Szabolcs Fischer
35213135500
Publications - 112
Investigation of the Load-Bearing Capacity of Resin-Printed Components Under Different Printing Strategies
Publication Name: Applied Sciences Switzerland
Publication Date: 2025-08-01
Volume: 15
Issue: 15
Page Range: Unknown
Description:
This study examines the influence of different printing orientations and infill settings on the strength and flexibility of components produced using resin-based 3D printing, particularly with masked stereolithography (MSLA). Using a common photopolymer resin and a widely available desktop MSLA printer, we produced and tested a series of samples with varying tilt angles and internal structures. To understand their mechanical behavior, we applied a custom bending test combined with high-precision deformation tracking through the GOM ARAMIS digital image correlation system. The results obtained clearly show that both the angle of printing and the density of the internal infill structure play a significant role in how much strain the printed parts can handle before breaking. Notably, a 75° orientation provided the best deformation performance, and infill rates between 60% and 90% offered a good balance between strength and material efficiency. These findings highlight how adjusting print settings can lead to stronger parts while also saving time and resources—an important consideration for practical applications in engineering, design, and manufacturing.
Open Access: Yes
DOI: 10.3390/app15158747
QUANTITATIVE ANALYSIS AND OPTIMIZATION OF ENERGY EFFICIENCY IN ELECTRIC MULTIPLE UNITS
Publication Name: Facta Universitatis Series Mechanical Engineering
Publication Date: 2025-08-01
Volume: 23
Issue: 2
Page Range: 351-375
Description:
The increasing urgency for sustainable transportation solutions necessitates a thorough examination of energy efficiency within railway systems. This study investigates the energy performance of Siemens Ventus (i.e., Siemens Desiro ML type) electric multiple units on Austria's Raaberbahn network, focusing on route-specific energy consumption and the optimization of regenerative braking. Utilizing data collected from January to May 2023, the research employs a robust methodology that integrates statistical analysis, curve-fitting, and geospatial modeling to assess energy trends along routes connecting Vienna, Bratislava, and Deutschkreutz. The findings reveal that terrain, operational practices, and external environmental factors significantly contribute to energy inefficiencies. Specifically, hotspots of energy overconsumption were identified, leading to the development of tailored optimization models for each route. The analysis also produced heatmaps that illustrate critical spatial and temporal patterns, which are essential for implementing targeted interventions aimed at enhancing energy efficiency.
Open Access: Yes
Investigation of Convective and Radiative Heat Transfer of 21700 Lithium-Ion Battery Cells
Publication Name: Batteries
Publication Date: 2025-07-01
Volume: 11
Issue: 7
Page Range: Unknown
Description:
Due to their high energy density and power potential, 21700 lithium-ion battery cells are a widely used technology in hybrid and electric vehicles. Efficient thermal management is essential for maximizing the performance and capacity of Li-ion cells in both low- and high-temperature operating conditions. Optimizing thermal management systems remains critical, particularly for long-range and weight-sensitive applications. In these contexts, passive heat dissipation emerges as an ideal solution, offering effective thermal regulation with minimal additional system weight. This study aims to deepen the understanding of passive heat dissipation in 21700 battery cells and optimize their performance. Special emphasis is placed on analyzing heat transfer and the relative contributions of convective and radiative mechanisms under varying temperature and discharge conditions. Laboratory experiments were conducted under controlled environmental conditions at various discharge rates, ranging from 0.5×C to 5×C. A 3D-printed polymer casing was applied to the cell to enhance thermal dissipation, designed specifically to increase radiative heat transfer while minimizing system weight and reliance on active cooling solutions. Additionally, a numerical model was developed and optimized using experimental data. This model simulates convective and radiative heat transfer mechanisms with minimal computational demand. The optimized numerical model is intended to facilitate further investigation of the cell envelope strategy at the module and battery pack levels in future studies.
Open Access: Yes
A Novel Method for Simulation Model Generation of Production Systems Using PLC Sensor and Actuator State Monitoring
Publication Name: Journal of Sensor and Actuator Networks
Publication Date: 2025-06-01
Volume: 14
Issue: 3
Page Range: Unknown
Description:
This article proposes and validates a novel methodology for automated simulation model generation of production systems based on monitoring sensors and actuator states controlled by Programmable Logic Controllers during regular operations. Although conventional Discrete Event Simulation is essential for material flow analysis and digital experimentation in Industry 4.0, it remains a resource-intensive and time-consuming endeavor—especially for small and medium-sized enterprises. The approach introduced in this research eliminates the need for prior system knowledge, physical inspection, or modification of existing control logic, thereby reducing human involvement and streamlining the model development process. The results confirm that essential structural and operational parameters—such as process routing, operation durations, and resource allocation logic—can be accurately inferred from runtime data. The proposed approach addresses the challenge of simulation model obsolescence caused by evolving automation and shifting production requirements. It offers a practical and scalable solution for maintaining up-to-date digital representations of manufacturing systems and provides a foundation for further extensions into Digital Shadow and Digital Twin applications.
Open Access: Yes
DOI: 10.3390/jsan14030055
Driver Distraction Detection in Extreme Conditions Using Kolmogorov–Arnold Networks
Publication Name: Computers
Publication Date: 2025-05-01
Volume: 14
Issue: 5
Page Range: Unknown
Description:
Driver distraction can have severe safety consequences, particularly in public transportation. This paper presents a novel approach for detecting bus driver actions, such as mobile phone usage and interactions with passengers, using Kolmogorov–Arnold networks (KANs). The adversarial FGSM attack method was applied to assess the robustness of KANs in extreme driving conditions, like adverse weather, high-traffic situations, and bad visibility conditions. In this research, a custom dataset was used in collaboration with a partner company in the field of public transportation. This allows the efficiency of Kolmogorov–Arnold network solutions to be verified using real data. The results suggest that KANs can enhance driver distraction detection under challenging conditions, with improved resilience against adversarial attacks, particularly in low-complexity networks.
Open Access: Yes
Expert Twin: A Digital Twin with an Integrated Fuzzy-Based Decision-Making Module
Publication Name: Decision Making Applications in Management and Engineering
Publication Date: 2025-04-01
Volume: 8
Issue: 1
Page Range: 1-21
Description:
Digitalization and the application of modern Industry 4.0 solutions are becoming increasingly important to remain competitive as product ranges expand and global supply chains grow. This paper presents a new Digital Twin framework to achieve robustness in manufacturing process optimization and enhance the efficiency of decision support. Most digital twins in the literature synchronously represent the real system without any control elements despite the bidirectional data link. The proposed approach combines the advantages of traditional process simulations with a real-time communication and data acquisition method using programmable logic controllers designed to control automated systems. In addition, it complements this by utilizing human experience and expertise in modeling using Fuzzy Logic to create a control-enabled digital twin system. The resulting "Expert Twin" system reduces the reaction time of the production to unexpected events and increases the efficiency of decision support; it generates and selects alternatives, therefore creating smart manufacturing. The Expert Twin framework was integrated, tested, and validated on an automated production sample system in a laboratory environment. In the experimental scenarios carried out, the method production increased production line utility by up to 28% and the number of re-schedules can be halved.
Open Access: Yes
Deformation Characterization of Glass Fiber and Carbon Fiber-Reinforced 3D Printing Filaments Using Digital Image Correlation
Publication Name: Polymers
Publication Date: 2025-04-01
Volume: 17
Issue: 7
Page Range: Unknown
Description:
The paper offers an in-depth deformation study of glass fiber-reinforced and carbon composite filaments of 3D printers. During the certification, the authors used DIC (Digital Image Correlation) as a full-field strain measurement technique to explore key material traits as a non-contact optical measurement method. The insights captured through the DIC technology enabled to better understand the localized strain distributions during the loading of these reinforced filaments. The paper analyzes the glass fiber and carbon fiber filaments used in 3D printing that are reinforced with these materials and are subjected to bending and compressive loading. The segment presents how loading affects the performance of reinforced filaments when varying such factors as the deposition patterns, layer orientation, and other process parameters. Different types and combinations of reinforcements and printing variables were tested, and the resulting dependencies of mechanical parameters and failure modes were established for each case. Key conclusions demonstrate that the mechanical behavior of both carbon- and glass fiber-reinforced filaments is strongly affected by the 3D printing parameters, particularly infill density, pattern, and build orientation. The application of Digital Image Correlation (DIC) allowed for a precise, full-field analysis of strain distribution and deformation behavior, offering new insights into the structural performance of fiber-reinforced 3D printed composites. The findings from the study provide guidance for the proper choice of filling material and the optimal parameters for the 3D printing process of models with high-performance indexes and seamless applications in the automotive and industrial manufacturing sectors.
Open Access: Yes
Effects of Crumb Rubber-Modified Asphalt as a Pavement Layer in Railways: A Scoping Review
Publication Name: Infrastructures
Publication Date: 2025-04-01
Volume: 10
Issue: 4
Page Range: Unknown
Description:
Railway track performance and durability face growing challenges from higher speeds, heavier axle loads, and changing environmental conditions. Crumb rubber-modified asphalt (CRMA) offers a sustainable solution by repurposing waste tires into a durable material for railway trackbeds, improving both performance and environmental impact. Following PRISMA-ScR guidelines, this scoping review synthesizes an extensive body of global research on the structural, mechanical, and environmental benefits of CRMA in railway trackbeds. A systematic literature search was conducted across major academic databases, covering studies published over several decades. Selection criteria focused on CRMA applications in railway trackbeds, using keywords such as “crumb rubber-modified asphalt”, “railway track vibration”, and “sustainable railway materials.” After rigorous screening and eligibility assessment, the most relevant peer-reviewed studies were included, emphasizing mechanical performance, durability, and environmental impact. Key findings indicate that CRMA effectively reduces ground vibrations, enhances load distribution, and lowers long-term maintenance costs while promoting sustainable waste management through tire recycling. However, challenges such as optimal mix design, potential emissions, and long-term bonding stability require further investigation. Additionally, the review was limited to English-language studies, potentially omitting relevant non-English research, and some reports were inaccessible during retrieval. This review maps critical research gaps, identifies key areas for future optimization, and highlights CRMA’s potential to advance resilient and eco-friendly railway infrastructure.
Open Access: Yes
Mathematical Modeling of the Rail Track Superstructure–Subgrade System
Publication Name: Geotechnics
Publication Date: 2025-03-01
Volume: 5
Issue: 1
Page Range: Unknown
Description:
The “rail track superstructure–subgrade” system is a sophisticated engineering structure critical in ensuring safe and efficient train operations. Its analysis and design rely on mathematical modeling to capture the interactions between system components and the effects of both static and dynamic loads. This paper offers a detailed review of contemporary modeling approaches, including discrete, continuous, and hybrid models. The research’s key contribution is a thorough comparison of five primary methodologies: (i) quasi-static analytical calculations, (ii) multibody dynamics (MBD) models, (iii and iv) static and dynamic finite element method (FEM) models, and (v) wave propagation-based models. Future research directions could focus on developing hybrid models that integrate MBD and FEM to enhance moving load predictions, leveraging machine learning for parameter calibration using experimental data, investigating the nonlinear and rheological behavior of ballast and subgrade in long-term deformation, and applying wave propagation techniques to model vibration transmission and evaluate its impact on infrastructure.
Open Access: Yes
The Use of Earth Observation Data for Railway Infrastructure Monitoring—A Review
Publication Name: Infrastructures
Publication Date: 2025-03-01
Volume: 10
Issue: 3
Page Range: Unknown
Description:
Satellite data have the potential to significantly enhance railway operations and drive the digitization of the rail sector. In the context of railways, satellite data primarily refers to the use of Global Navigation Satellite System (GNSS) data for applications such as navigation, positioning, and signalling. However, remote sensing data from Earth Observation (EO) satellites remain comparatively underutilized in railway applications. While the use of GNSS data in railways is well documented in the literature, research on EO-based remote sensing methods remains relatively limited. This paper aims to bridge this gap as it presents a comprehensive review of the use of satellite data in railway applications, with a particular focus on the underexplored potential of EO data. It provides the first in-depth analysis of EO techniques, primarily examining the use of synthetic aperture radar (SAR) and optical satellite data for key applications for infrastructure managers and railway operators, such as assessing track stability, detecting deformations, and monitoring surrounding environmental conditions. The goal of this review is to explore the diverse range of EO-based applications in railways and to identify emerging trends, including the integration of thermal EO data and the novel use of SAR for dynamic and predictive analyses. By synthesizing existing research and addressing knowledge gaps, the presented review underscores the potential of EO data to transform railway infrastructure management. Enhanced spatial resolution, frequent revisit cycles, and advanced AI-driven analytics are highlighted as key enablers for safer, more reliable, and cost-effective solutions. This review provides a framework for leveraging EO data to drive innovation and improve railway monitoring practices.
Open Access: Yes
Evaluating 3D-Printed Polylactic Acid (PLA)-Reinforced Materials: Mechanical Performance and Chemical Stability in Concrete Mediums
Publication Name: Applied Sciences Switzerland
Publication Date: 2025-02-01
Volume: 15
Issue: 4
Page Range: Unknown
Description:
The optimization and evaluation of 3D-printed polylactic acid (PLA) materials for reinforcing concrete elements present a promising avenue for advancing sustainable construction methods. This study addresses the challenges associated with PLA’s dual nature—biodegradable yet mechanically limited for long-term applications—while leveraging its potential to enhance concrete reinforcement. The research identifies gaps in understanding PLA’s mechanical and chemical behavior in alkaline environments, particularly its interactions with concrete matrices. To bridge this gap, four distinct PLA variants (high-impact PLA, engineering PLA, electrical ESD PLA, and gypsum PLA) and ABS (acrylonitrile butadiene styrene) were subjected to dissolution tests in NaOH solutions (pH 12 and 12.55) and mechanical evaluation under three-point bending using digital image correlation (DIC) technology. Test specimens were prepared using optimized 3D printing strategies to ensure structural consistency and were embedded in concrete beams to analyze their reinforcement potential. Force–displacement data and GOM ARAMIS measurements revealed significant differences in mechanical responses, with peak loads ranging from 0.812 kN (high-impact PLA) to 1.021 kN (electrical ESD PLA). Notably, electrical ESD PLA exhibited post-failure load-bearing capacity, highlighting its reinforcement capability. Chemical dissolution tests revealed material-specific degradation patterns, with high-impact and Gypsum PLA showing accelerated surface changes and precipitation phenomena. Observations indicated white crystalline precipitates, likely lime (calcium hydroxide—Ca(OH)2 ), residue from the dissolution tests (sodium hydroxide—NaOH), or material-derived residues formed on and near PLA elements, suggesting potential chemical interactions. These findings underline the critical role of material selection and optimization in achieving effective PLA–concrete integration. While PLA’s environmental sustainability aligns with industry goals, its structural reliability under long-term exposure remains a challenge. The study concludes that electrical ESD PLA demonstrates the highest potential for application in reinforced concrete, provided its chemical stability is managed, as its peak value (1.021 kN) showed 25.7% higher load-bearing capacity than high-impact PLA (0.812 kN) and did not lose any of its structural stability in the dissolution tests. This work advances the understanding of PLA as a sustainable alternative in construction, offering insights for future material innovations and applications.
Open Access: Yes
DOI: 10.3390/app15042165
Quantifying the Effect of Frame Stiffness – The Substitution Inertia of Meier's Calculation
Publication Name: Lecture Notes in Networks and Systems
Publication Date: 2025-01-01
Volume: 1258 LNNS
Issue: Unknown
Page Range: 46-57
Description:
The internationally accepted method for assessing track stability is the calculation based on Meier's theory. A critical point is the inclusion of the equivalent track bending stiffness. Practical measurements have often given contradictory results in determining this, so the authors present a purely theoretical determination in this article. For this purpose, the Nemesdy theory, which is used in Hungarian practice, is invoked. By applying this theory, the paper introduces an auxiliary factor that allows us to calculate the value of the inertia of the two rails on the vertical axis. Stopping at this point in the theoretical derivation and recognizing the possibility, an iterative solution is proposed by which the magnitude of the substitute inertia can be considered in Meier's calculation without performing the necessary calculations using Nemesdy's theory.
Open Access: Yes
Production and Testing of 3D Printed PLA Structures with DIC Technology for the Reinforcement of Concrete Elements
Publication Name: Lecture Notes in Networks and Systems
Publication Date: 2025-01-01
Volume: 1258 LNNS
Issue: Unknown
Page Range: 175-187
Description:
3D printing technologies are now extensively utilized across numerous industries and scientific fields due to their ability to facilitate the practical testing of various design concepts cost-effectively and sustainably. This research focuses on PLA-based materials, known for their ease of recyclability. FDM printing technology was employed to identify the optimal printing layout for 3D-printed reinforcement elements in concrete, as this is not a standard parameter. Various material compositions and layout structures were analyzed using multiple printing strategies to find the most effective combination for innovatively enhancing the stiffness and strength of concrete structures. The GOM Aramis 5M DIC system, coupled with FDM printing technology, was used in this investigation, marking a novel approach in civil engineering.
Open Access: Yes
Exploring the Impact of Fiber Content on the Mechanical Performance of Steel Fiber Reinforced Concrete: Consistency and Compaction Time Analysis
Publication Name: Lecture Notes in Networks and Systems
Publication Date: 2025-01-01
Volume: 1258 LNNS
Issue: Unknown
Page Range: 162-174
Description:
The evolution of building materials and technologies is imperative in response to the growing demands for large-scale infrastructure. Steel fiber-reinforced concrete (SFRC) has gained widespread usage due to its notable benefits, such as enhanced crack-bridging capacity and increased shear strength, reducing the need for traditional reinforcement. This study investigates the effects of varying fiber content and compaction times on the mechanical properties of SFRC. Laboratory tests were conducted on 24 different concrete mix designs, producing a total of 216 specimens, including blocks, cubes, and beams. The findings indicate that the optimal fiber content and compaction time significantly influence the compressive, flexural, and tensile strengths of SFRC. A detailed mathematical and statistical analysis highlights the importance of these parameters, providing insights for optimizing SFRC performance in construction. Future research directions are suggested to enhance further the understanding and application of SFRC in the construction industry.
