Science and Transport Progress

17-24

Authors: M. M. Biliaiev, M. O. Oladipo

Purpose. The article aims to develop 2D numerical models for the prediction of atmospheric pollution during transportation of coal in the railway car, as well as the ways to protect the environment and the areas near to the mainline from the dust emission due to the air injection installation. Methodology. To solve this problem there were developed numerical models based on the use of the equations of motion of an inviscid incompressible fluid and mass transfer. For the numerical integration of the transport equation of the pollutant the implicit alternating-triangular difference scheme was used. For numerical integration of the 2D equation for the velocity potential the method of total approximation was used. The developed numerical models are the basis of established software package. On the basis of the constructed numerical models it was carried out a computational experiment to assess the level of air pollution when transporting bulk cargo by rail when the railway car has the air injection. Findings. 2D numerical models that belong to the class «diagnostic models» were developed. These models take into account the main physical factors affecting the process of dispersion of dust pollution in the atmosphere during transportation of bulk cargo. The developed numerical models make it possible to calculate the dust loss process, taking into account the use of the air injection of the car. They require a small cost of the computer time during practical realization at the low and medium power machines. There were submitted computational calculations to determine pollutant concentrations and the formation of the zone of pollution near the train with bulk cargo in «microscale» scale taking into account the air curtains. Originality. 2D numerical models taking into account the relevant factors influencing the process of dispersion of pollutants in the atmosphere, and the formation of the zone of pollution during transportation of bulk cargo by rail were created. A way to protect the atmosphere from pollution during the emission of bulk cargoes from the rail car, which is based on the principle of the air injection, was developed. Practical value. The efficient numerical models which can be used in the development of environmental protection measures in the operation of railway transport were considered. The proposed model allows calculating 2D dynamics of wind flow, taking into account the installed air injection, and mass transfer process of pollutants in the atmosphere.

33-47

Authors: O. M. Pshinko, V. V. Skalozub

Purpose. The paper aims to develop rating models and related information technologies designed to resolve the tasks of strategic planning of the administrative and territorial units’ development, as well as the tasks of multi-criteria control of inhomogeneous multiparameter objects operation. Methodology. When solving problems of strategic planning of administrative and territorial development and heterogeneous classes management of objects under control, a set of agreed methods is used. Namely the multi-criteria properties analysis for objects of planning and management, diagnostics of the state parameters, forecasting and management of complex systems of different classes. Their states are estimated by sets of different quality indicators, as well as represented by the individual models of operation process. A new information technology is proposed and created to implement the strategic planning and management tasks. This technology uses the procedures for solving typical tasks, that are implemented in MS SQL Server. Findings. A new approach to develop models of analyze and management of complex systems classes based on the ratings has been proposed. Rating models development for analysis of multicriteria and multiparameter systems has been obtained. The management of these systems is performed on the base of parameters of the current and predicted state by non-uniform distribution of resources. The procedure of sensitivity analysis of the changes in the rating model of inhomogeneous distribution of resources parameters has been developed. The information technology of strategic planning and management of heterogeneous classes of objects based on the rating model has been created. Originality. This article proposes a new approach of the rating indicators’ using as a general model for strategic planning of the development and management of heterogeneous objects that can be characterized by the sets of parameters measured on different scales. At this the control of separate elements is realized by the way of individual mental models construction and application of functioning processes. The procedure for evaluating of the prediction reliability based on multivariate linear extrapolation method was proposed. Practical value. The proposed method of strategic planning of the complex systems’ development based on rating models and developed information technology are representing the complex of automated tools to ensure effective economical and technological control of non-uniform sets of multiparameter objects. The new solutions of typical tasks of strategic planning and development of complex objects management procedure are implemented in the information technology of rating estimation (rating definition, sensitivity analysis, clustering, diagnostics, forecasting, resource allocation, multi-criteria analysis etc.). Application of the proposed information technology can automate the task of analysis and strategic planning of the administrative-territorial complexes. The technology can be used for monitoring, analysis, strategic planning and management of several complex system types simultaneously.

61-68

Authors: S. A. Semenov, E. V. Mikhailov, O. H. Reidemeister

Purpose. The article is aimed to the definition of technical and economic efficiency from the use of wheels of perspective structural scheme in the undercarriage of the rail vehicles (wagon). Methodology. The use efficiency of wheels of promising design scheme by reducing the motion resistance and wear of the wheel flanges is estimated by calculated values of estimated annual economic effect of implementation and payback period of the costs required for the development and implementation of the proposed wheel. Non-recurring costs include the cost associated with conducting research and development work, as well as the additional costs required for the manufacture of wheels of promising design scheme. Findings. In the course of computation and analysis of the economic efficiency from introductions of wheels of promising design concept, carried out on the basis of the initial data for the South-West railway, it was determined the profit which can be obtained by reducing the following operating costs: cost of returning the wheel flange on wheel sets; cost of fuel and energy resources for train traction; the value of the idle of cars in the current uncoupling repair; cost of repairs and current maintenance of rail track. In addition, it can be additionally released a number of cars by reducing their downtime. The calculation of net discounted income is carried out with the following assumptions: calculation period; estimated increase in the cost of wheel sets with wheels of promising constructive scheme compared to the model, the values of net profit for the accounting period, which was calculated by calculating the average value minus the cost of research, development and manufacturing of wheelset park with wheels of new design scheme. For a given billing period, the calculated value of the net discounted income was obtained and the payback period of the project was determined. Originality. The approaches to the perfection of design scheme of wheels, used in running gear of railway vehicles were substantiated. Practical value. The calculation method proposed in this publication allows evaluating the technical and economic feasibility of using the wheels of promising design scheme in the running gears of railway vehicles.

79-87

Authors: O. S. Krasheninin, O. V. Klymenko, O. V. Ponomarenko

Purpose. The research work focuses on forecasting of performance evaluation of the tractive and non-tractive vehicles that will satisfy and meet the needs and requirements of the railway industry, which is constantly evolving. Methodology. Analysis of the technical condition of the existing fleet of rolling stock (tractive and non-tractive) of Ukrainian Railways shows a substantial reduction that occurs in connection with its moral and physical wear and tear, as well as insufficient and limited purchase of new units of the tractive and non-tractive rolling stock in the desired quantity. In this situation there is a necessity of search of the methods for determination of rolling stock technical characteristics. One of such urgent and effective measures is to conduct forecasting of the defining characteristics of the vehicles based on the processes of their reproduction in conditions of limited resources using a continuous exponential function. The function of the growth rate of the projected figure degree for the vehicle determines the logistic characteristic that with unlimited resources has the form of an exponent, and with low ones – that of a line. Findings. The data obtained according to the proposed method allowed determining the expected (future) value, that is the ratio of load to volume of the body for non-tractive rolling stock (gondola cars) and weight-to-power for tractive rolling stock, the degree of forecast reliability and the standard forecast error, which show high prediction accuracy for the completed procedure. As a result, this will allow estimating the required characteristics of vehicles in the forecast year with high accuracy. Originality. The concept of forecasting the characteristics of the vehicles for decision-making on the evaluation of their prospects was proposed. Practical value. The forecasting methodology will reliably determine the technical parameters of tractive and non-tractive rolling stock, which will meet the modern requirements of the railroading, including at the design stage and while upgrading the vehicles.

96-104

Authors: O. M. Darenskiy, Yu. L. Tuley, D. O. Potapov, A. S. Malishevskaya

Purpose. Despite the steady increase in the length of sections of continuous welded rail on concrete sleepers, wooden railway sleepers, as one of the options of under-rail bearings, are still operated on a sufficiently large number of areas, in particular, remain uncontested in the curve of up to 350m radius, as well as on the main ways of subways. The main types of fasteners in the most common types of intermediate rail fastenings for wooden sleepers are track screws and spikes. Since the «wheel-rail» system contact peculiarities existing in track curved sections have a significant impact on the processes of interaction between the railway track and rolling stock, it is necessary in this work to determine the rigidity of the track screws and spikes, which are directly involved in the formation of spatial rigidity of the intermediate rail fastening nodes under the influence of horizontal transverse forces. Methodology. The study of the track screw and spike rigidity was conducted experimentally for the two types of intermediate rail fastenings – D0 and «Metro». To carry out experimental tests, 10 test sites were selected on the roads of the regional branch of «Southern Railway» of «Ukrzaliznytsia», and 8 – in the main routes of KP «Kharkiv Metro». Each of the test sites was in approximately the same operating conditions, but had different values of passed tonnage. Findings. The values of the track screw and spike rigidity were obtained. Originality. The authors first obtained the experimental data on variation in rigidity of track screw and spike, depending on the useful life for the main railways and subway routes. This allows calculation of the horizontal shear forces in track curved sections (particularly in curves of up to 350 m radius), as well as the forecast evaluation of their level change during operation. Practical value. Based on the experimental data, it was found that variation in rigidity of track screw and spike depending on the lifetime is nonlinear. These experiments allow a more rational approach to the issue of determining the optimal design of the intermediate rail fasteners, based on the specific operating conditions, and may also contribute to the development of measures to improve the reliability of the components of intermediate rail fastenings for wooden sleepers.

