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The article discusses issues of simulation modeling of technological processes of repair of rolling stock components. A model of the technological process of repairing a trolley (mod. 18-100) of a gondola car in an ARENA environment is given.

The subject of the study - is a terminal network. The purpose of this study is to develop a set-theoretic model of terminal network. Research methodology bases on set theory, theory of transport systems, General systems theory and the author's methodology of terminalistics. In this study describes of the terminal network, its key elements and its logistics facilities; the factors affecting the composition and configuration of the terminal network. Also this study develops the model of the terminal network as a logistics chain, and its proposed integrated set-theoretic model of the terminal network of the region. A graphic model of the terminal network as a supply chain presents in the study. The task of finding the best option terminal network in this formulation becomes a three-tier and two-stage. The results of the study can be used as mathematical tools in the design, planning, development and evaluation of objects of terminal and warehouse infrastructure of Russian Railways.

The article presents a nonlinear mathematical model of heating a two-layer body with allowance of the finite velocity of heat propagation and the temperature dependence of the properties of materials. A numerical solution of the nonlinear hyperbolic heat conduction problem is obtained for the case when the absorption of the radiation energy is modeled by a volumetric heat source. The implementation of the grid method using a three-layer implicit difference scheme in solving a nonlinear heat conduction problem in a two-layer body with allowance for the relaxation of the heat flux and the conjugation conditions in the case of ideal contact at the interface junction is considered. The described algorithm for calculating the temperature field for high-intensity heating of a coated body, taking into account the dependence of the thermophysical characteristics of materials from temperature, is based on the implementation of the sweep method with iterative correction of the coefficients. Programs are developed and the results of calculating the temperature fields are presented using nonlinear hyperbolic heat conduction equations and the corresponding linear ones taking into account the average integrated thermal and optical characteristics of the materials. Based on a comparison of the results obtained the necessity of taking into account the temperature dependence of the properties of materials during the study of processes of high-intensity heating of bodies.The developed mathematical model on the basis of a system of nonlinear hyperbolic equations can be used to create technological processes using methods for processing the surface of multilayer bodies by laser radiation.

The problem of optimizing train driving modes continues to be relevant for a long time, despite a large number of scientific research and development in this subject area. This is due both to the general complexity of the implementation of the technological process of running the train, and to parametric uncertainty and significant variations in the parameters of the control object itself and the external environment. Well-known methods for calculating energy-optimal train driving modes (calculus of variations, the maximum principle, dynamic programming) and auto-driving systems based on them assume some simplifications of the original problem, and, as a result, implement quasi-optimal control in practice. In this regard, the development of methods for searching for the global extremum of a functional defined on the set of permissible trajectories of a train as a dynamic system is both theoretically and practically a significant task. The aim of the work is to create a computationally efficient metaheuristic algorithm for searching for energy-optimal control as a global extremum of the objective function, the values of which are calculated using a reference model of the control object. The authors have developed a problem-oriented evolutionary algorithm for calculating the optimal control of train movement based on the theory of random search. Its features are the proposed specialized operators of local random search, taking into account the specifics of the control object as a multi-mode system; combined procedures of local and global optimization based on the concept of a multi-island population algorithm with superpopulation, as well as a method of selection (selection) of promising options based on the clustering algorithm. Computational experiments have shown good convergence of the algorithm and repeatability of the calculation results. Based on the solutions obtained, a train running time controller can be implemented that implements asymptotically optimal control.

Resistive heating of the pantograph head due to the flow of traction current through the conductive elements of the upper node, has an uneven distribution along the frame structure and depends on the location of the contact wire on the insert. The aim of the work is to develop a mathematical model for calculating power losses in the pantograph panhead, allowing to estimate its value, taking into account the zigzag of the contact wire during the movement of electric rolling stock. The subject of the study is the pantograph panhead. The paper gives an example of calculating the frame skid of a pantograph equipped with carbon strips. Experimental studies of the current distribution over the shunts of the panhead depending on the position of the contact wire were carried out in February 2021 in the laboratory "Designs of contact networks, power lines and current collection devices" using a complex for testing current collection devices. The calculation of the heating power of the panhead is determined by the Joule-Lenz law. The results of the calculation showed that the maximum heating power is observed when the contact wire is in the middle of the panhead, while the places of the greatest losses located along its edges are above the places where the shunts are attached. The model makes it possible to obtain a functional dependence of the heating value along the panhead. The obtained results of the skid heating power distribution make it possible to supplement the complex model of the thermal state of the pantograph developed at the Omsk State Transport University with the participation of the authors of the article. The versatility of the developed model makes it possible to investigate various zigzags of the contact wire and evaluate the effect on the distribution of traction current along the panhead, depending on the location of the shunts and their number.