Open Access: Yes
Investigation of the Modified Ballast Breakage Index for a Laboratory Test Series using the Proctor Compactor Machine
Publication Name: Acta Polytechnica Hungarica
Publication Date: 2025-01-01
Volume: 22
Issue: 4
Page Range: 137-157
Description:
The rock physics properties of the crushed railway ballast include resistance against breakage and wear. The qualification of such materials and their compliance with requirements is mainly considered by two standard tests: The Los Angeles abrasion and Micro-Deval wear resistance tests. These tests are indispensable for the legally mandatory qualification of aggregates, but several measurement methods have been developed that better simulate operating conditions and provide an even more accurate classification of these materials. A Proctor compactor machine was applied to induce a top impact load more similar to the operating conditions of ballast. Pre-screened, sorted, washed, and dried samples of andesite aggregate from four quarries with different rock physics characteristics were used to conduct the test series. The impact load was applied with increasing numbers of blows, i.e., 64, 128, 256 and 1024. Several parameters and indexes were calculated to reveal different relationships, which had to be modified in some cases to obtain estimates as close as possible to those obtained in individual tests. The original Ballast Breakage Index seemed to be an appropriate measure of the change in ballast material quality during deterioration for over a decade. The original calculation method was not consistent with the newly introduced test method. Keeping the principle, however, a modified BBI index calculation method has been developed that fundamentally simplifies the calculation of ballast fragmentation. The whole series of measurements aimed to provide, by material and number of impacts, a series of fragmentation and degradation curves for each of the three repeated measurements, which would give the degradation of samples with different rock physics and grain sizes.
Open Access: Yes
Vehicle Dynamics Measurements with a Unique Measuring System for Trams
Publication Name: Lecture Notes in Networks and Systems
Publication Date: 2025-01-01
Volume: 1258 LNNS
Issue: Unknown
Page Range: 24-33
Description:
One of the paramount challenges in contemporary urban transport is the efficient maintenance and operation of tramway tracks, aiming to maximize their lifespan while ensuring safe and comfortable passenger travel. Traditional methods of examining superstructure systems through observation and geometric measurements are insufficient; understanding the dynamics of vehicles adhering to their schedules is equally critical. To address this, we developed an innovative portable vehicle dynamics measurement system equipped with accelerometers and a GPS module (with GNSS system), facilitating real-time tram dynamics testing. This versatile device can be deployed at any time and on any tram, enabling continuous monitoring of track conditions. The dynamic data gathered can be systematically compared with geometric measurements, providing comprehensive insights into the railway track's condition and informing maintenance strategies. The paper consists of several examples for comparison (geometric and dynamic data series) and discusses how to develop the instrument further.
Open Access: Yes
A Fuzzy Framework for Assessing and Prioritizing Railway Infrastructure Retrofitting against Seismic Hazards – A Case Study
Publication Name: Acta Polytechnica Hungarica
Publication Date: 2025-01-01
Volume: 22
Issue: 4
Page Range: 263-283
Description:
The railway system plays a crucial role in a nation's economy and society, extending beyond mere transportation. In earthquake-prone regions like Razavi Khorasan in Iran, railway infrastructure is highly vulnerable to natural disasters, which can severely disrupt train operations. Ensuring the safety of critical infrastructure, including stations, bridges, tunnels, and railway lines, is essential for maintaining operational integrity and public safety. This study evaluates and prioritizes seismic retrofitting measures for railway infrastructures in Razavi Khorasan. The fuzzy Delphi method is used to gather expert opinions, while the Fuzzy VIKOR method facilitates the prioritization process. Key assessment criteria include seismic intensity potential, vulnerability potential of the zone in terms of distance from the fault, the degree of criticality of the infrastructure in terms of the possibility of continuing transportation operations and the current state of the infrastructure in terms of the state of retrofitting against seismic hazards. The findings reveal critical railway segments that require immediate retrofitting interventions and highlight overall vulnerabilities within the system. This paper underscores the effective application of fuzzy logic methodologies in complex decision making scenarios, offering actionable recommendations to enhance the seismic retrofitting of railway infrastructures.
Open Access: Yes
Dynamic Modeling Possibilities of Embedded Rail Structures
Publication Name: Acta Polytechnica Hungarica
Publication Date: 2025-01-01
Volume: 22
Issue: 4
Page Range: 29-43
Description:
In Hungarian design practice, the Zimmermann-Eisenmann quasi-static design method is employed to dimension track structures with embedded rails. This method determines the mean values of deformations and stresses using an infinitely long elastically embedded beam as the static frame. After establishing these mean values, the effects of track condition and speed are considered through Eisenmann multiplication, enabling the definition of design values. Conversely, international practices include methods that calculate deformations and stresses based on dynamic models incorporating viscoelastic embedding, directly accounting for speed but not dynamic effects due to track characteristics. This paper presents a solution to the dynamic problem, extending it to studying rotating frames beyond the commonly considered uniaxial solution. Each factor's effect is separately analyzed for track structures with embedded rail tracks, leading to a recommendation for the value of the "load multiplication factor".
Open Access: Yes
Performance of PMMA and SBS Modified Asphalt Mixtures in Railway Supplementary Layers and Road Pavements
Publication Name: Periodica Polytechnica Transportation Engineering
Publication Date: 2025-01-01
Volume: 53
Issue: 3
Page Range: 334-346
Description:
The use of recycled waste elastic materials provides a cost-effective and environmentally friendly option for further modifying the performance of asphalt mixtures. Therefore, the effects of different proportions of (PMMA) polymethyl methacrylate derived from waste plastic material were evaluated using the Indirect Tensile Strength Test (ITST) of lab-prepared specimens. Since numerous methods of modifying the conventional asphalt binder are available, in this research, the virgin binder was modified with 1%, 2%, 3%, 4% and 5% PMMA for evaluating optimum performance proportions in terms of Marshall stability and ITST of asphalt mixtures. Furthermore, stiffness modulus tests were performed at frequency values of 1.2 Hz, 1.9 Hz, 3.9 Hz and 5 Hz. The effect of the loading rate from 10 MPa/s to 70 MPa/s was evaluated with an increment of 10 MPa/s for all proportions. Moreover, finite element modeling was performed using the data obtained from dynamic modulus tests with modified Burger's Logit model for evaluation of rutting progression. Results show improved performance of asphalt mixtures with the addition of PMMA, leading to variation in properties including penetration, softening point, Marshall stability and rutting resistance. It is recommended to use 5% PMMA for increased indirect tensile strength, Marshall stability, rutting and fatigue damage resistance.
Open Access: Yes
DOI: 10.3311/PPtr.39763
The Usability of Polymethyl Methacrylate in Marshall Samples for Asphalt Pavements Using in Railway Supplementary Layers
Publication Name: Lecture Notes in Networks and Systems
Publication Date: 2025-01-01
Volume: 1258 LNNS
Issue: Unknown
Page Range: 34-45
Description:
In today's world, construction and infrastructure projects necessitate innovative solutions in environmental sustainability and materials engineering. In this context, research efforts to improve the properties of asphalt mixtures, reduce environmental impacts, and contribute to recycling hold great significance. This study focuses on modifying stone mastic asphalt mixtures with waste material derived from Polymethyl Methacrylate. Using Polymethyl Methacrylate as waste plastic material represents a significant step forward in recycling and sustainable material usage. In the study, Marshall specimens were obtained using Polymethyl Methacrylate in different proportions in bitumen and aggregate. The results of the Marshall specimens were evaluated to determine the usability and optimum ratios of Polymethyl Methacrylate. This study aims to evaluate the impact of Polymethyl Methacrylate on stone mastic asphalt mixtures as a support layer in railway tracks to help reduce noise and vibration. The results demonstrate that varying concentrations of Polymethyl Methacrylate in both aggregate and bitumen significantly alter the mechanical and thermal properties of the asphalt. For instance, incorporating 2.5% Polymethyl Methacrylate in the aggregate increased the VMA to 21, resulting in VFA values of 66. Furthermore, using Polymethyl Methacrylate in the aggregate increased the asphalt samples’ height, ranging from 69 to 72 mm. These findings underscore the effectiveness and feasibility of Polymethyl Methacrylate in sustainable asphalt projects. Following highway technical specifications, incorporating Polymethyl Methacrylate in specific proportions in stone mastic asphalt mixtures can enhance their performance, representing a significant step towards sustainable road construction. However, when the concentration of Polymethyl Methacrylate in the bitumen increased, the bitumen formed deteriorated. Therefore, using waste Polymethyl Methacrylate between 4% and 5% can be considered suitable for improving the properties of bitumen against sustainability and temperature concerns.
Open Access: Yes
The Road Pavement Structure as a Forgotten Element of the Transport Infrastructure System
Publication Name: Lecture Notes in Networks and Systems
Publication Date: 2025-01-01
Volume: 1258 LNNS
Issue: Unknown
Page Range: 248-262
Description:
Despite rapid advancements in vehicle and human integration within road transport systems, the role of road pavement structures has been largely overlooked. This paper is motivated by the critical need to address this gap, particularly in light of the growing challenges posed by global climate change. The road transport system, as an integrated “human-vehicle-road” unit placed within the environment, has undergone significant changes to this day. However, this rapid development has been predominantly confined to two elements of the system: humans and vehicles. Vehicles and their drivers are receiving increasingly specific and targeted information about traffic processes, and the role of humans in processing this information is progressively being assumed by vehicle intelligence. As a result, humans and vehicles, as system components, are becoming increasingly integrated. As an innovation in infrastructure, the road pavement structure has largely been unaffected by current developments in material technology and vehicle advancements, with no significant breakthroughs beyond typical alternatives to asphalt or concrete pavements. This article explores whether the presumed future impact of global climate instability might reshape the developmental trajectories of certain elements of the road transport system and whether the need to address weather extremes could bring research related to the resilience and climate adaptation potential of road pavement structures to the forefront, potentially at the expense of the vehicle and driver, the other two system elements.
Open Access: Yes
Void Geometry Identification with Track-Side Rail Deflection Measurements
Publication Name: Lecture Notes in Networks and Systems
Publication Date: 2025-01-01
Volume: 1258 LNNS
Issue: Unknown
Page Range: 188-202
Description:
One of the most common failure types that rapidly deteriorates track geometry is sleeper voids or unsupported sleepers. Ballast pulverization, or so-called “white spots”, is a sign that indicates the presence of the high sleeper voids in the track. However, the objective estimation of the size and form of voids is possible by time- and cost-consuming track-side measurements at many points along the track. The study presents an efficient model-based approach for the identification of the void geometry by the track-side experimental measurements of rail deflection in one point. A robust 3-beam track model with a two-mass vehicle model together with a time-effective surrogate optimization algorithm is used for the multidimensional search of the void geometry that is fitting to experimental data. The results show that the void geometry could be found precisely with one-point measurements, significantly reducing the time and cost involved in the process. Therefore, a practical, simplified method of determining the void zone's depth and length is proposed. It is based on analyzing the relation between void sizes and the rail deflection wave sizes. Unlike the void depth, the void length cannot be found by the simple difference between the deflection waves in the void and the reference zones. The proposed method assumes wave estimation by applying deflection thresholds, ensuring a practical and reliable approach. The reliability of the proposed method in estimating void length and depth instills confidence in the effectiveness of the approach. Finally, it was used to estimate the void length and depth for many problem zones in ballast tracks that were inspected with track-side measurements. The result analysis shows that the void length and depth are subjected to a non-linear relation: the long-length voids have unproportionally higher depths than short voids. The results indicate that the settlement intensity of the neighbor-to-void sleepers is much lower than that of the hanging sleepers.
Open Access: Yes
Visual Inspection in Transport Using Autonomous Robots
Publication Name: Lecture Notes in Networks and Systems
Publication Date: 2025-01-01
Volume: 1258 LNNS
Issue: Unknown
Page Range: 132-143
Description:
The development of new technologies, which include advanced sensors and the application of artificial intelligence, has led to the moment that some operations done by workers can be changed in the maintenance domain. Visual inspection is one of the operations that will be changed in the future. Today, there are various legal regulations regarding the maintenance and control of vehicles in the transport sector, which cause additional costs for operators. There is a need to reduce those costs by integrating autonomous robots for the visual inspection of various vehicles. In addition to reduced costs, the benefits are reflected in improved human safety, greater efficiency, and reduced errors during the visual controls. This paper explores various applications of autonomous robots in various transport domains, including rail systems, road and bridge networks, aerospace, and maritime industries. It also shows a real example of visual control of locomotive undercarriage in railways.
Open Access: Yes
Laboratory Investigation on Seams between Rails and Hardened Fine-grained, as well as Hadfield Steel Plates with Manual Arc Welding
Publication Name: Acta Polytechnica Hungarica
Publication Date: 2025-01-01
Volume: 22
Issue: 4
Page Range: 83-102
Description:
In the last decade, hardened fine-grained plate components have been used in turnouts and crossings on Western European urban rail networks, as well as in Hungary, in place of traditional rail or Hadfield steel components. The first crossing was built in Hungary in 2016. These components have many advantages, such as the ease with which they can be machined in the factory; they are less prone to cracking than rails due to their block design (high load-bearing cross-section); however, their weldability to rails and lifetime repairability present numerous challenges for railway turnout manufacturers and operators. There have been numerous studies on joint and repair welding of rails and hardened finegrained materials, but there is little or no information available on joint welding with manual arc welding of these two different materials. The current study aims to investigate the welds of coated electrode manual arc welding of rails (R260 and R400 HT) and hardened finegrained plates (in this case, Hardox 500) under non-laboratory conditions while strictly adhering to technological specifications, in comparison to manual arc welding of rails and Hadfield steels. Laboratory tests included raw material chemical composition, macroscopic tests, micro-hardness measurements, tensile, shear, and bending tests.
Open Access: Yes
Innovative Technologies and Cognitive Factors for Enhancing Safety of Train and Car Movement at Level Crossings
Publication Name: Lecture Notes in Networks and Systems
Publication Date: 2025-01-01
Volume: 1258 LNNS
Issue: Unknown
Page Range: 1-13
Description:
Safety in transportation is an exceptionally complex and multifaceted concept. The research focuses on the functioning processes of hazardous transportation facilities - railway crossings with varying intensity and transportation parameters, which require solutions to a wide range of theoretical, practical, and organizational tasks. The integration of innovative technologies, a beacon of hope, to modernize existing crossings and implement cognitive direction systems can help create a safer environment at railway crossings. To reduce the likelihood of human error and improve safety, it is recommended to utilize both existing technologies and innovative opportunities to develop new safety solutions for railway crossings, considering cognitive processes - mental operations used for perception of information, its retention in memory, processing, analysis, interpretation, and utilization for decision-making and problem-solving.
Open Access: Yes
Investigation of Digital Light Processing-Based 3D Printing for Optimized Tooling in Automotive and Electronics Sheet Metal Forming
Publication Name: Journal of Manufacturing and Materials Processing
Publication Date: 2025-01-01
Volume: 9
Issue: 1
Page Range: Unknown
Description:
This study addresses the emerging need for efficient and cost-effective solutions in low-volume production by exploring the mechanical performance and industrial feasibility of cutting tools that are fabricated using stereolithography apparatus (SLA) technology. SLA’s high-resolution capabilities make it suitable for creating precise cutting dies, which were tested on aluminum sheets (Al99.5, 0.3 mm, and AlMg3, 1.0 mm) under a 60-ton hydraulic press. Measurements using digital image correlation (DIC) revealed minimal wear and deformation, with tolerances consistently within IT 0.1 mm. The results demonstrated that SLA-printed tools perform comparably to conventional metal tools in cutting and bending operations, achieving similar surface quality and edge precision while significantly reducing the production time and cost. Despite some limitations in wear resistance, the findings highlight SLA technology’s potential for rapid prototyping and short-run manufacturing in the automotive and electronics sectors. This research fills a critical gap in understanding SLA-based tooling applications, offering insights into process optimization to enhance tool durability and broaden material compatibility. These advancements position SLA technology as a transformative tool-making technology for flexible manufacturing.
Open Access: Yes
DOI: 10.3390/jmmp9010025
Investigation of FDM-Based 3D Printing for Optimized Tooling in Automotive and Electronics Sheet Metal Cutting
Publication Name: Applied Sciences Switzerland
Publication Date: 2025-01-01
Volume: 15
Issue: 1
Page Range: Unknown
Description:
Within the scope of the work, the possible use of fused deposition modeling (FDM) technology in executing rapid prototypes of cutting tools for aluminum sheets was systematically studied. Relevant investigations have thus far mainly concentrated on tools for the 3D printing of bent and deep-drawn pieces, yet the implementation of FDM tools in cutting has been insufficiently covered. This study aims to determine the characteristics of FDM cutting tools, such as wear and tear, dimensional stability, and cutting efficiency. Various tool designs were tested under different wall thicknesses and orientations with respect to the feed of Al99.5 sheets with thicknesses of 0.22 mm and 0.3 mm. According to the results, in the best case, three-dimensional printed PLA tools performed six cuts with no burrs and an acceptable wear level due to the IT tolerances (IT9 and IT10). Tools with thicker walls and more appropriate orientations were found to be more robust. However, some designs failed when subjected to greater loads, revealing a deficiency in some of the strength properties of the material. These observations suggest that it is possible to create 3D printed tools for modeling and small-scale production at considerably cheaper and faster rates than conventional methods. Future work will integrate advanced materials and designs to enhance tool performance, further solidifying FDM as a transformative approach in industrial tool manufacturing. With this research, the authors wanted to demonstrate that FDM technology can also be used to produce a classic sheet cut, which, of course, is still of great importance for prototyping or setting up production processes. This research demonstrated that FDM printing can play a role in this area.
Open Access: Yes
DOI: 10.3390/app15010442
Field Application of Austenitic Filler Metals for Repairing Rail Surface Defects in Paved Tracks
Publication Name: Lecture Notes in Networks and Systems
Publication Date: 2025-01-01
Volume: 1258 LNNS
Issue: Unknown
Page Range: 87-95
Description:
Previous research by the authors identified a welding technology to repair rail defects in tramways with partial disassembly and partial preheating, with the following main advantages for the operator: the process can be carried out during operational downtime or even during traffic, disassembly, and repair costs are reduced, and traffic disruption is reduced compared to conventional hard surfacing welding technologies. After welding, the hardening under traffic should approach the vehicle wheels’ hardness values (310–350 HB). In the track measurements under investigation, welds were made on two different rail grades using austenitic weld metal with high elongation relative to the rails, which was also compared with welds made by conventional hard surfacing welding. The present study aims to determine the hardening function of austenitic dowel bars at different layer counts by performing continuous hardness measurements at the investigated sites. The hardening shows a power function at the initial stage and a linear trend after about 2.5 million MGT.