115-123

Authors: V. V. Netrebko, I. P. Volchok

Purpose. This paper focuses on obtaining the dependencies of the manganese content in the metallic base (Mno) and its interphase distribution coefficient (KPMn) on the cast iron’s chemical composition in the system Fe–C–Cr – Ni –Mn. Methodology. The cast irons containing 1.09…3.91% С, 0.6…5.4 % Mn, 11.43…25.57 % Crand 0.19…3.01 % Ni have been studied. The active experiment design techniques were applied to build a mathematical model of manganese distribution. Cast iron was smelted in the induction furnace with the capacity of 60 kg, with basic lining.Findings.Manganese, being a carbide-forming element, distributed between carbides and the metallic base. With the use of the mathematical statistics methods, regression dependencies of the manganese concentration in the base and its interphase distribution coefficient on the С, Mn, Cr and Ni content in the cast iron were established. The manganese concentration in the base varied from 0.37 % at 1.09 % С, 0.6 % Mn, 11.43 % Cr and 3.01 % Ni to 5.79 % at1.09% С, 5.4 % Mn, 25.57 % Cr and 0.19 % Ni. The minimum value of the interphase distribution coefficient was 0.16 in the cast iron containing 1.09 % С, 0.6 % Mn, 25.57 % Cr and 3.01 % Ni. When the КРMn coefficient values were lower than 1, manganese concentrated predominantly in the metallic base. The maximum value of the КРMn coefficient was 2.48 at 3.91 % С, 0.6 % Mn, 11.43 % Cr and 0.19 % Ni. The manganese distribution pattern was determined by the carbides’ quantity and chromium and carbon ratio that determined the carbide type. The carbides’ composition was formed as a result of carbide-forming elements contention. Originality. Regression dependencies of the manganese content in the base and its interphase distribution coefficient on the cast iron’s chemical composition in the system Fe–C–Cr – Ni –Mn have been obtained. The dependency of the manganese distribution on the carbide forming processes has been established. Practical value. The obtained dependencies allow predicting the manganese content in the metallic base and may be used during the elaboration of the new wear resistant cast irons compositions.

136-157

Authors: V. M. Bohomaz, M. V. Borenko, S. V. Patsanovskyi, O. O. Tkachov

Purpose.One of the main elements of the inclined belt bucket elevators is their drive. To determine the drive power, it is necessary to carry out calculations according to standard methods, which are described in the modern literature. The basic design parameters are the productivity, lifting height, type and properties of the transported material, the angle of inclination. It is necessary to build a parametric dependence of the driving power of the elevator on its design parameters, which takes into account the standard sizes and types of buckets and belts. Methodology. Using the methodology of traction calculation of inclined belt bucket elevator there were built parametric dependences of efforts in specific points of the route of the elevator, as well as the parametric dependences of the drive power of high-speed elevators with deep and shallow buckets on their design parameters and characteristics. Findings. On the basis of constructed parametric dependencies, it was found that the function of changing the value of the elevator’s power from design capacity (at fixed lifting height, type of cargo, belt speed) is piecewise constant and monotonically increasing. It was built a graphical representation of elevator drive power on the angle of its inclination within acceptable limits of change. The resulting relationship is non-linear and monotonically decreasing. In general terms the intervals of project performance values, which provide a constant value of drive power of inclined elevator were defined. As an example of the obtained results it was observed the process of dependence construction of the drive power on design capacity and inclination angle of the elevator for transporting the fine coal. Originality. For the first time there were constructed the parametric dependences of drive power of inclined bucket elevator on its design parameters that take into account the standard sizes and types of buckets and belts. Practical value. Using the constructed dependencies enables relatively quick determination of the approximate value of the drive power of high-speed inclined elevators with deep and shallow buckets at the design stage and high-quality selection of its basic elements in the design of specific characteristics: type of cargo, productivity, lifting height, angle of inclination.

166-174

Authors: D. V. Rudenko

Purpose. The article focuses on investigation of the stress state of a modified in-situ concrete of natural hardening. Methodology. To achieve the aim, the research of the microstructure of the modified cement matrix of concrete, as well as the mechanism of structure formation of modified concrete with natural hardening was conducted; the methods for reliable evaluation of concrete strength were defined. Findings. The development of internal stresses affects the properties of concretedifferently. With an increase in temperature-shrinkage deformations in time and, thus, with increasing structural stresses in the cement sheath around the grains of the filler two opposite processes may develop: zone of plastic flow or cracking. Originality. It was established that the structural features complex of the modified concrete when the load transfer leads to the formation of extensive zones of prefracture which is able to absorb a significant amount of elastic strain energy that provides the design deformation properties of the concrete for special purposes. Ideas about the definition of the criteria of cracking modified concrete, hardening under natural conditions had further development. Practical value. The resulting equations allow to solve the problem about the minimum level of structural stress in monolithic concrete in a saturated large placeholder, as well as to assess the influence of structural stresses on the properties of concrete. In normal concrete with a relatively thin cement sheath at temperature-shrinkage deformations, high tangential and low radial tension occur. In vivo, this stress is higher as a result of higher values of Δε(τ), which is not observed in the modified concrete. In the modified concretes only tangential stresses are the greatest danger to structures. The change of shrinkage stress with time is straightforward. The total temperature-shrinkage deformations have a sawtooth graph. For modified concrete the amplitude is 48…53% less. This will allow solving a number of technological challenges in the construction of monolithic buildings.

22-29

Authors: M. M. Biliaiev, M. O. Oladipo

Purpose. The scientific work is concentrated on development of 3D, 2D numerical models for the prediction of atmospheric pollution during transport of bulk cargo in the railway car. Methodology. To solve this problem numerical models were developed, based on the use of the motion equations of inviscid incompressible fluid and mass transfer, to determine the field of wind velocity near the cars and dispersion of dust in the atmosphere. For the numerical integration of the pollutant transport equation implicit alternating-triangular difference scheme was used. When constructing a difference scheme splitting of the transport equation is carried out that allows us to construct an efficient algorithm for solving a differential problem. Unknown value of the pollutant concentration at every step of splitting is determined by the explicit scheme – the method of point-to-point computation, which provides a simple numerical implementation of splitting equations. For numerical integration of the 3D equation for the velocity potential method of Richardson is applied. For numerical integration of the 2D equation for the velocity potential the method of total approximation is applied. The developed numerical models are the basis of established software package. On the basis of the constructed numerical models a computational experiment to assess the level of air pollution when demolition of coal dust from the gondola car was carried out. Findings. 3D, 2D numerical models that belong to the class «diagnostic models» were developed. These models take into account the main physical factors affecting the process of dust pollution dispersion in the atmosphere during transportation of bulk cargo, but require small costs of the computer time in the practice at the low and medium power machines. These models are used for serial calculations of various situations of scenarios related to issues of environmental protection and pollution intensity diagnostics for different weather conditions. Computational calculations to determine pollutant concentrations and formation of pollution zone near the cars with bulk cargo in «microscale» scale were submitted. Originality. 3D, 2D numerical models were created. They allow taking into account the relevant factors, influencing the process of pollutants dispersion in the atmosphere, and formation of the pollution zone during transport of bulk cargo by rail. Practical value. Efficient numerical models «diagnostic models» for rapid calculation of the atmosphere pollution level during transportation of bulk cargo by rail were considered. Models can be used in the development of environmental protection measures at the operation of rail transport. Proposed model allows calculating 3D, 2D hydrodynamics of wind flow and mass transfer process of pollutants in the atmosphere.

