes Datenmanagement von Monitoringdaten aus Structural Health Monitoring Anwendungen und daraus gewonnenen Trainingsdaten bei Spannbetonbrücken N2 - Beim Structural Health Monitoring entstehen eine Vielzahl von Daten, Metadaten und Modellen mit hohem Wert für die Beurteilung des Bauwerkszustands und der Prognose von Veränderungen. Kontinuierlich anwachsende Datenbestände müssen nachhaltig geteilt, genutzt und über die Bauwerkslebensdauer archiviert werden. Dabei stellen die Vielfalt der Messaufgaben, die Heterogenität der Daten, die dezentrale Erfassung und z. T. der Umfang eine Herausforderung für die beteiligten Akteure dar. Für den Datentransfer der Monitoringdaten zwischen der Straßenbauverwaltung und den Monitoringausführenden wird ein flexibles Abstimmungsverfahren vorgeschlagen und ein Lösungskonzept für ein föderiertes Datenmanagement skizziert. Eine weitere Herausforderung stellt die bauwerksübergreifende Zusammenstellung von Trainingsdaten für konkrete KI-Anwendungen dar. T2 - 11. Jahrestagung des DAfStb mit 63. Forschungskolloquium der BAM Green Intelligent Building CY - Berlin, Germany DA - 16.10.2024 KW - Structural Health Monitoring KW - Spannbetonbrücke KW - Datenmanagement KW - Auftraggeber-Daten-Anforderungen (ADA) KW - Bauwerkschäden PY - 2024 AN - OPUS4-61780 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hering, Marcus T1 - Impaktversuche an Stahlbetonplatten N2 - Seit 1977 ist der Flugzeugabsturz ein wesentliches Belastungsszenario bei der Auslegung von Kernkraftwerken. Zur Untersuchung dieses Szenarios wurden umfassende Studien durchgeführt, welche die Reaktion von Stahlbetonkonstruktionen unter Stoßbelastung analysieren. Da großmaßstäbliche Experimente teuer und aufwendig sind, gewinnen skalierte Versuche zunehmend an Bedeutung. Im Rahmen eines Forschungsprojekts der TU Dresden und der BAM wurden Grundlagen für skalierte Impaktversuche im großen Maßstab geschaffen, um die Übertragbarkeit vom Labor- auf Realmaßstab zu ermöglichen. T2 - 11. Jahrestagung des DAfStb mit 63. Forschungskolloquium der BAM Green Intelligent Building CY - Berlin, Germany DA - 16.10.2024 KW - Stahlbetonplatten KW - Impaktversuch KW - Sicherheit Kernkraftwerke PY - 2024 AN - OPUS4-61770 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thiele, Marc T1 - Monitoring an Türmen von Onshore Windenergieanlagen in Betonbauweise im Hinblick auf Ermüdung N2 - Der Beitrag stellt das Messkonzept sowie dessen Umsetzung für ein umfassendes Monitoringsystem an einer onshore Windenergieanlage mit einem Hybridturm vor. Dieses ist Bestandteil des Forschungsvorhabens Win-ConFat–Structure, welches neben der Validierung geeigneter Sensorik auch die Bewertung des Zustands und der möglichen Restlebensdauer der ermüdungsbeanspruchten Betonstruktur zum Ziel hat. Neben dem Monitoringsystem werden erste Messergebnisse aus den Betriebsdaten sowie vom Verhalten der Turmstruktur vorgestellt. T2 - 11. Jahrestagung des DAfStb mit 63. Forschungskolloquium der BAM Green Intelligent Building CY - Berlin, Germany DA - 16.10.2024 KW - Onshore Windenergieanlagen KW - Ermüdung KW - Lebensdauerbewertung KW - Monitoring KW - WinConFat PY - 2024 AN - OPUS4-61773 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simon, Patrick T1 - Temperatureinfluss auf Strukturmonitoring – aktuelle Versuche N2 - Strukturmonitoring kann wertvolle Daten für die Zustandsbewertung und Schadensdetektion von Infrastruk-turbauwerken liefern. Umgebungsbedingungen wie die Temperatur beeinflussen die Bauwerke und somit die Messdaten jedoch erheblich. Um Methoden für den Umgang mit Temperatureinflüssen zu entwickeln, wurden an der BAM Versuche an Stahlbeton- und Asphaltbalken unter kontrollierten Temperaturen von -40 °C bis 60 °C und definierten Schädigungen durchgeführt. Die Daten ermöglichen die Erforschung und Validierung neuer, auch unter Temperatureinfluss zuverlässiger Methoden des Strukturmonitorings. T2 - 11. Jahrestagung des DAfStb mit 63. Forschungskolloquium der BAM Green Intelligent Building CY - Berlin, Germany DA - 16.10.2024 KW - Structural Health Monitoring KW - Strukturmonitoring KW - Temperatureinfluss KW - Klimakammer KW - Bayesian Updating PY - 2024 AN - OPUS4-61573 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hering, Marcus A1 - Fiedler, Georg T1 - Investigation of multiple impact-damaged reinforced concrete structures as a reference for liquid penetration behavior and tomographic studies N2 - The structural integrity of outer reinforced concrete (RC) containments of nuclear power plants provides an essential shield against external hazards. If this containment is damaged by an impact event, such as an