Science and Transport Progress

7-22

Authors: S. YU. Buryak, V. I. Gavrilyuk, O. O. Hololobova, A. M. Beznarytnyy

Purpose.Considerable responsibility for safety of operation rests on signal telephone and telegraph department of railway. One of the most attackable nodes (both automation systems, and railway in whole) is track switches. The aim of this investigation is developing such system for monitoring and diagnostics of track switches, which would fully meet the requirements of modern conditions of high-speed motion and heavy trains and producing diagnostics, collection and systematization of data in an automated way. Methodology. In order to achieve the desired objectives research of a structure and the operating principle description of the switch electric drive, sequence of triggering its main units were carried out. The operating characteristics and settings, operating conditions, the causes of failures in the work, andrequirements for electric drives technology and their service were considered and analyzed. Basic analysis principles of dependence of nature of the changes the current waveform, which flows in the working circuit of AC electric point motor were determined. Technical implementation of the monitoring and diagnosing system the state of AC electric point motors was carried out. Findings. Signals taken from serviceable and defective electric turnouts were researched. Originality. Identified a strong interconnectionbetween the technical condition of the track switchand curve shape that describes the current in the circuit of AC electric point motor during operation which is based on the research processes that have influence on it during operation. Practical value. Shown the principles of the technical approach to the transition from scheduled preventive maintenance to maintenance of real condition for a more objective assessment and thus more rapid response to emerging or failures when they occur gradually, damages and any other shortcomings in the work track switch AC drives.

37-42

Authors: V. D. Zelikman, YU. A. Sonina

Purpose. Determination and substantiation of ways to improve accounting and internal audit of receivables at the enterprises. Methodology.The basic principles and ways for improvement of accounting and internal audit systems that should help Ukrainian enterprises to optimize receivables are considered. Findings. It is proved that the receivables optimization is possible on the basis of improving its accounting and internal audit. The basic ways for improvement of accounting and internal audit of receivable are determined. They are: improvement of normative coverage of receivables at the enterprises; providing further harmonization of financial and tax accounting in the part of formation of the doubtful debt receivables, accounting of bad and doubtful receivables and etc. The formation of department for internal audit to control the doubtful and bad debts; providing the timely control of the receivables and payables ratio; determination and support of the optimal value of the receivables at the enterprises. Originality. Improvement of accounting and internal audit of receivables at the enterprises by the way of development of internal audit system and optimization of the receivables size. Practical value. The proposed recommendations will improve the accounting and internal audit system of receivables at the enterprises of Ukraine.

52-59

Authors: O. I. Kharchenko

Purpose. Modern transport systems are not stable and can not stand up to the destabilizing factors. Global track record in the economic and commercial management systems is the use of the concept of sustainable development. It is necessary on the basis of analysis of literary sources to define the directions of efficiency increase of functioning of railway transport subdivisions from the point of view of sustainable development. Methodology. To achieve the purpose the features of the use of sustainable development conception and its realization were investigated at a management of the complex systems. The existent models were also analyzed in the field of efficiency increase of functioning of railway transport subdivisions. Findings. On the basis of literary sources analysis, keeping up the conceptual essence of the sustainable development, the main directions of efficiency increase of subdivisions functioning were selected. They take into account the basic requirements of steady development and should be considered as a complex. Originality. New directions to consider the efficiency increase issues from position of sustainable development were offered by the author. Three components of conceptions of sustainable development (economic, ecological and social) should be examined in a balanced way. Thus, the above mentioned theoretical studies can promote the forming of new economy model corresponding to the purposes and principles of sustainable development. Practical value. The conducted analysis development confirms the necessity of researches on perspective directions of development of railway transport subdivisions, which are marked by the guidance of Ukrzaliznytsia. It enables to select basic directions for further research in the area of efficiency increase.

67-74

Authors: A. M. Afanasov

Purpose. Loading-back systems are used for post-maintenance acceptance tests of electric traction motors of electric rolling stock (ERS) in mainline and industrial transport. The aim of the research is justification of choice method of the rational loading-back parameters of traction electric motors during the tests for heating. Methodology. At the heart of the choice method justification of the rational loading-back parameters is a theory of heating the homogeneous solid body and well-known methods of heating calculations of traction electric machines. Findings. Expediency of heating tests for electric traction motors at load currents equal to the starting current (for ERS of mainline transport) or fifteen minutes current (for ERS of industrial transport) was substantiated. It was shown that this increase of load current will reduce the electricity costs of the tests for 20–30% and shorten the tests duration for three–four times while ensuring the corrected power minimum of energy sources in loading-back system. Originality. It is shown that the energy costs for heating tests of the traction motors can be reduced by both the increasing the energy efficiency of the loading-back system and by the optimizing of loading mode of traction electric machines. Choice technique of rational modes of loading-back for electric traction motors of rolling stock in mainline and industrial transport was grounded. Practical value. Load current increase of traction electric motors during their tests for heating will reduce the total electricity consumption for the acceptance tests, reduce test time and total material costs for repair of the electric traction motors of rolling stock in mainline and industrial transport.