43-53

Authors: I. V. Zhukovytskyy, I. A. Kliushnyk

Purpose. The article considers the process of development and improvement of tachometer data collectors for the data-measuring diesel locomotive hydraulic transmission test system, which will give the possibility of obtaining the source data to conduct further studies of the technical condition of diesel locomotive hydraulic transmission. It is supposed to provide a solution to the problem of development and improvement of tachometer data measuring tools of the previously created data-measuring diesel locomotive hydraulic transmission test system, starting out from the possibility of modification of the existing locomotive hydraulic transmission test-bench at the Dnepropetrovsk Diesel Locomotive Repair Plant «Promteplovoz». Methodology. The researchers proposed in the work a method of modifying the existing tachometer sensor of the automated microprocessor system for the locomotive hydraulic transmission test-bench in the conditions of a diesel locomotive repair plant. It is applicable by substantiating the choice of the required tachometer sensor measuring method, as well as by using the necessary hardware and software to accomplish the goal with the ability to integrate into the data-measuring system for diesel locomotive hydraulic transmission testing. Findings. The available equipment of the locomotive hydraulic transmission test-bench allowed for design of the optical type speed sensor based on the existing sensor D-2MMU-2. The factory testing with the use of a sensor prototype resulted in determination of the required and sufficient sampling time for sensor operating microcontroller. Originality. The available equipment of the locomotive hydraulic transmission test-bench allowed for design of the optical type speed sensor based on the existing sensor D-2MMU-2. We developed the operation algorithms for the microcontroller that processes the signals from this sensor. The sensor was factory-tested. According to the data sample obtained during the tests, we showed the possibility of reducing the sensor information retrieval frequency. Practical value. The designed sensor significantly reduces the cost of development of the diesel locomotive hydraulic transmission test-bench, besides it can be used when developing similar hydraulic transmission test-benches of other wheeled vehicles and the like. The designed sensor has a greater accuracy than that of D-2-2MMU and considerably lower production cost in comparison with current tachometer sensors. The measurement results are input data to perform further studies in order to determine the technical condition of UGP750-1200 hydraulic transmission during the factory post-repair testing.

64-78

Authors: M. A. Arbuzov, O. M. Patlasov, S. O. Tokariev

Purpose. Recently on the Ukrainian railways network more attention is paid to the cases of violations in the maintenance of crossovers, which may lead to deterioration of the train traffic safety conditions. As a rule, such violations occur as a result of inaccuracies during crossover pegging and laying, as well as are the consequence of impact of rolling stock and thermal forces. The appearance of geometrical irregularities can also be triggered by violation of the scheme of layout of concrete sleepers in the crossover turnout curve with intertrack spaces of less than 5.3 m. Therefore, we have decided to analyze the impact of the presence of deviations from the layout scheme of the sleepers and geometric irregularities on the conditions of track and rolling stock interaction based on the results of experimental investigations. It was also decided to establish a connection between the stress-strain states of the track and the presence of short sleepers. Methodology. The effect of deviations from the layout scheme of the sleepers and geometric irregularities on the interaction conditions of track and rolling stock was studied by means of theoretical calculations and experimental research. The experimental research covered the area on the non-public railway tracks that meets the required conditions for scientific and research work on the territory of «Transinvestservice» company. Findings. The distribution of stresses and forces acting on a railway track depending on speed movement of experienced rolling stock was obtained. In addition we obtained the data on the influence of the sleeper geometric parameters on its stress-strain state. Originality. For the first time the paper assessed the impact of rolling stock in the presence of geometrical irregularities and asymmetrically truncated sleepers within the crossover connection part on the stress-strain state of track in this zone. In addition, we compared the results for the area with common and shortened sleepers. Practical value. The obtained experimental data allowed determining that the stress-strain state of the track structure in the crossover turnout curve at rolling stock speeds of up to 40 km/h fulfills the conditions of strength and stability. These results can be used to test mathematical models and theoretical studies on the development of standards for the maintenance of crossovers. The level of the obtained vertical, lateral forces and stresses practically does not depend on the presence of the truncated part of the sleepers, which are stacked in crossovers.

92-100

Authors: S. T. Djabbarov

Purpose. The scientific paper highlights research of aerodynamic pressure and distribution of airflow velocity field along the moving high-speed train. Methodology. The study of velocity field distribution around the moving high-speed train is produced by simulating its movement as axially symmetric body with the ogive-shaped head and tail parts in compressible (acoustic) environment. Findings. The values of the absolute velocity (theoretical) of air flow generated by the body movement is determined (for the case when the body moves at a constant speed (200, 250, 350, 400 km / h) at a certain height from the ground), for the points located at different distances from the axis of the moving body (high-speed train). The calculations results allowed building the graphs of the air flow velocity in the acoustic environment along the moving body at different distances from it. Using the Bernoulli law (pressure change dependences on the flow velocity), the values of the overpressure generated by the air stream from the moving body were determined. Originality. This is the first theoretical study of the aerodynamics of the high-speed train as axially symmetric body with the ogive-shaped head and tail parts in compressible (acoustic) environment, moving with steady speed. The research results allow us to establish the distribution of the excess air flow pressure generated along the moving high-speed train. Practical value. The obtained results allows determining of the following parameters: 1) requirements for physical-mechanical and strength characteristics of the individual elements of the railway infrastructure in the areas of high-speed train movement, subject to aerodynamic pressure; 2) minimum distance from the track safe for people location during high-speed train passage.

114-124

Authors: S. S. Belimenko, V. O. Ishchenko, V. O. Gabrinets

Purpose. Currently, one of the priorities of energy conservation is a cost savings for heating in commercial and residential buildings by the stored thermal energy during the night and its return in the daytime. Economic effect is achieved due to the difference in tariffs for the cost of electricity in the daytime and at night. One of the most common types of devices that allow accumulating and giving the resulting heat are solid heat accumulators. The main purpose of the work: 1) software development for the calculation of the temperature field of a flat solid heat accumulator, working due to the heat energy accumulation in the volume of thermal storage material without phase transition; 2) determination the temperature distribution in its volumes at convective heat transfer. Methodology. To achieve the study objectives a heat transfer theory and Laplace integral transform were used. On its base the problems of determining the temperature fields in the channels of heat accumulators, having different cross-sectional shapes were solved. Findings. Authors have developed the method of calculation and obtained solutions for the determination of temperature fields in channels of the solid heat accumulator in conditions of convective heat transfer. Temperature fields over length and thickness of channels were investigated. Experimental studies on physical models and industrial equipment were conducted. Originality. For the first time the technique of calculating the temperature field in the channels of different cross-section for the solid heat accumulator in the charging and discharging modes was proposed. The calculation results are confirmed by experimental research. Practical value. The proposed technique is used in the design of solid heat accumulators of different power as well as full-scale production of them was organized.

136-151

Authors: O. A. Haivoronskyi

Purpose. The paper assumes to set the basic laws in determining the structure and physical-mechanical properties of wheel steels during arc welding technology and to develop the recommendations for reconstruction of railway wheel wear surfaces that will improve the reliability and safety of traffic in terms of increasing operating loads. Methodology. To achieve this purpose the paper studied 1) the influence of operating loads on structural changes and properties of metal wheels; 2) the impact of arc welding on structural and phase composition and properties of the metal heat-affected zone, its resistance to brittle and slow fracture; 3) the impact of welded metal on the formation of the stress state of the welds and their resistance to formation cracks; 4) wear resistance of built up metal during friction-slip of the «wheel-rail» pair. Findings. The most intense zone of the rolling profile of freight railway wheels during operation is a place of transition from rolling surface to the ridge. Therefore, the wheel building up by welding requires first of all the increased resistance to brittle fracture of metal in this area. It is established that welding in the metal of the wheel heat-affected zone cause formation of the hardened bainite-martensite structures. The minimum metal cooling rate, at which the martensite start forming is 8°C / s (in the range of 600…500°C) when the content of carbon in steel is 0.58% and 2°C/s at 0.65% of carbon. It is shown that to increase resistance to cracking it is necessary to limit the cooling rate to 16.0°C/s when the carbon content is C < 0.60% and to 8.0°C / s when C = 0.60…0.65%. Under these conditions, the metal has rather high ability to mikroplastic deformation without cracking. It was founded that to improve the critical stress intensity factor К1С at brittle fracture it is necessary to provide conditions when welding would result in the built up structure that does not contain upper bainite and the martensite share does not exceed the number of lower bainite (ratio of M/Bn < 1). It is proved that exposure of wheels within 3.5-4.5 hours at 100°C after welding, during their slow cooling improves resistance to brittle fracture of metal heat-affected zone by 1.8-2.3 times. This is due to the removal of diffusion hydrogen from the metal and reduction of the ІІ type stress in the lath volume of bainite and martensite by 1.5. Originality. The author has developed the idea of the structural-phase changes that occur in the metal of railway wheels during arc welding. The relation between the carbon content in steel, cooling rate during welding and resistance to cracking and brittle fracture was found. The authors determined the influence of after-welding wheel cooling conditions on the metal properties. Practical value. Technological recommendations for railway freight wheel building up by welding were developed. Their application will improve quality of the railway wheels built up by welding, reliability and safety of traffic in conditions of growing operating loads.

