Search

Input kinematic parameters during the movement of the mechanism for opening and closing the roof of Tagnpps 95 m3 wagon were analyzed. This included studying all components including the steering wheel, motion transmissions, and the roof of the wagon. The process of creating a 3D model of the mechanism for opening and closing the wagon roof in SolidWorks software is described, as well as the procedure of kinematic analysis of the mechanism in SolidWorks Motion. The manual force required to operate the mechanism for opening and closing the roof is calculated. To optimize the existing mechanism, the case of replacing the current reducer gear with a reducer of a smaller gear ratio is taken into consideration. [ABSTRACT FROM AUTHOR]

The higher efficiency of international transportation necessitates the introduction of combined transport systems. One of the most successful among these is train ferry transportation. And in order to provide safe transportation of wagons by sea, it is important to formulate the operational requirements for railway-sea transportation. And one of the loading modes for wagons is rolling on the train ferry. The article presents the results of determining the dynamic load of the open wagon body when rolling on the train ferry. The calculation was made for the open wagon placed on 18-100 bogies. A mathematical model was formed, which made it possible to determine the main dynamic indicators that characterize the movement of the wagon. The results of the calculations were used to determine the permissible inequality amplitude in the zone of interaction between the rail tracks of the bridge and the ferry deck so that the indicators of the car dynamics would be within the permissible values. The permissible value of the inequality amplitude was 0.021 m. The conducted studies will contribute to the database of developments on ensuring the operational safety of wagons used for international railway-sea transportation. [ABSTRACT FROM AUTHOR]

Railway infrastructure relies on the dynamic interaction between wheels and rails; thus, assessing wheel wear is a critical aspect of maintenance and safety. This paper focuses on the wheel–rail wear indicator T-gamma (Tγ). Amidst its use, it becomes apparent that Tγ, while valuable, fails to provide a comprehensive reflection of the actual material removal and actual contact format, which means that using only Tγ as a target for optimization of profiles is not ideal. In this work, three different freight wagons are evaluated: a meter-gauge and a broad-gauge heavy haul vehicles from South American railways, and a standard-gauge freight vehicle operated in Europe, with different axle loads and dissimilar new wheel/rail profiles. These vehicles are subjected to comprehensive multibody simulations on various tracks. The simulations aimed to elucidate the intricate relationship between different wear indicators: Tγ, wear index, material removal, and maximum wear depth, under diverse curves, non-compensated lateral accelerations (Anc), and speeds. Some findings showed a correlation of 0.96 between Tγ and wear depth and 0.82 between wear index and material removed for the outer wheel. From the results, the Tγ is better than the wear index to be used when analyzing wear depth while the wear index is more suited to foresee the material lost. The results also show the low influence of Anc on wear index and Tγ. By considering these factors together, the study aims to improve the understanding of wheel–rail wear by selecting the best wear analysis approaches based on the effectiveness of each parameter. [ABSTRACT FROM AUTHOR]

The article is devoted to the study of the influence of flexural deformation of the body of a freight wagon on the indicators of the interaction of rail fleet with rails. The considered indicators depend both on the design of the rail fleet, its condition and speed, and on the design and condition of the railroad track. A theoretical study was carried out using a model of spatial vibrations of a freight wagon as part of a homogeneous train. When carrying out calculations, the wagon body was considered as an absolutely rigid body and as a discrete multi-mass system with elastic connections between the masses. When choosing a design scheme, it was assumed that the wagon body is a deformable body and, when bending, has finite rigidity in the vertical and horizontal planes. As a result of the research, the dependences of the dynamic indicators of a freight wagon on the flexural deformation of the body and the speed of movement were obtained. Based on theoretical calculations, the influence of the deformability of the body on the interaction of rail fleet with the railroad track on a tangent level track and curved section with irregularities was assessed. [ABSTRACT FROM AUTHOR]

Rail transport has been the leading sector of the whole transport network. In order to improve the efficiency of its functioning, it is important to develop measures that may help reduce the maintenance cost. To improve the open wagon hatch door strength, it is proposed to make it with rectangular corrugations. The results of calculations show that, taking into account the proposed solution, the weight of the improved hatch door is almost 10% lower than the weight of a typical one. The strength of the hatch door under static loads was calculated. The results of calculations show that the strength of the hatch door under the diagrams considered is ensured. The study will contribute to the development of best practices for modern structures of railway vehicles and increase their cost-effective operation. [ABSTRACT FROM AUTHOR]