86-94

Authors: I. O. Vakulenko, S. O. Plitchenko, D. M. Makarevych

Purpose. The purpose of work is a comparative analysis of chemical compounds influence on the process of electric arc forming and condition of its burning. Methodology. Material for an electrode was a wire 3 mm in diameter of low carbon steel with contain of carbon 0.15%. As chemical compounds, which determine the terms of forming of arc welding were used kaolin; CaCO3 with the admixtures of gypsum to 60%; SiO2 and Fe – Si with the iron concentration to 50%. Researches were conducted at the use of direct electric current and the arc of reverse polarity. As a source of electric current the welding transformer of type PSO-500 was used. On the special stand an initial gap between the electrode and metal-plate was equal to 1–1.5 mm. The interelectrode interval was filled with the probed chemical compounds and it was formed an electric arc. In the moment of electric arc arise the values of electric current and the arc voltage were determined. After the natural break of electric arc, the final size of the gap between electrodes was accepted as the maximal value of the arc lengths. Findings. In the conditions of experiment the metal transfer in interelectrode interval corresponded to the drop mechanism. According to external characteristics the ratio between the maximal arc length and the power of electric discharge has the appearance of exponential dependence. Specific power of electric arc characterizes environment of interelectrode interval in the moment of arc forming per unit of its length. Originality. 1. On the basis of influence analysis of the studied chemical compounds on the formation processes of electric arc inversely proportional relationship between the power of the electric current and the maximum arc length to the moment of its natural break is defined. 2. The ratio between the maximal arc length and the power of electric current with sufficiently high correlation coefficient is subjected to the exponential dependence. Influence of the studied compounds on the process of electric arc forming is determined using the degree values of the obtained ratio. 3. The value of specific power of electric current in the moment of electric arc forming per unit of its length can be accepted as the parameter, which characterizes the environment in the interelectrode interval. Practical value. In the conditions of identical adjusting strength of electric current it is determined the gradation of the studied chemical compounds in the order of increase of their influence on the process of the arc burning. Kaolin has the minimum influence and Fe – Si – the maximal one.

101-110

Authors: A. M. Okorokov

Purpose. Making the qualitative administrative decisions defining strategy and tactics of transport cargo complexes development, and also its subsystems, is possible only in the presence of flexible optimization model. This model has to consider multiparametricity and multicriteriality of the given task, uncertainty and vagueness of input information, and also to provide process automation of searching the best parameters of the given production facility. The purpose of the research is to develop procedures for the strategic management of complex with view of the most important factors and their stochastic nature, which will execute the improvement of technical equipment of TCC. Methodology. The problem of strategic management is based on solving the complex of issues of the optimal number of shunting locomotives, optimal processing capability of handling the front and rational capacity of warehouses. The problem is solved on the basis of the proposed optimality criterion – the specific set of profit per unit of capital assets of freight industry. The listed problems are solved using simulation modeling of the freight industry. Findings. The use of developed procedure allows one to improve the technical equipment of the freight stations and complexes. Originality. For the first time it was developed the procedure of strategic management of development. This procedure allows taking into account the probabilistic nature of demand for services of transport freight complexes and technological processes of client services on the complex stations. The proposed procedure can be applied during when planning the investments in the creation of transport freight complexes. Practical value. Use as a basic tool of simulation models of complex cargo operation allows estimating the effectiveness of the capital investments, the level of operating costs, as well as the quality of meeting the demands of potential customers in transportations at the stage of transport cargo complex.

119-126

Authors: O. S. Krasheninin, V. A. Gogaiev

Purpose. Efficiency of function multiple units park (MUP) as a complex system considerably depends on the modes and conditions of its operation, which is defined as the state of their eigenstate and state of the system content. The purpose is the decision scientifically - a technical problem of system of the content of maintenance operation and repair of a rolling stock. Methodology. Article is devoted to a question of the maintenance operation and repair of a rolling stock of Ukraine. On the basis of theoretical probe, the situation which has developed on maintenance operation and repair of MVPS is analysed. The comparative analysis of a railway, motor and air transportation is provided. On the basis of the analysis and comparison by authors it is offered transition from scheduled preventive to system of service of railway transport to service on an actual state. Findings. According to given theoretical comparison of the put perspective in different types of transport it is possible to note that experience and features of operation rolling stock in allied industries is the base for revision and improvement of system of the maintenance rolling stock, including at various stages of its operation. Originality. This article provides the comparative theoretical analysis, concerning contents and repair system between railway, automobile and by air. Practical value. Introduction new approaches of the maintenance operation and rolling stocks repair will allow carrying out gradual transition from maintenance operation and repairing existing scheduled preventive system in repair system «on an actual state». Thus it is possible maximum cutting-down of number of sudden refusals in operation, providing high coefficient of operational readiness of a rolling stock (to 0.95). A comparative analysis of the maintenance system and repair is the basis of the transition feasibility.

139-147

Authors: A. V. Radkevych, A. N. Netesa

Purpose. One of the main technological operations of buildings construction on the basis of monolithic frame systems is the production of mesh reinforcement. The current interest is the new ways specification of advanced bonding armature techniques without reliability weakness and design of the building in whole, as well as the finding of use prospects of screw-threaded joint of armature as the most technological and economic method of re-bars joints. Methodology. Advantages and disadvantages analysis of existing rebar compound technologies was implemented by couplings of different types and constructions. The most promising vertical constructions for the vertical bars joints in frameworks were determined. Findings. Researches of existing technologies of rebar joints by the couplings of different construction were carried out. The installation method of mesh reinforcement of vertical structural elements with the use of the special catching devices was developed. It allows considerably accelerating installation of mesh reinforcement. Originality. Regularity of labor intensiveness change of mesh reinforcement installation of columns at armature joint in vertical position by threaded couplings with the help of catching devices using special construction was determined. This allows substantially reducing the labor expenditures during installation of these elements. Dependency of labor intensiveness and cost of lap welding armature joints, by tub-seam welding and by thread coupling depending on its diameter was designated. Regularity of labor intensiveness changes of installation at armature joints by different methods taking into account preparatory works was defined. Practical value. The analysis of mechanical armature joints techniques was conducted. It will allow selecting methods of armature joints to increase the speed of construction works more economical and effective.