168-177

Authors: L. A. Muradian

Purpose. The article aims to develop an algorithm and a sequence of description and determination of car reliability to predict certain quantitative indicators of the studied elements, parts and units, or a car as a whole on the basis of probabilistic-physical approach. Methodology. For the calculation of the indicators of reliability, durability and safety of cars the probabilistic-physical method was used, which takes into account the resources consumption inevitable in the operation of cars. The methodology of quantifying the reliability is based on the study of the physical-mechanical and physical-chemical properties and parameters of various elements, with the identification of principles of the aging processes of the elements or parts (with operating time) to determine the analytical dependencies of these processes from the indicators of cars reliability. Findings. On the basis of probabilistic-physical approach it was developed a model to describe and determine the reliability of the cars. At this the method of calculation based on probabilistic-physical model is fundamentally different from all known rigorous probabilistic methods by the fact that it considers a continuous set of states of the elements, parts and systems of the car during continuous time. If there exists or (if it possible to find) the information parameter about the resource consumption of the car element with evaluation of its change speed, and knowing its limit, based on the built car reliability model with the involvement of probabilistic-physical approach, one can predict all the necessary quantitative indicators of reliability of the studied elements, parts and units or a car as a whole. Originality. The methodology of the reliability construction with the use of probabilistic-physical model with DN-distribution was further developed in the article. The specific physical interpretation of the constants of DN-distribution of failures makes it possible to evaluate them according to the results of the study of certain parameters characterizing the technical condition of the car. On the basis of probabilistic-physical approach the algorithm and the sequence of description and determination of cars reliability to predict certain quantitative reliability indicators of the studied elements, parts and units, or a car as a whole were developed. Practical value. The results make it possible to calculate in practice the quantitative indicators of reliability of cars or their individual elements for further prediction of the overall reliability during operation.

15-23

Authors: Ya. V. Bolzhelarskyi, Yu. H. Sobolevska, S. S. Dovganyuk, А. V. Batig

Purpose. The purpose of this work is to determine the energy losses in the shock absorber of the freight car whose wheel-set moves in the derailed state on the track panel depending on the axle load and structural parameters of spring suspension. Methodology. On the basis of spring suspension construction analysis and operating principle of the friction shock absorber of the freight car bogie the authors provide the method for determining the energy absorbed by it. The calculations take the maximum values of the absorber elements displacement and the regulatory values of spring suspension parameters. Findings. The authors obtained the calculated formula for determining the energy absorbed by shock absorber for regulation-set mounting schemes of elastic bogie elements depending on the axial load. The mentioned curves are parabolic. Originality. The work examines the crash mode of the wheel-set movement on the track panels after its derailment. It is shown that the energy dissipation in the shock absorbers is the reason for increase in resistance to rolling stock movement. The formulas for calculating the amount of energy dissipated in the shock absorber with a maximum displacement of its elements are derived. This energy depends on the axle load and structural parameters of spring suspension. Practical value. The proposed method allows setting the value of the additional resistance to motion that occurs in crash mode which makes it possible to increase the accuracy of traction calculations.

37-46

Authors: D. M. Kozachenko, S. V. Grevtsov, T. V. Bolvanovska

Purpose. The research aims development of methods for calculating the estimated capacity humps for the loss conditions of brake power retarders. Methodology. The operation of humps is connected with large number of random factors, such as the characteristics of cuts, environmental conditions, the value of braking power implemented by retardants and others. In this regard, to research the set tasks the methods of simulation modeling and mathematical statistics are used. Determination of speed and motion time of cuts on the routes is carried out on the basis of rolling down modeling of their rolling down from the humps. Findings. If the brake power of retarders of the rolling down part of humps is not enough to stop the cuts, it should be provided the intervals during break-up to release the rolling routes from the preliminary cuts. The dependencies allowing to set the duration of these intervals were determined using the methods of the probability theory If the brake power of retarders at the rolling down part of humps and at the classification tracks is not enough to meet the requirements of the aimed regulation of the cuts rolling speed, it is necessary the use the additional brake shoes. The work develops the methods that on the basis of simulation modeling of the humping process allow one to set the desired value of the break-up duration increase. They ensure the traffic safety at the given number of car motion speed regulators. Originality. Authors firstly proposed the improved methods for determining the estimated capacity of humps. Unlike the existing ones, allow taking into account the technological limitations caused by the requirements of the humping process safety and can be used to assess the performance of the humps in the conditions of parametric failures of the retarders. Practical value. The use of the proposed methods allows assessing the influence of the retarders’ disrepair on the performance degradation of humps for the existing volumes of work.

55-62

Authors: V. O. Polyakov, M. M. Khachapuridze

Purpose. Traction force implementation (TFI) by the motor of magnetic levitation train (MLT) occurs in the process of electric-to-kinetic energy transformation at interaction of inductor and armature magnetic fields. Ac-cordingly, the aim of this study is to obtain a correct description of such energy transformation. Methodology. At the present stage, a mathematical and, in particular, computer simulation is the main and most universal tool for analysis and synthesis of processes and systems. At the same time, radical advantages of this tool make the precision of selection of a particular research methodology even more important. It is especially important for such a large and complex system as MLT. Therefore the special attention in the work is given to the rationale for choosing the research paradigm selective features. Findings. The analysis results of existing TFI process model versions indicate that each of them has both advantages and disadvantages. Therefore, one of the main results of this study was the creation of a mathematical model for such process that would preserve the advantages of previous versions, but would be free from their disadvantages. The work provides rationale for application (for the purposes of research of train motor TFI) of the integrative holistic paradigm, which assimilates the advantages of the theory of electric circuit and magnetic field. Originality. The priority of creation of such paradigm and corresponding version of FI model constitute the originality of the research. Practical value. The main manifestation of practical value of this research in the opportunity, in case of use of its results, for significant increase in efficiency of MLT dynamic studies, on the condition that their generalized costs will not rise.

71-80

Authors: M. P. Nastechik, R. V. Marcul

Purpose. To date, there is a tendency concerning complete transition of main tracks to concrete sleepers. The reason for this is the lack of wooden sleepers, their high cost and low lifetime that in the curved track sections with the radius R≤300 m is only 5-7 years (this is 5 times less than the lifetime of concrete sleepers). After introduction of fastening type СКД65-Б it is possible to smoothly expand the track from 0 mm to 14 mm, and to narrow from 0 mm to 28 mm with a step 1 mm. At the increased train load on the track of 75…130 kN in a horizontal plane, which is characteristic for the curved track sections R≤300 m the violations in terms of track geometry often take place. It results in the frequent surfacings, periodicity of which at the fastening type СКД65-Б is absent for today. Therefore the purpose of the article is the development of recommendations concerning maintenance of the track in a plan with the fastening type СКД65-Б. Methodology. The methodology of research is based on the comparative estimation of influence of the track width change dynamics on the periodicity of surfacing in the plan in the case of the use of fastening type ДО and СКД65-Б. Findings. With the help of the developed research methodology it was established that the first implementation of adjusting the track width at fastening type ДО is necessary to be executed on the 14th month and at the fastening type СКД65-Б on the 28th month of operation. Originality. It was first described and expressed using the empiric dependence the process of the track width change, and periodicity of its adjusting in the case of the fastening type СКД65-Б use. Practical value. The developed recommendations will allow in time to execute adjusting of the track width at fastening type СКД65-Б and ensuring the safety of train motion at the same time.

