2013
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Browsing 2013 by Author "Myamlin, Serhiy V."
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Item Determination of Dynamic Performance of Freight Cars Taking into Account Technical Condition of Side Bearers(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2013) Myamlin, Serhiy V.; Neduzha, Larysa O.; Ten, Oleksandr O.; Shvets, Angela A.EN: Purpose. The railway transport plays an important role in social and economic life of the country and carries out the large containment of transportation activities. The transport industry should migrate towards innovation changes and increase its significance as an important transit subsystem on the way of renovation of both the infrastructure and the strategy of all transportation process components including the interaction with other transport modes. At present the life sets strategic challenges for the railway branch, and the basic goals among them are as follows: high-speed train traffic development, increase of the weight of freight trains, new rolling stock development etc. Due to the urgency of this subject, the researchers should cope with the task devoted to one of aspects of improving the freight transportation efficiency, namely to the study of effects of various factors and characteristics of technical conditions of the freight cars running gears (which are unavoidable to arise during operation) on their basic dynamic indices. The deviations of technical conditions of running gears from the normal state of the wedge system of bogie swing suspension also play an important role among them. The purpose of the paper is to investigate the influence of different factors of the technical conditions of freight car running gears (size deviation in both the bearers and the wedge system during operation) on their basic indices – coefficients of horizontal and vertical dynamics, vehicle body acceleration, frame strength, and derailment stability coefficient. Methodology. The study was conducted by numerical integration and mathematical modeling of the freight car dynamic loading using the software package “Dynamics of Rail Vehicles” (“DYNRAIL”). Findings. As a result of the research for freight car dynamic coefficients determination taking into account technical conditions of the side bearers, the dependencies of the basic freight cars dynamic coefficients on the parameters of side bearers (the clearances in the side bearers and the wedge system conditions of the bogie swing suspension) considering running speed in the tangent and curved track sections of minor and mean radii were obtained. Originality. The impact of the technical condition of the car running gears on the traffic safety factors is determined. Practical value. The theoretical research results in determination of freight car dynamic indices taking into consideration the technical conditions of the side bearers of freight cars allow for an adequate assessment of effect of the freight car bogies’ technical conditions, namely the bearers parameters, on the railway traffic safety factors (coefficients of horizontal and vertical dynamics, vehicle body acceleration, frame strength and derailment stability coefficient).Item Dynamic Performance of Freight Cars on Bogies Model 18-1711(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2013) Bubnov, Valerii M.; Myamlin, Serhiy V.; Mankevych, Mykola B.EN: Purpose. To analyze the results of study of dynamic parameters of the tank-car model 15-1900 and gondola car model 12-1905, equipped with the bogies model 18-1711 with axle loading of 25 ton and unified according to major parts and joints with the cars of previous generation. According to results of the study to conclude about the possibility of using bogies model 18-1711 as the running parts of the freight rolling stock of the new generation of 1520 mm track with increased axle loading. Methodology. The dynamic performance of the rolling stock running parts directly affects the safety of railway traffic. Experimental studies of the car dynamic qualities are an important step in the modernization of existing bogie constructions and in the creation of the new ones. These tests allow one to confirm the results of theoretical studies and to check the correctness of the constructive solutions. Findings. Basic results of dynamic studies are presented as the graphs of dynamic performance dependencies on the motion speed of the experimental train. Results show that the freight cars on the bogies model 18-1711 have satisfactory dynamic properties meeting current regulatory requirements. Originality. The dynamic characteristics of freight cars on bogies model 18-1711, which give a complete view of the car loading allow us to estimate the dependency of the car dynamic performance on the bogie design parameters. Practical value. The bogie model 18-1711 with axle loading 25 ton can be used as a freight car undercarriages of the new generation of 1520 mm track.Item Evaluation of Longitudinal Loading of Tank Trains During Motion in Longitudinal Changes of Gradient(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2013) Myamlin, Serhiy V.; Romanyuk, Yanina N.EN: Purpose. To research the tank train longitudinal loading during motion by track sections with changes of gradient. The trains of different length that consist of bogie tank wagons should be examined. Influence of cargo type on longitudinal loading of train during motion in concave section of track should be evaluated. Methodology. The level of the largest longitudinal forces was estimated by mathematical simulation. It was assumed that change of gradient is formed by two grades with baffle platforms, length 50 meters, so that the algebraic difference of limiting grades vary from 10 to 40 ‰, pitch 10 ‰. The initial speeds were 40, 60, 80, 100, 120 km/h. For evaluation of the longitudinal loading the regulating braking and motion «by coasting» was considered. For evaluation of buffing loads the entry to the concave gradient change of expanded train is considered, and in order to determine the quasi-static forces the compressed train is considered. Findings. As a result of calculations the dependencies of maximal longitudinal forces in the trains on the cargo type, the algebraic difference of the grades, the number of tank wagons, the initial speed, motion modes, and initial gaps condition in the train were obtained. Originality. The longitudinal loading of freight cars of different length formed by the similar bogie tank wagons with one locomotive was obtained. The locomotive is placed in the train head during motion in concave track sections with various algebraic difference of the grades «on coasting» and during the regulating braking mode. The obtained results can be used for parameters standardization of profile elevation of the track. Practical value. The obtained results show that during operation of tank trains on track sections of complex breakage the most dangerous is regulating braking of preliminary compressed trains during entering on concave parts of track. Level of the greatest buffing and quasi-static longitudinal forces is almost independent of cargo and slightly depends on the initial speed.Item To the Question of Modeling of Wheels and Rails Wear Processes(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2013) Manashkin, Lev A.; Myamlin, Serhiy V.EN: Purpose. There is a need of wear process modeling in the wheel-rail system. This is related to the fact that the wear processes in this system are absolutely different in the initial and final stages. The profile change of rail and, especially, of the wheels caused by the wear significantly affects the rolling stock dynamics, traffic safety and the resource of the wheels and rails. Wear modeling and the traffic safety evaluation requires the accounting of the low frequency component forces (including the modeling of transitional areas) affecting the wheel on the side of the rail and carriage in motion of rolling stock, so the statistical analysis is not possible. Methodology. The method of mathematical modeling of the wheel set and the rail interaction was used during the research conducting. Findings. As a result of the modeling of the wheel set motion on the rail track, the mathematic model with 19 freedom degrees was obtained. This model takes into account the axle torque and studies wheels constructions as the components of the mechanical systems, consisting of a hub and tire. Originality. The mathematic model allows evaluating the wear degree of the wheels and rails when using on the rolling stock not only all-metal wheel sets, but also compound ones with the use of spring wheels and independent rotation of semi-axes with the wheels. Practical value. The development of the improved mathematical model of freight car wheel set motion with differential rotation of the wheels and compound axles allows studying the wear processes of wheels and rails.