Science and Transport Progress

20-29

Authors: A. Y. Kuzyshyn, А. V. Batig

Purpose.The article is aimed to construct the mechanical model of the diesel train DTKr-2 of the Kryukivsk Railway Car Building Works based on the analysis of undercarriage construction. This model will be used in the study of dynamic properties of the vehicle. When constructing the model the design features and its loading methods should be displayed as much as possible. Methodology. When constructing the mechanical model of the diesel train DTKr-2 car, the pneumatic spring, which is the main element of the central spring suspension, was modeled using Kelvin-Voigt node. This node includes elastic and viscous element. Hydraulic shock absorbers that are used both in the central and axle-box spring suspension were modeled as a viscous element. During research, the rigidity of the pneumatic spring, which is associated with the change in its effective area under deformation, was assumed to be zero. Findings. This article analyzed the design of car undercarriage of the diesel train DTKr-2. The mathematical models of its main units were presented, namely, in the central spring suspension – the model of pneumatic spring. Taking into account the peculiarities of design of the diesel train DTKr-2 undercarriage it was developed its mechanical model, which will be used in the future when studying dynamic properties. Originality.For the first time for the diesel train DTKr-2 car it was developed its mechanical model taking into account the features of the interaction of individual elements of its design. It has been proposed as a pneumatic spring to use the Kelvin-Voigt node, which includes parallel arranged elastic and viscous elements. Practical value. On the basis of the proposed mechanical model, a system of ordinary differential equations of car undercarriage movement of the diesel train DTKr-2 (mathematical model) will be compiled. This model is further planned to be used when studying dynamic interaction of the diesel train car undercarriage wheel set with a track in the straight and curved track sections.

40-48

Authors: M. B. Kurhan, D. M. Kurhan

Purpose. The tasks of modeling the interaction of track and rolling stock are basic ones for most areas of mo-dern scientific research of railway transport. The compilation of the model by the principle of Lagrange d'Alembert has found a very wide application for solving the problems of rolling stock dynamics. Representation of the railway track in the model of crew movement can be implemented in several ways, which, among other things, will differ in detail. The purpose of this work is to create a methodology for representing the railway track in mathematical mo-dels of interaction with rolling stock and obtaining practical results for different characteristics and design of the track and the level of maximum speed. Methodology. The problem consists of determining such characteristics of the path as the reduced mass, the stiffness coefficient, and the dissipation coefficient. As a tool for solving this problem it was used the model of the stress-strain behavior of the railway track based on the joint use of the elastic wave propagation equations to describe the geometry of the outline of the part of the system space that is involved in the interaction at a given time and the equations of dynamic equilibrium of its deformation. This makes it possible to take into account the dynamics of the deflection of the under-rail base, which is especially important for the conditions of passenger traffic, which can be carried out at high speed. Findings. Theoretically justified stiffness and dissipation coefficients of the railway track for calculating the dynamics of rolling stock in modern models based on systems of equations in accordance with the Lagrange d'Alembert principle are obtained. The established va-lues, in contrast to those given in other sources, have a reasonable dependence on the design of the path and the speed of movement. Originality. The approaches of railroad track representation in models of rolling stock described by systems of equations by the Lagrange-d'Alembert principle are expanded. A method for determining the characteristics of the railway track for such models is developed based on the results of variant calculations of the dynamic deflection of the rail from the passage of the wheel. Practical value. The values of the stiffness and dissipation coefficients of the railway track are obtained depending on the design and speed of motion for practical use in appropriate models of interaction between track and rolling stock.

61-69

Authors: L. A. Muradian, D. O. Podosenov, V. Y. Shaposhnyk

Purpose. The paper considers the interaction of the cylindrical surfaces of the friction pair «center plate – center pad» of the freight car and theoretically investigates the wear process. It is also necessary to obtain the wear value dependence of center pad on the mileage, taking into account the power load, the physical-mechanical and tribo-technical properties of the interacting materials for the subsequent modeling and control of the value of overhaul mileage by the wear criterion of the corresponding resource-determining elements of freight cars. Методика. For theoretical studies of the wear value of friction pair «center plate – center pad» on the freight car mileage, the theory of friction and wear of solids was used. Findings. In this paper interaction of cylindrical surfaces of the friction pair «center plate – center pad» of a freight car in the form of a «shaft-sleeve» model is considered. Dependences of the permanent and variable wear of a given friction pair are proposed for cases in which forces act in the transverse and longitudinal directions. Obtained dependence of the wear value of center pad on the freight car mileage takes into account the power load, physical and mechanical and tribo-technical properties of the conjugated materials. On its basis, using new materials for repair with various properties, one may simulate the wear state of cylindrical surfaces of the friction pair «center plate – center pad», which will make it possible to control the value of overhaul mileage of freight car. Also (on the example of gondola 12-7023) on the basis of obtained expression there were constructed dependences of the average wear value of center pad for the cases of different values of the mileage use coefficient and the train movement speed. It was shown that with an increase in the train speed to 100 km/h, the average wear value of the gondola 12-7023 center pad is lower by 25% than at the speed of 80 km/h. Originality. In the work on the wear criterion, the interaction of cylindrical surfaces of the friction pair «center plate – center pad» of a freight car is considered. For the first time it was obtained the dependence of wear value of center pad on the mileage taking into account the power load, physical and mechanical and tribo-technical properties of the conjugated materials. Applying new materials for repair with different properties, based on the obtained dependence one can carry out a simulation of the wear state of cylindrical surfaces of friction pair «center plate – center pad», that is to control the value of between-repair mileage of freight car. Practical value. The results of the work make it possible to establish the wear value of canter pad for the corresponding operating mileage of the freight car.