aircraft crash, the question arises to which degree the reinforced concrete containment still has its protective capability. This concerns both purely structural protection and protection against liquids penetrating the interior of the containment. Due to the dimensions of the containment structures, it is difficult to perform real scale impact experiments, so in the past decades plate geometries at medium scale have been used for investigations. Detailed investigations on the structural behaviour of RC members or RC plates subjected to impact loading have already been presented in Just et al., Hering, Hering et al., Bracklow et al., Hille et al. and Nerger et al. The following investigations deal with the single and multiple impact event (first hard impact and/or subsequent soft impact) on a RC specimen, which provides the basis for further investigations. A description of the test setup and the test procedure as well as a presentation of the test results from the impact tests are provided. Furthermore, the experimental program is presented, which the damaged RC specimens are to undergo to deal with the question of how much the impact-damaged RC structure has become permeable to liquid media, such as water and kerosene, depending on the intensity of the impact. The aim of these following investigations is to develop a test setup that can be applied to investigate the liquid penetration behaviour (LPB) of small, medium, and large-scale RC members. In addition to the liquid penetration experiments, the damaged specimens are to be examined by planar tomography to obtain the damage inside the specimen. The combination of damaging event, fluid penetration behaviour and tomography should enable a comprehensive understanding of the damage to the RC specimen. T2 - Conference: 27th International Conference on Structural Mechanics in Reactor Technology (SMiRT) CY - Yokohama, Japan DA - 04.03.2024 KW - Drop Tower KW - Hard Impact KW - Multiple Impact KW - Soft Impact PY - 2024 AN - OPUS4-61991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Ronald T1 - Kontinuierliche sensordaten- und modellgestützte Bewertung von Infrastrukturbauwerken in der Praxis N2 - Ein Einsatz von kontinuierlichen sensorbasierten Verfahren komplementär zu den zeitlich diskreten bildbasierten Verfahren haben ein enormes Potenzial, die bisher hauptsächlich visuellen Prüfprozesse zu transformieren. Zur Ermöglichung eines strategischen Einsatzes des sensorbasierten Monitorings im Erhaltungsmanagement von Ingenieurbauwerken ist das übergeordnete Ziel des Projektes AISTEC-Pro die Demonstration des praktischen Mehrwerts des sensorbasierten Monitorings. Dies wird durch praktische Anwendungen an der Maintalbrücke Gemünden und einem neu ausgewählten Referenzbauwerk unter Berücksichtigung von typischen Einsatzszenarien im Bereich der Bauwerkserhaltung erreicht werden. Die Einsatzszenarien werden in enger Abstimmung mit den Endanwendern entwickelt und fortgeschrieben. Hierbei wird insbesondere Bezug auf die aktuelle Neufassung der DIN 1076 genommen, in der erstmals die Anwendung von sensor- und bildbasierten Monitoringverfahren in der Bauwerksprüfung geregelt wird. T2 - AISTEC-Pro Auftakttreffen CY - Weimar, Germany DA - 02.12.2024 KW - Sensorbasiertes Monitoring KW - Erhaltung KW - Verkehrsbrücken PY - 2024 AN - OPUS4-61919 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herrmann, Ralf T1 - SHM system integration and experiments at a high speed railway bridge N2 - The long-term preservation of our infrastructure requires not only intelligent sensor technology and highly developed monitoring procedures, but also innovative digital tools for analyzing, evaluating and utilizing the results. This includes mathematical and, in particular, probabilistic methods for damage detection and tracking as well as for calculating service life and maintenance cycles and data management. The example project Maintal Bridge Gemuenden as part of the AISTEC project shows the workflow for the implementation of structural health monitoring and experimental tests with a train of Deutsche Bahn. The influence lines, as one possible way for damage detection, were measured with a highly accurate GNSS System to locate the trains position when crossing the bridge. The results were compared to measurements from 1987 just before the bridge went in operation. T2 - Structural Health Monitoring Using Statistical Pattern Recognition CY - Berlin, Germany DA - 20.03.2023 KW - SHM KW - Maintal Bridge Gemuenden KW - Load Test KW - Damage Detection KW - Railway PY - 2023 AN - OPUS4-57242 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gerards-Wünsche, Paul 