96-115

Authors: E. V. Parusov, А. B. Sychkov, S. I. Gubenko, I. N. Chuiko, L. V. Sahura

Purpose. To determine the universal empirical relationships that allow for operational calculation of scale mass and decarbonized layer depth based on the parameters of the technological process for rolled coil steel production. Methodology. The research is carried out on the industrial batches of the rolled steel of SAE 1006 and SAE 1065 grades. Scale removability was determined in accordance with the procedure of «Bekaert» company by the specifi-cations: GA-03-16, GA-03-18, GS-03-02, GS-06-01. The depth of decarbonized layer was identified in accordance with GOST 1763-68 (M method). Findings. Analysis of experimental data allowed us to determine the rational temperature of coil formation of the investigated steel grades, which provide the best possible removal of scale from the metal surface, a minimal amount of scale, as well as compliance of the metal surface color with the require-ments of European consumers. Originality. The work allowed establishing correlation of the basic quality indicators of the rolled coil high carbon steel (scale mass, depth of decarbonized layer and inter-laminar distance in pearlite) with one of the main parameters (coil formation temperature) of the deformation and heat treatment mode. The re-sulting regression equations, without metallographic analysis, can be used to determine, with a minimum error, the quantitative values of the total scale mass, depth of decarbonized layer and the average inter-lamellar distance in pearlite of the rolled coil high carbon steel. Practical value. Based on the specifications of «Bekaert» company (GA-03-16, GA-03-18, GS-03-02 and GS-06-01) the method of testing descaling by mechanical means from the surface of the rolled coil steel of low- and high-carbon steel grades was developed and approved in the environment of PJSC «ArcelorMittal Kryvyi Rih». The work resulted in development of the rapid method for determination of total and remaining scale mass on the rolled coil steel surface of low- and high-carbon steel grades depending on the temperature coil formation. There was obtained the patent of Ukraine for invention no. 91760 «The method for de termining the total and remaining amount of scale on the rolled steel surface».

125-133

Authors: J. Kalivoda, P. Bauer

Purpose. Although the advancements in computer simulation technology have paved way to provide very reliable simulation results, track tests still play an essential role during the process of development and homologation of any railway vehicle. On the other hand, track tests depend on weather conditions, are difficult to organize and are not suitable for testing vehicles in critical situations. On a roller rig, the tested vehicle is longitudinally fixed and a track is replaced by rotating rollers. Such device offer testing of railway vehicle running dynamics in safe and stable laboratory environment. The purpose of an article is to investigate and describe roller rig testing at the Czech technical university in Prague (CTU). Methodology. In the paper it is shown the history of development of the scaled CTU roller rig from the earlier stages until the current projects for which the CTU roller rig is utilized for. The current design of the experimental bogie, roller rig, sensors instrumentation and types of experiments conducted at the CTU roller rig are described in more detail. Findings. Although the differences in vehicle behaviour on a track and a scaled model on a roller rig are not negligible, scaled roller rig experiments are found as a relatively inexpensive way for verification and demonstration of computer simulations results. They are especially useful for verification of multibody system simulations (MBS) of entirely new running gear concepts. Originality. The CTU roller rig is currently used for the experiments with active controlled wheelset guidance. According to simulations results published in many papers such systems offer, in principle, better performance compared to conventional passive vehicles. However, utilization and testing of active controlled wheelset guidance on vehicles is still rare. CTU roller rig serves as a tool to verify computer simulations and demonstrate benefits of active wheelset guidance. Practical value. Experiments conducted on the CTU roller rig confirm the possibility to significantly influence railway vehicle running dynamics by actively controlled wheelset guidance. Such concept could be regarded as a possible and likely approach for the design of future railway vehicles running gears.

141-150

Authors: O. M. Gibalenko

Purpose. The paper highlights development the principles of robust (sustainable) design in the constructive decisions substantiation of the primary and secondary protection for steel structures based on the control of corrosion risk level of construction projects, structural adaptation, and technological rationality when operating in conditions of corrosive environments impact. Methodology. The computational methods for assessing the reliability and structural safety were used and developed by authors. In the base of methods there is a construction of information-analytical databases attributive parameters on the corrosion state of metal construction for the improvement and control measures the primary and secondary corrosion protection. Findings. The basis was proposed for setting and implementing management tasks exploitation service life of buildings and structures in corrosive environments. It achieved by improving the quality and reliability of primary and secondary protection steel structures considering corrosion level hazards management of process safety within a specified period of Builder-structures service. Originality. The principles of robust design of corrosion protection, taking into account the established reliability and constructive security with combined metal structures under corrosive environments based on the methodology of limit states of structures (taking into account the level of danger of corrosion) were developed. The metering method confirmation of conformity corrosion protection measures for reserving a workable and tasks of the service life composite structures and their protective coatings was used. Practical value. The substantiation methodology of the design solutions and assessment of their conformity upon corrosion risks indicators of construction projects was developed. Technical solutions providing the level reduction of risk emergency situations were realized.

161-168

Authors: V. D. Petrenko, O. L. Tiutkin, I. O. Sviatko

Purpose. The aim of this work is to identify dependencies and options to strengthen the roadbed and a weak base by grouting piles. Analysis of software package SCAD to assess the effect of the selected option of strengthening the construction of spatial subgrade models. Methodology. In this paper the method of calculation of the soil mass in the software package SCAD is considered, which is a universal accounting system of finite-element analysis of structures and is focused on solving problems of designing buildings and structures rather complex structure. The finite element method is among the most modern and effective methods for the calculation of structures for various purposes. In the simulation, we get a complete picture of the stress-strain state of the study area, as well as the value of the limit load, rainfall, and so on. The spatial model based on the finite element volume, to better address the real characteristics of the soil mass, meets all the geometric characteristics of size and natural subgrade and the top structure the path that has been adopted in Ukraine. Findings. It was found that the most effective option to strengthen the roadbed, when applying grouting piles at the base of the subgrade and body, is to strengthen the five piles. At the same time there is even strengthen the soil mass at the level of 25 … 30% of the entire depth. However, even with the strengthening of the only two piles at the base of the effect of the strengthening of 14.1%. Established equation is linear and describes the decrease in strain. Taking into account the results of the research can be concluded that the consolidation is proportional to the depth with any number of piles. The dependence of the strain on the number of piles adheres to a polynomial function. Strengthening the bases of the subgrade and body depth also occurs in proportion with any number of piles. Originality. Design scheme generation algorithm for the calculation of the subgrade on a weak basis by finite element method was determined. The selection of strength characteristics of soils and the design parameters for use during the numerical simulation was completed. Load process simulation of the system by rolling stock was grounded. Practical value. Analysis of stress-strain state of «weak base-subgrade» allows you to see the basic laws work the soil and take the necessary measures to enhance the cross-section profile of jet-grouting elements.

20-27

Authors: A. Bialon, D. Adamski, Ju. Furman

Purpose. Axle counters are more and more often applied in train detection systems. The wheel sensor is a main part of each axle counter system. In parallel, more and more complex railway vehicles, especially traction ones, are a potential source of interferences influencing the operation of these train detection systems. It is the reason to verify the electromagnetic compatibility (EMC) between the signalling equipment, particularly train detection systems and new vehicles in the process of obtaining the permission for their exploitation. The measurement of interfering magnetic fields generated by vehicles is one of tests to be carried out. Methodology. For the simplification and unification purpose of the applied interference test methods the EN 50238 standard and TS 50238-3 technical specification were developed. The specification defines unified testing procedures. However, it is necessary to verify if it may replace different testing methods used in particular European states. It is the goal of the European research project financed from the TEN-T network resources. Findings and originality. This project is part of the larger project of facilitation and speeding up the ERTMS system deployment. One of nine measurement campaigns planned in the frame of this project was conducted in Poland by Railway Research Institute.

41-48

Authors: M. Kycko

Purpose. The publication presents the importance and influence of railway traffic control system documentation on its safety. Furthermore, it presents certain selected issues of formal and semi-formal descriptions. Methodology. Development of correct and complete descriptions of the informal, semi-formal and formal becomes important in terms of safety requirements. Background documentation and forms of command-control and signaling system description are the base documents of safety proof. It seems necessary to implement the analysis of the design, manufacture process and operation of safety-related equipment into the work of the Polish railways. Firstly it is applied to traffic control devices. Findings. This publication also shows the importance of risk analysis, which is essential when deciding on the implementation of signaling systems to operate, which are required both in the regulations and making rational decisions about the implementation of the systems. Originality. The presented a problem changes the approach to certain data and makes us aware of their validity. Practical value. The presented problems can help understand certain legal requirements.