83-92

Authors: Anurag Virendra Tiwari, Y.R.M. Rao

Purpose. Plastic waste has become a major environmental issue of concern due to its exponential growth due to rapid urbanization. The paper investigates utility of plastic waste as an additive for bituminous concrete using wet process of mixing. Methodology. The methodology for the present paper has been designed with complex research consisting of Marshall mix design of the bituminous mix added with plastic waste for modifying bitumen using wet process of mixing, performing the tests on the samples and analyzing the results in the form of table and figures. In the present paper LDPE and HDPE type of plastic waste are used to modify the bitumen. Finding. The results show that addition of 6 percent of bitumen improves the Marshall properties of the mix. Use of plastic to modify the bitumen not only makes the road surface more durable but also it is an eco-friendly way of proper disposal of plastic waste. Originality. The processes used for mixing the plastic waste to the bitumen are dry process and wet process. Dry process of mixing the plastic waste to the bituminous mix is most common and lot of study is carried out on its application. In the present paper wet process of mixing has not yet been studied much. Practical Value. The practical application of utilizing the plastic waste to modify bitumen in the bituminous mix improves the stability values resulting in the more durable road surface. Also the method ensures the proper disposal of plastic waste in eco-friendly way.

102-111

Authors: S. V. Myamlin, Y. V. Kebal, O. P. Severyn, S. O. Yakovliеv, O. I. Shaptalа

Purpose. Comprehensive and uninterrupted logistical support of troops is considered one of the main factors of successful conduct of hostilities by any state. The logistics support system, created in peacetime, is intended for use in the course of a military company. It is the link between the front and the economy of the country, and at the same time, it is one of the important factors affecting the combat operation. According to experts, changes in the geopolitical and military-strategic situation in Europe resulted also changes in the armed forces of states, including their logistical support, which is undergoing changes and is developing under the direct influence of the military strategy, the achievement of whose goals it is intended to provide. All this necessitates the search for new, more effective ways of solving logistical problems in modern combat. This is true today, including for the Armed Forces of Ukraine. Therefore, the purpose of the work is to consider and implement in practice the logistic support of the state power structures of innovations in the form of a new, improved product - the creation of modular complexes, including various block containers (kitchen-dining room, shower room, laundry, post-office, dispensary and others). They will dramatically change in the future the quality of resolving the issues of everyday life of servicemen during the performance of combat missions in emergency zones and with participation in armed conflicts. Methodology. The methodology is based on the main measures to improve the logistic support system in the near future, including the reorganization of the existing logistic support system and the creation of modular structures of forces and means that are easily adapted and subsequently targeted for specific tasks. Findings. A set of design documentation for the block - container for laundry and shower in the field is offered. Technological modules for combat (block-post), rear (kitchen-dining room), medical (mobile ambulance), and others are also being developed. Originality. One of the peculiarities of reforms carried out in the Armed Forces of Ukraine is their scientific justification. For the theoretical support, development and justification of promising ideas for improving the life support of servicemen during long-term deployment in the field, the use of block containers-mobile multifunctional premises - is proposed for the first time. Practical value. Considering that the military and political leadership of Ukraine considers the logistic support of the troops as one of the components of the all-round support of the armed forces in peacetime and wartime, the use of the proposed ideas for improving the life of the troops will help to form a new image of the material and technical support system of the Armed Forces of Ukraine.

120-127

Authors: Y. V. Ulyanov

Purpose. To determine the parameters of soils of loess formation, which are considered difficult in the construction or operation of housing and industrial facilities it is provided an analysis of the obtained field test data in order to use them in calculations to predict the situation, which can be complicated during operation of the facilities. The main purpose is: 1) improvement of our ideas about soils of loess formation using the example of determining possible changes in parameters of the loess mass, which is under load from the total weight of the structure; 2) testing the methodology of sounding by introducing improved manual probes: comparing the data of these studies with those obtained by other methods; 3) determination of the ways of further research using manual probes. Methodology. The directions of engineering-geological research were updated with the help of analysis and synthesis methods. Dynamic sounding was performed as a tool. Findings. The authors analyzed the data of dynamic sounding of soils by probes of the type DIIT-5 made by the Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan (DNURT). Also, it was sounded the research object in difficult engineering-geological conditions: in a built-up area, the soil of which is represented by forests. The sounding was carried out using the small-sized LIATE probe. Further, the dynamic soil resistance to sounding was determined and the dependency formula between the obtained indices was derived. Originality. The sounding of the unwatered loess soils was carried out by light non-standard probe developed by the DNURT and, for comparison, by a self-developed probe of a group of authors, including the author of the article. The probe was used at the first time. Practical value. Dynamic sounding, which had spread significantly during engineering research in the construction of 60-70 years of the last century, is currently used rare. As for research of loess soils in their various states (watered, unwatered, disturbed and undisturbed, etc.) it is practically not developed. Therefore, the derivation of correlation formulas that confirm the rights to use existing formulas and design coefficients precisely for the loess mass (and this is about 90% of modern Quaternary soils of Ukraine) seems to be a topical subject.