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 PY - 2023 AN - OPUS4-57245 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Aubram, Daniel T1 - Vorstellung OWA VERBATIM N2 - Das Risiko von Pfahlfussbeulen ist ein wesentlicher Grund für hohe Pfahlwandstärken bei Monopiles. Das Projekt VERBATIM - Verifikation des Beulnachweises und –verhaltens großer Monopiles zielte darauf ab, Beulphänomene zu untersuchen, die sich sowohl auf die plastischen Verformungen der Pfahlspitze während der Installation als auch auf das Beulen des eingebetteten Pfahls in der Nähe des Seebodens beziehen. Auf der Basis aufwändiger Versuche wurden numerische Modelle entwickelt und validiert. Dies ermöglicht ein besseres Verständnis des Beulverhaltens, um die Wanddicke zu reduzieren, was Kosteneinsparungen bei der Stahlmenge sowie die Entwicklung sicherer und optimierter Strukturen erlaubt. Die bisherigen Designverfahren konnten die erfolgreiche Installation der Monopiles gewährleisten. Da die Größe von Monopiles jedoch stetig zunimmt, wird die Entwicklung verbesserter Designverfahren für sichere und kostengünstige Fundamente immer wichtiger. Der Rückenwind-Vortrag gibt eine Übersicht zu den durchgeführten Untersuchungen und Ergebnissen T2 - Rückenwind Aktuelles aus der Windenergieforschung (PTJ) CY - Online meeting DA - 21.06.2024 KW - Offshore Windenergy Pile Buckling PY - 2024 AN - OPUS4-60349 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Eichner, Lukas A1 - Weise, Sigurd T1 - Digital building management for OWEC-structures N2 - The presentation summarizes the data management and Digital modeling processes in the recurring inspection of wind turbines as developed in DiMoWind-Inspect. T2 - Windforce 2024 CY - Bremerhaven, Germany DA - 10.06.2024 KW - DiMoWind RDS-PP Maintenance Digital Twin Offshore Wind Energy PY - 2024 AN - OPUS4-60351 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Weise, Sigurd T1 - Digitalization of Maintenance Processes N2 - Main aspects of Digitalization of Maintenance Processes are summarized and discussed. Introduction to the Windforce2024 session organised by BAM. T2 - Windforce 2024 CY - Bremerhaven, Germany DA - 11.06.2024 KW - Maintenance Digital Twin Offshore Wind Energy PY - 2024 AN - OPUS4-60350 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Ronald A1 - Herrmann, Ralf T1 - Sensorbasiertes Monitoring der Maintalbrücke Gemünden N2 - Monitoringsysteme erfassen kontinuierlich Bauwerksdaten wie z.B. Bauwerksbeschleunigungen, auf deren Grundlage Bauwerksschäden mit Hilfe von SHM-Methoden quantifiziert werden können. Mit den gewonnenen Informationen über den aktuellen Bauwerkszustand können Vorhersagen des Bauwerkszustandes und der Bauwerkszuverlässigkeit aktualisiert und erforderliche Inspektionen und Instandhaltungsmaßnahmen vorausschauend geplant werden. Im BMBF-Forschungsvorhaben AISTEC entwickeln der Fachbereich 7.2 „Ingenieurbau“ innovative Monitoringverfahren zur Systemidentifikation und automatischen Detektion, Lokalisierung und Quantifizierung von Schäden an Infrastrukturbauwerken anhand von gemessenen dynamischen und statischen Bauwerksdaten. Im Rahmen dieses Projektes werden die Verfahren an der Maintalbrücke bei Gemünden angewendet, welche Teil der ICE-Strecke Hannover-Würzburg ist. In diesem Vortrag wird das für die Maintalbrücke Gemünden geplante und umgesetzte Monitoingsystem vorgestellt. T2 - 4. Verbundtreffen AISTEC CY - Weimar, Germany DA - 24.09.2020 KW - Zivile Sicherheit KW - Brücken KW - Structural Health Monitoring PY - 2020 AN - OPUS4-51333 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thiele, Marc T1 - Fatigue crack detection methods for high-cyclic loaded steel structures and challenges in mechanical testing N2 - For the generation of renewable energy offshore wind farms play an important role. The majority of these wind generators are connected to steel foundation structures. Steady increasing power output of these wind turbines leads to new challenges as well for engineers of the related support structures. Caused by the high-cyclic loading of these structures by wind and waves fatigue plays a very important role. Besides the consideration of fatigue within the design process it is additionally an important topic and challenge to monitor the existing steel structures relating to potential fatigue cracks occurring during their lifetime. This plays a role for a fundamental understanding of mechanisms as investigated in testing but also for inspection in real structures. Since the structures of the offshore wind generators are very large and in addition partially under water effective and reliable