Current Rail Research Articles

Analytical Method for Predicting Tunnel Deformation Caused by Overlying Excavation Considering the Dewatering

ABSTRACTPredicting the tunnel deformation caused by overlying excavation is a crucial catch in current rail transit construction. Most theoretical studies overlook the effect of dewatering on tunnel response. This study utilized Mindlin's stress solution and an improved incremental method to calculate the additional load resulting from excavation. The load increment due to dewatering was determined based on the effective stress principle and a modified Dupuit infiltration curve. Treating the tunnel as a series of segment rings on a Vlazov foundation, the energy variance method and a collaborative deformation model were employed to develop a tunnel deformation prediction model. The proposed model's validity was confirmed by examining two traceable cases. Based on this, further discussion addressed the impact of dewatering depth, tunnel burial depth, tunnel‐pit relative distance, and intersection angle on existing tunnel deformation. Finally, combining the proposed model with multiple regression analysis, a semi‐empirical method was established to determine the tunnel's maximum vertical displacement. The study found that dewatering extends the tunnel force range, and the tunnel subsidence was positively correlated with groundwater level drop depth. The increase in the tunnel burial depth and distance from the excavation center led to a longer soil unloading transfer path, resulting in reduced disturbance to the tunnel. A smaller intersection angle between the excavation's short edge and the tunnel led to less disturbance of the underlying tunnel, which should be avoided in practical engineering. The developed semi‐empirical formulae have sufficient engineering accuracy, guiding the reinforcement of the underlying tunnel.

Pixel-level automatic detection and quantification of running bands on rail surfaces

The running band on the rail surface serves as a crucial indicator of the wheel-rail contact relationship, making quantitative detection of the running band vital for railroad inspection and maintenance. However, current rail running band detection methods remain manual, and leveraging state-of-the-art deep learning technology can significantly enhance detection efficiency and minimize the reliance on human labor. This paper presents an improved version of ShuttleNet, called ShuttleNetM2T, for rail surface running band detection, emphasizing high stability. Efficient self-attention in ShuttleNetM2T captures global information, maintaining efficiency and rectifying issues like misrecognition and incomplete edges. Experimental results show ShuttleNetM2T achieves 0.9823 average F-measure and 0.9653 average Intersection-Over-Union on test images. For automatic running band width detection, we propose a pixel-to-physical distance conversion-based calculation, yielding just 0.625% relative error. Overall, the findings in this paper facilitate accurate detection and automatic calculation of the running band width, with promising applications in intelligent rail surface detection.

Acoustic emission-based assessment of weld effects on the health monitoring of the rail section: an experimental study

Railways are a vital lifeline for both passengers and freight, with an extensive network connected by robust welded joints. This study explores the potential of Acoustic Emission (AE) techniques in rail health monitoring, particularly in the context of rail sections and their relationship with welds. While AE-based health monitoring has gained attention, a significant gap exists in understanding welds’ influence. This research bridges this gap by examining the interplay between welds and health monitoring. Welds introduce complexities in AE wave propagation, crucial for precise health assessments. Through artificial AE source simulation using the Pencil Lead Break (PLB) method across diverse rail segments, specialized sensors capture AE signals. Rigorous analysis, involving signal processing and statistical methods, reveals how welds impact AE wave behaviour and health assessment accuracy. Importantly, this research underscores how welds alter AE wave propagation, ensuring accurate health evaluations. This study’s insights hold far-reaching implications, not only for enhancing current rail system maintenance but also for advancing our understanding of the critical interrelationship between welds and health monitoring, thus contributing to the longevity and reliability of rail systems.

A communication platform demonstrator for new generation railway traffic management systems: Testing and validation

Current rail traffic management and control systems cannot be easily upgraded to the new needs and challenges of modern railway systems because they do not offer interoperable data structures and standardized communication interfaces. To meet this need, the Horizon 2020 Shift2Rail OPTIMA project has developed a communication platform for testing and validating the new generation of traffic management systems (TMS), whose main innovative features are the interoperability of the data structures used, standardization of communications, continuous access to real-time and persistent data from heterogeneous data sources, modularity of components and scalability of the platform. This paper presents the main components, their functions and characteristics, then describes the testing and validation of the platform, even when federated with other innovative TMS modules developed in separate projects. The successful validation of the system has confirmed the achievement of the objectives set and allowed a new set of objectives to be defined for the reference platform for the railway TMS/Traffic Control systems.