Open Access: Yes
An Analytical Method for Determining the Stress–Strain State of a Subgrade with Combined Reinforcement
Publication Name: Infrastructures
Publication Date: 2024-12-01
Volume: 9
Issue: 12
Page Range: Unknown
Description:
This article presents the fundamentals of an analytical method for determining the stress–strain state of a railway subgrade reinforced with geosynthetic material. The reinforcement described is a combined system where the geosynthetic material forms an open shell containing a layer of compacted crushed stone. The overall stress–strain state is proposed to be viewed as a superposition of two states of the subgrade. The stresses and displacements in the first state refer to the unreinforced subgrade (matrix), while the stress–strain state of the reinforcement element is determined using analytical constructs from composite theory. The dependencies of the overall stress–strain state are applied in a numerical analysis, which confirms the positive effect of reduced subgrade deformations. A small-scale experimental model further validates the accuracy of the analytical approach.
Open Access: Yes
INVESTIGATION OF HEAT-AFFECTED ZONES OF THERMITE RAIL WELDINGS
Publication Name: Facta Universitatis Series Mechanical Engineering
Publication Date: 2024-12-01
Volume: 22
Issue: 4
Page Range: 689-710
Description:
The paper investigates the heat-affected zone (HAZ) of several rail joints executed by thermite rail welding (TW). The examined rail profile was 54E1 (UIC54). The rail steel categories were different: R260 and R400HT. The welding portions of the TWs fitted R350HT and R260 rail categories with normal welding gaps. The rail pieces were brand new, i.e., without any usage in the railway track. The authors executed Vickers-hardness tests (HV10) and material texture tests on the running surface of the rail head, as well as on slices cut from the rail head. The cutting was performed by the water jet method, five longitudinal direction slices with vertical cutting lines. The considered specimen lengths were 2×70 mm (i.e., 70 mm from the mid-point of the rail joint), however, the depths were 20 mm from the running surface. Therefore, the measuring spaces were 5 mm lengthwise and 2 mm in depth. The variation of the hardness values was determined considering the microstructures of the base steel material and the TW. For comparison, previously measured Elektrothermit SoW-5 and earlier own research were taken into consideration.
Open Access: Yes
Detection of Bus Driver Mobile Phone Usage Using Kolmogorov-Arnold Networks
Publication Name: Computers
Publication Date: 2024-09-01
Volume: 13
Issue: 9
Page Range: Unknown
Description:
This research introduces a new approach for detecting mobile phone use by drivers, exploiting the capabilities of Kolmogorov-Arnold Networks (KAN) to improve road safety and comply with regulations prohibiting phone use while driving. To address the lack of available data for this specific task, a unique dataset was constructed consisting of images of bus drivers in two scenarios: driving without phone interaction and driving while on a phone call. This dataset provides the basis for the current research. Different KAN-based networks were developed for custom action recognition tailored to the nuanced task of identifying drivers holding phones. The system’s performance was evaluated against convolutional neural network-based solutions, and differences in accuracy and robustness were observed. The aim was to propose an appropriate solution for professional Driver Monitoring Systems (DMS) in research and development and to investigate the efficiency of KAN solutions for this specific sub-task. The implications of this work extend beyond enforcement, providing a foundational technology for automating monitoring and improving safety protocols in the commercial and public transport sectors. In conclusion, this study demonstrates the efficacy of KAN network layers in neural network designs for driver monitoring applications.
Open Access: Yes
Mechanism of cross-level settlements and void accumulation of wide and conventional sleepers in railway ballast
Publication Name: Railway Engineering Science
Publication Date: 2024-09-01
Volume: 32
Issue: 3
Page Range: 361-383
Description:
The cross-level and twist irregularities are the most dangerous irregularity types that could cause wheel unloading with the risk of derailments and additional maintenance expenses. However, the mechanism of the irregularities initiation and development is unclear. The motivation of the present study was the previous experimental studies on the application of wide sleepers in the ballasted track. The long-term track geometry measurements with wide sleepers show an enormous reduction of the vertical longitudinal irregularities compared to the conventional track. However, wide sleepers had higher twist and cross-section level irregularities. The present paper aims to explain the phenomenon by discrete element method (DEM) modeling the development process of sleeper inhomogeneous support at cross-level depending on the sleeper form. The DEM simulations show that the maximal settlement intensity is up to 3.5 times lower for a wide sleeper in comparison with the conventional one. Nevertheless, the cross-level differential settlements are almost the same for both sleepers. The particle loading distribution after all loading cycles is concentrated on the smaller area, up to the half sleeper length, with fully unloaded zones under sleeper ends. Ballast flow limitation under the central part of the sleeper could improve the resilience of wide sleepers to the development of cross-level irregularities. The mechanism of initiation of the cross-level irregularity is proposed, which assumes the loss of sleeper support under sleeper ends. The further growth of inhomogeneous settlements along the sleeper is assumed as a result of the interaction of two processes: ballast flow due to dynamic impact during void closing and on the other side high pressure due to the concentration of the pressure under the middle part of the sleeper. The DEM simulation results support the assumption of the mechanism and agree with the experimental studies.
Open Access: Yes
Effect of the Particle Size Distribution of the Ballast on the Lateral Resistance of Continuously Welded Rail Tracks
Publication Name: Infrastructures
Publication Date: 2024-08-01
Volume: 9
Issue: 8
Page Range: Unknown
Description:
While the effect of ballast degradation on lateral resistance is noteworthy, limited research has delved into the specific aspect of ballast breakage in this context. This study is dedicated to assessing the influence of breakage on sleeper lateral resistance. For simplicity, it is assumed that ballast breakage has already occurred. Accordingly, nine granularity variations finer than No. 24 were chosen for simulation, with No. 24 as the assumed initial particle size distribution. Initially, a DEM model was validated for this purpose using experimental outcomes. Subsequently, employing this model, the lateral resistance of different particle size distributions was examined for a 3.5 mm displacement. The track was replaced by a reinforced concrete sleeper in the models, and no rails or rail fasteners were considered. The sleeper had a simplified model with clumps, the type of which was the so-called B70 and was applied in Western Europe. The sleeper was taken into consideration as a rigid body. The crushed stone ballast was considered as spherical grains with the addition that they were divided into fractions (sieves) in weight proportions (based on the particle distribution curve) and randomly generated in the 3D model. The complete 3D model was a 4.84 × 0.6 × 0.57 m trapezoidal prism with the sleeper at the longitudinal axis centered and at the top of the model. Compaction was performed with gravity and slope walls, with the latter being deleted before running the simulation. During the simulation, the sleeper was moved horizontally parallel to its longitudinal axis and laterally up to 3.5 mm in static load in the compacted ballast. The study successfully established a relationship between lateral resistance and ballast breakage. The current study’s findings indicate that lateral resistance decreases as ballast breakage increases. Moreover, it was observed that the rate of lateral resistance decrease becomes zero when the ballast breakage index reaches 0.6.
Open Access: Yes
Ballast Settlement Accumulation in Zones with Unsupported Sleepers
Publication Name: Transportation Infrastructure Geotechnology
Publication Date: 2024-08-01
Volume: 11
Issue: 4
Page Range: 2598-2637
Description:
The high influence of impact and vibration on the behavior of crushed stone and ballast materials has been known for a long time. The zones with unsupported sleepers, which are always present in transition zones, crossings, welds, etc., are typically characterized by impact interaction, ballast full unloading, and additional preloading. However, no studies on ballast layer settlements consider impact vibration loading. Moreover, the influence of the cyclic loading on the ballast settlement intensity is considered ambiguously, with both decelerating and accelerating trends. The comprehensive literature review presents the influence of factors on settlement intensity. The present study aims to estimate the long-term processes of sleeper settlement accumulation depending on the loading factors: impact, cyclic loading, and preloading. The typical for a void zone ballast loading pattern was determined for various void sizes and the position along the track by using a model of vehicle-track interaction that was validated by experimental measurements. The loading patterns were parametrized with four parameters: maxima of the cyclic loading, impact loading, sleeper acceleration, and minimal preloading. A specially prepared DEM simulation model was used to estimate the ballast settlement intensity after initial settlement stabilization for more than 100 loading patterns of the void zone cases. The settlement simulation results clearly show that even a low-impact loading pattern causes many times increased settlement intensity than ordinary cyclic loading. Moreover, the initial preloading in the neighbor-to-void zones can cause even a decrease in the settlement intensity compared to the full ordinary or partial unloading. A statistical analysis using a machine learning approach and an analytic one was used to create the model for the intensity prediction regarding the loading patterns. The analytic approach demonstrates somewhat lower prediction quality, but it allows to receive plausible and simple analytic equations of the settlement intensity. The results show that the maximal cyclic loading has a nonlinear influence on the settlement intensity that corresponds to the 3–4 power function, and the impact loading is expressed by the linear to parabolic function. The ballast’s minimal preloading contributes to the reduction of the settlement intensity, especially for high cyclic loadings that are typical for neighbor-to-void zones. The results of the present study could be used for the complementing of the present phenomenological equations with the new factors and further application in the algorithms of the settlements accumulation prediction.
Open Access: Yes
Laboratory and Numerical Investigation of Pre-Tensioned Reinforced Concrete Railway Sleepers Combined with Plastic Fiber Reinforcement
Szabolcs Fischer
Mykola Sysyn
Zoltán Major
Sarah Khaleel Ibrahim
Dmytro Kurhan
Vivien Jóvér
Szabolcs Szalai
Hanna Csótár
Klaudia Madarász
András Pollák
Dániel Harrach
Bálint Molnár
L. Gaspar
Bence Hermán
Szabolcs Kocsis Szurke
Attila Németh
I. Fekete
Richárd Nagy
Gusztáv Baranyai
Miklós Kuczmann
M. Movahedi Rad
Publication Name: Polymers
Publication Date: 2024-06-01
Volume: 16
Issue: 11
Page Range: Unknown
Description:
This research investigates the application of plastic fiber reinforcement in pre-tensioned reinforced concrete railway sleepers, conducting an in-depth examination in both experimental and computational aspects. Utilizing 3-point bending tests and the GOM ARAMIS system for Digital Image Correlation, this study meticulously evaluates the structural responses and crack development in conventional and plastic fiber-reinforced sleepers under varying bending moments. Complementing these tests, the investigation employs ABAQUS’ advanced finite element modeling to enhance the analysis, ensuring precise calibration and validation of the numerical models. This dual approach comprehensively explains the mechanical behavior differences and stresses within the examined structures. The incorporation of plastic fibers not only demonstrates a significant improvement in mechanical strength and crack resistance but paves the way for advancements in railway sleeper technology. By shedding light on the enhanced durability and performance of reinforced concrete structures, this study makes a significant contribution to civil engineering materials science, highlighting the potential for innovative material applications in the construction industry.
Open Access: Yes
Bus Driver Head Position Detection Using Capsule Networks under Dynamic Driving Conditions
Publication Name: Computers
Publication Date: 2024-03-01
Volume: 13
Issue: 3
Page Range: Unknown
Description:
Monitoring bus driver behavior and posture in urban public transport’s dynamic and unpredictable environment requires robust real-time analytics systems. Traditional camera-based systems that use computer vision techniques for facial recognition are foundational. However, they often struggle with real-world challenges such as sudden driver movements, active driver–passenger interactions, variations in lighting, and physical obstructions. Our investigation covers four different neural network architectures, including two variations of convolutional neural networks (CNNs) that form the comparative baseline. The capsule network (CapsNet) developed by our team has been shown to be superior in terms of efficiency and speed in facial recognition tasks compared to traditional models. It offers a new approach for rapidly and accurately detecting a driver’s head position within the wide-angled view of the bus driver’s cabin. This research demonstrates the potential of CapsNets in driver head and face detection and lays the foundation for integrating CapsNet-based solutions into real-time monitoring systems to enhance public transportation safety protocols.
Open Access: Yes
Investigation of the Vertical Stability of Embedded Rail Structures
Publication Name: Advances in Transdisciplinary Engineering
Publication Date: 2024-01-01
Volume: 59
Issue: Unknown
Page Range: 37-43
Description:
In the case of embedded rail structures, the rails are fixed with a flexible embedding material that runs through a specially designed steel or reinforced concrete channel. The majority of the rail cross-section is embedded in these channels, eliminating the possibility of horizontal buckling as a failure mode. This paper investigates vertical stability, aiming to determine the stability resistance of a rail loaded with an initial failure in the vertical plane while considering elastic resistance. Vertical plane buckling is assumed to be a non-hazard for conventional rails because the wide rail footing can significantly inhibit vertical displacement, even without adhesion between the rail surface and the embedding material. However, the adhesion of the embedding material to the channel is adequate. Some rail sections lack adhesion between the rail and the embedding material due to the narrow width of the rail foot, making the phenomenon of "form-locking" uncertain, or the rail is partially embedded. In this article, the authors present a theoretical calculation method to investigate this problem, to transfer the results to everyday practice as simply as possible, and to present a solution suitable for manual calculation. Measuring the vertical spring constant in the method's input parameters under laboratory conditions is a difficult task, but by utilizing the possibilities provided by finite element modeling, the design can be significantly simplified. The introduced method has the significant advantage of quantifying the effect of vertical plane misalignments in the track compared to simpler solutions in the literature.
Open Access: Yes
DOI: 10.3233/ATDE240524
Sustainable Uses of 3D Printing Applied to Concrete Structures †
Publication Name: Engineering Proceedings
Publication Date: 2024-01-01
Volume: 79
Issue: 1
Page Range: Unknown
Description:
This study investigates the application of honeycomb-patterned PLA as a reinforcement in concrete structures. The research focused on identifying the optimal 3D printing layout for this reinforcement and examining how the orientation of 3D-printed PLA affects the mechanical properties of the concrete. The study compares the performance of concrete reinforced with 3D-printed PLA to both unreinforced concrete and concrete reinforced with recycled amorphous aggregate from printing waste. The results demonstrate how printing orientation influences concrete strength and the potential for using recycled PLA to enhance sustainability in construction.
Open Access: Yes
Integrating Renewable Energy into Railway Systems: a Path to Sustainable Transportation – A Review
Publication Name: Chemical Engineering Transactions
Publication Date: 2024-01-01
Volume: 114
Issue: Unknown
Page Range: 817-822
Description:
Integrating renewable energy sources into railway systems presents a promising solution to mitigate rising CO2 emissions, growing energy demands, and environmental degradation. This paper reviews the potential of incorporating renewable energy technologies such as solar, wind, bioenergy, and kinetic energy recovery into railway infrastructure. By employing intelligent multi-agent systems to manage rail microgrids, the study demonstrates significant enhancements in energy efficiency, operational cost reduction, and system reliability. Strategic deployment of these energy solutions has shown a potential reduction in energy consumption by up to 30 %. This paper underscores the importance of advanced energy storage and management systems to address the variability of renewable sources, ensuring a stable and consistent energy supply. These findings highlight the critical role of smart grid technologies and AI-driven energy management in advancing the sustainability of railway operations and contributing to global sustainable development objectives.
Open Access: Yes
DOI: 10.3303/CET24114137
Innovative Approaches in Railway Management: Leveraging Big Data and Artificial Intelligence for Predictive Maintenance of Track Geometry
Publication Name: Tehnicki Vjesnik
Publication Date: 2024-01-01
Volume: 31
Issue: 4
Page Range: 1245-1259
Description:
This paper introduces and describes a method for extracting, processing, and analyzing large amounts of track geometrical data. It allows for a more accurate description of the orbital deterioration correlations than currently applied procedures, and it seems to be more valuable and efficient in practice. The initial data were the track geometry measurement and classification data for the whole national network provided by the Hungarian State Railways, i.e., the MÁV PLC. The MÁV provided data for the whole Hungarian railway network for 27 half-years, measured and recorded by the FMK-004 type special diesel locomotive (i.e., track geometry measuring car). The paper discusses the development of a procedure to automatically compute important condition ratings from the available data set of millions of units according to the algorithms created for railway industry colleagues, thus helping the maintenance and renewal decision-making process. Functions have been developed to classify the track geometry condition of a given railway line, to predict how long the service level can be maintained without intervention (i.e., e.g., lining, leveling, and tamping with a mechanized maintenance train), to determine the time of the necessary maintenance intervention, the time of the upgrade (rehabilitation or modernization), and to develop a track geometry prediction procedure that makes full use of the mathematical and computational possibilities of the present day.
Open Access: Yes
Sustainable 3D-Printing Filaments and their Applications
Publication Name: Chemical Engineering Transactions
Publication Date: 2024-01-01
Volume: 114
Issue: Unknown
Page Range: 967-972
Description:
The growing demand for sustainable materials has driven research into 3D printing technologies, particularly those focused on environmentally friendly filaments such as Polylactic Acid (PLA) and its composites. This study explores the mechanical performance and applications of four distinct PLA-based materials: conventional PLA, PLA Advanced PRO, Glass Reinforced PLA, and Foam PLA. Through a combination of tensile testing and Digital Image Correlation (DIC) analysis, the research highlights the displacement behavior and internal structural evolution of these materials under load-bearing conditions. Glass Reinforced PLA demonstrated the highest performance, showing a 10-15 % increase in displacement capacity compared to conventional PLA, while PLA Advanced PRO exhibited a 10 % improvement, and Foam PLA showed a modest 3-5 % enhancement. Infill density significantly impacted layer adhesion, especially for Glass Reinforced PLA, where an infill density above 30 % greatly enhanced structural integrity. This study not only underscores sustainable filaments' environmental and mechanical benefits but also emphasizes their potential as viable alternatives for complex, load-bearing applications in various industries. The findings contribute to the ongoing development of greener, high-performance 3D printing materials and suggest avenues for future research to optimize the balance between sustainability and material performance.