Purpose. Highlighting the results of the analysis of the stress-deformed state of the wagon body of the 918 model under non-typical loads with bulk cargo. Such an analysis was carried out with the aim of investigating the possibility of transportation of various types of bulk cargo (for example, various types of raw materials, agricultural products, construction materials, etc.) in the existing design of the section of the refrigerated wagon. Methodology. In order to ensure uninterrupted railway transportation in today’s difficult conditions, it is proposed to use scientific and applied approaches to develop the possibility of using existing models of wagons for types of transportation that are not typical for them. Namely, to consider the possibility of using refrigerated wagons for the transportation of bulk cargo. A systematic approach is used to conduct such research. This included: determination of the study of the specifics of the impact of bulk cargo on rolling stock structures; analysis of design and technological documentation to create a spatial 3D model of the wagon under investigation; creation of a calculation model using a modern software complex; checking the adequacy of the developed model and the accuracy of the data obtained with its help; application of non-typical design loads; obtaining and analyzing pictures of stress-strain states by the finite element method. Findings. A 3D model of the body module of the model 918 wagon was developed. The results of the analysis of the equivalent stress plot according to the first mode proved that the greatest stresses are 800 MPa, that is, they significantly exceed the permissible ones. According to the third mode, the highest stresses are 320 MPa and also exceed the permissible ones. The results of the analysis of the plot of equivalent stresses, which occur during expansion, proved that the loads are excessive. The cladding, supported only by racks, cannot hold the load from the bulk cargo. Originality. A strength analysis of the existing design of a refrigerated wagon section was conducted under non-typical bulk cargo loads. Practical value. The obtained results of the analysis of the stressed-deformed state of the body of the model 918 wagon when loaded with bulk cargo made it possible to assess the potential possibilities of such transportation. It is expedient to use such results when carrying out research and development works on the improvement (modernization) of the existing sections of refrigerated wagons to ensure the possibility of transporting bulk cargo in them. This, in turn, will increase the efficiency of the domestic fleet of freight wagons. [ABSTRACT FROM AUTHOR]

The object of this paper is the processes of perception and redistribution of loads in the roof of a railroad covered wagon with a frame in the form of a triangular arch. To reduce the tare of the covered wagon, it is proposed to improve the structure of its roof. A feature of this improvement is that the roof frame is made in the form of a triangular arch with a reinforcing belt. This contributes to the reduction of the total mass of the roof compared to a typical structure. The selection of execution profiles of the beams forming the arch is carried out according to the maximum values of the moments that act in their cross-section. Taking into account the chosen profile of the arches, the calculation of the strength of the roof when it receives vertical loads was carried out. It was established that the strength of the roof under the considered load schemes is within the permissible stress values. Since the improvement of the roof structure contributes to the reduction of its weight by 1.8 % compared to the prototype, the movement of the covered wagon was evaluated under conditions of moving while empty. To this end, a mathematical modeling of the load of the covered wagon in the vertical plane during its movement along the joint unevenness was carried out. On the basis of the performed calculation, it was established that the movement of the wagon is assessed as “good”. Special feature of the results is that the reduction of the tare of the supporting structure of the wagon was achieved by improving its roof, as the least loaded unit. The field of practical application of the results is railroad transport, including other areas of mechanical engineering. The conditions for the practical use of the results are a symmetrical roof load scheme in operation. The results of this research could contribute to advancements related to the design of modern structures of freight cars with improved technical and economic indicators. [ABSTRACT FROM AUTHOR]

This article explores the historical significance of ox wagons in South Africa and their impact on urban heritage. Despite the introduction of railways, ox wagons continued to be used for transportation until the early 1900s. They played a crucial role in the diamond diggings and the development of cities like Pretoria and Johannesburg. During the Second South African War, ox wagons were used to supply troops, and the article highlights the contributions of African and "Coloured" transport drivers during this time. The author emphasizes the lasting imprint of ox wagons on South Africa's urban landscape. [Extracted from the article]