A fault localization approach based on multi-system PCA and dynamic SDG: Application in train lifting equipment

The development of the current rail transportation is increasingly rapid, and train maintenance is closely related to the high-efficiency running of rail transportation. Train lifting equipment (TLE) is important for train maintenance, for which stable operation is crucial. TLE fault is characterized by early abnormally weak and capable of propagation. Early anomaly detection and fault diagnosis are the keys to TLE fault maintenance, and this paper proposes a TLE fault localization methodology to address these two problems. For early anomaly detection, a combination of sequence-based and principal component analysis-based methods is utilized to address the problem. For fault diagnosis, the signed directed graph-based method is utilized to ensure the completeness of reasoning results, and the system division mechanism and dynamic division mechanism are utilized to narrow down the scope of faults and accelerate the reasoning process, respectively. The experiments prove that the proposed method can reduce the loss caused by equipment faults and improve the reliability and stability of the equipment.

Development of an Artificial Intelligence based Railway Crack Detection and Monitoring System using Internet of Things

This study suggests the concept of crack locating robot vehicle in the railway rails. India railways participates an important posture in asset with the necessary transportation to preserve needs of a rapidly emergent financial system. India now has the world's fourth-largest railway network. Therefore, travelling by train is risky. It does not work with the existing railway control system in India. Thus, robust, well-organized, and reliable new technology is required for both fracture detection in railway track and identification of objector items. This study proposes and clarifies a robust monitoring system to meet the limitations of the current rail surveillance system for detecting fractures of the railway tracks. Therefore, robust, well-organized, and reliable new technology is required for both fracture detection in railway track and the identification of objects or items. This study proposes and clarifies a robust monitoring system to meet the limitations of the current rail surveillance system for detecting fractures of the railway tracks. The goal of this study is to build and create an IoT-enabled robot that uses artificial intelligence (AI) to report to a railway controller any information it gathers concerning broken or cracked track. To solve this issue, we will be sending all data over wireless communication based devices and developing a corresponding application..

Effects of predeformation on torsional fatigue in R260 rail steel

Rolling contact loading induces severe plastic deformations and initiates cracks near the rail surface. Prevention of such rolling contact fatigue cracks requires a better understanding about the mechanical behavior of the deformed material in this region. Even so, current rail standards do not consider the plasticity-induced changes to mechanical behavior. They only evaluate the mechanical performance of virgin rail steels under uniaxial loading conditions, which is not representative for the material’s performance after years of service. This study proposes a new method for fatigue life evaluation of deformed material under loading conditions similar to rolling contact loading. Both virgin and predeformed test bars with a circumferential notch were subjected to strain-controlled torsional fatigue loading to evaluate the influence of axial loading, predeformation, and torsional loading direction. Superimposed compressive axial loads increase the fatigue life without affecting the torque response. The predeformed test bars exhibited longer lives, an effect we attribute to the combination of different torque responses, hardening, and anisotropy.

A Hybrid Magnetic Current Sensor With a Multiplexed Ripple-Reduction Loop

This article presents a hybrid magnetic current sensor for galvanically isolated measurements. It consists of a CMOS chip that senses the magnetic field generated by current flowing through a lead-frame-based current rail. Hall plates and coils are used to sense low-frequency (dc to 10 kHz) and high-frequency (10 kHz to 5 MHz) magnetic fields, respectively. With the help of on-chip calibration coils, the biasing current of the Hall plates is trimmed to match the sensitivity of the Hall and coil signal paths. The sensitivity drift of the coil path with temperature is compensated by using temperature-dependent gain-setting resistors, while the drift of the Hall path is compensated by biasing the Hall plates with a proportional-to-absolute-temperature (PTAT) current. The resulting sensitivity drift is less than 9% from –40 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\circ}$</tex-math> </inline-formula> C to 80 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\circ}$</tex-math> </inline-formula> C. The offset of the Hall plates is reduced by the current spinning technique, and the resulting ripple is suppressed by a multiplexed ripple-reduction loop (MMRL). Fabricated in a standard 0.18- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu$</tex-math> </inline-formula> m CMOS process, the current sensor occupies 4.6 mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{2}$</tex-math> </inline-formula> and draws 7.8 mA from a 1.8-V supply. It achieves a gain variation of only <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pm$</tex-math> </inline-formula> 2% in a 5-MHz BW. It also achieves high energy efficiency, with an figure of merit (FoM) of 1.6 fW/Hz.