The article is devoted to numerical methods for solving nonlinear heat conduction problems with considering for the relaxation of heat flow. A mathematical model is developed on the basis of a non-linear heat equation of the hyperbolic type for calculating the temperature field in an infinitely extended (unlimited) plate. The implementation of the grid method using a three-layer implicit difference scheme for solving the nonlinear hyperbolic heat conduction problem is presented for the case when the absorption of radiation energy is modeled by a volumetric heat source. A numerical solution of the nonlinear heat conduction problem in an unbounded plate is obtained taking into account the relaxation of the heat flow on the basis of the finite difference technique using the sweep method and iterative refinement of the coefficients. A calculation algorithm with a graphical representation of the results of calculating the temperature field in an unbounded plate under the influence of concentrated energy flows is described. A comparison of the results of calculations of temperature fields in mathematical modeling on the basis of the nonlinear hyperbolic heat equation and the corresponding linear model using the mean integral values of thermophysical and optical characteristics is presented. The significant differences obtained between the temperature fields corresponding to the nonlinear and linear problems justify the need to take into account the temperature dependence of the thermophysical characteristics and the absorptivity in the study of high-intensity processes of heating the bodies. The developed nonlinear mathematical model of body heating with allowance for the finite speed of heat distribution and the temperature dependence of the material properties, can be used to select the modes for processing mode bodies with high-intensity energy flows.

Shotcrete lining is one of the most common types of temporary supports in tunnel construction. The influence of shotcrete lining on design calculations of permanent lining is difficult, because there is no method of designing at the present time. This leads to increasing in consumption of materials and labour of construction. The information about the influence of the basic mechanical properties of soils, geometrical size of construction per value of temporary shotcrete lining factor was obtained during research. These data formed the basis for futher development method of designing.

To improve the accuracy of the diagnosis of the technical condition of rolling stock, it is necessary to develop new algorithms for the digital processing of signals coming from sensors at the time of the passage of the axes of wheeled pairs of wagon carts during the uniform movement of the train on the straight section of the railway track. The use of modern mathematical application software packages to model digital-based data processing algorithms reduces the cost and time of developing automated systems to diagnose the technical condition of the rolling stock of railways. To assess the accuracy of the fixation by the magneto-induction sensor of the moment of passage of wheel pairs axly, an asthigmatic model is proposed, allowing to investigate not only the energy properties of the sensor, but also the shape of the output signal, taking into account the real dimensions of its magnetic core. The developed model allows you to classify the pore. The developed model allows to classify the order of astigmatism model magnetoinduction sensor based on a set of discrete virtual sensors

Currently, much attention is paid to the creation of terminal «dry port» for maintenance of traffic node. «Dry port» is one of the possible ways to increase capacity of the transport node. The capacity of transport node depends on the following interrelated elements: infrastructure solutions, technological, technical, organizational, and exogenous. Insufficiency of technical equipment, low level of production culture, informational inconsistency - lead to excessive downtime of vehicles at berths and terminal and warehouse facilities of the port. Technical devices, shunting locomotives, lifting and transport equipment cannot cope with the increasing flow of transportation of containers and cargo, leading to paralysis of the movement of freight flows. The result is the accumulation of cars at the entrances to the transportation hub the formation of «abandoned» trains. The lack of logistics management principles of traffic promotion in the organization of multimodal transport required a modern approach to organization of effective work of the transport node. In this work the effective interaction between various types of transport in the transport node is represented in the form of a set-theoretic model. Considered the elements that contribute to the throughput of dry ports and sea port. The efficiency of technological processes systems of interaction of railway and marine transport in the node depends on the following conditions: the actual time of wagons in transportation must comply with regulatory process time; organization supply wagons in accordance with the processing capabilities of the cargo platforms; ensuring the maximum amount of overload of goods on the «direct option». To implement these conditions it is necessary to organize the interaction of different modes of transport in the transport node together with the terminal «dry port» in the system «terminal - station - port», in which the capacity of the railway component of the transport node is treated comprehensively along with the «dry port». Further technical and technological development of transport nodes is organization of cargo handling outside the port terminal «dry port».

The article presents the results of research of a point magneto-induction sensor based on a mathematical model, which allows you to increase the reliability of automated systems for diagnosing technical condition rolling stock in the course of train movement by improvement the accuracy of the initial information, that is, the moments of fixation passing of wheelset axles over magneto-induction sensors. At the first stage of developing a stigmatic mathematical model the analytical dependence of the value of the magnetic flux in the magnetic core and the output EMF value on resistance of the air gap between the sensor and the wheel crest. At the second stage of development of the mathematical model found time dependence of the magnetic resistance of the air gap between the core of the magneto-induction sensor and the comb wheels of a railway car moving along a straight track at a constant speed. On the basis of application the developed stigmatic model allows evaluating the energy parameters of magneto-induction sensors depending on the properties of modern magnetic materials. The simulation results showed that the MMF value is constant the magnet determines the main parameters of magneto-induction sensors, so the use of modern magnets based on rare earth they allow to eliminate the traditional disadvantage of outdated types of magneto-induction sensors, that is, to reduce their size and weight. The application of the proposed stigmatic model expands the scope of possible solutions to extreme problems for selection and justification parameters of magneto-induction sensors, helps to improve the accuracy of systems for diagnosing the technical condition of the car fleet and traffic safety on railway transport.

