Abstracts Archive

Using axle box accelerations (ABA) measured from rail vehicles is a cost-efficient way of monitoring railway track conditions. Existing techniques are focused on identifying a specific type of degradation, usually at a single track layer, such as at the rail top, fastenings, insulated joints, ballas...

The infrastructure manager (IM) DB Netz AG (Germany) is responsible for a safe infrastructure under the traffic operated. The infrastructure is on average 80 years old and designed for the traffic and the respective load models known at the time of construction. Traffic changes, not in the maximum a...

This work focuses on the development and application of a methodology for detecting wheel polygonization in a Laagrss type rail freight vehicle based on dynamic responses induced by it on the track. To achieve that, a numerical train-track interaction model was adopted to simulate the passage of a t...

For railway bridges on high-speed lines, dynamic analyses are usually required to ensure that vibrations from passing trains do not exceed certain limits, e.g. regarding the vertical deck acceleration. Using over-simplified models may lead to inaccurate results that sometimes show theoretical exceed...

With increasing axle loads and train speeds, predicting the dynamic behavior of railway bridges under high-speed traffic plays an increasingly important role in assessing bridge structures. However, the discrepancy between vibrations measured on structures and those predicted by calculations reveals...

Nowadays, the society is highly dependent on railways, since it is the most effective mode of transportation that has the lowest greenhouse gas emissions in the transports sector. Because of that, there has been an increase in rail transport, with great dependence on transport infrastructure such as...

ABSTRACT Nowadays, transport policy is decisively influenced by environmental concerns, with railways expected to play a key role in achieving climate neutrality by 2050, according to the Green Deal proposed by the European Commission. The increase in railway traffic will require the expansion of th...

This work is devoted to the analysis of the vibratory response of High-Speed (HS) multi-track railway bridges composed by short-to-medium simply-supported spans. The vibrational response of such struc-tures may be influenced by three-dimensional modes (first torsion and first transverse bending mode...

The High-Speed Rail (HSR) is a complex system involving numerous technical aspects such as operations, infrastructure, and rolling stock. Among the most used infrastructures, bridges play a crucial role in allowing the railway to connect regions without interruption. Although the HSR's increased run...

Strong crosswinds may significantly affect the runnability of trains moving over viaducts. However, the actual influence of the viaduct’s behaviour under these circumstances in the performance of the train is still not rigorously discussed, particularly in high-pier viaducts characterized by large...

This contribution presents the structure of a developed software for static and transient linear-elastic coupled Finite Element (FE) – Boundary Element (BE) analyses and demonstrates its application for the analysis of soil-structure interaction of portal frame bridges in two and three dimensions ...

This paper investigates energy harvesting on railway bridges. The electromechanical behaviour of a cantilever-based energy harvester is represented by an analytical model for the estimation of the energy harvested from train-induced bridge vibrations. A genetic algorithm constrained to geometry and ...

Examining the correctness of the structural health state and projecting its future strength are the two main goals of Structural Health Monitoring (SHM). Recently, researchers have been closely studying the inclinometer-based structural damage detection procedures. For instance, the measurement of v...

The presence of unbalanced loads on freight trains can potentially cause higher levels of deterioration or even the failure of railway track components, as well as situations of risk of derailment. This paper aims to develop an unsupervised methodology for the early detection of unbalanced load scen...

The dynamic response of high-speed railway bridges is a key performance parameter, both for designing new bridges (1, 2) and for evaluating existing bridges (3). In order to establish long-term continuous monitoring based on vibration measures, it is required to develop an efficient and realistic nu...

A realistic and economical computational assessment of the dynamic behaviour of railway bridges requires, first and foremost, input parameters that correspond to reality. In this context, the computationally applied damping properties of the structure have a decisive influence on the results in the ...

The current regulations address the limit-state of running safety of non-ballasted railway bridges by applying the same concept as for ballasted bridges. In this context, an uncalibrated safety factor of two is applied to an arbitrarily chosen bridge deck vertical acceleration threshold (i.e., 10 m/...

High-speed railway networks in Europe include thousands of bridges, which constitute potential points of failure. Presently, the assessment of running safety is reflected in the Eurocode in the form of deck acceleration limits. However, this indirect metric does not relate unambiguously to an evalua...

This study summarizes the experimental and computational studies carried out for the robust-ness assessment of steel riveted bridges based on truss-type structures. This paper describes a unique case of a 21 m full-scale bridge span tested under laboratory conditions with an exten-sive monitoring sy...

Vehicle-bridge systems are continuously subjected to environmental and operational variations that complicate the process of identifying structural damage. In general, damage is defined both as a substantial alteration of the physical characteristics of the material, as well as the modification of t...

In this work, a method is proposed to detect and assess discontinuous/ fractured rail by analyzing the axle-box acceleration. The method uses a combination of unsupervised-machine learning algorithm and time-frequency analysis to detect the defect. In the previous work, fishplate rail joints modelin...

Transition wedges are widely used in Spain, Portugal and other European countries to mitigate transition problems in railway tracks. These wedge shaped backfills are used to smoothen the stiffness transitions as experienced by the moving load. On the one hand, this solution has proved to be promisin...

In this work, the dynamic response of six portal frame bridges are experimentally evaluated through full-scale controlled dynamic testing. The study aims to (i) experimentally identify the modal characteristics of portal frame railway bridges with different span lengths and subsoil conditions, (ii) ...

The reliability of railway bridges is significantly influenced by so-called resonance states that appear in case the excitation frequency of the passing train is close to one of the natural frequencies of the railway bridge. In these resonant conditions, the dynamic response of the bridge is signifi...

Vibration-based damage detection commonly relies on a monitoring of the modal characteristics of a structure over time. It is assumed that damage will result in a change of the structural stiffness, which will in turn lead to a change of the natural frequencies and the displacement/strain mode shape...

Noise barriers, that are built parallel to the railway to reduce the noise pollution, will be subjected to strong and transient aerodynamic pressure from the trains running with high speed and have the significant dynamic responses under such pressure. Geometric of high-speed trains, especially for ...

The railway track is subject to the spatial stresses imposed by the vehicle and to the stresses generated by the typical temperature ranges of the seasons, increased by the running away actions of the waters that undermine the roadbed below the rail. The imposed stresses are static and dynamic. The ...

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...