methods for fatigue crack detection are required. This contribution will present results of recent investigations on different crack detection methods applied on high-cycle fatigue tests on small welded steel samples as well as on welded steel components. The comparison of these measurements will show what are the advantages and disadvantages of the different methods and which method is potentially more suitable for the application on real offshore wind structures. It is outlined where challenges for detection methods exist. Furthermore, in this context the resulting challenges for the execution of material testing especially caused by the increasing dimensions of wind energy converters will by exemplarily presented. T2 - EERA JP Wind & SETWind Online Annual Event 2020 CY - Online meeting DA - 14.09.2020 KW - Fatigue KW - Crack detection KW - Steel structures PY - 2020 AN - OPUS4-51356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Ronald T1 - Kontinuierliches Bauwerksmonitoring – Sensor-basiert (AP4) N2 - Kontinuierliche sensorbasierte Bauwerksmessungen leisten einen wichtigen Beitrag zur Sicherheit von Verkehrsbauwerken. Hierzu werden im Vorhaben AISTEC Referenzbauwerke und Referenzverfahren untersucht mit Schwerpunkt auf den Einfluss klimatischer Bedingungen. Der Vortrag stellt den aktuellen Projektstand des FB 7.2 vor. T2 - 3. Verbundtreffen AISTEC CY - Online meeting DA - 05.05.2020 KW - Zivile Sicherheit KW - Brücken KW - Structural Health Monitoring PY - 2020 AN - OPUS4-50796 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simon, Patrick T1 - Vibration-based Structural Health Monitoring of a Reinforced Concrete Beam Subjected to Varying Ambient Conditions Using Bayesian Methods N2 - Inspection and maintenance contribute significantly to the lifetime cost of bridges. There is significant potential in using information obtained through structural health monitoring to update predictive models of the condition and performance of such structures, and thus ena-ble an improved decision-making regarding inspection and maintenance activities. Within the AISTEC project funded by the German Federal Ministry of Education and Research, we develop vibration-based structural health monitoring systems aimed at continuously provid-ing information on the structural condition of bridges. Environmental variations such as changing ambient temperatures can significantly influence the dynamic characteristics of bridges and thus mask the effect of structural changes and damages. It remains a challenge to account for such influences in structural health monitoring. To study the effect of ambient temperatures on the dynamic characteristics of beam structures, we monitor the vibration response of a reinforced concrete beam in the uncracked and cracked state at varying tem-peratures in a climate chamber. We postulate a set of competing parameterized probabilistic structural models, which explicitly account for the effect of varying ambient temperatures on the mechanical properties of the system. We then combine the information provided by the structural models with the information contained in the recorded vibration data to learn the parameters of the temperature-dependent structural models and infer the plausible state of the beam using Bayesian system identification and model class selection. T2 - EURODYN 2020, XI International Conference on Structural Dynamics CY - Online meeting DA - 23.11.2020 KW - Bayesian methods KW - Environmental effects KW - Structural health monitoring PY - 2020 AN - OPUS4-51732 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Viefhues, Eva T1 - Fault detection for linear parameter varying systems under changes in the process noise covariance N2 - Detecting changes in the eigenstructure of linear systems is a comprehensively investigated subject. In particular, change detection methods based on hypothesis testing using Gaussian residuals have been developed previously. In such residuals, a reference model is confronted to data from the current system. In this paper, linear output-only Systems depending on a varying external physical parameter are considered. These systems are driven by process noise, whose covariance may also vary between measurements. To deal with the varying parameter, an interpolation approach is pursued, where a limited number of reference models { each estimated from data measured in a reference state { are interpolated to approximate an adequate reference model for the current parameter. The problem becomes more complex when the different points of interpolation correspond to different noise conditions. Then con icts May arise