The main objective of this article is to describe the experimental way of verifying the ability of a tank wagon to deal with longitudinal forces in opposite track curves. In the methodology part, the ...measured and assessed quantities are described as well as the testing equipment. Next, the trainset composition used during the measurement is presented. Finally, measured results are presented and compared to the limit values given by UIC leaflet. These results show good quality of design solution of parts of the vehicle and vehicle as a whole.
Over the past 20 years, undergraduate railway engineering education has been on the rise in Brazil. However, a long period without investments in the sector led to the absence of up-to-date material ...in Portuguese to back up the teaching of specific courses in the program. To help bring the program up to speed, this work presents the development of a wagon design support tool, based on the principles of the design methodology process. The proposed tool combines data from the national railway sector with classic tools such as functional modeling and the morphological matrix. As the result, an instrument that directs the student to a more realistic solution for the design possibilities is presented to support wagon design. One of the observed benefits is the focus shift from the search to the analysis of the technical possibilities arising from using the working principles presented.
At the present stage of development of the railway industry it is necessary to introduce new innovative solutions during the design of the flat wagons of articulated type for their structural design. ...To reduce the material consumption of flat wagons, in article was proposed to produce bearing elements of their structures from pipes of a circular cross section. Flat wagon of articulated type was designed on the basis of the developed construction in order to improve the operational efficiency of the wagon. The innovation design of a flat wagon of articulated type from round pipes are presented. The mathematical model of the bearing structure dynamic load of the flat wagon from round pipes in the main operational modes are made. Accelerations which act on the bearing structure of articulated flat wagon under I rated conditions (tension – jump) are presented.
The article covers information from the field of static strength tests of freight wagons, in this case the static strength test was performed on a Zans 95 m3 tank wagon. The introduction of the ...article contains the division and significance of freight wagon tests. Various types of test load in static tests which affect the vehicle structure are also mentioned. Subsequently, the test requirements are written together with the technical parameters of the tested wagon. The next chapter deals with measured quantities and the instruments used for measurement, as well as a schematic sketch of the location of some sensors. The final chapter contains a description of the individual tests, where the procedure of loading, stay, unloading and reading of values for all static tests examined within the article are given. In the conclusion, verbal opinion is added to the summary of measurement results and the wagon construction is evaluated in terms of meeting the required strength conditions. The article contains graphs and tables from the outputs of some measurements.
Railway transportation plays an important role in many disaster relief and other emergency supply chains. Based on the analysis of several recent disaster rescue operations in China, the paper ...proposes a mathematical model for emergency railway wagon scheduling, which considers multiple target stations requiring relief supplies, source stations for providing supplies, and central stations for allocating railway wagons. Under the emergency environment, the aim of the problem is to minimize the weighted time for delivering all the required supplies to the targets. For efficiently solving the problem, we develop a new hybrid biogeography-based optimization (BBO) algorithm, which uses a local ring topology of population to avoid premature convergence, includes the differential evolution (DE) mutation operator to perform effective exploration, and takes some problem-specific mechanisms for fine-tuning the search process and handling the constraints. Computational experiments show that our algorithm is robust and scalable, and outperforms some state-of-the-art heuristic algorithms on a set of problem instances.
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The transport of goods on the Brazilian railway networks has been growing over the last decades, reflecting growth in industries in this segment, including those related to the design of railway ...wagons. The general objective of this paper is to propose a method for designing railway wagons capable of developing the usual wagon models and meeting specific design demands, which can be applied in industrial environments and education. The proposed method combines practices identified in the literature on the design of railway wagons with traditional product development methods. It was structured in three phases: Informational Design, Conceptual Design, and Detail Design. The proposed method was evaluated by wagon manufacturers in Brazil and applied in teaching environments, demonstrating its feasibility. The method proposed for the design of railway wagons presented in this work has a high affinity with the practices adopted by the industry and is easy to apply in the academic environment, helping both in the training of human resources and in the execution of new wagon design projects.