Investigating the effect of different adhesion materials on electrical resistance using a high pressure torsion rig

This paper presents an assessment of newly-developed conductive adhesion materials (Products A-E) in comparison to standard rail sand used in Britain. Current rail sand is an insulating material which can affect track circuits; newly-developed conductive materials could reduce the risk of this and allow for more material to be applied to further mitigate against low adhesion. The particles were characterised to determine their densities, and size and shape distributions. Bulk behaviour was assessed through three characteristics: angle of repose, bulk shear strength, and particle breakage index. Materials were then assessed using a high pressure torsion approach to measure their effects on adhesion and electrical resistance in dry, wet, and leaf contaminated conditions. It was found that all products produced better or equivalent conductivity compared to the currently used GB rail sand and that Product D and Product E should be considered for future field testing.

Simulation of Eddy Current Rail Testing Data for Neural Networks

The present work is part of the AIFRI project (Artificial Intelligence For Rail Inspection), where we and our project partners train a neural network for defect detection and classification. Our goal at BAM is to generate artificial ultrasound and eddy current training data for the A.I. This paper has an exploratory nature, where we focus on the simulation of eddy current signals for head check cracks, one of the most important rail surface defects. The goal of this paper is twofold. On the one hand, we present our general simulation setup. This includes geometric models for head check cracks with features like branching and direction change, a model for the HC10 rail testing probe, and the configuration of the Faraday simulation software. On the other hand, we use the Faraday software to simulate eddy current testing signals with a strong focus on the influence of the damage depth on the signal, while differentiating between different crack geometries. Here, we observe an early saturation effect of the test signal at a damage depth of 2 mm (at a crack angle of 25◦ to the surface). That is about 2 mm earlier than we would expect from measurements at a crack angle of 90◦ . This behavior will be investigated further in a future paper. Finally, we interpolate the simulated signals in a two-step curve fitting process. With these interpolations we may generate eddy current test signals for any damage depth within the simulated range.

Research on Automatic attitude adjustment Technology of Suspension rail of the Unfolding frame

Spacecraft solar wings, antennas, and other space deployment mechanisms need to be unloaded by gravity during the ground launch test. At present, the most widely used is the guide rail type Micro-gravity unfolding frame, and the rail needs to be adjusted horizontally before the test is carried out. Aiming at the shortcomings of the current rail debugging relying on labor, difficult high-altitude operation, and low debugging efficiency, a guide rail automatic attitude adjustment device is proposed, which can quickly realize the efficient adjustment and attitude maintenance of the rail level. After test verification, the system can increase the local level of the guide rail from the traditional 0.02 mm/m to 0.01 mm/m, the overall level from the original 0.1 mm/m to 0.02 mm/m, and shorten the commissioning time from the original 4 h to 1 h. The power-off holding ability is strong, which greatly improves the efficiency of the ground test. The research results have been applied to other spatial deployment institutions that conduct tests based on rails.

Cross-Sectoral Transfer of Budgetary Subsidies Through Differential Railway Tariffs

The paper exposes and analyses a serious flaw in Russia’s current rail freight tariffs. Subsidized sectors of the Russian economy are overcharged while a range of other sectors are undercharged. This transfers budgetary subsidies from one sector to another in a way that is opaque to regulators. The article details how this transit subsidy is part of conveyer belt that runs from the national budget to refining, rail transport and ultimately to coal mining. Analysis shows that the transit subsidies from differential railway tariffs are quite large (from 2019 to 2021 coal industry revenues were augmented by an annual average of RUB 270 billion through this technique). The article also demonstrates that subsidizing coal production through differential railway tariffs cannot be justified by rational economic considerations, as it only prolongs the life of many hopelessly unprofitable enterprises and thus hinders sustainable economic development in coal-mining regions. The paper studies the feasibility of eliminating this kind of subsidy by making tariffs for oil and coal transportation converge. If those subsidies had been eliminated in 2023, the author concludes that it would have been relatively painless for the industry and could potentially bring about a RUB 245 billion reduction in annual state budget subsidies by 2050. The funds saved could be redirected to economic diversification and social development in the regions where the coal industry is concentrated.