Open Access: Yes
DOI: 10.3303/CET24114162
Deformation Analysis of Different Lithium Battery Designs Using the DIC Technique
Publication Name: Energies
Publication Date: 2024-01-01
Volume: 17
Issue: 2
Page Range: Unknown
Description:
The growing number of electric vehicles and devices drives the demand for lithium-ion batteries. The purpose of the batteries used in electric vehicles and applications is primarily to preserve the cells and extend their lifetime, but they will wear out over time, even under ideal conditions. Most battery system failures are caused by a few cells, but the entire system may have to be scrapped in such cases. To address this issue, the goal is to create a concept that will extend the life of batteries while reducing the industrial and chemical waste generated by batteries. Secondary use can increase battery utilization and extend battery life. However, processing a large number of used battery cells at an industrial level is a significant challenge for both manufacturers and users. The different battery sizes and compositions used by various manufacturers of electric vehicles and electronic devices make it extremely difficult to solve the processing problem at the system level. The purpose of this study is to look into non-destructive battery diagnostic options. During the tests, the condition of the cells is assessed using a new diagnostic technique, 3D surface digitalization, and the fusion of electrical parameters. In the case of surface digitalization, the digital image correlation (DIC) technique was used to estimate the cell state. The tests were conducted on various cells with widely used geometries and encapsulations. These included a lithium polymer (soft casing), 18650 standard sizes (hard casing), and prismatic cells (semi-hard). The study also included testing each battery at various charge states during charging and discharging. The findings help to clarify the changes in battery cell geometry and their localization. The findings can be applied to cell diagnostic applications such as recycling, quality assurance, and vehicle diagnostics.
Open Access: Yes
DOI: 10.3390/en17020323
Development of High-Speed Railway Network in Europe: A Case Study of Ukraine
Publication Name: Periodica Polytechnica Transportation Engineering
Publication Date: 2024-01-01
Volume: 52
Issue: 2
Page Range: 151-158
Description:
The current task today is the development of theoretical and methodological approaches, as well as practical recommendations for determining the technical feasibility of creating high-speed railway (HSR) lines in the European context. The development of railways in individual countries, followed by the creation of a pan-European high-speed railway network, has raised questions about the compatibility of the technical systems of individual national HSRs. This paper addresses these issues using the example of Ukraine. The research is based on an analysis of scientific developments related to the design of HSR lines and the synthesis of European experience in identifying priority route directions in Ukraine. For comparing various scenarios for the development of railway connections, the authors have developed a forecasting and efficiency assessment model based on the Net Present Value (NPV) indicator. It has been demonstrated that considering the population attracted to HSR and the volume of transit passenger transportation alone is insufficient to achieve the normative investment payback. This situation can only be rectified by implementing mixed traffic involving high-speed passenger trains and accelerated freight trains. However, mixed traffic of passenger and freight trains on high-speed rail lines may face numerous issues and constraints that require careful planning and coordination.
Open Access: Yes
DOI: 10.3311/PPtr.23464
The Application of DIC in Criminology Analysis Procedures to Measure Skin Deformation
Publication Name: Journal of Applied and Computational Mechanics
Publication Date: 2024-01-01
Volume: 10
Issue: 4
Page Range: 817-829
Description:
In engineering, DIC is a widely used measurement technique. Its major advantage is that it provides real-time results (displacements, accelerations, stresses, strains, deformations) of the surface under examination relatively quickly and without contact. However, its application in medicine, biomechanics, and the field of criminalistics is novel. The present research focuses mainly on the frontier areas of forensics and medicine. The research aims to define the test boundary conditions and preparatory activities to measure the surface of the animal and then human skin. Injuries caused by low-energy ballistic bullets, blunt-force trauma, and cuts and punctures caused by knives and/or blades will be investigated. The present research focuses on puncture injuries in animal skin. The main challenge is to create a speckle pattern on the surface that can track deformation well. The research is about developing and validating this. The GOM ARAMIS measurement system was applied for the measurements. This paper demonstrates that a suitable preparation, painting procedure, and measurement setup has been established to measure the above effects, i.e., to identify displacements and deformations of up to tenths of a millimeter with sufficient accuracy. The evaluation of the results will also show that this method could be used in forensic applications, the automotive industry, medical orthopedics, and the textile industry.
Open Access: Yes
CRUSHED STONE SUPPLY CHALLENGES FOR INFRASTRUCTURE DEVELOPMENT IN HUNGARY
Publication Name: Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu
Publication Date: 2024-01-01
Volume: Unknown
Issue: 6
Page Range: 28-37
Description:
The rapid expansion of Hungary’s infrastructure projects, especially in railway construction, has significantly increased the demand for crushed stone. Both national and EU-funded initiatives have strained supply chains, resulting in logistical challenges and material shortages. With limited domestic production capacity, efficient resource management is crucial to keeping projects on track. This paper evaluates Hungary’s supply chain for crushed stone, identifying key weaknesses and proposing solutions to enhance sustainability. Purpose. This study investigates the logistical and supply chain difficulties in delivering crushed stone for Hungary’s railway infrastructure projects. It evaluates current supply limitations, proposes ways to improve domestic resource management, and offers strategies to reduce reliance on imports while emphasizing sustainability. Methodology. The research applies Geographic Information System (GIS) modeling to analyze transportation routes for crushed stone, suggesting ways to streamline logistics. It examines the production capacities of Hungarian quarries, some producing 15,000–25,000 tons monthly, and assesses the impact of European and Hungarian regulations on material quality and availability. The potential for integrating recycled materials into the supply chain is also explored. Findings. Hungary’s domestic quarries cannot meet the high demand for railway ballast, estimated at 192,000 tons annually, leading to import reliance. GIS modeling shows optimized transportation routes could cut costs and carbon emissions. Incorporating smaller stone fractions and recycled materials could mitigate shortages, with recycled materials potentially comprising 40 % of railway ballast. Originality. By integrating geological, logistical, and regulatory insights, this paper provides novel approaches for addressing Hungary’s crushed stone supply chain challenges. The use of GIS modeling and recycled materials offers innovative solutions for reducing environmental impacts. Practical value. The findings present actionable strategies for improving Hungary’s supply chain efficiency, promoting recycling, and optimizing logistics. These solutions are applicable to Hungary and other regions facing similar infrastructure material supply challenges.
Open Access: Yes
TESTING THE FRAGMENTATION OF RAILWAY BALLAST MATERIAL BY LABORATORY METHODS USING PROCTOR COMPACTOR
Publication Name: Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu
Publication Date: 2024-01-01
Volume: Unknown
Issue: 1
Page Range: 58-68
Description:
The physical classification of crushed stone and gravel used in railway construction is based on their strength and endurance and is performed by a laboratory test method using a rotating drum or a mortar method. The values of fracture resistance calculated using the Los Angeles method and abrasion calculated using the Micro-Deval method show a corresponding correlation and require further investigation. Purpose. The development of a new method for measuring rock material fracture that is consistent with widely used standards while also being more comparable to real-world railway operating conditions. Certainly, both standard tests are essential for ensuring product homogeneity during production, so the new recommended method is only a supplement. Methodology. The Proctor device was used to induce so-called shock loads from above, similar to railway loading conditions. Unlike the standard method, the andesite material was placed in a standard cylinder in these tests. The samples were pre-screened and sorted; the specified weight was approximately 1,300 g, and the specified sizes of the individual particles were 6.3, 8.0 and 11.2 mm. Only prewashed and dried materials of NZ (fine crushed stone) or KZ (special crushed stone) from four different quarries (Tállya, Szob, Nógrádkövesd, Recsk) with different rock physics characteristics were considered. The Proctor compactor machine was used because of its calculable labor (19.86 J/impact) and the crushing effect of the calculable impacts (64, 128, 256 and 1,028 blows). Even after loading different numbers of impacts, homogeneous samples from different quarries were sieved to measure the masses of fragments per fraction. Findings. The set of measurements made it possible to establish a series of fragmentation and degradation curves for each of the three repeated measurements based on the composition of the material and the number of blows, which showed the degradation of samples with different physical and mechanical properties of the rock material and particle sizes. With an increasing number of impacts, the amount of crushed material in the sample increased, but the distribution of crushed material did not decrease evenly and proportionally as the number of impacts increased. Parameters and indices were also computed to identify various correlations (i. e., FV , d < 22.4, d < 0.5, d < 0.063 mm, CU , M ratio, λ ratio). Some of them (e. g., FV ) needed to be changed, but they were predefined due to the nature of the tests. Originality. While many standard and alternative railway track ballast fragmentation test methods and measurement tools are available, this paper proposes a new laboratory method and demonstrates the specific measurement and application effectiveness. Practical value. In addition to standard tests that are already widely used, the new method for measuring the fractional composition of railway ballast can help simulate real-world operating conditions of a railroad track in the laboratory. This method will improve the safety of railway operations.
Open Access: Yes
Optimum Train Weighing in Motion using Inertial Sensors
Publication Name: Acta Polytechnica Hungarica
Publication Date: 2024-01-01
Volume: 21
Issue: 1
Page Range: 221-240
Description:
Continuous monitoring with advanced equipment and innovative scientific techniques is essential for timely and perfect maintenance. The interaction and dynamic force between wheel and rail is one of the most widely monitored issues. In this paper's case study of ballasted railway tracks in Iran, a set consisting of two separate strain gauge arrays and three different positions for installing accelerometers were designed according to the conditions. After installation, the system was calibrated with a predetermined passing axle load. The dependency of the arrays' and the equipment's installation location with the velocity of the passing axle load was examined as part of the field study after repeated investigation and comparisons of the setups' results. In order to gather data with the least error and the highest level of accuracy, it was decided on the more appropriate array with less dependence and a better installation position.
Open Access: Yes
ADVANTAGES OF USING CONCRETE CANVAS MATERIALS IN RAILWAY TRACK CONSTRUCTION
Publication Name: Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu
Publication Date: 2024-01-01
Volume: Unknown
Issue: 1
Page Range: 50-57
Description:
Purpose. Justification of the feasibility of using new types of drainage materials, such as Concrete Canvas (CC), under the upper structure of the railway permanent way. Methodology. The tasks were solved by a complex research method, including analysis and generalization of literary and patent sources, analytical, experimental studies, using computer and mathematical modeling methods. Tests were conducted with and without the CC layer in a multi-level shear box. After the shear test, the specimens were also tested for load-bearing capacity (E2 , according to the Hungarian standard) and particle breakage. The contact surface between the bottom of the ballast and the CC was measured using a precision 3D laser scanner (GOM ATOS) and visualized graphically using AutoCAD software. Findings. Experimental testing of the vertical load during connection and analysis compared with the test results of geocomposite/geogrid structures, internal shear resistance, and other parameters proved the structure’s higher load-bearing capacity with the CC layer. Based on the results, the Concrete Canvas structure provides higher reinforcement than the average geogrid type. Originality. The advantages of using new Concrete Canvas materials in the structure of a railway track have been demonstrated for the first time to provide greater internal shear resistance than the average for geogrids. Practical value. These results may provide primary data for using Concrete Canvas in railway tracks and superstructures in the future.
Open Access: Yes
DES and IIoT fusion approach towards real-time synchronization of physical and digital components in manufacturing processes
Publication Name: Reports in Mechanical Engineering
Publication Date: 2023-12-01
Volume: 4
Issue: 1
Page Range: 161-174
Description:
Today's manufacturing systems offer more products to meet specific needs. Complex production systems in rapidly changing environments result from product variation, shorter product life cycles, and supply chain expansion. A cyber-physical production system (CPPS) can use manufacturing and logistics data to plan, monitor, and control production. Discrete event simulation (DES) and digital twin (DT) technology can model and evaluate manufacturing and logistics processes using high-level decision support and process monitoring. The cost of collecting input data from different enterprise data sources and mapping it into models and the lack of qualified experts prevent the widespread use of these methods in industry, especially in small and medium-sized enterprises and larger multinational companies. This research aims to create a modular digital twin framework for manufacturing process optimization and real-time monitoring in an industrial environment with few components. The system can identify and track the product through the manufacturing cycle while updating the DT in real-time and can be used independently to collect input parameters for discrete event-driven simulations and even for automatic simulation building in the future. The framework's operation will be shown through an example. With the proposed IIoT (industrial internet of things) system integration, it can detect faults and warn of deviations from normal operation, and DT can drastically reduce data collection and model building and support model reusability, increasing sustainability.
Open Access: Yes
Studying the Relation of the Residual Stresses in the Ballast Layer to the Elastic Wave Propagation
Publication Name: Transportation Infrastructure Geotechnology
Publication Date: 2023-12-01
Volume: 10
Issue: 6
Page Range: 962-987
Description:
During track construction or ballast bed maintenance, ballast layer compaction quality plays an essential role in the following track irregularity accumulation, its lifecycle, and maintenance costs. The ballast compaction process is characterized by its compaction and the accumulation of the stressed state. The elastic wave propagation methods are an effective way for the identification of the ballast bed compaction properties. The paper presents the theoretical and experimental studies of the ballast consolidation under the vibration loading of the sleeper. The practical laboratory study is given by the 1:2.5 scaled physical model of one sleeper and the corresponding ballast layer box. The measurements of ballast pressure and deformations under the vibration loading in the ballast layer and the photogrammetric recording of the ballast flow are carried out. The measurements demonstrate the accumulation of the residual stresses under the ballast layer. Furthermore, the measurements of elastic wave time of flight (ToF) using the shakers under the sleeper and acceleration sensors under the ballast show the substantial increase of the ToF velocities after the tamping process. Moreover, the distribution of the velocities along the sleeper is spatially inhomogeneous. The numeric simulation using the discrete element method (DEM) of the tamping and the testing processes proves the inhomogeneous wave propagation effect. The modeling shows that the main reason for the wave propagation inhomogeneity is the accumulated residual stress distribution and the minor one – the compaction density. Additionally, a method for identifying wave velocity spatial distribution is developed by wave tracing the inhomogeneous medium. The procedures allow ballast identification in the zones outside the shakers.
Open Access: Yes
ALTERNATIVE USES FOR CRUSHED STONE PRODUCTS GENERATED TO MEET THE RAW MATERIAL NEEDS OF ASPHALT PRODUCTION IN HUNGARY
Publication Name: Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu
Publication Date: 2023-11-30
Volume: Unknown
Issue: 5
Page Range: 66-71
Description:
In Hungary, quarries that produce stone products for wearing courses of asphalt pavements also produce a significant amount of 0/4, 0/8 and 4/8 mm fractions. Because of Hungary’s pavement design and asphalt production practices, these fractions do not have a suitable market and can thus be sold on alternative markets. Purpose. To demonstrate the feasibility of using crushed fractions of 0/4 and 0/8 mm in the protection and base layers of asphalt pavements instead of sandy gravel with 0/22 mm fraction. Methodology. The CBR method was applied to evaluate the comparability of characteristics such as particle size distribution and loadbearing capacity. The combination of the Proctor and CBR tests allowed someone to compare the expected technological characteristics of the dominant and alternative aggregate types, such as their sensitivity to water and loadbearing capacity. Findings. The results demonstrated that the performance characteristics of conventionally used sandy gravel with a size of 0/22 mm can be achieved and exceeded by crushed material with much smaller maximum grain sizes – i.e., 0/4 and 0/8 mm. Originality. The paper presents an original study that contradicts the industry’s actual decline of crushed stone (0/4 and 0/8 mm fractions) for asphalt pavement protection layers. The potential effectiveness and functionality of the proposed coating are demonstrated through convincing tests, and thus new data and insights are introduced into the Hungarian construction industry’s practice. Practical value. The test results greatly helped in achieving the high demands of the private industrial project by proposing an alternative variant of crushed stone of 0/8 mm fraction rather than the originally planned dominant sand and gravel material. The asphalt paving experience on this site clearly demonstrated the viability of the alternative aggregate option for Hungarian roads.
Open Access: Yes
Investigation of the Causes of Railway Track Gauge Narrowing
Publication Name: Vehicles
Publication Date: 2023-09-01
Volume: 5
Issue: 3
Page Range: 949-977
Description:
On behalf of MÁV Hungarian State Railways Ltd., the authors carried out a research and development (R&D) project on behalf of the Budapest University of Technology and Economics, Department of Highway and Railway Engineering, on the subject of “Research and investigation of the causes of gauge narrowing by finite-element modeling in running track and turnout, and under operational and laboratory conditions”. The main objective of the research was to investigate the causes of localized defects of gauge narrowing in railway tracks based on machine and manual track measurements, laboratory measurements, and theoretical considerations. The measures proposed as a consequence of identifying the causes could significantly contribute to reducing the number and extent of local defects in the future. Furthermore, the research aims to develop new theories in less scientifically mature areas and provide procedures and instructions that professional engineers and practitioners can easily apply. The main areas of research, which are not exhaustive, are as follows: (i) the evaluation of the measurement results provided by track geometry measuring and recording cars; (ii) on-site investigations in the railway track in terms of gauge and rail profile measurements; and, based on these, (iii) the selection of concrete sleepers, which were removed from the track and subjected to more detailed geometrical investigations in the laboratory, together with the components of the rail reinforcement; (iv) the track–vehicle connection, tight running in straight and curved track sections under track confinement; (v) modeling of the stability and deflection of the rail when the rail fastenings lose part of their supporting function; and (vi) finite element modeling of the concrete sleepers under operating conditions such as slow deformation of the concrete, temperature variation effects, and lateral support on the ballast. In the already-narrowed track section, the tight vehicle running is not the cause of the track gauge narrowing but a consequence, so it is not investigated in this paper.
Open Access: Yes
Investigation of the Bearing Capacity of Transport Constructions Made of Corrugated Metal Structures Reinforced with Transversal Stiffening Ribs
Publication Name: Infrastructures
Publication Date: 2023-09-01
Volume: 8
Issue: 9
Page Range: Unknown
Description:
Methods of increasing the bearing capacity of corrugated metal structures of transport constructions using transversal stiffening ribs in the form of additional corrugation and stiffeners are given. Based on the theory of elasticity, a mathematical model for estimating the stress-strain state of transport constructions made of corrugated metal structures reinforced with stiffening ribs in the form of double corrugation was developed. The method of determining equivalent forces during rolling stock passage is offered. It has been established that double corrugation increases the bearing capacity of corrugated metal structures. Therefore, additional corrugation of corrugated metal structures reduces stresses by up to 20% and deflections by 50%. The obtained results show that the increase in rolling stock speed does not lead to a significant increase in stresses and strains in CMS when the railway track corresponds to the design state.
