Serhii Raksha

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• Dr. Sci.
• Professor (Full) at Ukrainian State University of Science and Technologies

The reliability of work according to the criteria of vibration stability of the stand for testing the axles of wheelsets for endurance is largely determined by the natural vibration frequencies of the stand. The work considers a stand with a lever structure for loading the tested axles. In order to determine the influence of the parameters of the c...

One of the tasks that need to be solved in order to predict the life of wheelsets is to assess the contact strength and wear of their parts. Thus, the purpose of this work is to develop a scheme and justification of the parameters of the life-test bench for railway wheelsets in conditions close to real operating ones. This bench simulates a contact...

Purpose. The purpose of the work is to determine and analyze the technical parameters of the bench for railway wheels complex tests, providing for the combination of fatigue and contact strength tests, their simultaneous performing on same test-bench. Methodology. Determination of the technical parameters of the test-bench was carried out based on...

Tests and research can be greatly accelerated by applying a multi-point load to the test wheel. The aim of this work is to substantiate rational parameters of the stand for accelerated life tests of railway wheelsets, in which a multi-point load applies to the rolling surface of the test wheel. On the basis of the laws of the theory of elasticity,...

The motivation of the research and further development of the new type combined knife system on the non-return bulldozer blade and the results of the first series of laboratory studies of the process of the soil digging with the non-return blade of the bulldozer with the first set of its physical models, which indicate the feasibility of continuing...

Purpose. The article is aimed to form and justify the energy efficiency indicators of ropeways of traditional design and ropeways with self-propelled wagons based on the determination and comparison of their values. The substantiation of the energy efficiency criteria of ropeway wagons allows us to determine fully the direction of further research...

The effectiveness of research on the basis of mathematical models (linear, nonlinear) describing the dynamics of bridge cranes and cargo oscillations during transitional modes of movement, increases significantly with the use of numerical methods and simulation models created by visual programming tools. Purpose. To develop and evaluate proposed si...

The processing by pulses of electric current (PEC) of a fragment of the rim of a railway wheel was carried out on the DS10D equipment. When the density of the electric current is from 3 to 17 A/mm ² , the processing cycle consisted of the action of a pulse with a duration of 2.5-3 s and a pause between pulses of 4 s. After 150 cycles of PEC, the ha...

The operation safety of the railway rolling stock depends directly on the strength of the base part of the wheelset – its axle. Therefore, in recent years numerous studies of theoretical and experimental nature, both for means of rail transport, and for machines containing rail track equipment are carried out. This paper substantiates the main para...

Wheelset axles are essential parts of railway and mine site rolling stock. For fatigue testing of axles, various test-benches are designed to implement the cyclic loads. The effectiveness of test-bench vibration analysis grows with the use of numerical approach and simulation models created with the aid of visual programming tools. The purpose of t...

Цель. Увеличение скорости движения и грузоподъемности поездов приводит к увеличению нагрузки на железнодорожный путь и, в свою очередь, нагрузки на земляное полотно. Это вызывает необходимость уточнения методов расчета, как верхнего строения, так и земляного полотна железнодорожного пути. Целью работы является разработка метода определения напряжен...

Purpose. The research was carried out to improve the design process of the balancing unit for portal crane. In order to achieve the purpose one should: 1) to develop a dynamic and mathematical model that allows describing the movement of balancing unit and the boom system of portal crane, when derricking; 2) to propose the way for determining and t...

The paper outlines the basic principles of constructing frequency diagrams and specifies the features of their application for the analysis of the dynamic state of the vehicle drive with cable traction on the example of a ropeway. To draw up the frequency diagrams, the ropeway traction circuit was presented as a dynamic system containing lumped mas...

The paper considers the algorithm for calculating the pneumatic transport systems of the main constructions: with high vacuum and with different pressures. The analysis of the dependence of all calculation elements on the design data of the transport system of the considered structures was carried out. In order to accelerate the calculation of such...

Purpose. Subject to the smooth and efficient operation of each production line, is the use of vehicles transporting high specification. It worked well in practice for transporting construction machines, which are used during the vibration. The use of vibration machines requires optimization of their operation modes. In the form of elastic link in t...

Purpose. In the study is necessary: 1) to justify aligning drums of a new design of belt conveyors; 2) to develop a method for calculating and determining the rational design parameters of drums depending on the technical parameters of the conveyor belt (the length of the conveyor, belt width, the performance of the conveyor, the diameter of the dr...

Purpose. Formation of recommendations about rational profiling of ropeways taking into account energy saving. Methodology. As criterion of power consumption the specific power of the drive as the relation of power consumption to ropeway carrying capacity is accepted. The cycle of movement of cars was conditionally divided into three stages, charact...

Purpose. To estimate influence of elastic deformations of the track cable arising at movement of cars, on effort in a hauling rope of the aerial ropeway. Methodology. The method of consecutive approaches was used for research influence of elastic deformations of a track cable on effort in a hauling rope. Thus, definition of a tension of a track cab...

The coupled instability of thin-walled columns with a preliminary local buckling is considered taking into account the overall initial imperfection, eccentricity of the compression force application and interaction of overall and local buckling modes.

The two-criteria optimum design problem for thin-walled members with two axes of symmetry (of H-type) subjected to compression and bending is solved. Components of the objective function vector are the compressive force and the bending moment in the web plane. Pareto-optima and “compromise” optimal projects have been obtained and compared with stan...

An analytical dependence to determine the ratio of rolling friction has been proposed, with account of generally accepted mechanical characteristics of materials and the geometrical parameters of wheel and. This allows specifying the starting time of the bridge crane moving drive and the coefficient of coupling the working wheels with the rail.

Solution of coupling buckling problem for compressed thin-walled trapezoidal column in the first asymptotic approximation is presented. Effect of the secondary local mode on the threshold loads under various cross-section configurations and initial imperfections is studied. It is shown that the mode interaction results in the threshold stress decre...