The transportation of shipments by rail is usually more expensive than other modes of transport. The costs are dependent on different factors, like the length of the train route, energy consumption based on traction, or the number of crew members in the train. The total price for using the railway infrastructure is also calculated, as is the total weight of the railway vehicle—the weight of the shipment and the weight of the wagon. The different types of wagons have different properties. For the operators, it is an ideal situation to have good values of the technical coefficient of tare. In the case of good values, the operator has effectively used their vehicle park. Railway transport should be affordable for customers. By operating non-efficient wagons, transport is more expensive and has low efficiency. By reducing the dead weight of the wagon, it is possible to reduce the cost rate. In synergy with this, more efficient and eco-friendly transportation can be achieved by reducing energy consumption. By reducing energy consumption, it is possible to get closer to the goal of the European Union, which is to reduce greenhouse gases from transport. [ABSTRACT FROM AUTHOR]

Introduction. Solutions to car weight-bearing capacity problems currently tend to benefit from the properties of aluminium alloys. Aluminium alloy wagon units are about three times lighter than steel ones, which helps to carry more freight with the same number of cars while maintaining the specified axle load. The Ural Wagon Factory was the first to use aluminium as a structural material for the manufacture of axle box mount in the 1950s.Materials and methods. This paper reviews the research on the production of wagon wheel pair axle boxes from aluminium alloys in Russia and abroad. It examines the manufacturing techniques of the aluminium axle box and the results of bench and operational tests.Results. The analysis of production technologies of aluminium alloy axle boxes and the results of operational tests of the pilot batch of axle boxes revealed the advantages and disadvantages of this design and led to the conclusions about its feasibility.Discussion and conclusion. The authors propose to resume the use of aluminium alloys in wagon axle boxes considering modern operating conditions. Confirmation of its technical and economic efficiency requires a set of bench and operational tests with the use of modern diagnostic tools.

Leaf springs are critical components for the railway vehicle safety in which they are installed. Although these components are produced in high-strength alloyed steel and designed to operate under cyclic loading conditions in the high-cyclic fatigue region, their failure is still possible, which can lead to economic and human catastrophes. The aim of this document was to precisely characterise the mechanical crack growth behaviour of the chromium–vanadium alloyed steel representative of leaf springs under cyclic conditions, that is, the crack propagation in mode I. The common fatigue crack growth prediction models (Paris and Walker) considering the effect of stress ratio and parameters such as propagation threshold, critical stress intensity factor and crack closure ratio were also determined using statistical methods, which resulted in good approximations with respect to the experimental results. Lastly, the fracture surfaces under the different test conditions were analysed using SEM, with no significant differences to declare. As a result of this research work, it is expected that the developed properties and fatigue crack growth prediction models can assist design and maintenance engineers in understanding fatigue behaviour in the initiation and propagation phase of cracks in leaf springs for railway freight wagons. [ABSTRACT FROM AUTHOR]

The analysis of the statistical values of wear of brake pads in operation, based on which a wear model was developed, is presented in this paper. This model can be used for predicting the remaining service life of brake pads according to the wagon mileage. The distribution function of wear on the upper and lower parts of the pad was determined, which made it possible to find the main qualitative characteristics, namely, the wear intensity, the γ-percentage wear, and the average pad wear at a specified wagon mileage. The results of the study can be factored for solving complex engineering problems of excessive wear of composite brake pads used for freight rolling stock; they could also help to extend the guaranteed overhaul period and improve the railway traffic safety. [ABSTRACT FROM AUTHOR]

Ensuring the safe operation of trains hinges on precise bearing condition monitoring, given the pivotal role bearings play in railway wagons. The status and maintenance of wagon bearings are of paramount concern, necessitating a shift from traditional maintenance approaches reliant on schedules and experience, which often lack real-time precision and efficiency. To address this challenge, our research focuses on enhancing the sparrow search algorithm by incorporating logistic chaos mapping and the levy flight strategy. This enhanced algorithm optimizes variational mode decomposition parameters, utilizing intrinsic mode components' average dispersion entropy as the fitness function. This optimization is integrated with a multi-level convolutional neural network for bearing fault diagnosis. Our findings demonstrate the improved algorithm's enhanced spatial search capabilities and reduced modal aliasing in the frequency components. Experimental validation on public datasets and the group's experimental platform for railway wagons shows that multi-level convolutional neural networks have higher diagnostic accuracy and faster convergence speeds than traditional models such as LeNet-5, AlexNet, and convolutional neural network. Our research introduces a highly accurate and widely applicable methodology for mechanical equipment fault diagnosis, aligning with the requirements of the "smart" era. [ABSTRACT FROM AUTHOR]