Open Access: Yes
Face Detection Using a Capsule Network for Driver Monitoring Application
Publication Name: Computers
Publication Date: 2023-08-01
Volume: 12
Issue: 8
Page Range: Unknown
Description:
Bus driver distraction and cognitive load lead to higher accident risk. Driver distraction sources and complex physical and psychological effects must be recognized and analyzed in real-world driving conditions to reduce risk and enhance overall road safety. The implementation of a camera-based system utilizing computer vision for face recognition emerges as a highly viable and effective driver monitoring approach applicable in public transport. Reliable, accurate, and unnoticeable software solutions need to be developed to reach the appropriate robustness of the system. The reliability of data recording depends mainly on external factors, such as vibration, camera lens contamination, lighting conditions, and other optical performance degradations. The current study introduces Capsule Networks (CapsNets) for image processing and face detection tasks. The authors’ goal is to create a fast and accurate system compared to state-of-the-art Neural Network (NN) algorithms. Based on the seven tests completed, the authors’ solution outperformed the other networks in terms of performance degradation in six out of seven cases. The results show that the applied capsule-based solution performs well, and the degradation in efficiency is noticeably smaller than for the presented convolutional neural networks when adversarial attack methods are used. From an application standpoint, ensuring the security and effectiveness of an image-based driver monitoring system relies heavily on the mitigation of disruptive occurrences, commonly referred to as “image distractions,” which represent attacks on the neural network.
Open Access: Yes
Investigation of the Geometrical Deterioration of Paved Superstructure Tramway Tracks in Budapest (Hungary)
Publication Name: Infrastructures
Publication Date: 2023-08-01
Volume: 8
Issue: 8
Page Range: Unknown
Description:
In the 21st century, one of the key requirements is to develop and maintain our infrastructure facilities most efficiently using the available resources. Tramways are of significant national economic importance and represent an important national asset. There are currently seven different types of superstructure systems in Hungary, based on the national regulations and the related requirements currently in force. This paper compares the paved tramway superstructure systems in the context of track geometry, through-rolled axle tons of track, and the age of track sections. Paved tracks have many benefits, but the main ones are easier maintenance and road traffic use. Elastically supported continuous rail bedding (ESCRB; in Hungary, this is known as “RAFS”) and “large” slab superstructure systems are used to create paved superstructure systems. Road crossings use the latter systems, while heavily loaded lines use several ESCRB systems. This article examines the geometrical changes in several ESCRB superstructure systems. A TrackScan 4.01 instrument was used to take measurements in June and September 2021 and in April 2022, September 2022, and May 2023. Track gauge, alignment, and longitudinal level are examined. Regardless of the ESCRB superstructure system or age, a medium-loaded line’s track gauge trendline increases, which means that the track gauge is widening and, regardless of traffic load or age, the average longitudinal level is constantly increasing from year to year. When it is a medium-loaded line, the average value of alignment increases slightly, and the trendline is almost straight, but it decreases when it is an extremely heavily loaded line. The authors will analyze how the reference track section will change in the future. Based on the results, it is important to assess how subsequent measurements affect the trend lines. Because the data evaluations show similar results, comparing open tramway tracks to paved ones is crucial.
Open Access: Yes
Determining the Deformation Characteristics of Railway Ballast by Mathematical Modeling of Elastic Wave Propagation
Publication Name: Applied Mechanics
Publication Date: 2023-06-01
Volume: 4
Issue: 2
Page Range: 803-815
Description:
The article solves the problem of theoretically determining the deformable characteristics of railway ballast, considering its condition through mathematical modeling. Different tasks require mathematical models with different levels of detail of certain elements. After a certain limit, excessive detailing only worsens the quality of the model. Therefore, for many problems of the interaction between the track and the rolling stock, it is sufficient to describe the ballast as a homogeneous isotropic layer with a vertical elastic deformation. The elastic deformation of the ballast is formed by the deviation of individual elements; the ballast may have pollutants, the ballast may have places with different levels of compaction, etc. To be able to determine the general characteristics of the layer, a dynamic model of the stress–strain state of the system based on the dynamic problem of the theory of elasticity is applied. The reaction of the ballast to the dynamic load is modeled through the passage of elastic deformation waves. The given results can be applied in the models of the railway track in the other direction as initial data regarding the ballast layer.
Open Access: Yes
IIoT-Supported Manufacturing-Material-Flow Tracking in a DES-Based Digital-Twin Environment
Publication Name: Infrastructures
Publication Date: 2023-04-01
Volume: 8
Issue: 4
Page Range: Unknown
Description:
Manufacturing processes can be cited as significant research areas when examining infrastructure systems and infrastructure, as they are inextricably linked to both. Examples include automobile manufacturing, the production of traffic signs, etc. Connecting and utilizing Industry 4.0 technologies and processing simulation solutions to address industry challenges, such as process optimization and fault detection, are gaining in popularity. Cyber-physical systems and digital twins connect the physical and cyber worlds to enable intelligent manufacturing capabilities, increased system flexibility, decreased manufacturing-cycle times, and improved quality. This paper presents a solution that improves the synchronization between the real (physical) and simulation (digital) layers, using discrete-event-driven simulations to create more efficient and accurate digital-twin environments. Using a combination of inexpensive commercial microcontrollers and an inertial-measurement-unit sensor to enhance a standard programmable logic controller process, a discrete-event-simulation-based digital layer is updated in real time to produce a live digital twin. The system can accurately identify and track products throughout the production cycle while simultaneously updating the digital twin in real time. Even independently, the algorithm running on the microcontroller can be used to gather the input parameters required for the simulation of production processes. The implemented environment can serve as a suitable testing ground for investigating the practical applicability of digital-twin solutions.
Open Access: Yes
DETECTION PROCESS OF ENERGY LOSS IN ELECTRIC RAILWAY VEHICLES
Publication Name: Facta Universitatis Series Mechanical Engineering
Publication Date: 2023-04-01
Volume: 21
Issue: 1
Page Range: 81-99
Description:
The paper deals with the detection process of energy loss in electric railway hauling vehicles. The importance of efficient energy use in railways and cost-effective rail transport tendency toward regenerative braking energy are considered. In addition, the current situation and improvement opportunities to achieve efficient energy use are examined. Seven measurement series were performed with scheduled Railjet trains between Hegyeshalom and Győr railway stations in Hungary. This railway section is related to the Hungarian State Railways' No. 1 main railway line (between Budapest-Kelenföld and Hegyeshalom state board), which is a part of the international railway line between Budapest and Vienna (capitals of Hungary and Austria, respectively). This double-track, electrified railway line with traditional ballasted superstructures and continuously welded rail tracks is important due to the international passenger and freight transport between Germany, Austria, and Hungary. The value of the regenerative braking energy can be even 20-30% of the total consumed energy. This quite enormous untapped energy can be used for several aims, e.g., for comfort energy demand (air conditioning, heating-cooling, lighting, etc.) or energy-intensive starts. The article also investigates the optimization of regenerative braking energy by seeking the energy-waste locations and the reasons for the significant consumption. The train operator's driving style and habit have been identified as one of the main reasons. Furthermore, train driver assistance systems are recommended to save energy, which is planned for future research.
Open Access: Yes
Investigation of the Track Gauge in Curved Sections, Considering Hungarian Railway Lines
Publication Name: Infrastructures
Publication Date: 2023-04-01
Volume: 8
Issue: 4
Page Range: Unknown
Description:
In this paper, the authors examined the change in track gauges in curves for several railway lines with low and high traffic in Hungary (i.e., secondary lines and main lines). They covered the processing of raw data as well as statistical calculations. The considered curved sections were transition curves (TCs) and circular curves (CCs), as well as—in some cases—entire curves (ECs), including TCs and CCs, but not dividing them into parts. The change of track gauge parameter as a function of elapsed time was analyzed based on the distribution functions by calculating the Vaszary-type shape number. A statistical test with the Kolmogorov–Smirnov test was performed, in which the question as to whether the measurement data of the railway lines followed a normal or lognormal distribution was examined; additionally, the skewness and kurtosis parameters were calculated and analyzed. The authors also took into account the impact of the track system and the sleepers. For the selected curves, the authors observed how the average track gauge changes and categorized them according to tolerances. In presenting and summarizing the tests, the authors formulated a conclusion for each study fulfilled. Despite higher traffic loads, the value of track degradation over time is lower for mainline curves than for secondary line curves. It is because the main line has stricter tolerances due to the higher speeds allowed, and more maintenance work is carried out on these lines. The authors concluded that the type of the track system and the sleeper type also influence the change in track gauges in curves. The accurate deterioration ratios for all analyses are contained in the paper.
Open Access: Yes
A Risk Assessment Technique for Energy-Efficient Drones to Support Pilots and Ensure Safe Flying
Publication Name: Infrastructures
Publication Date: 2023-04-01
Volume: 8
Issue: 4
Page Range: Unknown
Description:
Unmanned Aerial Vehicles, also known as UAVs, play an increasingly important part in daily life. However, the ever-increasing number of UAVs pose an ever-increasing threat to the transportation infrastructure. Despite their precision and general efficiency, infrastructural-scale Unmanned Aerial Systems (UASs) have a disadvantage regarding their capability of being implanted in the ecosystem. There are several reasons for this, but the primary bottleneck is that their systems are not transparent to society and have very complicated processes. As a result, the authors decided to investigate the functional properties of UASs and make improvements to those properties. Throughout the study, the authors’ primary focus was on analysis, which boosts productivity and ensures a significant level of safety for routine flights. The amount of power that a UAV uses depends on several variables, including the amount of power that its individual components require, the temperature of its surroundings, and the condition of the battery that it is powered by. Therefore, critical parameters and interdependencies are taken into account in the risk assessment strategy for energy-efficient Unmanned Aerial Vehicles (UAVs). In the case of UAVs, the algorithm performs a risk calculation before take-off to estimate the amount of risk that can be associated with the given flight time when using the provided battery. On the one hand, several instances of the pre-take-off state and how its parameters interact are investigated. On the other hand, they demonstrate the calculation of the risk while in flight, which is based on actual flight data.
Open Access: Yes
Prediction system of rolling contact fatigue on crossing nose based on support vector regression
Publication Name: Measurement Journal of the International Measurement Confederation
Publication Date: 2023-03-31
Volume: 210
Issue: Unknown
Page Range: Unknown
Description:
It is essential to assess the rolling contact fatigue (RCF) of turnouts and maintain them in advance. It saves a lot of money while protecting the safety of railway operations. In Germany, the damage on rails, especially crossing noses, mainly depends on the subjective judgment of experts. There are no objective and comprehensive evaluation criteria. This paper presents the application of image processing and supervised machine learning algorithms to crossing nose fatigue judgment. The fatigue characteristics of the crossing nose rolling contact surface along the life cycle of the crossing nose are analyzed. The study used crack information from magnetic particle inspection (MPI) images of crossing nose surfaces. It uses basic image processing methods to collect physical information about features of fatigue cracks in images. Existing feature selection methods are used to exclude irrelevant features and retain valuable features. And we select the best feature selection method through the regression results. Statistically significant crack features and combinations that depict the surface fatigue state are found. In this paper, by comparing several usually machine learning regression algorithms, it is found that the supervised learning of support vector machine regression (SVR) has achieved the best results in the regression fitting of the crack feature data in this paper. The regression results form a simple system to evaluate the life cycle of crossing nose. The system finds the location of cracks that can create dangerous defects in the crossing nose surface. The research result consists of the early prediction of rail contact fatigue.
Open Access: Yes
Optimization of 3D Printed Rapid Prototype Deep Drawing Tools for Automotive and Railway Sheet Material Testing
Publication Name: Infrastructures
Publication Date: 2023-03-01
Volume: 8
Issue: 3
Page Range: Unknown
Description:
The main objective of this research is to identify optimal printing strategies and PLA (polylactic acid) filament materials to produce rapid prototype deep drawing tools. Additive 3D printing technologies have been applied for a long time to produce tools, but the research is unique in that it uses conventional and various reinforced PLA materials with conventional FDM (Fused Deposition Modeling) printers. The advantage of this method is that PLA is easy to print and recycle and does not require expensive or special printers, this also gives the article its novelty. A further aim was to produce the tools using commercially available low-end printers. DX53D 0.8 mm thick body steel and AlMg3 2.5 mm thick sheet were the materials to be molded for the tests. The test tool was an Erichsen deep drawing punch. Tool wear was tested using the GOM ATOS measuring system, an optical coordinate measuring machine based on the DIC (Digital Image Correlation) principle, which is also popular in the automotive industry. The study aims to determine the 3D printing and material parameters that can safely produce a minimum batch of 100 parts.
Open Access: Yes
Testing Road Vehicle User Interfaces Concerning the Driver’s Cognitive Load
Publication Name: Infrastructures
Publication Date: 2023-03-01
Volume: 8
Issue: 3
Page Range: Unknown
Description:
This paper investigates the usability of touch screens used in mass production road vehicles. Our goal is to provide a detailed comparison of conventional physical buttons and capacitive touch screens taking the human factor into account. The pilot test focuses on a specific Non-driving Related Task (NDRT): the control of the on-board climate system using a touch screen panel versus rotating knobs and push buttons. Psychological parameters, functionality, usability and, the ergonomics of In-Vehicle Information Systems (IVIS) were evaluated using a specific questionnaire, a system usability scale (SUS), workload assessment (NASA-TLX), and a physiological sensor system. The measurements are based on a wearable eye-tracker that provides fixation points of the driver’s gaze in order to detect distraction. The closed road used for the naturalistic driving study was provided by the ZalaZONE Test Track, Zalaegerszeg, Hungary. Objective and subjective results of the pilot study indicate that the control of touch screen panels causes higher visual, manual, and cognitive distraction than the use of physical buttons. The statistical analysis demonstrated that conventional techniques need to be complemented in order to better represent human behavior differences.
Open Access: Yes
Numerical Investigation of Pre-Stressed Reinforced Concrete Railway Sleeper for High-Speed Application
Publication Name: Infrastructures
Publication Date: 2023-03-01
Volume: 8
Issue: 3
Page Range: Unknown
Description:
The current paper deals with the numerical investigation of a unique designed pre-stressed reinforced concrete railway sleeper for the design speed of 300 km/h, as well as an axle load of 180 kN. The authors applied different methodologies in their research: traditional hand-made calculations and two types of finite element software. The latter were AxisVM and ABAQUS, respectively. During the calculations, the prestressing loss was not considered. The results from the three methods were compared with each other. The hand-made calculations and the finite element modeling executed by AxisVM software are adequate for determining the mechanical inner forces of the sleeper; however, ABAQUS is appropriate for consideration of enhanced and sophisticated material models, as well as the stress-state of the elements, i.e., concrete, pre-stressed tendons, etc. The authors certified the applicability of these methodologies for performing the dimensioning and design of reinforced concrete railway sleepers with pre-stressing technology. The research team would like to continue their research in an improved manner, taking into consideration real laboratory tests and validating the results from FE modeling, special material models that allow calculation of crackings and their effects in the concrete, and so that the real pattern of the crackings can be measured by GOM Digital Image Correlation (DIC) technology, etc.
Open Access: Yes
Optimization of Surface Preparation and Painting Processes for Railway and Automotive Steel Sheets
Publication Name: Infrastructures
Publication Date: 2023-02-01
Volume: 8
Issue: 2
Page Range: Unknown
Description:
The article deals with DIC (Digital Image Correlation) tests on steel plates used in the automotive and railway industries, as well as in the construction industry. The most critical part of DIC tests is the quality of proper surface preparation, painting, and random patterns. The paint mediates the deformation of the optical systems, and its quality is paramount. The authors’ goal in this research is to determine the optimal dye–cleaning–drying time parameters for DIC studies. Commercially available surface preparation and cleaning agents were tested alongside commercially available spray paints. Standard and specific qualification procedures were applied for the measurements. Once the appropriate parameters were determined, the results were validated and qualified by GOM ARAMIS tests. Based on the results, DIC measurements can be performed with higher accuracy and safety in laboratorial and industrial conditions, compared to the traditional deformation measurements executed by dial gauges or linear variable differential transformers.
Open Access: Yes
Investigation of “Open” Superstructure Tramway Tracks in Budapest
Publication Name: Infrastructures
Publication Date: 2023-02-01
Volume: 8
Issue: 2
Page Range: Unknown
Description:
The most important thing nowadays is to use available resources to develop infrastructure as efficiently as possible. In this regard, evaluating the deterioration of tramway tracks is critical from both a technical and an economic viewpoint. In Hungary, seven types of superstructure systems are currently differentiated in the case of tramway transport, but the geometrical deterioration, lifecycle, and lifecycle cost of the tramway tracks are not accurately known. The current study aimed to evaluate and compare the results of track geometry measurements of two different “open” tramway superstructure systems depending on their traffic load and age. The geometry measurements we re executed by TrackScan 4.01 instrument, developed and maintained by a Hungarian developer company called Metalelektro Méréstechnika Ltd. The evaluation of the measurements showed a clear relationship between the traffic load, age, and track deterioration. Based on the results, it can be generally stated, concerning “open” superstructure systems, that regardless of the “open” superstructure system or the level of traffic load, the average value of alignment is decreasing; however, the average value of the longitudinal level is increasing. Furthermore, the deterioration of an older ballasted track with lower traffic is similar to that of a younger ballasted track that has a higher traffic load. Another significant result was that the deterioration of the track gauge parameter in the case of concrete slab tracks is clearly described as the broadening of the track gauge.
Open Access: Yes
Optimization of Surface Cleaning and Painting Methods for DIC Measurements on Automotive and Railway Aluminum Materials
Publication Name: Infrastructures
Publication Date: 2023-02-01
Volume: 8
Issue: 2
Page Range: Unknown
Description:
The preparatory operations of DIC (Digital Image Correlation) tests were investigated in this study, with special emphasis on specimen cleaning and painting operations. As it is well known, DIC tests are non-contact and applied in materials research, the analysis of complex structures, and, nowadays, the construction industry. The use of DIC technologies has seen a dynamic increase in all scientific fields. In our study, aluminum body panels for automotive and railway applications were tested using this technique. There are many articles on proper patterning in the literature but fewer on preparation and priming. These are critical for a successful DIC measurement. This paper looks at different surface cleaners and primers with different grading procedures and will also determine the time window within which the paint should be applied. Finally, the GOM ARAMIS system was applied to measure and characterize the painted surface and visible deformation defects resulting from inadequate painting.
