Verkehrsinfrastrukturen
Filtern
Dokumenttyp
- Vortrag (182)
- Zeitschriftenartikel (74)
- Beitrag zu einem Tagungsband (60)
- Posterpräsentation (15)
- Forschungsbericht (5)
- Forschungsdatensatz (4)
- Buchkapitel (3)
- Dissertation (3)
- Sonstiges (3)
- Preprint (2)
Schlagworte
- Korrosion (61)
- Spannungsrisskorrosion (32)
- Corrosion (28)
- Spannstahl (23)
- Concrete (21)
- Wasserstoff (18)
- Structural health monitoring (17)
- SHM (12)
- Atmosphärische Korrosion (10)
- Stress corrosion cracking (10)
Organisationseinheit der BAM
- 7 Bauwerkssicherheit (216)
- 8 Zerstörungsfreie Prüfung (123)
- 7.6 Korrosion und Korrosionsschutz (104)
- 7.2 Ingenieurbau (79)
- 8.2 Zerstörungsfreie Prüfmethoden für das Bauwesen (78)
- 7.1 Baustoffe (30)
- 8.6 Faseroptische Sensorik (24)
- 8.4 Akustische und elektromagnetische Verfahren (14)
- 9 Komponentensicherheit (9)
- 9.4 Integrität von Schweißverbindungen (9)
Paper des Monats
- ja (4)
Verdeckte Risse in Eisenbahn-Spannbetonschwellen können zum plötzlichen Versagen der Schwelle und dem Verlust der Spurhaltefähigkeit führen. Im schlimmsten Fall kann dies bei Überfahrt eines Schienenfahrzeugs eine Entgleisung bewirken. Einige Risstypen entstehen im Inneren der Schwelle und breiten sich unerkannt aus. Dies führt weit vor der äußeren Sichtbarkeit bereits zu einer deutlichen Minderung der Querschnittsfestigkeit und damit Instabilität der Schwelle.
Measurement results of train-induced vibrations are evaluated for characteristic frequencies, amplitudes and spectra, leading to a prediction which is based on transfer functions of the vehicle–track–soil system, the soil, and the building–soil system. The characteristic frequencies of train-induced vibrations are discussed following the propagation of vibrations from the source to the receiver: out-of-roundness frequencies of the wheels, the sleeper passage frequency, the vehicle–track eigenfrequency, the car-length frequency and multiples, axle-distance frequencies, bridge eigenfrequencies, the building–soil eigenfrequency, and floor eigenfrequencies. Amplitudes and spectra are compared for different train and track types, for different train speeds, and for different soft and stiff soils, where high frequencies are typically found for stiff soil and low frequencies for soft soil. The ground vibration is between the cut-on frequency due to the layering and the cut-off frequency due to the material damping of the soil, but the dominant frequency range also changes with distance from the track. The frequency band of the axle impulses due to the passing static loads obtains a signature from the axle sequence. The high amplitudes between the zeros of the axle-sequence spectrum are measured at the track, the bridge, and also in the ground vibrations, which are even dominant in the far field. A prediction software is presented, which includes all three parts: the excitation by the vehicle–track interaction, the wave transmission through the soil, and the transfer into a building.
Evaluation of AI for eddy current testing according to the reliability framework for rail inspection
(2026)
The requirements for using AI algorithms are highly stringent for safety-critical and high-risk applications, such as in the field of non-destructive testing (NDT). Furthermore, there is a regulatory need for conclusive metrics to evaluate AI for high-risk applications. This article introduces a process for evaluating AI used in NDT methods. Based on a commonly used AI evaluation metric adapted for the NDT field, the evaluation aligns with the well-known NDT reliability processes. This evaluation process is applied to analyzing eddy current (ET) data in rail inspection. The aim is to quantify the capability of AI-supported data evaluation against that of the testing setup itself. However, the available real-world dataset of rail inspection data was insufficient for training, validation and demonstrating the reliability of the ET process and AI. To address this, simulated ET data was used to generate a large dataset for evaluation purposes. Using this simulated data, a reference probability of detection (POD) curve was created to provide a benchmark for assessing the performance of the AI using a newly introduced metric called Reliability Metric Score (RESa). The AI model analyzed ET data for crack-like defects. The results were then evaluated and compared to the reference POD. This article explores the evaluation process, highlighting potential misinterpretations and situations where an operator’s judgment is necessary to determine the effectiveness of the AI model in specific cases. This process revealed different regions of interest, which are very useful for further assessment of the AI process and continued development.