•Failure analysis of parabolic spring belonging to a railway wagon.•The failure occurred in the contact zones between the leaf springs.•Finite element analyses were performed taking into account the ...service conditions.•The Goodman's criterion shows a safety factor of approximately 1, not enough to prevent the fatigue failuren.
This paper describes the study of three fractured parabolic springs belonging to a two-axle wagon suspension system. In order to determine the causes of the failures, a material analysis was performed, followed by a detailed study of the fracture’s surface both visually and using optical and scanning electron microscopy. The observations of fracture surfaces of the three springs revealed that the fractures began in the contact zones between the leaf springs, suggesting a fretting fatigue mechanism. The mechanism of failure of the springs fracture was a fatigue process. The propagation of fatigue cracks is more pronounced and extensive in one of the leaf springs. Finite element analyses were also performed taking into account the service conditions in order to determine the stress and strain distribution along the leaf springs. From the numerical simulations it can be concluded that the maximum stresses occur in two different zones: in the central section of the leaf spring and along the distance to the central section, in the sections where the relationship between the thickness reduction of the leaf spring and the resulting bending moment is most unfavourable. The Goodman's criterion shows a safety factor of approximately 1 and it can be concluded that this value is not enough to prevent the fatigue failure.
This article presents an efficient methodology for the calibration and validation of a numerical model of a freight wagon based on a dynamic test under real operation conditions. The dynamic test ...takes place during a regular journey of the train and involved the installation of on-board accelerometers and LVDTs, whose number and location was conditioned by the space occupied by the goods and constraints associated with loading and unloading the wagon. The data derived from the dynamic test was used for the identification of carbody's modal parameters, namely the frequencies, mode shapes and damping coefficients and to extract accelerations and displacements time-histories. A three-dimensional (3D) FE numerical model of the freight wagon was developed and calibrated using a genetic algorithm. The methodology proves efficiency and robustness in precisely estimating three numerical parameters, besides a significant upgrade in relation to the model before calibration. Model validation involved the comparison between numerically simulated results, based on a vehicle-track dynamic interaction analysis, and the experimental observations. An excellent agreement between experimental and numerical after updating time-histories was obtained, especially for the carbody responses, whose behaviour is governed by lower frequencies (below 3.5 Hz), in which the calibration process was focused.
•The evolution laws of WDD and tread wear are analyzed based on the tracking measured data.•A freight wagons model considering Non-Hertz wheel-rail contact is developed for numical simulation.•The ...influence of WDD with the new profile and worn profiles on tread wear are studied.•The correlation analysis of wheel tread wear and the WDD is conducted based on the field test data.
Wheel wear is a fundamental problem for railway vehicles. The unequal wear rate of the two wheels of a wheelset results in the wheel diameter difference (WDD). The WDD and wheel wear not only affect the dynamic performances of rail vehicles, but also increase the maintenance cost. This paper presents an investigation of the effect of the WDD on tread wear for freight wagons based on extensive field measurements and numerical simulations. The evolution laws of the WDD and tread wear of 4 freight wagons are first analyzed based on the monitoring data in an operation period of 200,000 km. A freight wagon dynamics model considering wheel-rail non-Hertzian contact is then established to study the influence of the WDD on the wheel tread wear of a freight wagon. The correlation analysis of wheel tread wear and the WDD is conducted based on the field test data. The results show that the initial WDD significantly affects the shapes and stress distributions of wheel-rail contact patches. The WDD can lead to the asymmetric wear of the two wheels of a wheelset, which conversely aggravates the WDD in return.
Railway tank wagons are widely used for the transportation of liquid cargo as petroleum products, acids, alcohol etc. During the last years only tank wagons with bogies were manufactured (four axles ...wagons). The prototype of each wagon’s series is tested according with international standards in purpose to validate the design (the project). This paper present the static and dynamic test performed at the body of a four axles tank wagon.
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