Open Access: Yes
Testing of Lubricants for DIC Tests to Measure the Forming Limit Diagrams of Aluminum Thin Sheet Materials
Publication Name: Infrastructures
Publication Date: 2023-02-01
Volume: 8
Issue: 2
Page Range: Unknown
Description:
We investigated lubricants and thin teflon foils that can be applied in the formability testing of the thin aluminum sheets used in the electronics and automotive industries. For the tests, thirteen different industrial lubricants (oils and greases) (i.e., L1–L13) and two Teflon films (i.e., 0.08 and 0.22 mm thick) were applied. The authors conducted an Erichsen test, and the thickness reduction of the discs was measured first. In forming-limit curve (FLC) tests, it is crucial that the stresses are localized in the central area of the specimen during forming and that biaxial deformation is maintained throughout, if possible. We aimed to achieve and fulfill this task. To perform this measurement, the GOM ARAMIS measuring system was utilized. It is an optical measuring system based on the digital image correlation (DIC) principle, capable of measuring both stresses and displacements in real time. A specific validation method was also developed to qualify the DIC system. We concluded that there was a 5% difference in Erichsen indentation (IE) number diagrams between the best (L12) and worst (L4) cases for the lubricants and oils tested, which is a significant difference for thin plates. We found that this value could be increased and improved by using Teflon discs. Furthermore, the localization of stress maxima, i.e., the centering of cracks in the specimen, could be achieved by combining Teflon discs and L12 lubricant (with appropriate layer order), which significantly aids in the recording of standard FLC diagrams. Using foils is also advantageous because they are readily available, have no expiry date, and are of less environmental concern.
Open Access: Yes
Vibration Diagnostic Methods of Automatic Transmission Service Requirement Prediction
Publication Name: Infrastructures
Publication Date: 2023-02-01
Volume: 8
Issue: 2
Page Range: Unknown
Description:
Automatic transmission is a key factor for autonomous driving. The transmission condition is highly affected by the quality and quantity of transmission oil in the system. However, the oil condition is not monitored in the system, and the oil change interval and method are still a subject of discussion. This paper analyzes the effects of oil changes in automatic transmissions. The measurements were carried out before and after the oil change with the same external conditions. With the vibration measurement method, data can be collected without disassembling the parts and during operational conditions. Furthermore, time- and frequency-based analyses were conducted to compare different transmissions’ operations. The results have shown that the effect of oil degradation is measurable on the amplitude of the signals and, therefore, predictable with vibration diagnostics. During the evaluation, the maximum values were compared on measurements with at least a 2-s length.
Open Access: Yes
Investigation of Track Gauge and Alignment Parameters of Ballasted Railway Tracks Based on Real Measurements Using Signal Processing Techniques
Publication Name: Infrastructures
Publication Date: 2023-02-01
Volume: 8
Issue: 2
Page Range: Unknown
Description:
This paper deals with the time-frequency characteristic analysis for track geometry irregularities using field data recorded by a comprehensive track inspection train. The parameters of the track gauge and the left and right rail alignment are considered to identify their characteristic wavelengths and the locations of their waveforms. In addition to the conventional time and frequency domain analysis, auto-adaptive signal decomposition techniques are used on four pre-selected track sections. During the time series analysis of the track gauge, the cumulative difference from the mean value is calculated, which makes it possible to distinguish the track section constructed with non-standard initial track gauges. The sensitive wavelengths of the track irregularities are obtained from the proper allocation of wavelength ranges in the Fourier Amplitude Spectrum of the original signal and the Fourier transform of the components detected by the Variational Mode Decomposition. This analysis can elucidate the wavelengths and positions of track irregularities that affect vehicle responses.
Open Access: Yes
Examination of Concrete Canvas under Quasi-Realistic Loading by Computed Tomography
Publication Name: Infrastructures
Publication Date: 2023-02-01
Volume: 8
Issue: 2
Page Range: Unknown
Description:
The current paper concerns the investigation of CC (Concrete Canvas), a unique building material from the GCCM (geosynthetic cementitious composite mat) product group. The material is suitable for trench lining, trench paving, or even military construction activities, while the authors’ purpose is to investigate the application of the material to road and railway substructure improvement. This research was carried out to verify the material’s suitability for transport infrastructure and its beneficial effects. The authors’ previous study reported that the primary measurements were puncture, compression, and the parameters evaluated in four-point bending (laboratory) tests. However, based on the results, finite element modeling was not feasible because the testing of the composite material in a single layer did not provide an accurate indication. For this reason, the material characteristics required for modeling were investigated. A unique, novel testing procedure and assembly were performed, wherein the material was loaded under quasi-realistic conditions with a crushed stone ballast sample and other continuous particle size distribution samples in a closed polyethylene tube. In addition, the deformation of the material following deformed bonding was measured by computed tomography scanning, and the results were evaluated.
Open Access: Yes
Surface Preparation of 3D Printed Battery Housing Materials for DIC Measurements
Publication Name: International Conference on Electrical Computer Communications and Mechatronics Engineering Iceccme 2023
Publication Date: 2023-01-01
Volume: Unknown
Issue: Unknown
Page Range: Unknown
Description:
In this study, several 3D-printable PLA (polylactic acid) materials that can also be used to produce battery housings are evaluated. Proper testing is essential to developing better prototypes and final products, and DIC deformation tests are frequently utilized. To be able to evaluate the deformations of various parts and components, the surface of the product under test is randomly speckled. In DIC measurements, however, the deformation is transmitted to the measuring system via the paint, so preparation and paint quality play a crucial role. This research is focused on this underrepresented area in the literature. This article evaluates the DIC applicability of the most commonly used surface cleaning materials and paints.
Open Access: Yes
Bi-directional Evolutionary, Reliability-based, Geometrically Nonlinear, Elasto-Plastic Topology Optimization, of 3D Structures
Publication Name: Acta Polytechnica Hungarica
Publication Date: 2023-01-01
Volume: 20
Issue: 1
Page Range: 169-186
Description:
An extension of bi-directional evolutionary structural optimization, by considering three-dimensional geometrically nonlinear reliability-based elasto-plastic topology optimization, is presented in this study. Due to the important role of the existence of uncertainties to make structural design more practical, this study considers the reliability-based design. Thus, for probabilistic purposes, volume fraction is considered random. The reason of considering the volume fraction as random variable that the application of reliability-based topology optimization shows different topological results comparing to those which are obtained through deterministic designs. By adopting Monte-Carlo technique, the reliability indices are calculated based on the failure probabilities. Different values of volume fractions are considered to explore the effect of changing it on the resultant topologies in case of deterministic design. Furthermore, study the influence of considering different values of reliability indices on the results of probabilistic designs. The plastic-limit analysis is considered in this study in case of elasto-plastic models. A 3D elasto-plastic L-shape beam is considered as a benchmark problem to demonstrate the proficiency of the proposed method. In addition, 3D cantilever beam is considered for deterministic and probabilistic topology optimization designs in cases of elastic and elasto-plastic materials.
Open Access: Yes
Optimal Elasto-Plastic Analysis of Reinforced Concrete Structures under Residual Plastic Deformation Limitations
Publication Name: Acta Polytechnica Hungarica
Publication Date: 2023-01-01
Volume: 20
Issue: 1
Page Range: 45-62
Description:
In this study, an investigation regarding optimal elastic-plastic analysis method of different reinforced concrete (RC) structures is held by applying the residual plastic deformations limitations on the steel bars inside the reinforced concrete. Where different structures, including simple beam and slab, are selected as benchmarks and modelled numerically using ABAQUS in order to calibrate their experimental behaviour according to laboratory tests. Furthermore, concrete damage plasticity (CDP) constitutive model was applied to represent concrete behaviour in the numerical models considered. Then, an objective function was established for optimizing the applied plastic loads for each structure where the process of controlling plastic deformations was carried out by applying constraints on the complementary strain energy of the residual internal forces initiated inside the steel bars. This methodology was applied by authors by writing MATLAB code and linking it with ABAQUS to determine the corresponding applied plastic load for each entered complementary strain energy. Generally, applying optimization problem for each model showed that the complementary strain energy of the residual forces reflects the general behaviour of the structures and may be assumed as a constraint controlling the plastic behaviour of the structures whereas the obtained results indicated how structures acted differently when possessing different complementary strain energy values turning from elastic into elasto-plastic condition and then reaching plastic state.
Open Access: Yes
Sustainability in Railways – A Review
Publication Name: Chemical Engineering Transactions
Publication Date: 2023-01-01
Volume: 107
Issue: Unknown
Page Range: 7-12
Description:
This paper examines the sustainability of railways. A comprehensive international literature review was conducted on railway vehicles, traction, and railway permanent way. The main goal was to find the factors and parameters that affect railway sustainability the most. CO2 emissions from transportation, mining, raw material production, manufacturing, use, operation and maintenance, and demolition and restoration must be significantly reduced. Naturally, the attention will be on the considerable energy and financial savings. This article's main topics are sustainability, affordable and clean energy, industry, innovation, infrastructure, sustainable cities and communities, responsible consumption and production, climate action, and life on land. Building materials come from quarries and gravel pits, but availability is decreasing. Future pavement construction and maintenance require recycling demolition and industrial waste. Engineers must choose materials and technology that extend track lifetimes to ensure reliability, availability, maintainability, safety, sustainability, and economy in permanent railroad ways. Life-cycle costs can be reduced, e.g., by Building Information Modeling. Electric machinery is preferred for construction equipment, materials, and management. Sustainability, like grassed tracks and recyclable plastics, has improved urban life. Sheet metal forming using recycled materials and sustainability shows how important environmental protection is in car and train design. Electric road and rail propulsion are driven by environmental concerns, while supercapacitors and batteries are studied. In conclusion, by preferring rail for freight and passenger transport, both for private and public transport, energy savings and CO2 emissions can be up to 2-10 times higher than for other modes of transport.
Open Access: Yes
DOI: 10.3303/CET23107002
Method of Railway Subgrade Diseases (defects) Inspection, based on Ground Penetrating Radar
Publication Name: Acta Polytechnica Hungarica
Publication Date: 2023-01-01
Volume: 20
Issue: 1
Page Range: 199-211
Description:
Due to the impact of climatic and natural factors, the normal-speed railway subgrade is vulnerable to mud pumping, water accumulation, subsidence and other defects, hereafter called diseases, that frequently occur, after a period of service. It is imperative to quickly detect subgrade diseases. On the basis of studying the law of geological radar electromagnetic signal propagation along the railway subgrade, according to the results of site excavation and verification, this paper proposes a method for railway subgrade disease inspection based on ground penetrating radar. In addition, radar image features of typical subgrade diseases are clarified herein. Practical application results show that this inspection method is effective to accurately identify subgrade diseases. In particular, it is of great significance to the rapid inspection of hidden subgrade diseases. In addition, an analysis of inspection results and distribution of subgrade diseases along the line is conducive to determining the key section for treatment of subgrade diseases.
Open Access: Yes
The Prospect of Using the Dual Gauge Line for the Ukraine–Hungary Railway Connection
Publication Name: Periodica Polytechnica Transportation Engineering
Publication Date: 2023-01-01
Volume: 51
Issue: 1
Page Range: 70-78
Description:
There are several international transport corridors in Hungary. Záhony railway station is one of the largest hubs in Europe, providing a railway connection between Ukraine and the European Union. Two different railway tracks meet and come together here, such as the standard (1435 mm) and broad (1520 mm) gauges. The availability of a developed infrastructure of the dual gauge on the territory of Hungary presupposes the corresponding development of the railway connection by Ukraine. In order to effectively use the dual gauge line and solve problems of special design, it is necessary to ensure the appropriate train flows. This research aims to provide scientific support for express analysis of the railway routes' competitiveness between Ukraine and the European Union to define the determining factors. The application of such approaches provides a tool for establishing the prospects for the development of existing railway lines, considering their features. Scientific approaches to creating methods for determining the priority areas of railway transport have been further developed. Apart from involving such essential indices as average speed and traffic volumes, the authors added the possibility of considering the presence of lines with such design features as single-track sections, non-electrified, dual gauge, etc., on the route. The theoretical background is applied as a tool for rapid calculations for increasing the competitiveness of the Chop–Záhony dual gauge line.
Open Access: Yes
DOI: 10.3311/PPtr.20572
Analysis of the Stressed State of Sand-Soil Using Ultrasound
Publication Name: Infrastructures
Publication Date: 2023-01-01
Volume: 8
Issue: 1
Page Range: Unknown
Description:
The maintenance of the ballast substructure is an important cost-driver for railway systems. The problem is that today’s condition monitoring methods are insufficient to collect detailed data on the compaction and stress allocation inside the ballast bed. That makes it challenging to improve the maintenance technology and organization. This study aimed to investigate the applicability of the ultrasound method for analyzing the state of stress of sand-soil and the relation between the residual stress and wave propagation velocity. The experiments on the sand in a box with different allocations of the ultrasonic receivers and pressure measurement cells were produced under different external loading. In addition, the vertical and horizontal stress distributions were measured. The results showed a correlation between the test load, the state of stress, and the ultrasound propagation velocity. Moreover, the residual stresses after the loading cycles were analyzed.
Open Access: Yes
Numerical Optimization of Battery Heat Management of Electric Vehicles
Publication Name: Journal of Applied and Computational Mechanics
Publication Date: 2023-01-01
Volume: 9
Issue: 4
Page Range: 1076-1092
Description:
Lithium-ion battery technology in the modern automotive industry utilizes highly temperature-sensitive batteries. Here, air cooling strategies will be the most applicable for the chosen example based on strategies for temperature control. Simulations have been utilized to evaluate the different thermal management strategies. A battery model was developed using the solutions offered by Computational Fluid Dynamics (CFD) simulation technology. It utilizes the heat produced by the discharge of the battery cells. Due to the simulation's limited computational capacity, the energy transfer model was implemented with a simplified but sufficiently complex physical mesh. Ten actual measurements were conducted in the laboratory to investigate the heating of the cell during the charging and discharging of 18650-type batteries. The results were applied to validate the simulation model. The simulation outcomes and thermal camera readings were compared. The cell-level numerical model was then extended to examine the temperature variation at the system level. The primary design objective is to achieve the highest energy density possible, which necessitates that the cells be constructed as closely as possible; however, increasing the distance between the cells can provide superior cooling from a thermal management perspective. The effect of varying the distance between individual cells on the system's heating was analyzed. Greater distance resulted in a more efficient heat transfer. It was also discovered that, in some instances, a small distance between cells produces inferior results compared to when constructed adjacently. A critical distance range has been established based on these simulations, which facilitates the placement of the cells.
Open Access: Yes
Experimental and Statistical Analysis of the Vertical Temperature Gradient, for Ballastless Railway Track, in Alpine and Plateau Environs
Publication Name: Acta Polytechnica Hungarica
Publication Date: 2023-01-01
Volume: 20
Issue: 1
Page Range: 123-142
Description:
Temporal temperature evolution of ballastless railway track is a random process caused by complex environmental actions. The vertical temperature gradient (VTG), varying continuously with time, has significant effects on the repeated deformation of ballastless track. However, few researchers have considered the statistical analysis of VTGs in alpine and plateau environs characterized by high altitude, strong solar radiation and high diurnal temperature differences. In this study, a temperature field test platform of ballastless track was established in Shannan City, Tibet and the temperature field of ballastless track was measured. Based on four statistical methods, a Monte Carlo simulation (MCS), Gaussian mixture model (GMM), Generalized Pareto distribution (GPD) and a third-order polynomial normal transformation technique (TPNT), the VTGs of ballastless track in alpine and plateau areas, are statistically analyzed. The results show that the applied statistical methods, used for predicting the VTG representative value, in ballastless track, are feasible within different application conditions. The recommended positive and negative representative values of the VTG of ballastless track are 91.58oC/m and-40.15oC/m, and 82.83oC/m and-35.03oC/m, with failure probabilities of 1% and 5% respectively, in alpine and plateau areas. The research results can provide a reference for the design and maintenance of ballastless track used in alpine and plateau environs.
Open Access: Yes
GEOMETRY VARIATION OF BALLASTED RAILWAY TRACKS DUE TO WEATHER CONDITIONS
Publication Name: Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu
Publication Date: 2023-01-01
Volume: Unknown
Issue: 1
Page Range: 74-79
Description:
Purpose. Investigate and establish the relationship between track geometry measurements and weather conditions to determine the parameters that influence the lifetime of railway tracks' superstructure system. The study of ballasted beds of railway tracks is very important for operation and maintenance in case of main lines, industrial sidings and mine transport. Methodology. Determination of the annual load of the selected section based on the regulations. Compari of the track parameters measurements made by TrackScan 4.01 instrument in different seasons and temperatures. Among the parameters measured by the instrument, the track gauge, alignment, longitudinal level, and superelevation parameters are considered and analyzed in this article.Since the main lines' traffic are permanently loaded with passenger and freight transport and the industrial sidings and mine tracks are used in the production process, the examinations can only be done on tramway tracks during the standstills at night. The results of these measurement on tramway tracks can help to understand the identify of railway tracks' lifetime and can be used in mainlines, industrial and mining railway tracks. Findings. The change in the average values of selected track geometrical parameters is analyzed, considering the typical weather conditions. Based on the measurement and results, there is an evident connection between the evaluated results of track geometry measurements and the change in weather conditions. Originality. Finding the relationship between changes in track geometry values and weather conditions on the basis of an evaluation of track geometry measurements taken on average every third month. Practical value. The results can then be used as input data for determining the service life of the track superstructure in the case of tramways, mainlines, industrial and mining railway tracks.