A Hybrid Approach for a Secured Information Security Using Modified Encryption Technique

This paper proposes a new approach called the RAES technique, which results from redesigning the current Rail Fence Cipher (RFC) using two basic phases, first using the Advanced Encryption Standard (AES) technique and then using the potential of the RFC technique to protect confidential messages for more secure information security. There are several conventional cryptographic methods, and because it is possible to crack cipher text, that is why it tries to suggest RAES techniques written in C++ programming to be more secure to protect information from cipher breaking. Mixing RFC ciphers with AES, it appears that the encryption and decryption of the modified RAES require the generation of the plaintext elements which are usually single letters written in a predetermined sequence into a matrix format which is basically a rectangle that has been decided by the transmitter and receiver in advance, and then it is read off according to another predetermined sequence across the matrix to get the cipher text. Through this RAES technique, not only the strength of the AES technique can be applied but also the RFC technique that uses keywords and salt can also be used making this mixed system perform ciphers that are difficult to break by attackers. Moreover, the strength of the RAES algorithm is in terms of faster and more secure execution times than existing substitution and transposition algorithms in addition to the improvement of confusion and diffusion characteristics. Meanwhile, the value of the avalanche effect for the RAES technique recorded also showed that it reached 60%.

Assessment of ride comfort of traction elevators using ISO 18738-1:2012 and ISO 2631-4: 2001 standards

PurposeRide comfort is one of the important factors affecting passenger health. Therefore, the elevator industry usually uses the International Organization for Standardization (ISO) 18738-1 standard to evaluate elevator ride quality and optimize elevator design. However, this method has certain limitations in its evaluation of comfort due to the problem of boundary division. The ISO 2631-4 standard is used as a general method of comfort evaluation in the current rail transit system, but it has not been applied in the elevator industry. In order to explore the difference and connection between the two standards, the author aims to conduct a detailed analysis on this.Design/methodology/approachBased on the elevator internet, a large amount of measured data of normal and abnormal vibration of elevator car were collected and analyzed and preprocessed; based on ISO 18738-1:2012 standard and ISO 2631-4:2001 standard, the differences of ride comfort assessment methods in the two standards were analyzed, and the ride comfort assessment study of elevator under normal and abnormal vibration conditions was carried out.FindingsThe experimental results show that the comfort assessment results of ISO 2631-4:2001 standard and ISO18738-1:2012 standard are consistent under two vibration conditions. At the same time, ISO 2631-4:2001 can not only provide a more accurate quantitative description of comfort, but also roughly determine the comfort interval of each vibration, which can provide theoretical reference for elevator vibration classification and car comfort design.Originality/valueThe authors designed an Internet of Things (IOT)-based elevator vibration signal acquisition method to address the shortcomings of the previous elevator ride comfort assessment methods, which can realize the dynamic assessment of elevator ride comfort; by comparing the assessment results of elevator ride comfort under normal vibration and abnormal vibration, the feasibility of ISO 2631-4:2001 for elevator ride comfort assessment was fully verified. In addition, the experimental results also give the influence of abnormal vibration on elevator riding comfort under the stages of start-stop, uniform speed, acceleration and deceleration, which can provide theoretical support for elevator vibration suppression and comfort transformation.

Making Regional Railroads More Attractive—Research Studies in Germany and Patronage Characteristics

This article summarizes current research on regional rail passenger service in Germany. The aim of the research was to help rail operators, municipalities along the rail lines, and transportation planners identify the most effective strategies for improving rail service and patronage. The article outlines study contents and purpose and then summarizes the most important study findings. It also presents action and research recommendations. In addition, current rail developments in Germany and methods for increasing patronage and reducing costs with special focus on the separation of infrastructure and operations are described. Finally, patronage data for different rail segments are compared to help determine whether improvement measures should be applied and what impacts they could have on patronage.

Study on the Evolution and Resilience of Rail Transit Time Networks—Evidence from China

In the network operation and management of rail transit systems, the occurrence of unexpected events causes damage to the network structure, further hindering regional accessibility performance and the function of the system. This study is based on the rail transit operation schedules in 2009, 2013, 2016, 2019 and 2022. We construct a directional weighted rail transit time network (RNNT) with train operation time as the weight, compare the betweenness centrality, sum of the shortest time path and entropy importance, etc., and quantitatively measure the network accessibility, connectivity and its resilience evolution. The results show that the current rail transportation network in China has a “small-world” effect, and there are a few stations with strong connections. The most densely distributed intervals of travel times between pairs of nodes changes from [440, 445] to [207, 210]. The fastest and best-performing disturbance to network connectivity and accessibility performance are both caused by the betweenness disturbance strategy. When the network connectivity remains 80% effective, the ratio of failed nodes under the static betweenness centrality strategy decreases from 3.96% in 2009 to 2.31% in 2022, with weaker connections between node pairs, and their network resilience diminishes. When the network accessibility remains 80% effective, the ratio of failed nodes under the static (dynamic) betweenness centrality strategy increases from 0.13% (0.13%) in 2009 to 0.20% (0.23%) in 2022. Therefore, the rail transit network can protect the corresponding rail stations based on the station ranking of the above strategies, and this research is beneficial to rail transit network protection and structure optimization.