Condition monitoring of railway track geometry using instrumented in-service vehicles has been the subject of extensive research aimed at replacing or enhancing the data provided by dedicated track recording vehicles. Lateral track irregularities present difficulties compared to vertical irregularities due to the lateral clearance between the wheel flanges and the rail head. Wheelsets don't necessarily follow the lateral trajectory of the track. Simulations of a freight wagon with three-piece bogies negotiating both discrete and cyclic lateral track irregularities showed that the resulting lateral displacements were highly dependent on the wavelength of the irregularities. The wheel/rail profiles also had a significant effect whilst the effect of speed was relatively minor. These findings highlight the complexities of identifying exceedances of track geometry standards using only inertial sensors on instrumented freight wagons. [ABSTRACT FROM AUTHOR]

This article presents the results of a study focused on identifying the main causes of the asymmetric (clinodual) wear of composite brake pads on freight wagons. A new scientific approach to determining the clinodual wear of composite brake pads on freight wagons is proposed. It is established that the harmful abrasion of the pad occurs during the movement of the freight train due to an imperfection in the bogie-brake lever transmission. The causes of the non-normative frictional wear of composite brake pads were investigated. This kind of wear leads to the tilting and abutting of the upper end of the brake pads against the rotating wheel during train running. The results of geometric and kinetostatic studies of the "pad–wheel" tribotechnical pair are provided to establish the causes and consequences of the accelerated clinodual frictional wear of composite brake pads on pendulum suspension in the bogies of freight wagons. The conditions of rotation of the wheels during braking "for" and "against" the clockwise direction depending on the direction of the train are considered. A new approach to brake-pad-wear prediction depending on the mileage of wagons under operational conditions is proposed. The research conducted in this study contributes to the development of the mechanical parts of freight-wagon brakes, increasing the efficiency of brake operation and improving the safety of train traffic. [ABSTRACT FROM AUTHOR]

The article presents the results of the study into the dynamic load of the container during its transportation by the train ferry. The peculiarity of the container is that its walls are made of sandwich panels. Such a solution will help to reduce the dynamic loads acting on the container at operating load modes, including when transported by sea as part of combined trains. To determine the dynamic loads acting on the container, a mathematical model was build that took into account the angular displacements around the longitudinal axis of the system "train ferry - flat wagon - container - freight". The calculations were made for the train ferry Geroi Plevny. The mathematical model was solved in MathCad. It was found that the value of acceleration acting on the container of the proposed design during transportation by sea was 4.3% lower than that acting on the container of a typical design. The acceleration value obtained, as a component of the dynamic load, was taken into account to determine the stability coefficient of the container in a typical diagram of its interaction with the flat wagon. The roll angle of the train ferry, at which the stability of the container placed on the flat wagon is ensured, was also calculated. The results of the study will contribute to the database of recommendations for the design of modern container structures and their safe operation in international rail and water traffic. [ABSTRACT FROM AUTHOR]

This article focuses on the assessment of the efficiency of the modernization of railway wagons intended for passenger transport. The modernization of railway wagons is an important step towards ensuring the safer and more efficient operation of railways. However, this modernization is not without risks and, in addition to its many positive effects, it can also bring new challenges in the form of breakdowns and technical problems. Failures in passenger rail vehicles are a challenge facing manufacturers and transport operators, and identifying the relationships between these failures can help to improve the design, manufacture, and maintenance of these vehicles. Passenger rail vehicle failures can vary in nature, whether mechanical, electrical, or inside the vehicle. This paper attempts to provide a comprehensive view of the effectiveness of passenger rail car retrofitting based on the data collected and statistical analyses. The article further focuses on the description of selected rail passenger wagons, describes the analyses of the statistical data using the correlation between the selected rail wagon failures and their significance, in addition to whether the impact of modernization reduces the number of rail wagon failures. The results of this statistical analysis can be used to better understand the impact of modernization on different aspects of passenger transport and will help in making future investment and policy decisions in this area. © 2017 Elsevier Inc. All rights reserved. [ABSTRACT FROM AUTHOR]