Open Access: Yes
INNER SHEAR RESISTANCE INCREASING EFFECT OF CONCRETE CANVAS IN BALLASTED RAILWAY TRACKS
Publication Name: Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu
Publication Date: 2023-01-01
Volume: Unknown
Issue: 2
Page Range: 64-70
Description:
Purpose. To prove that the GCCM (geosynthetic cementitious composite mat) – type Concrete Canvas (CC) – is an adequate supplementary layer on the top of the subgrade. As its drainage function is known, this article tries to prove the reinforcement possibility. This layer is relatively thin; nevertheless, it can behave like the geogrids. It is the main path to finding out the opportunity of the interlocking effect and its impact on the railway ballast’s inner shear resistance. Methodology. The laboratory measurements were performed in a multilevel shear box, which allows simulating the multilevel shift of the ballast layer. The tests were planned with and without the CC layer. After shearing, the samples were also tested for loadbearing capacity (E2 ; according to the Hungarian Standard) and particle breakage. On the other hand, the contact surface between the lowest part of the ballast and CC was also measured by a sophisticated 3D laser scanner (GOM ATOS) and graphically by AutoCAD software. Findings. After the results of the laboratory experiments are analyzed, the following parameters are calculated and determined: 1) the reinforcement ratio as the tangent of the inner shear resistance curves in the 5–15 mm horizontal shearing interval as well as the area under graphs by integration in the 0–40 mm interval; 2) the change in loadbearing capacity of the layerstructure with and without CC; 3) the amount of the cement particles; 4) the amount of the broken particles; 5) contact surface between the lowest layer of ballast and CC; 6) flatness of CC sheets after shearing. Based on the results, the Concrete Canvas provides significant reinforcement to the railway ballast. Originality. Any other type of measurement with Concrete Canvas in a multilevel shear box is unknown. The topic is unique. Practical value. In the future, these results may provide baseline data to verify the suitability of the Concrete Canvas in the railway sub or superstructure for various types of transport.
Open Access: Yes
Cell Fault Identification and Localization Procedure for Lithium-Ion Battery System of Electric Vehicles Based on Real Measurement Data
Publication Name: Algorithms
Publication Date: 2022-12-01
Volume: 15
Issue: 12
Page Range: Unknown
Description:
Vehicle safety risk can be decreased by diagnosing the lithium-ion battery system of electric road vehicles. Real-time cell diagnostics can avoid unexpected occurrences. However, lithium-ion batteries in electric vehicles can significantly differ in design, capacity, and chemical composition. In addition, the battery monitoring systems of the various vehicles are also diverse, so communication across the board is not available or can only be achieved with significant difficulty. Hence, unique type-dependent data queries and filtering are necessary in most cases. In this paper, a Volkswagen e-Golf electric vehicle is investigated; communication with the vehicle was implemented via an onboard diagnostic port (so-called OBD), and the data stream was recorded. The goal of the research is principally to filter out, identify, and localize defective/weak battery cells. Numerous test cycles (constant and dynamic measurements) were carried out to identify cell abnormalities (so-called deviations). A query and data filtering process was designed to detect defective battery cells. The fault detection procedure is based on several cell voltage interruptions at various loading levels. The methodology demonstrated in this article uses a fault diagnosis technique based on voltage abnormalities. In addition, it employs a hybrid algorithm that executes calculations on measurement and recorded data. In the evaluation, a status line comprising three different categories was obtained by parametrizing and prioritizing (weighting) the individual measured values. It allows the cells to be divided into the categories green (adequate region), yellow (to be monitored), and red (possible error). In addition, several querying strategies were developed accordingly to clarify and validate the measurement results. The several strategies were examined individually and analyzed for their strengths and weaknesses. Based on the results, a data collection, processing, and evaluation strategy for an electric vehicle battery system have been developed. The advantage of the developed algorithm is that the method can be adapted to any electric or hybrid vehicle battery.
Open Access: Yes
DOI: 10.3390/a15120467
Evolution of Rail Contact Fatigue on Crossing Nose Rail Based on Long Short-Term Memory
Publication Name: Sustainability Switzerland
Publication Date: 2022-12-01
Volume: 14
Issue: 24
Page Range: Unknown
Description:
The share of rail transport in world transport continues to rise. As the number of trains increases, so does the load on the railway. The rails are in direct contact with the loaded wheels. Therefore, it is more easily damaged. In recent years, domestic and foreign scholars have conducted in-depth research on railway damage detection. As the weakest part of the track system, switches are more prone to damage. Assessing and predicting rail surface damage can improve the safety of rail operations and allow for proper planning and maintenance to reduce capital expenditure and increase operational efficiency. Under the premise that functional safety is paramount, predicting the service life of rails, especially turnouts, can significantly reduce costs and ensure the safety of railway transportation. This paper understands the evolution of contact fatigue on crossing noses through long-term observation and sampling of crossing noses in turnouts. The authors get images from new to damaged. After image preprocessing, MPI (Magnetic Particle Imaging) is divided into blocks containing local crack information. The obtained local texture information is used for regression prediction using machine-supervised learning and LSTM network (Long Short-Term Memory) methods. Finally, a technique capable of thoroughly evaluating the wear process of crossing noses is proposed.
Open Access: Yes
DOI: 10.3390/su142416565
Optical Rail Surface Crack Detection Method Based on Semantic Segmentation Replacement for Magnetic Particle Inspection
Publication Name: Sensors
Publication Date: 2022-11-01
Volume: 22
Issue: 21
Page Range: Unknown
Description:
Railway damage detection is of great significance in ensuring railway safety. The cracks on the rail surface play a key role in studying the formation and development process of rail damage, predicting the occurrence of rail defects, and then improving the service life of the rail. However, due to the small shape of the cracks, the typical detection method is relatively complicated, and the speed is quite slow. Although traditional magnetic particle inspection technology is fairly accurate at detection, it is costly and inconvenient to carry and install, while also limiting the detection speed and affecting the system’s operation. In this paper, a semantic segmentation detection method is developed by using various collected rail surface crack data and deep learning through a neural network. By comparing the inspection of the same rail surface with magnetic particle inspection technology, only inexpensive cameras are used and the inspection speed is increased while maintaining relatively high accuracy. In addition, the method can achieve fast detection speeds if it is extended to be combined with high-frequency cameras. It is an economical, efficient, and environmentally friendly method for future rail surface detection.
Open Access: Yes
DOI: 10.3390/s22218214
Geogrid reinforcement of ballasted railway superstructure for stabilization of the railway track geometry – A case study
Publication Name: Geotextiles and Geomembranes
Publication Date: 2022-10-01
Volume: 50
Issue: 5
Page Range: 1036-1051
Description:
Background: This article deals with a unique topic related to railway infrastructure, civil and geotechnical engineering, and modern materials. In the past 20–30 years, more and more synthetic materials have been applied in engineering and everyday life. Geogrid and geotextile products are adequate for substituting lacking abilities of the soils, and granular materials, mainly low tensile and shear strength, etc. This paper aims to introduce the result of the author's research dealing with investigating the behavior of geogrid-reinforced railway ballast based on a long-term field test in the busiest main railway line in Hungary. The duration of the test is more than eleven years. Methods: Five different types of geosynthetics were installed in the superstructure of the No. 1 main railway line (Kelenföld – Hegyeshalom state border) in Hungary in 2010. More than eleven years have elapsed since the installation. The experiences are formulated in this paper. Mathematical-statistical analysis was performed to compare the (sub)sections with each other and with the designated reference sections where no geogrids were applied. Results: As a result of the examination, the author summarized the main differences in the behavior of railway track geometry, and the geometrical deterioration rates, considering the different types of reinforcement products.
Open Access: Yes
Comparison of the effects and efficiency of vertical and side tamping methods for ballasted railway tracks
Publication Name: Construction and Building Materials
Publication Date: 2022-01-03
Volume: 314
Issue: Unknown
Page Range: Unknown
Description:
The relatively high maintenance costs of the ballast track are related to the short lifecycle of the ballast layer. The current vertical ballast tamping technology (e.g., Plasser & Theurer, Matisa, etc.) causes high ballast destruction and is neither applicable for unconventional sleepers’ designs nor slab tracks. The side tamping method presents an alternative, ballast saving, and sleeper form independent ballast tamping technology. This paper compares the ballast layer compaction and its resistance to permanent settlements accumulation after the vertical and the side tamping methodologies. Scaled models of ballast layer and tamping units and scaled simulation with discrete element method (DEM) were applied for the comparison. In the laboratory tests, the ballast compaction along the sleeper was estimated using the measurements of elastic wave propagation. The settlements resistance for both tamping methods was estimated under the vibration loading. The tests’ results show 5–7% higher compactness of the ballast layer under the sleeper ends for the side tamping method. The settlement intensity of the ballast layer after the vertical tamping is higher than for the side tamping method. In discrete element modeling, the performed laboratory tests were simulated. The compactness of the ballast bed, as well as the residual stresses, were determined in MATLAB. The side tamping technology provided five times higher residual stresses in the ballast layer below the sleeper than in the case of vertical tamping, which can be explained by the more stable and dense layer resulting from the side tamping ensures higher interlocking between the grains. The simulation of the wave propagation shows an influence of the residual stresses on the wave propagation velocities. The simulated wave propagation velocity was more than two times higher for the side tamping than for the vertical one.
Open Access: Yes
Investigation of deformations of a lithium polymer cell using the Digital Image Correlation Method (DICM)
Publication Name: Reports in Mechanical Engineering
Publication Date: 2022-01-01
Volume: 3
Issue: 1
Page Range: 116-134
Description:
This research aims to investigate the adaptability of a measurement system or a process in determining the parameters of batteries. Methods are suggested for different applications, and properties gained by these measurements are specified. Deformations of lithium polymer batteries measured by various methodologies are also analyzed in detail. Changes in the geometry of worn-out batteries and the localization of the changes can be better understood by applying the results. The GOM ATOS and the GOM ARAMIS systems were applied to characterize lithium polymer batteries. Discontinuous tests were performed and the battery was discharged to 0 V and then fully charged for both methods. The advantages and disadvantages and the applicability of the two measurement systems were analyzed in this topic.
Open Access: Yes
Investigation of the Horizontal Track Geometry regarding Geogrid Reinforcement under Ballast
Publication Name: Acta Polytechnica Hungarica
Publication Date: 2022-01-01
Volume: 19
Issue: 3
Page Range: 89-101
Description:
This paper was written concerning a test section with geogrid-reinforced railway ballast based on field tests. I aim to introduce the variation of the alignment track geometry parameter taking into consideration the geogrid reinforcement. The main advantage of the ballast reinforcement with geosynthetic inclusions is the reduction of the longitudinal level faults and the deterioration speed. I observed the alignment (i.e., the horizontal geometry) changes. The duration of the field test is approximately 11.5 years. Five different geogrid types were incorporated below the ballast bed on the Kelenföld-Hegyeshalom state board (No. 1) railway line in Hungary in 2010. The test section is only straight for 700 m in length (with reference sections with the same geometry and structural set-up), i.e., the horizontal geometry of the track does not influence the results. A statistical analysis was executed to compare the behavior of the sections, based on both the geogrid-reinforced sections and reference sections. As a result of the investigation, it can be concluded that there were some geogrid types, which seemed to be adequate to decrease the deterioration speed of the alignment parameter of the ballasted railway track. A very high variance (standard deviation) was observed in the results, this is because they cannot be determined as a general horizontal railway track stabilizing solution.
Open Access: Yes
DOI: DOI not available
STATISTICAL ANALYSIS OF TRACK GEOMETRY PARAMETERS ON TRAMWAY LINE NO. 1 IN BUDAPEST
Publication Name: Baltic Journal of Road and Bridge Engineering
Publication Date: 2022-01-01
Volume: 17
Issue: 2
Page Range: 75-106
Description:
The article examines the superstructures of the tramway tracks of tramway line No. 1 in Budapest (the capital of Hungary). Since the first appearance of tramways, several technological advancements have been made to serve passenger needs as efficiently as possible. Several types of tramway track superstructure systems can be differentiated, which are implemented differently in each project. Furthermore, these superstructure types have different degradation times (both geometrical and structural), which depend on several factors. Nowadays, visual inspections are no longer considered sufficient in monitoring the tracks’ condition and deterioration, thus it is necessary to consider examinations carried out using the sensors mounted on the vehicles. Adopting appropriate methods, the measured data can be modeled and the life cycle of superstructures and structural elements can be determined as a result of sufficiently long-term studies (i.e., life cycle costs, the whole lifetime, etc.). First, the authors present a review of the relevant international literature, after that they conduct analysis of track geometry parameters of the superstructures related to five sections on the investigated tramway line based on the results of the measurements performed for three consecutive years between 2019 and 2021. The analyses consist primarily in statistical examination of the measured and calculated parameters.
Open Access: Yes
Investigation of the Track Gauge in Straight Sections, Considering Hungarian Railway Lines
Publication Name: Acta Polytechnica Hungarica
Publication Date: 2022-01-01
Volume: 19
Issue: 3
Page Range: 155-166
Description:
In this work, considering the MÁV’s (i.e., the Hungarian Railways) five small and five high-traffic railway lines, the statistical distribution and change of the track gauge parameter were analyzed, under a ten year, on time-series analysis, related to straight track sections. The analysed data, were bottom track gauge measurements, of the FMK-004 and FMK-007 type railway track geometry, measuring and recording car & wagon. Taking into account the railway tracks, the track gauge parameter cannot be controlled and improved upon by large machine methods, but its permitted value depends on the allowed speed (and vice versa). The main independent variables were the elapsed time and the through-rolled axle tons (as a function of time, i.e., the MGT). To generate the statistical analyses, Vaszary-like shape numbers were computed, considering the distribution functions of the measured data series of the track gauge parameter every 25 cm. The authors examined the change of the shape numbers, the average and standard deviation values of the track gauge, and the shape of the distribution functions (skewness and kurtosis properties). In the end, a spectrum analysis of the measured data series was produced. In conclusion, the Authors provide relevant statements regarding the track gauge parameter.
Open Access: Yes
DOI: DOI not available
Laboratory Tests and FE Modeling of the Concrete Canvas, for Infrastructure Applications
Publication Name: Acta Polytechnica Hungarica
Publication Date: 2022-01-01
Volume: 19
Issue: 3
Page Range: 9-20
Description:
The Concrete Canvas (CC) material, is a promising material for application in many civil engineering fields, such as, water construction, pipelining, slope protection, military applications, etc. The authors believe that this material has more potential and could be helpful in infrastructure applications. The infrastructure design requirements are known; the CC has to be fit into the track structure. Several relevant investigations were performed to show the materials adequacy, and using collected data, FE (Finite Element) models were built to determine more of the physical parameters. From the results and the hardening experiences, it can be stated, that after the laying of CC and the spraying of water, the material has to be loaded to reach the best shape and push the material down to the supporting protection layer. In FE modeling, it was shown that the material is a composite structure, i.e. one material's physical properties is not enough for modeling (it has to be improved). Moreover, it means that dynamic examinations can be initiated.
Open Access: Yes
DOI: DOI not available
Investigation of deformations of ballasted railway track during collapse using the Digital Image Correlation Method (DICM)
Publication Name: Reports in Mechanical Engineering
Publication Date: 2022-01-01
Volume: 3
Issue: 1
Page Range: 168-191
Description:
This paper summarizes the results of laboratory tests in which the authors investigated the effects of extremely high vertical load to a railway track segment. The segment consisted of a cut concrete sleeper (contact area: 290×390 mm) with a pair of direct-elastic rail fasteners; the sleeper pieces had a standard, full height; the structure had a typical 350 mm depth railway ballast, underneath approx. 200 mm sandy gravel supplementary layer. The whole assembly was built in a 2.00×2.20 m area wooden rack. The deformations due to the approx. 150 kN static concentrated vertical force were measured and recorded by Digital Image Correlation Method (DICM), ensuring the GOM ATOS technology. The 150 kN peak load meant 1326 kPa vertical stress at the sleeper-ballast interface. The 3D geometry was scanned before the loading and after the collapse. In this way, the comparison was able to be executed. The maximum vertical deformation was 115 mm. The DICM technique is a relatively new methodology in civil engineering; however, it has been applied for more than ten years in mechanical engineering. Therefore, the authors investigated the applicability of DICM in this field. As a result, the pre and the post-states were determined in 3D. The displacement of the ballast particles was able to be defined with the possibility of drawing the displacement trajectories of given points. The DICM can be a valuable methodology in railway engineering, e.g., laboratory tests and field test applications.
Open Access: Yes
Modeling of the Dynamic Rail Deflection using Elastic Wave Propagation
Publication Name: Journal of Applied and Computational Mechanics
Publication Date: 2022-01-01
Volume: 8
Issue: 1
Page Range: 379-387
Description:
There is a class of tasks that requires considering the dynamics not only for rolling stock but also for the response of the railway track. One of the directions of railway transport development, which encourages the transition to fundamentally newdynamic models of the railway track, is undoubtedly an increase in traffic speed. To solve such problems, the authors applied amodel of the stressed-strained state of a railway track based on the dynamic problem of elasticity theory. The feature of this modelis the calculation of dynamic stresses and deformations induced by the spread of elastic waves through the objects of the railwaytrack. Based on the mathematical modeling of stress propagation in the under-rail basis, authors have shown the influence ofvarious objects of a railway track on the formation of the outline of the front of the elastic wave and determined the main timeintervals. Furthermore, the authors propose the following analytical method, which, in addition to the soil's physical andmechanical properties, considers the properties of the ballast as a layer that transmits pressure to the roadbed and takes an activepart in the formation of the interaction space
Open Access: Yes
Investigation of the Effects of Thermit Welding on the Mechanical Properties of the Rails
Publication Name: Acta Polytechnica Hungarica
Publication Date: 2022-01-01
Volume: 19
Issue: 3
Page Range: 37-49
Description:
This current paper deals with the investigation of the variation of the hardness of the rail steel material in the heat-affected zone (HAZ) of a rail joint made by thermit welding (TW). The tested rail is a normal R260 type rail steel category; its production date is 1977, the rolling mill was Diosgyor (Hungary), rail profile is MÁV 48.5. This rail has not been in railway track before the test. The authors performed hardness tests on the rail head’s surface even after the rail welding, as well. After the welding and hardness tests, the rail joint was cut with +/–200 mm by a rail cutter and transported to the laboratory. Water jet cutting was applied to shape six longitudinal direction slices with five vertical cutting lines from the rail piece’s head. The slices’ length was 400 mm, the width of these slices was approx. 10 mm; the TW rail joint was in the mid-point of the slices. Micro-Vickers (HV10) hardness tests were executed on these slices, in the –150…+150 mm interval lengthwise and in the 3, 6, and 10 mm depth points below the rail head’s top surface. As a result, the authors received a very detailed hardness functions of the HAZ of rail joint made by TW. These variation functions were compared to the official Elektrothermit’s SoW-5 hardness tests’ results. It can be concluded that the variation of the hardness of rail steel in the area of the HAZ correlated with the Elektrothermit’s results; however, there were some critical points where significant differences were able to be found. The highest deviation was concluded in 50 mm distance measured from the axis of welded rail joint. The authors gave possible valuable explanations for these phenomena.
