Science and Transport Progress

17-27

Authors: A. A. Kosolapov

Purpose. Development of the reliability calculating methodology of fuzzy systems with components, reliability parameters of which are described by the membership functions of various kinds. Methodology. Systematic analysis of the known approaches to the assessment of the reliability of fuzzy systems with vague boundaries and different kinds of membership functions. Findings. A unified description and the new tabular algorithm of various arithmetic operations run between the various types of fuzzy sets are proposed and tabular methods of reliability analysis of the basic structures of fuzzy systems are developed. Originality. A generalized description of triangular and trapezoid-shaped accessory functions of fuzzy boundaries in a special tuples is introduced, analytical expressions for the formation of tabular schedules of their functions and the calculation of the reliability of fuzzy systems with complex structures are obtained: sequential, redundant - parallel, serial-parallel, parallel-serial. The practical value.The obtained models and tabular algorithms simplify the calculations of the reliability of complex electro-mechanical human-machine automation systems with fuzzy parameters and vague boundaries.

35-48

Authors: U. S. Barash, L. V. Martsenyuk

Purpose. Development of theoretical and methodological foundations of efficiency of freight cars operating companies in railway reform through improved management structure them. Methodology. A theoretical and methodological approach for building effective management structure of freight wagons operating companies of different ownership forms is proposed, its introduction will significantly reduce detention of cars on technical stations under loading operations and maintenance, and thereby to improve the quality parameters of rolling stock usage in reform conditions of Ukraine railway transport. Findings. An improved control mechanism of cargo transportation is developed, it is different from the existing by its adaptation to the conditions of the reformed sector and the organization of management companies which together with the Ukrainian Transport and Logistics Center (UTLC) centralize management of all freight cars of domestic and foreign operating companies. Originality. It is proposed for management of cargo transportation in wagons operating companies of different ownership to organize a series of management companies that would have the right to dispose of universal cars of other domestic operating companies, being on leasehold basis, and to direct them to current and scheduled repairs by themselves; to organize the cargo transportation in wagons of domestic and foreign operating companies on a contractual terms, depending on the type and content of the contract, on the basis of additional contracts for a separate fee to perform current and scheduled repair of freight cars; the management company organizational structure is developed, it includes simultaneously two directions of activity: commercial and repair, it will reduce the stay time of rolling stock on the engineering stations during loading and in a non-operating park as far as this company will manage a significant part of the production cycle of the transportation process. Practical value. For efficient use of freight cars operating companies of different ownerships a new theoretical and methodological approach is proposed. It will improve the quality parameters of the rolling stock usage. The new technology of cargo transportation control of domestic and foreign operating companies through management companies and Ukrainian Transport and Logistics Center with the distribution of traffic depending on rolling stock type, owner cars or railway administration, organization of transportation is offered. The technique of the organizational structure of the management company, which includes a combination of two types of activities: commercial and cars repair of different ownership is developed.

56-63

Authors: T. M. Mishchenko

Purpose. The essence and basic characteristics of calculation methods of transient electromagnetic processes in the elements and devices of non–linear dynamic electric traction systems taking into account the stochastic changes of voltages and currents in traction networks of power supply subsystem and power circuits of electric rolling stock are developed. Methodology. Classical methods and the methods of non–linear electric engineering, as well as probability theory method, especially the methods of stationary ergodic and non–stationary stochastic processes application are used in the research. Findings. Using the above-mentioned methods an equivalent circuit and the system of nonlinear integra–differential equations for electromagnetic condition of the double–track inter-substation zone of alternating current electric traction system are drawn up. Calculations allow obtaining electric traction current distribution in the areas of feeder zones. Originality. First of all the paper is interesting and important from scientific point of view due to the methods, which allow taking into account probabilistic character of change for traction voltages and electric traction system currents. On the second hand the researches develop the most efficient methods of nonlinear circuits’ analysis. Practical value. The practical value of the research is presented in application of the methods to the analysis of electromagnetic and electric energy processes in the traction power supply system in the case of high-speed train traffic.

76-82

Authors: I. A. Vakulenko

Purpose. The purpose of the paper is an estimation of degree of metal hardness change for the railway wheel with martensite structure during rolling. Methodology. As strength characteristic the Rockwell hardness is used. Wear tests were conducted in the conditions of normal loading with (10%) and without sliding on the test equipment SMTs-2. Parameters of the fine crystalline structure (tetragonality degree of the crystalline grid, dislocation density, scale of coherent scattering regions, and disturbance value of the crystalline grid of second kind) are determined by the methods of X-ray structural analysis. Findings. During operation of the railway wheels with different strength level, origin of defects on the wheel thread is caused by simultaneous action of both the friction forces and the cyclically changing loadings. Considering that formation of damage centers is largely determined by the state of metal volumes near the wheel thread, one should expect the differences in friction processes development at high contact stress for the wheels with different strength level and structural state. Originality. During the wear tests softening effect of carbon steel with martensite quenching structure is obtained. Softening effect equaled 3.5–7% from the level of quenched metal hardness. The softening effect is accompanied by the reduction of tetragonality degree of the crystalline structure of martensite, reduction of coherent scattering regions, dislocation density increase and crystalline grid disturbance of the second kind. Practical value. The results point out the necessity for further studies to clarify the resulted softening effect mechanism.