The article presents the results of measurements of electricity on active and passive sectioning posts the traction power supply system direct current sections of railways with III and IV path profile type. Basic characteristics of operating modes sectioning posts for the purpose of assessing the amount of electricity transferred and duration of work electricity storage in different modes are considered. The most observed voltage values, volumes of transmitted energy and duration of each case are defined. Choice of theoretical distribution laws, allowing to use the experimental values obtained in further calculations in modeling of operating modes electricity storage is completed.

Analysis of failures bogie side frames of freight cars in the network of JSC «Russian Railways» for the period from 2006 to 2013. Disadvantages of the well-known constructions of trucks of the car of model 18-100. Mathematical modeling of movement of a wheel pair bogie 18-100, set the negative impact of the spread of the values of structural parameters of the chassis of the car on the indicators of its dynamic qualities and driving safety.

The authors consider the question of the limits of applicability of the capacitor method for measuring the real part of the dielectric constant of printed circuit boards and telecommunications cabled rail transport using the example of FR-4 fiberglass laminate and the cable PK-75-4-12 in the frequency range from 10 Hz to 100 MHz. The measurements were carried out at a constant temperature and humidity of a known material. Comparison of the obtained values with the passport data on the material is carried out; a measurement procedure is developed with overlapping frequency ranges by changing the values of the measuring resistors from larger to smaller with increasing frequency of the input signal. It is shown that in the high-frequency region, the measurement accuracy is directly affected by the parasitic inductance of the capacitor sample under study, as well as the active resistance of the leads and plates and its increase due to the skin effect. The article also discusses the ways of accounting and calculating the parasitic elements of a capacitor. One of these ways is to study the characteristics of the elements of the sample at the first proper serial resonance of the capacitor under study.

In the article presents the network model of processes of planning and the accounting of transportations, and also processes of execution of documentation at freight dispatch in the intra republican message of the railroads of Uzbekistan by means of composite document management. Composite document management provides the movements of documents in paper and in electronic medium, and also their composite decisions. The special the automated system (AS) will support processes of electronic document management and to make the reporting in the automated mode. For mathematical modeling of process of document management in this work it is used methods of network planning and management. It is described characteristics of the offered technology of planning and the accounting of transportations, and also execution of carriage documents at freight dispatch in the intra republican. It is applied, the PERT method for calculation of accidental temporary characteristics of works. Temporary characteristics of events are determined by a method of a critical way. Tables with the sequence of works with the indication of optimistic, probabilistic and pessimistic assessment of duration of performance, and also with results of calculations for determination of average time and dispersion are made. The network schedule of works, in compliance of technology of document management by means of which terms of performance of work are evaluated, entering document management process is made. Durations of critical and noncritical ways are determined. The results received in article confirm efficiency of the offered technology of document management. Use of this technology providing filling of documents electronically and fixing with the digital signature (DS), it is expected to lower expenses of time of consignors and the railroad, to increase productivity of works and quality of the provided services, to create the centralized information base.

Today the most part of world commodity and cash flows is concentrated in the Pacific Rim. The strategy of development for the Far East is based on increase in export to Asia-Pacific countries and also growth of volume of foreign investments. In September, 2018 in Vladivostok at the IV East economic forum the VaninoTransUgol company will submit the construction project in seaport Vanino of transport transshipment facility with transshipment capacities to 40 million tons. In 2017 the volume of transfer of freights in Vanino port was 7,2 million tons, the seaport continues to increase the refinery capacities, but the insufficient capacity of infrastructure of railway transport is the limiting element of development of the transport hub. Construction of the new terminal for transfer of coal will demand corresponding development of railway infrastructure of the Vanino transport hub. In the conditions of increase in volumes of transfer of freights, it is necessary to resolve an issue of the extreme number of cars which can be processed in "the railway station-seaport" system. The author has developed the program of imitating modeling which allows to determine the capacity of a railway component of the transport hub at the existing hardware and in the conditions of increase in loading of "the station-the port" system. In this work results of imitating modeling of work of the Vanino transport hub at increase in unloading of coal by 40% up to 280 cars a day are presented. The working park of the Vanino station has made 305 cars and continued to increase, ways of the station have been filled with cars waiting for operations. Two groups of possible ways of increase in capacity of the transport hub - infrastructure and technology solutions are presented. In the conditions of limitation of territorial development, construction of additional railway infrastructure becomes impossible therefore it is possible to increase the capacity of the transport hub due to change of specialization of moorings of port. It will allow to reduce the number of the cars which are on the ways of the station waiting for unloading and to accelerate processing of the rolling stock. After re-equipment of moorings of port, the working park of the Vanino station has made 230 cars and the capacity reserve for reception of an additional traffic volume has appeared. By means of this program of imitating modeling it is necessary to analyse work of key transport hubs of the Far East for definition of the maximum traffic volume at which transport hubs will steadily function, in the optimum mode.