Train configurations give rise to a primary wagon pass forcing frequency and their multiples. When any one of these frequencies coincides with the natural frequency of vibration of the bridge, a resonant response can occur. This condition can amplify the dynamic response of the bridge, leading to increased levels of displacement, stresses and acceleration. Increased stress levels on critical bridge structural elements increases the rate at which fatigue damage accumulates. Increased bridge acceleration levels can affect passenger comfort, noise levels, and can also compromise train safety. For older bridges the effects of fatigue, and being able to predict the remaining life, has become a primary concern for bridge engineers. Better understanding of the sensitivity of fatigue damage to the characteristics of the passing train will lead to more accurate remaining life predictions and can also help to identify optimal train speeds for a given train–bridge configuration. In this paper, a mathematical model which enables the dynamic response of railway bridges to be assessed for different train configurations is presented. The model is based on the well established closed from solution of the Euler–Bernoulli Beam (EBB) model, for a series of moving loads, using the inverse Laplace–Carson transform. In this work the methodology is adapted to allow different train configurations to be easily implemented into the formulation in a generalised form. A generalised equation, which captures the primary wagon pass frequency for any train configuration, is developed and verified by presenting the results of the bridge response in the frequency domain. The model, and the accuracy of the equation for predicting the primary wagon pass frequency, is verified using independently obtained measured field train–bridge response data. The main emphasis of this work is to enable the practicing engineer, railway operators and bridge asset owners, to easily and efficiently make an initial assessment of dynamic amplification, and the optimal train speeds, for a given bridge and train configuration. This is visually presented in this work using a Campbell diagram, which shows dynamic amplification and compares this with those calculated based on the design code, across a range of train speeds. The diagram is able to identify train speeds at which a resonance response can occur, and the wagon pass frequency, or its multiples, which are causing the increased dynamic amplification. The model is implemented in Matlab and demonstrated by analysing a range of short- to medium-single span simply supported plate girder railway bridges, typically found on the UK railway network, using the standard BS-5400 train configurations. The model does not consider the effects of the train mass and suspension system as this would require a non-closed form numerical solution of the problem which is not practical for the purposes of an initial assessment of the train–bridge interaction problem. [ABSTRACT FROM AUTHOR]

This article focuses on the assessment of the efficiency of the modernization of railway wagons intended for passenger transport. The modernization of railway wagons is an important step towards ensuring the safer and more efficient operation of railways. However, this modernization is not without risks and, in addition to its many positive effects, it can also bring new challenges in the form of breakdowns and technical problems. Failures in passenger rail vehicles are a challenge facing manufacturers and transport operators, and identifying the relationships between these failures can help to improve the design, manufacture, and maintenance of these vehicles. Passenger rail vehicle failures can vary in nature, whether mechanical, electrical, or inside the vehicle. This paper attempts to provide a comprehensive view of the effectiveness of passenger rail car retrofitting based on the data collected and statistical analyses. The article further focuses on the description of selected rail passenger wagons, describes the analyses of the statistical data using the correlation between the selected rail wagon failures and their significance, in addition to whether the impact of modernization reduces the number of rail wagon failures. The results of this statistical analysis can be used to better understand the impact of modernization on different aspects of passenger transport and will help in making future investment and policy decisions in this area. © 2017 Elsevier Inc. All rights reserved.

The violent goods vibration during curve negotiation is a huge threat to the vehicle running safety. Qualified load restraint assemblies that can significantly suppress the cargo vibration are necessary. This study proposes a novel method for evaluating the essential restraint strength, focusing on the relative motion between cargo and wagon. In the beginning, as a comparison, current methods are used to calculate the necessary stiffness of lashings, which are adopted to restrain the cargo vibration on the wagon. Based on the data of the field test, the accuracy of the established wagon-cargo coupled dynamics model is validated. The loaded wagon model negotiates the curve under different running and loading conditions. The simulation results and analysis demonstrate effective strategies for suppressing the vibration of the cargo and reveal the necessary lashing stiffness. The comparison among the results of different evaluation methods shows that the stability of the cargo can be improved by optimizing the lashing stiffness with the method of dynamics simulations. We hope this study will make a positive contribution to the safety of railway freight transportation. [ABSTRACT FROM AUTHOR]