Prestressed steel bridges that were constructed in the past using tempered prestressing steel can develop significant problems with regard to load-bearing capacity under unfavourable conditions during their construction. In particular, hydrogen-induced stress corrosion cracking during the construction of the bridge structures may have caused cracks in the prestressing tendons, which could lead to the failure of the bridge years later. The presentation specifically addresses the partial collapse of the Carola Bridge in Dresden.
Corrosion auf steel in convrete can have two different causes. At one hand the carbonation induced corroison, which lead to uniform corrosion and at the other hand the chloride induced corrosion which is indicated by so called macro elements. These macro elments could be detetected through potentials mapping measurements.
Jährlich werden ca. 2,5 Millionen Betonschwellen auf den Bahnstrecken Deutschlands ausgetauscht. Ob ein Austausch notwendig ist, wird durch Sichtprüfung, also anhand äußerer Schäden, entschieden. Derzeit werden keine Verfahren eingesetzt, die Bahnschwellen auch auf nicht sichtbare Schäden überprüfen. Hier setzt das luftgekoppelte Impakt-Echo-Verfahren an, das innenliegende Schäden diagnostiziert. Mit Hilfe eines Überschall-Freistrahls wird die Eigenfrequenz der Schwelle angeregt. Ist diese durch Risse geschädigt, sinkt die Frequenz deutlich. Die Anregung erfolgt berührungslos und kontinuierlich, so dass auch Messungen in Bewegung und bei Überfahrten möglich werden.
Prestressed steel bridges that were constructed in the past using tempered prestressing steel can develop significant problems with regard to load-bearing capacity under unfavourable conditions during their construction. In particular, hydrogen-induced stress corrosion cracking during the construction of the bridge structures may have caused cracks in the prestressing tendons, which could lead to the failure of the bridge years later. The presentation specifically addresses the partial collapse of the Carola Bridge in Dresden.
Der Vortrag behandelt Schadensmechanismen in Spannbetonbrücken mit Fokus auf die „stille“ Gefahr durch Mikrorisse im Spannstahl. Besonders hervorgehoben wird die wasserstoffinduzierte Spannungsrisskorrosion als Ursache für plötzliches, sprödes Versagen von Tragwerken. Abschließend werden Monitoring-Ansätze und offene Fragen zum Risswachstum und zur Bewertung geschädigter Bauwerke diskutiert.
Designing of structures with medium to high performance requirements is a demanding and challenging engineering task. Depending on the location and type of the planned structure, various pre-testing methods should be applied. In recent decades, there has been a focus on the durability of concrete. Concrete is a porous material with a relatively thin protective cover layer, making it vulnerable to the penetration of external agents such as carbon dioxide. Gas permeability testing (kT), a relatively new non-destructive method (NDT), should therefore be considered. This paper presents results of gas permeability testing on a set of larger concrete samples made under controlled conditions with some paroperty variations order to find initial kT parameters important for quality assurance.
We report on wire break detection and traffic load monitoring using embedded, distributed fiber optic sensors as part of a concept for structural health monitoring of solid bridges.
Fiber optic measurements provide real-time data for identifying loads, structural responses, and damages. The development includes methods for data evaluation and information extraction from large DFOS datasets, contributing to the digital transformation of bridge infrastructure.