49-59

Authors: Yu. V. Zelenko, L. O. Neduzha, A. O. Shvets

Purpose.The success of the traffic on the railways of Ukraine depends on the number and the operational fleet of electric locomotives. Today, the locomotive depot exploit physically and morally outdated locomotives that have low reliability. Modernization of electric locomotives is not economically justified. The aim of this study is to improve the safety of the traction rolling stock by the frequency analysis of dynamical systems, which allows conducting the calculation of the natural (of resonant) frequencies of the design and related forms of vibrations.Methodology.The study was conducted by methods of analytical mechanics and mathematical modeling of operating loads of freight locomotive when driving at different speeds on the straight and curved track sections. The theoretical value of the work is the technique of choice of constructive schemes and rational parameters of perspective electric locomotive taking into account the electric inertia ratios and stiffness coefficients of Lagrange second-order equations.Findings. The problems of theoretical research and the development of a mathematical model of the spatial electric vibrations are solved. The theoretical studies of the effect of inertia ratios and stiffness coefficients on the dynamic values and the parameter values of electric locomotive undercarriages are presented.Originality.The set of developed regulations and obtained results is a practical solution to selecting rational parameters of bogies of the freight mainline locomotive for railways of Ukraine. A concept of choice of constructive scheme and rational parameters of perspective locomotive is formulated. It is developed the method of calculation of spatial electric locomotive oscillations to determine its dynamic performance. The software complex for processing the data of experimental studies of dynamic parameters of electric locomotive and comparing the results of the theoretical calculations with the data of full-scale tests is implemented.Practicalvalue.The theoretical study allows objectively assessing the impact of the partial frequency of electric locomotive elements on both the rational parameters of its underframe, and the performance and physiological condition of the locomotive crew. Thus, the practical value of the whole complex of theoretical research was to develop an algorithm and program, choosing rational parameters and design scheme of electric locomotive running gear. Using a software package for the study of spatial fluctuations of electric locomotive made it possible to evaluate the dynamic performance of the electric locomotive underframe with sufficient accuracy for practical problems.

97-107

Authors: O. M. Pshinko, V. H. Kuznetsov, D. K. Yatsenko, V. O. Gabrinets

Purpose. The paper analyses the possibility and terms of increasing the efficiency of heating and ventilation systems of public buildings at the present stage of development and the specific climatic conditions of Ukraine. The main purpose is to develop specific measures for public buildings, which will lead to a significant reduction in energy costs for heating and air conditioning system. The example is similar system of DNURT compact campus, which is heated with its own autonomous boiler that uses natural gas. Methodology. The statistical heat loss analysis for the last 5 years allows defining the types and calculating the heat loss values for specific conditions. These losses are compared with those in the world practice and based on the comparison and analysis of the current system there are offered the ways to reduce the heat loss values through the use of various technical and organizational methods.The paper also proposes involvement for this purpose of secondary and alternative energy sources. The secondary energy resources include the heat that is emitted by people and that coming out with the air during ventilation of buildings. The renewable sources include solar and geothermal energy. To enhance the heat transfer medium temperature capacity it is proposed to use the heat pumps. Findings. The maximum possible use of the proposed measures and implementation of rational schematic and engineering solutions for heat and hot water supply systems cam reduce the energy loss for heating and hot water by 30-35%. Originality. The paper for the first time proposed the use of new integrated approaches to maintain the desired heat balance in the winter period, as well as the new schematic solutions for heating and ventilation systems, both in winter and in summer, based on the use of heat pumps and secondary energy resources. Practical value. The introduction of the proposed schematic solutions and approaches demand relatively small capital investments and do not require significant reconstruction of already installed systems.

120-129

Authors: L. V. Trykoz, I. V. Bahiiants

Purpose. The article deals with the insulation resistance of the track circuit as one of the parameters that affect the operating performance of the railway transport. To reduce the influence of the insulation resistance on the operation modes of the track circuits and the performance indicators of railway transport it is assumed to study the influence of crushed stone treatment on the value of dielectric permeability of the ballast bed. Methodology. The influence of material type for the surface treatment of crushed stone on the value of the dielectric permeability was assessed on the basis of the physical nature determination of the relative dielectric permeability. Determination of the relative dielectric permeability of granular media can only be indirect, as a consequence of incomplete adjoining of crushed stone grains and uncertainty of the pore volume. Thus, the calculations were performed by comparing the measured capacity for a medium with the known with measured medium capacity, for which it is necessary to define. That is, the more the measured capacity is changed, the more changes the dielectric permeability of the medium. Findings. Sleepers and ballast significantly change their electrical conductivity depending on the presence of moisture, ambient temperature changes, the presence of pollutants and other factors. The article analyzes the existing models to describe the dielectric properties of such systems. It has been established that coating the crushed stone ballast with organic substances influences the value of its relative dielectric permeability. The greatest effect of reducing this value is observed for the coatings based on rosin mixture and silicone. Originality. Authors proposed original method of dielectric properties increase of the permanent way by grains’ coating with nonwettable substances, on the surface of which is not formed a water film. Practical value. The article shows the possibility of minimizing the negative influence of reducing the isolation with maximum its elimination. It is proposed the solution of actual problem by eliminating the influence of insulation resistance on the modes of track circuits operation, which will eliminate the part of causes of the failure of signaling devices and reduce the number of cases of «false business».

138-147

Authors: V. V. Netrebko

Purpose. This article analyzes the formation conditions, transformation and systematization of carbide phases formed in the system Fe – C – Cr.Methodology. Conversion of the elements’ content from mass % into atomic % and vice versa was carried out using standard methods. In order to identify the structural components and etching of carbides the Marble etchant was applied. Cast iron 300Х28Н2 in cast state without heat treatment and after isothermal holding at 1050 °С during 4.5 hours with further normalization was studied. Findings. Isothermal state diagrams of the Fe–C–Cr system don’t take into account the existence of Fe7C3 carbide alloyed with chromium. But there is evidence of the existence of chromic carbides containing 24…37.6 % of chromium, which exceeds its maximum solubility in cementite, but is not enough to form Cr7C3.Analysis of chromium and carbon content in carbide phases which are formed in high-chromium cast irons allowed to substantiate the formation of Fe7С3 carbide, stabilized with chromium. Assessment of the carbide phase by chemical composition in mass percent doesn’t allow determining the main carbide-forming element with sufficient accuracy. It is shown that with the increase of chromium concentration in carbides, mass content of carbon increases. Areas of existence of carbides of different types depending on carbon and chromium content in them were determined. Maximum content of chromium in the carbide (Fe, Cr)7C3 is 44.0 %. Allocation of alloyed cementite occurs on the present carbides Ме7C3 or grain boundaries, and with the increase of cooling rate – in the grain volume. This process is thermodynamically inevitable due to the decrease of carbon solubility in ferrite or austenite at temperatures when chromium diffusion is impeded, and only carbon diffusion is possible. At high chromium concentrations carbide Fe7C3 is formed, which transforms into Cr7C3 carbide as chromium diffusion takes place. Originality. The model of laminated structure of carbides, formed out of the liquid phase in the system Fe–C–Cr was built. The identification of the carbide phase based on the elements’ concentration in atomic percent was suggested. The model of the change of carbon content in carbides of different types depending on chromium concentration was built. Practical value. The suggested system of carbide classification and their structural model allows optimizing the cast irons’ composition and heat treatment modes for different exploitation conditions.

161-170

Authors: L. M. Bondarenko, M. O. Babyak, S. O. Yakovlev, S. O. Istin, G. Yu. Moskalev

Purpose. About one of the causes of slip rolling is known from the second half of the 19th century, it was believed that the slip resistance appears at the place of contact due to different speeds on the arc of contact. Only in the mid-20th century it was proved that this resistance is negligible in rolling resistance. However (for some unknown reason) it is ignored the fact that in practice in rolling bearings may rotate both the inner ring with a stationary outer one, and vice versa almost in equal relations. It is not taken into account the fact that the ball or roller in the rolling bearings runs the different distance along the roller path of the outer and inner bearing cages in one revolution. This fact is not taken into account in determining the calculated values for the friction coefficient of a rolling bearing reduced to the shaft. Therefore, the aim of this work is to determine the influence of path length on the track riding the outer and inner race of the bearing on the determination of the calculated value of the coefficient of friction of rolling bearings is given to the shaft. Methodology. The solution technique is based on the theory of plane motion of a rigid body, the theory of Hertzian contact deformation and the analytical dependencies for determination of coefficient of rolling friction. Findings. The obtained dependences on determination of rolling resistance of the balls or rollers along the bearing tracks of inner and outer bearing cages as well as path difference metering of the rolling on them allows to analytically obtain the rolling resistance and slipping for any size of bearings and different devices of bearing units. It is also possible at the design stage of rolling nodes to handle not only the design but also the content of the node. Originality. Using the analytical dependences for determination of the rolling resistance of bodies at point and line contacts, and also account for the difference in the path of the rolling ball or roller on the outer and inner cages of the bearing one can more accurately find the rolling resistance in the bearings. Practical value. The obtained dependences allow designing the bearing units with minimal energy consumption.