The article discusses the recent surge in investments in railway infrastructure worldwide and the importance of ensuring the safety and integrity of these infrastructures. It highlights advancements in structural condition monitoring for railway infrastructures, including the integration of artificial intelligence and machine learning algorithms, as well as the use of unmanned aerial vehicles for inspections. The article also provides a summary of 10 specific contributions in the field, covering topics such as rail surface defect detection, overhead contact line monitoring, object detection using computer vision, and digitalization of freight wagons. These advancements contribute to the efficiency, reliability, and sustainability of railway transportation. [Extracted from the article]

This paper will present the evidence for two newly discovered words, gawzag and shagar , meaning "two-horse chariot/mail coach" and "wagon" respectively in the eastern Arabian dialect of Qaṭrāyīth (Syriac for "in Qatari") of the seventh and eighth centuries ce. They reveal the continued local knowledge of wheeled transport in Arabia and possible use long after its supposed disappearance in the Near East between the fourth and sixth centuries according to Richard Bulliet's well-known thesis in his seminal work The Camel and the Wheel (New York: Columbia University Press, 1990). The fact that this vernacular maintained two specific words for two different modes of wheeled transport likely suggests a practical need for them in everyday communication among the inhabitants of the Beth Qaṭraye region (Syriac for "region of the Qataris" in north-eastern Arabia). Moreover, their use in an Arabic dialect reveals that native words were developed for wheeled vehicles in the local language spoken by the inhabitants of the area well before the adoption of markabah as a neologism to mean chariot in nineteenth-century Arabic, according to Michael Macdonald's stimulating article "Wheels in a land of camels" (Arabian Archaeology and Epigraphy 20/2, 2009). Thus, the various rock drawings of two-wheeled carts and chariots in northern Arabia may in fact not only have been known but also used nearby in eastern Arabia, rather than being inaccurate representations reflecting a distant awareness of the existence of chariots elsewhere such as in Mesopotamia and Egypt as had been previously thought. This is a literary, philological. and historical study that aims at presenting newly discovered vocabulary in context for further analysis by linguists and others. [ABSTRACT FROM AUTHOR]

A large amount of vibration energy is dissipated in the secondary suspension systems of railway freight wagons, which can be harvested as renewable power supplies to serve more smart devices for onboard applications. This paper explores the vibration energy harvesting potential of freight wagons and deals with the systematic design issues of energy-regenerative shock absorbers (ERSAs). By considering the ERSA force interaction and realistic track irregularity, a vehicle-track coupled model is established to predict a more accurate vibration response. The parameter sensibility analysis reveals that the operation speed, vehicle load, and track irregularity are the most critical factors that can significantly affect the power generation performance. In addition, vibration energy harvesting potential assessment is conducted on American, German, and Chinese track spectrums and several field-measured freight lines, indicating an average power potential ranging from 33 to 960 W per absorber with a full-loaded freight wagon running at 90 km/h. Finally, a systematic design approach for ERSAs is proposed based on the prior feasibility assessment, a hybrid Grey Wolf Optimization and Particle Swarm Optimization (GWO-PSO) algorithm, and the vehicle-ERSA coupled model. The digital twin of an ERSA has been established and validated by a series of experimental tests. Taking the average power as the objective and setting the suspension vibration velocity, maximum generator rotation velocity, and maximum ERSA force as constraints, the optimized ERSA exhibits an output power of 63 W and 20.22% shock absorption on the secondary suspension. Meanwhile, the GWO-PSO has demonstrated an enhanced exploration ability than the conventional GWO in dealing with the constrained optimization problem of the ERSA design. [ABSTRACT FROM AUTHOR]