between the detection of changes in the eigenstructure due to a fault and the detection of changes due to different noise conditions. For this case, a new change detection approach is developed based on the interpolation of the eigenstructure at the reference points. The resulting approach is capable of change detection when both the external physical parameter and the process noise conditions are varying. This approach is validated on a numerical simulation of a mechanical system. T2 - 21st IFAC World Congress CY - Berlin, Germany DA - 13.07.2020 KW - Linear parameter varying systems KW - Fault detection KW - Changing process noise KW - Subspace-based residual KW - Model interpolation PY - 2020 AN - OPUS4-52366 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herrmann, Ralf T1 - Vorstellung des Bauwerksmonitoring der Maintalbrücke Gemünden im Vorhaben AISTEC N2 - Im Abteilungsseminar wird der aktuelle Umsetzungsstand des Bauwerksmonitorings an der Maintalbrücke Gemünden vorgestellt, sowie die nächsten Schritte zur Systemintegration von Konzepten an Realbauwerken. T2 - Abteilungs-Vortragsseminar Abteilung 7. Bauwerkssicherheit CY - Online meeting DA - 03.03.2021 KW - Structural Health Monitoring KW - Maintalbrücke Gemünden KW - Bauwerksüberwachung KW - Datenmanagement PY - 2021 AN - OPUS4-52221 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, Ronald T1 - Sensorbasiertes Monitoring (AP4 + AP7): Ein Überblick N2 - Im AISTEC Projekt erforscht der FB 7.2 Verfahren zur Bewertung von Verkehrsbrücken auf der Gruandlage von sensorbasierten Bauwerksmessungen. In diesem Vortrag wird ein Überlick über die Forschungsarbeiten des FB 7.2 präsentiert. Des Weiteren wird ein Ausblick zur quantitativen Integration von sensorbasierten Bauwerksmessungen in die risiko-basierte prädiktive Planung von Inspektionen und Reparaturen von Ingenieurbauwerken gegeben. T2 - AISTEC 5. Verbundtreffen CY - Online meeting DA - 24.06.2021 KW - AISTEC KW - Structural Health Monitoring KW - Brücken PY - 2021 AN - OPUS4-52982 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herrmann, Ralf T1 - AISTEC 5. Verbundtreffen - Messfahrt auf der Maintalbrücke Gemünden N2 - Der Vortrag stellt die Durchführung und die ersten Ergebnisse der Belastungsfahrten der BAM im Rahmen des AISTEC Projekts an der Maintalbrücke am 19.05. und 20.05.2021 vor. Es wurden Tragwerksreaktionen des Bauwerks mit dem installierten Dauermonitoringsystem und insbesondere dem Betongelenk mit zusätzlich installierter Sensorik aufgezeichnet. Für die Ermittlung der Lastposition wurden mehrere Verfahren eingesetzt und verglichen. T2 - AISTEC 5. Verbundtreffen CY - Online meeting DA - 24.06.2021 KW - AISTEC KW - Structural Health Monitoring KW - Einflusslinie KW - Messfahrt KW - Belastungszug PY - 2021 AN - OPUS4-52927 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Viefhues, Eva T1 - Stochastic subspace-based damage detection of a temperature affected beam structure N2 - Structural health monitoring (SHM) of civil structures often is limited due to changing environmental conditions, as those changes affect the structural dynamical properties in a similar way like damages can do. In this article, an approach for damage detection under changing temperatures is presentedand applied to a beam structure. The used stochastic subspace-based algorithm relies on a reference null space estimate, which is confronted to data from the testing state in a residual function. For damage detection the residual is evaluated by means of statistical hypothesis tests. Changes of the system due to temperature effects are handled with a model interpolation approach from linear parameter varying system theory. From vibration data measured in the undamaged state at some few reference temperatures, a model of the dynamic system valid for the current testing temperature is interpolated. The reference null space and the covariance matrix for the hypothesis test is computed from this interpolated model. This approach has been developed recently and was validated in an academic test case on simulations of a mass-spring-damper. In this paper, the approach is validated experimentally on a beam structure under varying temperature conditions in a climate chamber. Compared to other approaches, the interpolation approach leads to significantly less false positive alarms in the reference state when the structure is exposed to different temperatures, while faults can still be detected reliably T2 - 10th International Conference on Structural Health Monitoring of Intelligent Infrastructure, SHMII 10 CY - Online meeting DA - 30.06.2021 KW - Damage detection KW - Subspace