181-190

Authors: A. D. Malyi, T. V. Ulchenko, A. S. Shcherbak, Yu. Ya. Popudniak, T. V. Starosolskaya

Purpose. Study of geometric transformations. We will consider the so-called point transformations of space. Methodology. The most important are one-to-one transformations. They allow exploring and studying the properties of the transformed object using the properties of the original object (line, surface and figure) and the properties of the transformation. Cremona transformations occupy a special place in the set of one-to-one nonlinear transformations. Construction of one-parameter (stratifiable) transformations is carried out as one-parameter set of plane transformations, both linear and non-linear ones. The plane, in which the specific transformation is prescribed, moves in space by a certain law forming a one-parameter set of planes. The set of such plane transformations makes up the space transformation. Findings. The designed graphics algorithms and the established transformation equations allow building the visual images of transformed surfaces and conducting their research by analytical geometry methods. Originality. By completing elementary algebraic transformations of this equation, we obtain the cissoids equation. If the plane is continuously moved parallel to itself, it results in occurrence of surface, whose carcass will be the set of cissoids and the set of front-projecting lines. Practical value. The considered set of stratifiable algebraic transformations gives an effective means for exploring new curves and surfaces obtained by transforming the known algebraic lines and surfaces. These graphic algorithms allow graphically depicting the transformed lines and surfaces. The considered procedure of drawing up analytical formulas of specific transformations allows us to study the transformed surfaces and lines using the methods of analytic geometry. The above transformations can be of arbitrary high order, which is especially important during the design of complex technical surfaces such as aircraft components, parts of water and gas turbines, supports of the structures subject to strong flow of liquid, etc. Space modelling issues, including the building of graphic plane models of space, are relevant both in theoretical terms and in terms of application of the non-linear surfaces investigated on their basis for constructing the technical forms of parts and aggregates of construction machine movable elements, the middle surfaces of shells, the surfaces of turbulent blade, etc.

16-24

Authors: M. M. Biliaiev, S. G. Tsygankova

Purpose. The article highlights the question about creation the complex numerical models in order to calculate the ions concentration fields in premises of various purpose and in work areas. Developed complex should take into account the main physical factors influencing the formation of the concentration field of ions, that is, aerodynamics of air jets in the room, presence of furniture, equipment, placement of ventilation holes, ventilation mode, location of ionization sources, transfer of ions under the electric field effect, other factors, determining the intensity and shape of the field of concentration of ions. In addition, complex of numerical models has to ensure conducting of the express calculation of the ions concentration in the premises, allowing quick sorting of possible variants and enabling «enlarged» evaluation of air ions concentration in the premises. Methodology. The complex numerical models to calculate air ion regime in the premises is developed. CFD numerical model is based on the use of aerodynamics, electrostatics and mass transfer equations, and takes into account the effect of air flows caused by the ventilation operation, diffusion, electric field effects, as well as the interaction of different polarities ions with each other and with the dust particles. The proposed balance model for computation of air ion regime indoors allows operative calculating the ions concentration field considering pulsed operation of the ionizer. Findings. The calculated data are received, on the basis of which one can estimate the ions concentration anywhere in the premises with artificial air ionization. An example of calculating the negative ions concentration on the basis of the CFD numerical model in the premises with reengineering transformations is given. On the basis of the developed balance model the air ions concentration in the room volume was calculated. Originality. Results of the air ion regime computation in premise, which is based on numerical 2D CFD model and balance model, are presented. Practical value. A numerical CFD model and balance model for the computation of air ion regime allow calculating the ions concentration in the premises in the conditions of artificial air ionization taking into account the main physical factors determining the formation of ions concentration fields.

36-46

Authors: L. V. Martseniuk, O. V. Chornovil, K. V. Belaya, A. O. Udovychenko, Anoop Kumar Sharma

Purpose. The insurance market of Ukraine is still interesting for foreign investors. However, there is a range of negative factors. They are: 1) the old regulatory framework, public access and transparency of the insurance market for population; 2) low profitability of certain types of insurance; 3) low competitiveness of the insurance companies in comparison with commercial banks in attraction drive of free funds of legal entities and individuals; 4) insufficient state regulation and control does not allow the insurance market to develop effectively. Therefore, the purpose of the article is to analyze and identify the causes that hinder the development of insurance business in Ukraine, as well as to determine the directions of insurance market development. Methodology. To achieve this purpose the article determines the total number of insurance companies, composes the gross payment rating of the largest of them, presents the dynamics of net insurance premiums for basic insurance. This analysis allows you to identify problematic issues and activities of the insurance market. Findings. The analysis of the article revealed a number of factors that prevent successful development of insurance in Ukraine. The authors suggest priority areas for improving the situation in the insurance market. It was found that the main tasks of the development of insurance are: 1) legal framework reform; 2) improving competitiveness, investment attractiveness of the insurance companies; 3) development of modern infrastructure of the insurance market; 4) expanding the range of services and their compliance with international standards; 5) personnel development; 6) improvement of insurance activity licensing; 7) building of culture and public trust. At the same time the increase in the population solvency, economic and political stability in the country will contribute to the stabilization and intensive development of the insurance market. Originality. The article firstly developed a scientific approach to the determination of the system of factors, which the modern insurance market should correspond to. Рractical value. The solution of the presented problems with the help of the measures proposed by the authors will help the insurance market to develop successfully. And this, in its turn, will contribute to the stabilization of the national economy, because the insurance market is its integral segment.

61-69

Authors: V. A. Lakhno, V. M. Sobchenko

Purpose. This scientific work considers the further development of mathematical models and algorithms for automatic decision support for dispatching management of the city passenger traffic. Methodology. Systems of dispatching management for the city passenger transport are to provide the carrying out of the routes according schedules with minimal deviations from the planned ones through the using of appropriate control actions. The systems’ algorithm focuses on the selection of control actions that compensate the disturbances. It is proposed to use the index of the waiting time minimum for passengers of buses and taxis at stops as a criterion for evaluating of dispatching control systems work. Findings. Based on the conducted analysis of the research within the existing theory of traffic flow of vehicles, it was proposed the model for the system of dispatching management for urban passenger moving units considering the effect of the most important stochastic factors on the schedule of buses and taxis movement in large cities. The obtained system of equations that models the parameter of movement on the bus routes allows you to assess quickly the influence of disturbing effects on the service quality indicators of passengers and, if necessary, to draw up the optimal schedule. Originality. The authors propose a new model for decision support of dispatching management for the city passenger transport. They take into account the effect of the most important stochastic factors, such as the overflowing buses and taxis, their descent from the lines, delays, deviations from the speed limit on the route, etc., on indicators of service quality, as well as optimizing the schedule. Practical value. The results allow to improve approaches to building models using in the systems of dispatching management of urban bus routes, as well as to improve the selection of control actions for similar systems in large cities of Ukraine.

78-87

Authors: Yu. D. Polissky

Purpose. The purpose of this work is the theoretical substantiation of methods for increased efficiency of execution of difficult, so-called not modular, operations in non-positional residue number system for which it is necessary to know operand digits for all grade levels. Methodology. To achieve the target the numbers are presented in odd module system, while the result of the operation is determined on the basis of establishing the operand parity. The parity is determined by finding the sum modulo for the values of the number positional characteristics for all of its modules. Algorithm of position characteristics includes two types of iteration. The first iteration is to move from this number to a smaller number, in which the remains of one or more modules are equal to zero. This is achieved by subtracting out of all the residues the value of one of them. The second iteration is to move from this number to a smaller number due to exclusion of modules, which residues are zero, by dividing this number by the product of these modules. Iterations are performed until the residues of one, some or all of the modules equal to zero and other modules are excluded. The proposed method is distinguished by its simplicity and allows you to obtain the result of the operation quickly. Findings. There are obtained rather simple solutions of not modular operations for definition of outputs beyond the range of the result of adding or subtracting pairs of numbers, comparing pairs of numbers, determining the number belonging to the specific half of the range, defining parity of numbers presented in non-positional residue number system. Originality. The work offered the new effective approaches to solve the non-modular operations of the non-positional residue number system. It seems appropriate to consider these approaches as research areas to enhance the effectiveness of the modular calculation. Practical value. The above solutions have high performance and can be effective in developing modular computing structures.