Organizational and legal forms of parliamentary support for the development of territorial governance

The article considers the constitutional and legal problems of using organizational and legal forms of parliamentary support for the development of territorial governance, taking into account the peculiarities of martial law and the prospects for further use of these forms in the postwar period. The specifics of ensuring the transformation of territorial governance in the legislative, budgetary spheres, in scientific-expert, advisory activities of the parliament are studied. Suggestions are made for further improvement of the implementation of organizational and legal forms of parliamentary support for the development of territorial governance. A number of conclusions are made, in particular, that it is expedient to determine further ways to complete the renewal of constitutional regulation of the entire system of governance and, in particular, territorial governance in the postwar period given the declarations of radical transformation and restoration of Ukraine. Such an update should concern not only the decentralization of public power, but also the main constitutional institutions. In the transition from military to post-war government, territorial organization of power, territorial governance using organizational and legal forms of parliamentary support for the development of territorial governance, it is advisable to balance the current rails of centralization and decentralization, gradually return to broad decentralization of public power. Key words: constitution, parliament, governance, territorial governance, parliamentary support for the development of territorial governance

Rail Sample Laboratory Evaluation of Eddy Current Rail Inspection Sustainable System

Increasing the efficiency, frequency, and speed of rail defect detection can reduce maintenance costs and improve the sustainability of railways. The non-contact eddy current (EC) system can be operated along with a railcar for detecting rail flaws. Even if the EC can be utilized for rail defect identification and characterization, current commercial devices are not sufficient for defect classification on rails by providing highly sensitive signals for post-processing. In this study, we established an efficient and expandable eddy current rail inspection system and verified its capability for classification of different defect signals. The integrated hardware and software EC measurement system was firstly applied to detect notched cracks in steel samples with different crack depths and angles. The measured voltage and current analog inputs from the eddy current sensor were acquired and processed with a fast Fourier transformation (FFT) algorithm in the LabVIEW platform. The real-time impedance was then obtained by transferring signals to a normalized impedance plane plot. The processed EC signals showed adequate sensitivity and efficiency with changes of notched crack depths and angles during the sensor movement. A comparative case study on field rail samples was then conducted to examine the feasibility and capability of the established system on different types of actual rail defects. The experimental analysis and case study results demonstrate that the integrated eddy current system could possibly be used for non-destructive rail crack inspection and classification. The enhanced detection capability (especially on subsurface cracks) and real-time post-processing technique could further contribute to improving rail-life sustainability.

The substitution of short-haul flights with rail services in German air travel markets: A quantitative analysis

In recent years, a ban on short-haul flights for which alternative, more environmentally friendly transportation is available has been on European regulatory agendas, particularly in countries like Germany, with its well-developed high-speed rail (HSR) and a dense network of low-cost, point-to-point airline traffic. This study aims to quantify the potential impact on CO2 emissions of substituting short-haul flights with rail frequencies in 87 German air travel corridors. Using OAG data on passenger bookings and airline schedules for 2019, as well as current rail travel times, we determine the target flights by looking at the actual proportion of connecting passengers per frequency. We estimate a potential reduction in CO2 emissions of between 2.7% and 22%, depending on how strict the flight substitution is. However, the social benefits of those carbon emissions might fall short of the travel time losses experienced by the passengers. Increased investment to improve rail speeds and intermodal accessibility appears necessary before the substitution policies can be implemented.

Train Speed Profile Optimization for Energy Saving

This study aims to optimize energy consumption by modifying the train’s maximal speed and coasting velocity. The methods used in the simulation are brute force and genetic algorithm (GA). The introduction briefly introduces the aim and objectives of the study, as well as the scope and the methodology. The following section gives an overview of the current rail transit development and the existing issues. Despite the rapid development of rail transit and its successful operation, energy consumption is a major issue. The methodology of brute force and genetic algorithm is then introduced. The exact algorithm of the two methods in MATLAB is explained so as to make preparations for the latter simulation optimization. The results from the brute force and genetic algorithm methods are obtained and compared for data analysis. The driving strategy for using STS (Single Train Simulator) is then optimized for an advanced modification. By inserting more values in the code, an optimal speed profile is obtained, and the energy saving target is achieved. Overall, the energy consumption of the studied line could be decreased by optimizing the maximal speed of different sections between the stations and the coasting velocity. However, influencing factors such as service and infrastructure, application of acceleration, and braking power should also be considered as improvements in future studies.