methods KW - Temperature effects KW - Model interpolation KW - Climate chamber KW - Laboratory beam structure PY - 2021 AN - OPUS4-53000 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias T1 - Dynamisches Verhalten und Überwachung des Großen Fallturms der BAM in Horstwalde N2 - Falltürme sind Bauwerke, die als Versuchsanlagen sehr speziellen, impulsartigen Belastungen ausgesetzt sind. Am Fallturm auf dem Testgelände Technische Sicherheit (TTS) der BAM wurde bei Routineinspektionen eine Abnahme der strukturellen Integrität in Form von Vorspannungsverlusten in den Bolzen der Stahlverbindungen festgestellt. Um ein Verständnis für die zugrundeliegenden Trag- und Schädigungsmechanismen zu erlangen, wurde ein umfassendes Structural Health Monitoring (SHM) System geplant und am Bauwerk installiert unter Nutzung von digitalen Bauwerksmodellen. Für die Auslegung des Überwachungssystems, insbesondere aber zur Unterstützung der Untersuchung des Schädigungsprozesses, wurden Finite-Elemente-Modelle erstellt. Um sicherzustellen, dass die FE-Modelle das reale Tragwerksverhalten mit ausreichender Genauigkeit abbilden, mussten sie jedoch in Bezug auf die gemessenen Antworten des Tragwerks kalibriert werden. Der vorliegende Beitrag beschreibt experimentelle und numerische Untersuchungen zur Identifizierung des strukturellen Systems des Stahlrohrgitterturms in Vorbereitung einer Überwachungskampagne. Die Auswertung von gemessenen Schwingungen unter ambienter Anregung ermöglichte die Identifizierung der Eigenfrequenzen mehrerer globaler Schwingungsmoden des Fallturms. Zur Modellvalidierung wurde zunächst eine Sensitivitätsanalyse durchgeführt, um die Parameter mit dem größten Einfluss zu ermitteln. Anschließend wurde ein evolutionärer Algorithmus (EA) zur Optimierung nach dem Prinzip der Minimierung der Differenzen zwischen gemessenen und simulierten charakteristischen Antworten eingesetzt. Das aktualisierte Modell wurde schließlich an der dynamischen Reaktion der Turmstruktur infolge einer realen Falltest-induzierten Stoßbelastung validiert. Die Ergebnisse zeigten eine gute Übereinstimmung zwischen numerischen und experimentellen Ergebnissen. N2 - Drop test towers are structures subjected to very specific dynamic loadings. At the drop test tower at the Test Site Technical Safety (TTS) of BAM routine inspections revealed a decline of structural integrity in form of loss of pretension in bolts of structural steel connections. To get an understanding about the underlying damage mechanisms as well as to assure the structural safety in operation, a multifaceted Structural Health Monitoring (SHM) system was planned and installed at the structure with the help of digital models. For planning the monitoring system but especially for supporting the investigation of the damaging process finite element models are deployed. Though, to ensure the capability of the FE model to reproduce the real structural behavior in sufficient accuracy, it needs to be calibrated in respect to measured responses of the structure. The present contribution describes experimental and numerical investigations to identify the structural system of the steel tube lattice tower in preparation of the monitoring campaign. An ambient vibration test allowed the identification of the natural frequencies of several global vibrational modes of the drop test tower. For model updating first a sensitivity analysis is applied to identify the most influencing parameter. In succession a genetic algorithm was applied for optimization in the sense of minimization of the difference between measured and simulated characteristic responses. The updated model is finally validated on the dynamic response of the tower structure to a real drop test induced impact loading. The results showed a good agreement between numerical and experimental results though the robustness of the simulation should be improved by more sophisticated numerical modelling. T2 - 7. VDI-Fachtagung Baudynamik CY - Würzburg, Germany DA - 27.04.2022 KW - Großer Fallturm Horstwalde KW - Structural Health Monitoring KW - Belastungsversuch KW - Modalanalyse KW - Schwingungsdynamik KW - Finite Elemente Simulation PY - 2022 AN - OPUS4-55470 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Auersch, Lutz T1 - Characteristic Frequencies of Train-Induced Bridge, Track, Ground and Building Vibrations – Excitation and Mitigation N2 - The characteristic frequencies of train-induced vibrations are discussed in theory and experiment following the propagation of vibrations from the source to the receiver: 1. Out-of-roundness frequencies of the wheels, 2. sleeper-passage frequency, 