The object of the study reported here is the processes of occurrence, perception, and redistribution of loads in the improved structure of the hatch cover in a universal open wagon. In order to reduce the load on the cover of an open wagon hatch, and, accordingly, to improve its strength, it is proposed to improve its design by introducing sandwich components. The thickness of the sheets that form the hatch cover has been determined. The dynamic loading of the hatch cover in the vertical plane was studied. It was found that the accelerations acting on the hatch cover with the proposed improvement are almost 20 % lower than those acting on the typical structure. The basic strength indicators of the hatch cover under the operational modes of its load have been determined. The results of the calculation showed that the maximum stresses in the hatch cover are 22 % lower than permissible ones. In addition, within the framework of the study, the main indicators of the dynamics of the open wagon equipped with the proposed structure of hatch covers were determined. The movement of the open wagon under the condition of movement in an empty state is rated as “good”. At the same time, the maximum accelerations in the center of mass of the supporting structure of an open wagon were 4.6 m/s², and the coefficient of vertical dynamics was about 0.6. Special features of the results within the framework of this study are that the proposed improvement of the hatch cover helps improve its strength by reducing the dynamic load, and not by strengthening the structure. The scope of practical application of the results is the engineering industry, in particular, railroad transport. The conditions for the practical use of the research results are the use of energy-absorbing material in the sandwich-type components that form the hatch cover. The study reported here could contribute to devising recommendations for the construction of components in the structures of modern freight cars, thereby reducing the costs of maintaining them in operation, as well as increasing the profitability of railroad transportation. [ABSTRACT FROM AUTHOR]

The paper highlights the results of determining the strength of the brake pad of a freight wagon under uneven loading in operation. The main reasons for the uneven loading on the pad have been found. A mathematical tool for determining the strength of the pad unevenly loaded has been proposed. In the study, the pad is considered to be a rod system loaded with concentrated forces and bending moments. Sensors have been used in order to detect the load state of the brake pads. These sensors have been defined in the simulation software, and they have been placed on the working surface of the pad in the area of its interaction with the wheel. The operation of these sensors was simulated in the simulation software package. The results of the calculation have shown that the stresses in the pad are about 21.1 MPa; thus, they exceed the permissible values by 29%. Therefore, considering the uneven loading of the pad in operation, the strength of the pad is not ensured. To test the obtained results, the strength of the pad was determined using the finite element method. The Coulomb criterion was used for the calculation. It was found that the maximum stresses in the pad were about 19 MPa. These stresses were 21% higher than permissible values and occurred in the back of the pad. The study has proven that the uneven loading on the brake pad in operation can cause their destruction during braking. This may also cause traffic accidents with freight trains during their movement. The results of this study will contribute to the theoretical developments and recommendations aimed at improving the brake system of a freight wagon and rail traffic safety. It is considered that the tensometric sensors will be applied in future experimental tests for comparison and verification of the achieved results from the simulation computations. [ABSTRACT FROM AUTHOR]

This study proposes a theoretical method for evaluating the "safety against derailment" indicator of a specialized train composition for the transportation of very long rails. A composition of nine wagons, suitable for the transportation of rails with a length of 120 m in three layers, is considered. For the remaining recommended rail lengths, the number of wagons is reduced or increased, with the calculation model being modified depending on the required configuration. When the composition is in a curve with the minimum radius (R = 150 m), the rails bend, and some of them come into contact with the vertical stanchions of the wagon and cause additional lateral forces. These forces are then transferred through the wagon body, central pivot, bogie frame, and wheels and act on the wheel–rail contact points. They could potentially lead to derailment of the train composition. The goal of this study is to determine the additional lateral forces that arise because of the bent rails. For the purposes of this study, the finite element method was used. Based on the displacements of the support points of the rails (caused by the geometry of the curve), the bending line of the elastic load is determined and the forces in the supports are calculated. The resulting forces are considered when determining the derailment safety criterion. The analysis of the results shows that the wagon with fixing blocks is the most at risk of derailment. The front and intermediate wagons have criterion values very close to that of the empty wagon. This shows that the emerging horizontal elastic forces do not significantly influence the derailment process. The obtained results show that the transportation of long rails with specialized train composition can be realized on four layers. This will significantly increase the efficiency of delivering new long rails. [ABSTRACT FROM AUTHOR]