92-98

Authors: N. A. Logvinova

Purpose. Determination of the economic grounded sizes of motion of freight trains between the areas of railway direction with parallel runnings. A research task is distribution in the operative terms of train work at admission of freight trains between the areas of railway direction with parallel runnings. Methodology. Research is executed with the use of classic methods and methods of the linear programming. Findings. The rational train traffic volume distribution on a railway infrastructure with parallel runnings is presently carried out by an expert method on the basis of information about the before executed volumes of transportations without application of feasibility study. For the task solution of train traffic volume distribution between parallel runnings of railway direction a linear model and methods of the linear programming are used in operative terms. At a design all train traffic volume on a direction part on undistributed train traffic volume – which remaines unchanging for all variants of operative management and distributed – which it is possible to redistribute in some limits between parallel runnings of railway direction. Originality. From the scientific point of view the work is interesting and important by the methods of the linear programming, which allow conducting train traffic volume distribution between parallel runnings in operative terms. Practical value. The practical value of this research is in applying of the described economic and mathematical modeling methods of train traffic volume distribution between parallel runnings on direction Znamenka - Odessa. 10 pairs transmission of freight trains from basic direction Pomoshnaya – Kolosovka – Odessa on parallel direction Pomoshnaya - Kotovsk – Separate is Odessa can be included with the optimum variant.

106-117

Authors: S. A. Kostritsya, B. M. Tovt

Purpose. The results of the optimization investigation and the rational projects of the bearing structure of ballast leveling machine SPZ-5/UA are brought in this paper. The necessity of realization of structural optimization of the investigated machine is reasonable. Methodology. The statement of the optimization problem is executed: the beam cross-section square is taken as the objective function; the allowable stresses criterion is taken as the constraint in this problem statement. Findings. The simplified FE-model of structure of machine is worked out. The optimization problem of double-T cross-section is considered as a test case. For this problem we can obtain the analytical and numeral solutions. Originality. The rational designs for the bearing structure of the investigated machine are brought with the increased consumption of material with preservation of durability characteristics. Practical value. The optimization investigation is executed for bearing structure of the ballast leveling machine SPZ-5/UA by the use of the numerical structural optimization procedure. The obtained rational structural projects are compared to the structural projects with standard double-T cross-sections. It is shown that the use of structural projects with standard cross-sections makes it impossible to obtain the better structure as compared to the rational project. As a result the rational structural project of the ballast leveling machine is obtained, which have the sufficient safety factor. The cross-section of the main longitudinal beam of the bearing structure of leveling machine is decreased on 73%.

124-128

Authors: S. A. Ustenko, S. V. Didanov

Purpose. The movement of rail transport (speed rolling stock, traffic safety, etc.) is largely dependent on the quality of the track. In this case, a special role is the transition curve, which ensures smooth insertion of the transition from linear to circular section of road. The article deals with modeling of spatial transition curve based on the parabolic distribution of the curvature and torsion. This is a continuation of research conducted by the authors regarding the spatial modeling of curved contours. Methodology. Construction of the spatial transition curve is numerical methods for solving nonlinear integral equations, where the initial data are taken coordinate the starting and ending points of the curve of the future, and the inclination of the tangent and the deviation of the curve from the tangent plane at these points. System solutions for the numerical method are the partial derivatives of the equations of the unknown parameters of the law of change of torsion and length of the transition curve. Findings. The parametric equations of the spatial transition curve are calculated by finding the unknown coefficients of the parabolic distribution of the curvature and torsion, as well as the spatial length of the transition curve. Originality. A method for constructing the spatial transition curve is devised, and based on this software geometric modeling spatial transition curves of railway track with specified deviations of the curve from the tangent plane. Practical value. The resulting curve can be applied in any sector of the economy, where it is necessary to ensure a smooth transition from linear to circular section of the curved space bypass. An example is the transition curve in the construction of the railway line, road, pipe, profile, flat section of the working blades of the turbine and compressor, the ship, plane, car, etc.

136-143

Authors: A. S. Shcherbak

Purpose. To study the modern heat-insulating materials presented at the market of Ukraine and to estimate the efficiency of their application. Methodology. Research and analysis of heat-insulating materials presented at the market of Ukraine, according to the existing standards. Findings. To ensure the energy efficiency in buildings and constructions it is necessary to apply the domestic heat-insulating material, which possesses the given thermo technical characteristics, reduced indexes of water absorption, flammability and toxicity, as well as durability and relatively low self–cost. Originality. Basic heat-insulating materials, which are most widely used in construction are systematized, the researches of their properties are conducted and the foam glass is chosen as the most effective heat-insulating material. It is characterized by high thermo technical characteristics and possesses the best ecological indexes, as well as the sturdiness for aggressive factors influence. Practical value. Special attention deserves the insulating material foam glass, which is a synthetic silicate material with evenly placed pores (0.1 ... 5.0 mm) separated by thin septa with a vitreous substance possesses the necessary properties and by aforesaid may be accepted for studies aimed its improvement (modification). The results of researches can be applied in the foam glass production, which is used for heat-insulation of buildings and constructions, equipment, pipelines etc.