88-97

Authors: O. M. Patlasov, S. O. Tokariev, Ye. O. Patlasov

Purpose. Turnouts play a key role in the railway transportation process. One-sided and many-sided curved turnouts were railed over the last 20 years in difficult conditions (curved sections, yard necks). They have a number of geometric features, unlike the conventional one-sided turnouts. Today the normative documents prohibit laying such turnouts in curved track sections and only partially regulate the assessment procedure of their real condition. The question of establishment the permissible train speed within the curved turnouts is still open. In this regard, authors propose to set the train speed according to the driving comfort criterion using the results of field measurements of ordinates from the baseline for the particular curved turnout. Methodology. The article considers the criteria using which one can set the permissible speed on the turnouts. It defines the complexity of their application, advantages and disadvantages. Findings. The work analyzes the speed distribution along the length of the real curved turnout for the forward and lateral directions. It establishes the change rate values of unbalanced accelerations for the existing norms of the curved track sections maintenance according to the difference in the adjacent bend versine at speeds up to 160 km/h. Originality. A method for establishing the trains’ speed limit within the curved turnouts was developed. It takes into account the actual geometric position in the plan of forward and lateral turnout directions. This approach makes it possible to establish a barrier places in plan on the turnouts limiting the train speed. Practical value. The proposed method makes it possible to objectively assess and set the trains’ permissible speed on the basis of the ordinate measurement of the forward and lateral directions of the curved turnouts from the baseline using the driving comfort criteria. The method was tested using real turnouts, which are located within the Pridneprovsk Railway.

119-128

Authors: O. M. Gibalenko, T. S. Trofymchuk

Purpose. The research is aimed at improving the quality and reliability of measures of primary and secondary protection of metal structures at manufacturing companies, to prolong the service life of cyclically loaded structures of production facilities taking into account the corrosion level of danger. Methodology. Authors proposed to use the principles of process approach for statement and realization of management problems of operational service life in corrosion environments. The principles of ensuring reliability on the level of corrosion danger include justification of stages sequence for survivability assessment of a structural metalwork based on the strategy of DMAIC (define, measure, analyze, improve, control): definitions, measurements, analysis, improvement and monitoring of measures of primary and secondary corrosion protection. Findings. Providing control measures from corrosion according to the criterion of corrosion danger allows providing requirements of reliability of structural metalwork based on calculated provisions of the limiting conditions method and solving the problems of management in technological safety during the expected service life of structural objects. Originality. The developed strategy of maintenance of the industrial facilities on an actual state includes the process approach to resource management by creation of system for the account and the functional controlling, risk analysis and regulation of technological safety in production facilities of the enterprises. Realization of the principles of process approach to management of technological safety at the object level is directed to perfecting of tools and methods of anticorrosive protection, extension of a resource taking into account indexes of survivability (,) and justification of program measures to ensure the reliability of enterprises(PER). Practical value. On the basis of process approach to quality and reliability management, generalizations of the natural and numerical researches directed to justification of design solutions of primary and secondary protection of a metalwork at the given level of corrosion danger of a metalwork the organizational measures of PER including assessment of integral characteristics of constructional suitability, technological rationality and risk analysis of signs corrosion danger of objects are developed.

148-156

Authors: O. H. Reidemeister, V. O. Kalashnyk, O. A. Shykunov

Purpose. The main design requirements of the modernized cars are those allowing reduction of operating costs and improvement of economic efficiency of their use. Due to the relevance of this subject the work presents the complex of conducted research, which will allow in prospect to use the universal flatcar, converted according to the Technical specifications TU 3182-065-71390252-2911 for container service. The research includes: evaluation of strength, fatigue safety of the design elements and conformity assessment of the strength characteristics of the modernized flatcar elements to the regulatory documents. Methodology. The analysis covers the use of specialized and universal rolling stock for transportation of containers, as well as the issues of modernization of universal cars. The strength of the flatcar bearing structure is evaluated based on the complex of numerical and experimental studies. The experimental part includes the static, repair load and impact tests. The car strength qualities and the fatigue safety are evaluated on the basis of calculated and experimental data. Findings. The conducted static, repair load and impact tests, given the quasi-static longitudinal forces, allowed the evaluation of the car structure strength according to the regulatory documents. The calculated and experimental data make it possible to assess the fatigue safety of structural elements. The present work is completed by obtaining the results that allow performing reasonable re-equipment of universal flatcars with baseplates with fitting stops to fasten the containers. Originality. The results of calculated and experimental studies showed that the modernized flatcars meet the conditions of strength and have sufficient fatigue safety factor. This makes it possible to recommend the re-equipment of universal flatcars for all car-repair enterprises that submitted the prototypes. Practical value. The complex of works was conducted that demonstrated the possibility of re-equipment of universal flatcars for the transportation of large containers. Part of the car fleet, kept in reserve, with little material costs can be transferred to the operational fleet. The modernization – re-equipment of universal flatcars with stationary specialized devices will increase the car usability coefficient.

165-173

Authors: L. V. Ursuliak, G. Vaiciunas, Ya. M. Romaniuk, V. Petrenko, K. S. Stepchenkova

Purpose. As part of the scientific paper it is necessary to study the waveform impact of the braking cylinders filling on longitudinal train dynamics at different modes of braking. At this one should estimate the level of maximum longitudinal forces and braking distance size in freight cars of various lengths. Methodology. In this paper we attempt to approximate the actual diagram of braking cylinders filling with rational functions of varying degrees. In selection of coefficients in the required functions the highest values of the longitudinal forces and braking distances were used as controlled parameters. They were compared with similar values obtained as a result of experimental rides. The level of longitudinal forces and braking distances amount were evaluated by means of mathematical modeling of train longitudinal vibrations, caused by different braking modes. Findings. At mathematical modeling was assumed that the train consists of 60 uniform four-axle gondola cars, weight of 80 tons, equipped with air dispenser No. 483 included in the median operation, composite braking blocks, and one locomotive VL-8. Train before braking has been pre-stretched. Various types of pneumatic braking (emergency, full service and adjusting braking) of the freight train on the horizontal section of the track were simulated. As the calculation results were obtained values of the longitudinal forces, braking distances amounts and reduction time in speed at various braking modes. Originality. Waveform impact of the braking cylinders filling on the longitudinal forces level and braking distances amount in freight trains were investigated. Also the longitudinal loading of freight trains at various pneumatic braking was investigated. Practical value. Obtained results can be used to assess the level of largest longitudinal forces and braking distances in the freight trains of different lengths by mathematical modeling of different braking modes.

190-199

Authors: M. Sybis, A. Smoczkiewicz-Wojciechowska, A. Szymczak-Graczyk

Purpose. The development of a wide construction market and a desire to design innovative architectural building constructions has resulted in the need to create complex numerical models of objects having increasingly higher computational complexity. The purpose of this work is to show that choosing a proper method for solving the set of equations can improve the calculation time (reduce the complexity) by a few levels of magnitude. Methodology. The article presents an analysis of the impact of matrix inversion algorithm on the deflection calculation in the beam, using the finite element method (FEM). Based on the literature analysis, common methods of calculating set of equations were determined. From the found solutions the Gaussian elimination, LU and Cholesky decomposition methods have been implemented to determine the effect of the matrix inversion algorithm used for solving the equations set on the number of computational operations performed. In addition, each of the implemented method has been further optimized thereby reducing the number of necessary arithmetic operations. Findings. These optimizations have been performed on the use of certain properties of the matrix, such as symmetry or significant number of zero elements in the matrix. The results of the analysis are presented for the division of the beam to 5, 50, 100 and 200 nodes, for which the deflection has been calculated. Originality. The main achievement of this work is that it shows the impact of the used methodology on the complexity of solving the problem (or equivalently, time needed to obtain results). Practical value. The difference between the best (the less complex) and the worst (the most complex) is in the row of few orders of magnitude. This result shows that choosing wrong methodology may enlarge time needed to perform calculation significantly.