The paper shows the feasibility of building closed-form and fast-to-evaluate surrogate models via supervised kernel-based machine learning regressions behaving as digital twins for computationally expensive multibody simulations. The aforementioned surrogate models are adopted to predict the railway vehicle dynamics safety indexes defined in the international standards, depending on the wheel-rail forces, directly from the results of longitudinal train dynamics simulations. The digital twin models are trained with the outputs of Simpack multibody simulations of a reference freight wagon, to which the in-train forces calculated by an in-house MATLAB longitudinal train dynamics simulator are applied. Two machine learning techniques are considered: the support vector machine and the least-squares support vector machine regressions. Both techniques ensure a good accuracy even with a limited number of training samples. The derivation of the surrogate models can strongly enhance the modelling capabilities of common longitudinal train dynamics simulators, that cannot evaluate the wheel-rail contact forces. At the same time, the method shown in the paper allows to strongly reduce the total computational times, as the evaluation of the closed-form surrogate models allows to effectively estimate the safety indexes with no need for computationally demanding multibody simulations. [ABSTRACT FROM AUTHOR]

The condition monitoring of the health status of lubricating greases used in axle box bearings can be realized by applying well-established electrical or optical measurement principles. Furthermore, some novel methods have been reported that make use of humidity sensors or of dielectric thermoscopy. One of the most important grease condition parameters is the water content of the lubricating grease, as water can degrade grease to the point that it is no longer able to provide suitable lubrication and can also damage the bearing due to corrosion and cavitation. In this study, a new approach for water detection in lubricated wagon components is presented that is based on commercially available humidity sensors. The core element of this sensor system is a robust humidity sensor mounted in the immediate atmosphere of the grease-lubricated wagon axle bearing. In the case of water intake, the humidity of the gaseous atmosphere above the grease increases and can be detected by the customized sensor concept Humidity Sensor in Axle Bearings (HSAB). As this sensor system has to be sufficiently robust, it must be able to withstand environmental impact factors. The most important of these factors are temperature, relative humidity, and mechanical load, like vibrations and shocks, depending on the relevant railway application. To mimic these field effects under controlled laboratory conditions, the "lab-to-field" approach was set up and employed. Of the utmost importance was the installation of a development environment for the sensors that enabled the transfer of laboratory results to the respective rail field application. As a result, the HSAB system shows promise with respect to enhancing the reliability of railway wagons and decreasing maintenance costs, thereby reducing the downtime of railway wagons significantly. [ABSTRACT FROM AUTHOR]

A special case study of a rail transport consist comprised of 11 wagons on three-piece bogies was carried out using advanced multi-body vehicle simulations to evaluate if the safety and stability of the wagons would be compromised by loading 39 continuous welded rails on the wagon decks. Each rail was 139 m long and laterally fastened to the wagon decks. The wagon model components, including a car body, two bolsters, 4 sideframes and 4 wheelsets, were connected by non-linear spring and damping elements. A non-linear coupler was used to connect the adjacent wagon models. A twist simulation for a single wagon model was conducted and the results were compared with experimental data for validation. The lateral stability analysis found that the lowest critical hunting speed was 90 km/h for the empty wagon model, which satisfies the current operational speed range from 0 to 70 km/h. Safety simulations were conducted on the curved track geometry modelled from the actual track alignment and included FRA Class 4 track irregularities. The safety simulation results indicated that the 11-wagon consist performed within the maximum safety criteria limits as stipulated in the AS7509:2017 standard. [ABSTRACT FROM AUTHOR]

The assessment of safety against freight wagons' derailment is a mandatory element of the documents provided to the EU notifying authorities of the entry into service of new freight wagons. The assessment methodology is presented in EN 14363:2019. It is mainly aimed at the experimental measurement of certain parameters, and the data are used to calculate the safety criterion. The practical implementation of the tests is accompanied by many difficulties: finding a track with a proper radius, ensuring free access to the railway infrastructure for a long period of time, waiting for suitable metrological conditions, preparing the curve and the test wagon, etc. These difficulties are well known to the European legislators, and as a solution, they propose a large set of reference wagons that have undergone real tests. It is sufficient to demonstrate that the parameters of the new wagon relate to some of the reference wagon parameters to avoid such a requirement. Proving the "convergence" of the parameters of the new and the reference wagons is a lengthy, complex, and, in many cases, subjective process. To introduce an objective assessment, the authors set themselves the task of developing a theoretical method to assess safety against derailment. [ABSTRACT FROM AUTHOR]