3. the vehicle-track eigenfrequency, 4. band frequency of the impulses of the passing static axle loads, 5. car-length frequency and multiples, 6. axle-distance frequencies with two characteristic zeros, 7. bridge eigenfrequencies, 8. the cut-on frequency due to the layering, and 9. the cut-off frequency due to the material damping of the soil, 10. the building-soil eigenfrequency, 11. as a rigid building or flexible wall/column mode, 12. floor eigenfrequencies, 13. acoustic room resonances, 14. the „resonance“ frequency or cut-off frequency of a base isolation. Coincidences of some of these characteristic frequencies or frequency ranges can be typically problematic and mitigation measures at the track or at the building can be necessary. The bridge response to the passing static loads is deter¬mined by the axle-sequence spectrum, the eigenfrequency (transfer function) of the bridge, and the modal force or mode shape spectrum. The ground vibration has typically high frequencies for a stiff soil and low frequencies for a soft soil. The high amplitudes between the zeros of the axle-sequence spectrum are often measured in the ground vibrations, and they can be mitigated by soft support elements or a higher bending stiffness of the track. T2 - EVACES 2025 CY - Porto, Portugal DA - 02.07.2025 KW - Train-induced vibration KW - Axle-sequence spectrum KW - Vehicle-track eigenfrequency KW - Axle impulses PY - 2025 AN - OPUS4-63654 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - 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 - 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 T1 - Frequency-wavenumber method for the wave propagation through the soil and the soil-structure interaction of railway tracks and building foundations near railway lines N2 - In soil-structure interaction, the soil and the (flexible) structures are modelled as elastic continua. The partial differential equations of elasticity can be transformed to algebraic equations in frequency-wavenumber domain where they can be solved by matrix methods. The results for the soil and a structure can be coupled in frequency-wavenumber domain, and the solution in space domain is obtained by an infinite wavenumber integral (the back-transformation). This method has several applications for the prediction of the emission, transmission and immission of railway-induced vibrations. The wave propagation in homogeneous or layered soils is calculated for surface and tunnel lines by a single wavenumber integration (transmission). The response of ballast or slab tracks (for the emission problem) and the foundation stiffness (for the immission problem) need an additional integration across the track or foundation width. In wavenumber domain, tracks and foundations of infinite length are analysed. Finite structures can be calculated by finite element models where the soil is calculated by the boundary element method. The Green’s functions for the boundary element method are calculated by a wavenumber integration as for the transmission problem. Some example results for all these tasks will be shown. The immission into buildings will be analysed in detail, and the effect of stiff slab foundations and (basement) walls on the incoming wavefield is quantified in a parameter study. The transfer function (the amplitude ratio) structure to free field usually starts with 1 at 0 Hz and decreases continuously with frequency. The reduction is due to the structural stiffness against wave deformation which turns to be higher than the stiffness of the soil, for example above the structure-soil coincidence frequency of the slab foundation. The reduction is better for a high structural stiffness and for a low soil stiffness. Walls are stiffer than plates for the relevant frequency range, but even walls and especially low basement walls are not infinitely rigid and can follow the wave deformation to a certain extent. These basic rules from frequency-wavenumber analysis can well be used for real building projects near railway lines where stiff foundations can be an alternative reduction method to the commonly used base isolation by elastic elements. T2 - COMPDYN 2025 CY - Rhodos, Greece DA - 15.06.2025 KW - Frequency-wavenumber method KW - Wave propagation KW - Soil-structure interaction KW - Building foundations KW - Mitigation measures PY - 2025 AN - OPUS4-63468 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - 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 - 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 - 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 - 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 -