Open Access: Yes
DOI: DOI not available
Investigation of Tramway Line No. 1, in Budapest, Based on Dynamic Measurements
Publication Name: Acta Polytechnica Hungarica
Publication Date: 2022-01-01
Volume: 19
Issue: 3
Page Range: 65-76
Description:
Determining the deterioration of superstructure systems is technical and has national economic importance. In addition to geometric deterioration, it is also very difficult to monitor the changes in the dynamic characteristics of the vehicles. The data from geometric and dynamic measurements should be properly analyzed to determine the deterioration, lifetime/life-cycle costs of superstructure systems and the casual relationships should be researched between the characteristics. In this paper, the geometric and dynamic measurement results of the two examined sections are compared. This analysis is the first step in exploring and understanding the relationship between each feature. The authors recommended methodologies for using the synchronized (static and dynamic) measurements and their evaluation possibilities related to tramway tracks. The method is a well-known solution for public railways; however, the tramways greatly differ. In Hungary, there is a great opportunity to introduce the static-dynamic parallel method, which can be applied for the determination of the life-cycle costs (LCC) of the tramway tracks that are assembled with different (super)structures.
Open Access: Yes
DOI: DOI not available
Comparative Study of the Mechanical Behavior of Concrete Railway Sleeper Mix Design, using Waste Rubber and Glass Materials
Publication Name: Acta Polytechnica Hungarica
Publication Date: 2022-01-01
Volume: 19
Issue: 6
Page Range: 213-224
Description:
Waste rubber tires and glass powders, are hazardous materials for the environment. One of the methods to consume them, is their application in railway engineering projects. Rubber and glass materials, in this research, are provided from waste tires and glass bottles. Therefore, a modification is conducted to the concrete railway sleeper mix design, incorporated with waste rubber (R) and glass powder (GP). Three mechanical tests, including compressive, flexural and tensile splitting, have been studied on rubber and glass powder concrete specimens. Three different percentages of 5%, 10% and 15% by cement weight, for GP and by fine aggregate volume for R, are investigated herein. The results show that GP concrete has a better performance over the rubber concrete (RC), but lower than Ref. specimens. 5%GP as the best mix design, has compressive, flexural and tensile strengths of 45.4 MPa, 7.5 MPa and 5.82 MPa, respectively. Moreover, these strengths, for compressive and flexural, of 5%GP are about 24% and 6% lower than the Ref. strengths, respectively, while, tensile splitting strength is almost 14% higher than Ref. strength.
Open Access: Yes
DOI: DOI not available
Effects of Wheel Surface Defects on Ground Borne Vibration
Publication Name: Acta Polytechnica Hungarica
Publication Date: 2022-01-01
Volume: 19
Issue: 6
Page Range: 129-141
Description:
Wheel ground borne vibrations, may have a significant impact on human activity and on nearby buildings. In metropolitan cities, metro lines and their development may cause such vibrations. Despite many works and solutions for path and receiver, the excitation source could also have a great effect. Wheel and rail damages are the two sources of vibration which can increase the damage impact by a factor of 5x. Wheel damage would increase dynamic vertical force noticeably and an increase in ground-borne vibration is expected. In this study with the help of finite element modelling, wheel damage including wheel flat, spalling and wheel oval is studied for a slab track and results are discussed. The studied parameters are velocity and wheel damage and their effect on ground-borne vibrations are examined.
Open Access: Yes
DOI: DOI not available
Tutorial on the fragmentation of the railway ballast particles and calibration methods in discrete element modelling
Publication Name: Acta Technica Jaurinensis
Publication Date: 2021-02-24
Volume: 14
Issue: 1
Page Range: 104-122
Description:
This paper presents a short literature review related to the fragmentation of the railway crushed ballast particles. With the help of the processed articles with the main topic of discrete element modelling (DEM) we aim to provide some insight into the international achievements and forward progress of the subject. Rock materials as granular elements can be investigated from several perspectives. The elements can be examined in laboratory conditions purely from the quarry, or even by obtaining already fragmented particles from the real railway tracks. In addition, DEM models can be created by using computer software. This article tackles only a small segment of the literature. Though each DEM topic was unique, they all involved examination of degradation of particles in some way. This review focuses on model building, including particle construction and calibration. The selected publications do not cover the current state of the entire DEM research related to ballast degradation.
Open Access: Yes
Tutorial on the emergence of local substructure failures in the railway track structure and their renewal with existing and new methodologies
Publication Name: Acta Technica Jaurinensis
Publication Date: 2021-02-24
Volume: 14
Issue: 1
Page Range: 80-103
Description:
The construction and maintenance of a railway track is an expensive process. Therefore, nowadays, except for advanced countries, considerable attention must be paid to apply the optimal maintenance of railway lines. In Hungary, until 2020 nearly 11% of railway tracks were renewed and rehabilitated from EU support, which means millions of Euros, i.e. billions of Hungarian Forints. It also follows from the support that planned preventive maintenance works must be performed on the renewed and rehabilitated lines. On the other hand, it takes away significant costs from the non-renewed (non-rehabilitated) lines maintenance works, but naturally, less money does not mean less failures, so cost-effective technologies are needed. A segment of maintenance is the local substructure problem(s). In this article, this segment will be mentioned from the development of the failures, through the applied technologies, to the possible new solutions like injection and the using of geosynthetic cementitious composite mats (so called GCCMs).
Open Access: Yes
INVESTIGATION OF THE GLUED INSULATED RAIL JOINTS APPLIED TO CWR TRACKS
Publication Name: Facta Universitatis Series Mechanical Engineering
Publication Date: 2021-01-01
Volume: 19
Issue: 4
Page Range: 681-704
Description:
This article summarizes the research results related to our own conducted extensive laboratory tests of polymer composite and steel fishplated glued insulated rail joints (GIRJs), namely axial tensile tests as well as vertical static and dynamic tests. The investigation dealt with the examination of GIRJs assembled with steel and special glass-fiber reinforced plastic (polymer composite) fishplates, both of them for CWR railway tracks (i.e. so-called gapless tracks or, in other words, railway tracks with continuously welded rails). The exact rail joint types were MTH-P and MTH-AP, consistently. The MTH P types have been commonly applied for many years in the CWR tracks in Europe, mainly in Hungary. The MTH-AP rail joints consist of fishplates that are produced by the APATECH factory (Russia). They are made of a fiberglass-amplified polymer composite material at high pressure and controlled temperature. This solution can eliminate electrical fishplate lock and early fatigue failures just as it can ensure adequate electrical insulation. The advantage of such rail joints can be that they are probably able to ensure the substitution of the glued insulated rail joints with relatively expensive steel fishplates currently applied by railway companies, e.g. Hungarian State Railways (MÁV). The aim of the mentioned research summarized in this paper is to formulate recommendations on technical applicability and on the technological instructions that are useful in everyday railway operation practice on the basis of the measurements and tests carried out on rail joints in laboratory.
Open Access: Yes
Investigation of effect of water content on railway granular supplementary layers
Publication Name: Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu
Publication Date: 2021-01-01
Volume: 2021
Issue: 3
Page Range: 64-68
Description:
Purpose. To determine the relationship between water content of continuously graded granular supplementary layers for railway substructure and their inner shear resistance and load bearing capacity. Methodology. Four different ‘samples’ were produced as standard granular products from andesite. Two of them are common base courses for road construction in Hungary, the other two are common railway supplementary layers. The author performed laboratory measurements (multilevel shear box tests) that are adequate for the evaluation of inner shear resistance. The measurements of load bearing capacity and Proctor tests were executed in the laboratory of Colas Hungaria Ltd. The author performed measurements with the optimal water content values of each sample, as well as lower and higher values than them. This can show how the given granular material is sensible to the change of water content. Findings. It was proved that the granular supplementary layers, which are standardized products in road construction (as base courses), also seems to be adequate in railway construction; they are not so sensible to the variation of their water content. It does not mean that the other two granular layers are not adequate for railway substructures, but the application of road ‘products’ have to be considered as substitute products. Originality. The author tried to emphasize the adequacy of rock mining for construction of ballasted railway tracks, as well as the optimal use of mineral wealth in every country with its results. Practical value. The obtained results of the present paper can be useful in the area of rock mining, and railway infrastructure engineering. During construction procedures the optimal water content values should be taken into considerations for compaction to be able to reach maximal compactness (density), but too high water content has to be avoided, which is based on the results. They can be also considered in the design phase.
Open Access: Yes
Investigation of interlocking effect of crushed stone ballast during dynamic loading
Publication Name: Reports in Mechanical Engineering
Publication Date: 2021-01-01
Volume: 2
Issue: 1
Page Range: 65-76
Description:
The present paper deals with the experimental investigation of interlocking effect of crushed stone ballast material, assessing it as the relationship with the residual and dynamic stresses under the ballast layer during laboratory dynamic tests with the consideration of different boundary conditions. The laboratory experiments were executed with a scaled model of ballast under the sleeper. The measured pressure at the bottom surface of the ballast has two parts: dynamic and residual. The dynamic part depends on the external loading; the residual part remains after unloading. The measured residual stress was observed up to 3 times higher than the stress due to cyclic external loading. The relationship of the residual stress and interlocking effect to ballast particles angularity is analyzed. A simple interpretation of the distribution of residual stress is proposed, that depends on the measured cyclic stress and the elasticity of bounding walls. The study of interlocking effect of ballast could be potentially useful for many practical problems of railway track design as well as for the track maintenance issues.
Open Access: Yes
Smart economy and startup enterprises in the visegrád countries—a comparative analysis based on the crunchbase database
Publication Name: Smart Cities
Publication Date: 2020-12-01
Volume: 3
Issue: 4
Page Range: 1477-1494
Description:
The present study seeks to explore the concept of “smart economy” through the definition of the smart city. It also presents smart city subsystems and the smart city model. It focuses on smart and creative startups within the smart city model. The research examines medium-sized cities in the Visegrád countries (Czech Republic, Slovakia, Poland, Hungary) with a population ranging from 100,000 to 1 million inhabitants for startups. The research question is: Where are the medium-sized cities in the Visegrád countries that are both startup centers and smart cities? In the course of the research, the term “smart cities” was based on the definition set by the European Commission and the definition of startup centers was made using data analysis of the American Crunchbase database. As a result of the two studies, it can be concluded that there are no cities in the Visegrád countries with an above average level of both startup presence and smart cities.
Open Access: Yes
Investigation of railroad ballast particle breakage
Publication Name: Pollack Periodica
Publication Date: 2019-01-01
Volume: 14
Issue: 2
Page Range: 3-14
Description:
This paper summarizes the authors up-to-date results in the research topic of railway ballast particles breakage test with individual laboratory test. In the past few years there were a lot of railway rehabilitation and maintenance project in Hungary, as well as abroad. The largest part of worlds railways has traditional superstructure, i.e. they are so called ballasted tracks. The railway ballast is the highest mass in the railways superstructure. Nowadays, it is a naturally fact that there is enough quantity of railway ballast in adequate quality. However, due to the modifications and restrictions in the related regulations since 2010, there are only few quarries in Hungary, which are able to ensure adequate railway ballast material for railway construction and maintenance projects for speed values between 120 and 160 km/h. Quarrying industry is stricken by aggravated environmental, heritage and conservation regulations year by year, it limits the accessibility of mineral wealth in significant manner. This fact with quality requirements means supply and quality risk in production of railway ballast in medium term. The main goal of authors research is to be able to simulate the stress-strain effect of ballast particles in real and objective manner in laboratory circumstances, as well as in discrete element method modeling. This paper introduces the exact assembly of executed laboratory test and newest test results. The authors summarize the up-to-date international literature review, using that they give short outlook to the planned research with research directions in near future.
Open Access: Yes
Investigation of glued insulated rail joints with special fiber-glass reinforced synthetic fishplates using in continuously welded tracks
Publication Name: Pollack Periodica
Publication Date: 2018-08-01
Volume: 13
Issue: 2
Page Range: 77-86
Description:
In this paper the authors partially summarize the results of a research on glued insulated rail joints with fiber-glass reinforced plastic fishplates (brand: Apatech) related to own executed laboratory tests. The goal of the research is to investigate the application of this new type of glued insulated rail joint where the fishplates are manufactured at high pressure, regulated temperature, glass-fiber reinforced polymer composite plastic material. The usage of this kind of glued insulated rail joints is able to eliminate the electric fishplate circuit and early fatigue deflection and it can ensure the isolation of rails' ends from each other by aspect of electric conductivity.
Open Access: Yes
Breakage test of railway ballast materials with new laboratory method
Publication Name: Periodica Polytechnica Civil Engineering
Publication Date: 2017-10-24
Volume: 61
Issue: 4
Page Range: 794-802
Description:
This paper summarizes the results of a R&D work in 2014. Five different types of andesite railway ballast material with different LARB (%) (Los Angeles abrasion) as well as MDE RB (%) (Micro-Deval abrasion) values were investigated in laboratory with pulsating test which models the real condition much better (the used parameters were determined accordance with international dynamic design method). Grain size distributions related to the five several aggregates were defined before and after pulsating tests. Particle breakages were then calculated by different method publicized in international literature. Relationships were searched between particle breakages due to laboratory test and LARB (%) as well as MDE RB (%) values of railway ballast samples. Time interval (cycle) of ballast cleaning work were attempted to compute with help of special parameters used by Hungarian and other railway companies underlined the limits of calculation method. Finally recommendations were formulated related to use of this new laboratory test method for estimation of ballast particle breakage.
Open Access: Yes
DOI: 10.3311/PPci.8549
Comparison of railway track transition curves
Publication Name: Pollack Periodica
Publication Date: 2009-12-01
Volume: 4
Issue: 3
Page Range: 99-110
Description:
There are no design parameters related to speeds exceeding 160 km/h in the effective Hungarian railway design rules. In the relevant international standard (ENV 13803) a similar speed limit is 300 km/h. This paper deals with the comparative of these regulations. Parameters of two transition curves used in Hungary and other used in Austria are determined. The importance of the new design parameters provided by ENV 13803 is assessed. It is demonstrated that the usability of the clothoide transition curves is unnecessarily restricted for the speeds v≤120 km/h in the Hungarian regulations. © 2009 Akadémiai Kiadó.
Open Access: Yes
Testing Sustainable 3D-Printed Battery Housings with DIC Technology †
Publication Name: Engineering Proceedings
Publication Date: 2024-01-01
Volume: 79
Issue: 1
Page Range: Unknown
Description:
Three-dimensional printing has rapidly gained traction in the automotive industry, offering significant benefits in terms of design flexibility, production speed, and cost efficiency. However, as the use of 3D printing grows, there is a rising focus on incorporating sustainable materials to minimize the environmental footprint of automotive components. This study centers on using eco-friendly, 3D-printable materials to produce electric vehicle battery covers. The primary goal is to assess these sustainable battery housings’ mechanical properties, durability, and overall feasibility. Additionally, the research explores the potential of foaming polylactic acid filaments in measurement applications using Digital Image Correlation technology, which is widely employed in the automotive sector. The study also evaluates these housings’ manufacturability and real-world applicability, offering insights into their role in the future of automotive production, where sustainability is becoming increasingly important. The research seeks to contribute to the broader movement toward greener manufacturing processes within the automotive industry by conducting these analyses.
Open Access: Yes
Analysis of stress-strain state changes in railway tracks during transition to European gauge
Publication Name: Iop Conference Series Earth and Environmental Science
Publication Date: 2024-01-01
Volume: 1348
Issue: 1
Page Range: Unknown
Description:
The geographical location of Ukraine facilitates its integration into the transportation network connecting European countries. Various options exist for transitioning from the gauge of 1 520 mm to the European standard gauge of 1 435 mm. This paper aims to analyze the changes in the stress-strain state of railway track elements during the reconstruction of existing sections from the 1 520 mm gauge to the 1 435 mm European gauge or to a dual gauge of 1 435/1 520 mm. To perform these calculations, a spatial model of dynamic deformations in the railway track is employed, based on the principles of elasticity theory. The implementation of a combined railway track complicates the stress state of the ballast layer, leading to asymmetric stresses along the length of the sleepers, which vary depending on the track on which trains operate. There is also a redistribution of stresses acting on the ground structure, which has been in operation for many years. The research results identify changes in the stress-strain state of the railway track and can be used to justify measures for the appropriate reinforcement of the ballast layer and the ground structure.
Open Access: Yes
Deformation Test of 3D Printed Battery Case Using DIC Technology
Publication Name: International Conference on Electrical Computer Communications and Mechatronics Engineering Iceccme 2023
Publication Date: 2023-01-01
Volume: Unknown
Issue: Unknown
Page Range: Unknown
Description:
The study demonstrates the evaluation of various 3D-printed 18650 battery housings. The GOM Aramis measurement system performs real-time deformation analysis of the housings during testing. Using Fused Deposition Modelling (FDM) technology and various polylactic acid (PLA) materials, battery housings are 3D printed using Fused Deposition Modelling (FDM). Additionally, different layout designs will be investigated. The research's primary objective is to evaluate the suitability of the measuring system and the printing technology. In addition, the paper describes the raw materials used, preparation techniques, measuring system, and measurement outcomes.
Open Access: Yes
The Role of Domain Size and Boundary Conditions in Mathematical Modeling of Railway Tracks
Publication Name: Applied Mechanics
Publication Date: 2025-09-01
Volume: 6
Issue: 3
Page Range: Unknown
Description:
In developing a mathematical model of a railway track, the question of determining the dimensions of the modeling domain inevitably arises. If the modeling area is too small, boundary effects may significantly influence the results, reducing their accuracy. Conversely, excessively large areas can increase computational complexity without substantial improvements in accuracy. An optimal choice of dimensions enables the balancing of computational costs and accuracy. Solving this problem is non-trivial, as it depends on numerous factors, primarily the type of mathematical model and the problem being addressed. In most cases, preference is given to minimal domain sizes that ensure the approach’s adequacy. The aim of this study is to justify the dimensions of the modeling domain by addressing such tasks as load scaling, introducing additional boundary conditions, and making relevant assumptions. The main object of the study is the minimum adequate longitudinal length of the track for the spatial model. The research is based on the analytical application of modern approaches in the theory of elasticity. The results are analyzed using mathematical methods, such as modeling the railway track through the propagation of elastic waves and finite element modeling. These findings can be applied to a wide range of problems related to the mathematical modeling of the stress–strain state of railway tracks.
Open Access: Yes
