Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan

About: Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan is a education organization based out in Dnipro, Ukraine. It is known for research contribution in the topics: Track (rail transport) & Bogie. The organization has 736 authors who have published 655 publications receiving 1468 citations. The organization is also known as: Institute of Railway Transport Engineers.

Anthropological aspect of the nature of the state

Abstract: The purpose of the research is to find new ways and methods to substantiate ethic and moral standards as the basis of civil interference into the life of the state. The role and place of the state in social, political and spiritual transformations are not always considered due to the crisis of certain social theories and models of state development. Methodology of the research is based on comparative, historical and logical methods. The applied investigation methods enable to reveal and analyze specific models related to anthropological aspect in social relations used in definite types of state formations in order to find that dynamic outlook on future and personal fulfilment of a human.The scientific novelty is in concept to broaden the representation of freedom evolution of a human in different historic types of states. Comparative analysis of state development and the place of human freedom in them helps firstly, conceive anthropological determinant, the one that gradually places under control state institutions which are necessary for humanization of external conditions of human beings and secondly, find out possible directions of state development and freedom for human activity. Conclusions. Understanding and reasoning of paradigm systems development based on moral constituent of the state is an anchoring point for the reforming state towards human values. The state developing on moral human principles gravitates towards its self-destruction.ible directions of state development and freedom for human activity. Conclusions. Understanding and reasoning of paradigm systems development based on moral constituent of the state is an anchoring point for the reforming state towards human values. The state developing on moral human principles gravitates towards its self-destruction.

Metastable state of the Li 2 O-11.5GeO 2 glass-ceramics with a high electrical conductivity

Abstract: A glass of the Li2O-11.5GeO2 composition has been crystallized by heating and isothermal treatment near the devitrification temperature. The thermal properties and electrical conductivity σ of the glass in an alternating-current electric field have been investigated in the process of crystallization during the heating. The dependences σ(T) have been measured for isothermally crystallized Li2O-11.5GeO2 samples. Glass-ceramic samples in an intermediate metastable state with a high electrical conductivity have been synthesized by heat treatment of the initial glass. At T ∼ 500 K, the electrical conductivity of the intermediate state is one order of magnitude higher than that of the initial glass and three orders of magnitude higher than in the case of glass-ceramics consisting of Li2Ge7O15 crystallites and the GeO2 amorphous phase. It has been assumed that an increase in the electrical conductivity σ of the samples in the intermediate state is caused by the electrical conductivity of subsurface layers and is determined by the presence of a large number of nanometer-scale ordered regions in the structure.

Determination of the issue concerning the lift resistance factor of lightweight car

Abstract: Purpose. The analytical study of the connection between the longitudinal force, acting on the light-weight car, lateral and vertical forces of interaction in the contact zone «wheel – rail» with the lift resistance factor value is to provide a simple relationships between them. Methodology. Research was conducted by the method of mathematical modeling of loading the freight car when driving at different speeds on straight and curved sections of a track. Findings. Even in the absence of «lift» accordingly the classical train stability theory, as the hinge-rod system, the presence of the longitudinal compressive forces may become a factor provoking cars derailment. The main reason of wheel climbing on rails is the combination of processes of dynamic interaction between the hunting vehicle and the track with simultaneous action of longitudinal compressive forces, and not the destabilization of train as a hingedrod system. To assess the impact of the longitudinal forces value on the lift resistance factor there are presented the calculation results for the empty gondola car motion, model No. 12-532, on 250 m radius curve with 150 mm rise and cross starting of car underframe relating to the track axis in 50 mm guiding section. The calculations were made in such a curve excluding the inertial forces from outstanding acceleration and taking into account the unbalanced acceleration with the permissible speed of 65 km/h. Originality. This study provides the technique of determining the lift resistance factor by longitudinal forces, which is somewhat different from the standard one, as well as evaluates impact of rolling stock speed on this factor. Practical value. The authors clarify the current method of determining the lift resistance factor by longitudinal forces and assess the impact of rolling stock speed on the value of this factor. From these studies one can conclude that because of cars hunting their lift is possible even when the train as hinge-rod system does not lose stability. The developed proposals allow reducing the number of car derailment by taking into account important parameters and characteristics during the process of calculation and design that increase their stability in the rail track especially in case of increased speed of freight trains.

Three-element bogie side frame strength

Abstract: Purpose. To evaluate the effect of different loads on the stress-strain state of the freight car bogie side frame, as well as to evaluate the distribution of the stress fields in the design of the freight car bogie side frame supported through the horizontal surface and through the horizontal and inclined surfaces of the pedestal opening. Methodology. A volumetric finite element model of the side frame of ZK-1 bogie of the freight car was designed. The forces under the current regulatory documentation for theoretical research were applied to the model, the stress arising in the model elements were determined. The static tests of ZK-1 bogie side frame were conducted; they allowed determining the stresses in the key points of the frame under the action of forces in accordance with the existing procedure of static tests of the freight car bogie side frame. To check the quality of the finite element model we determined the stress in the model under the action of forces corresponding to the static requirements. The corresponding coefficients were determined to match the stress obtained through theoretical studies and static tests. The results of theoretical and experimental studies of stress for dangerous sections of the side frame design were compared. Findings . The regulatory documentation for carrying out experimental research of the side frame strength does not fully take into account the load acting on the frame during its operation and that provided while assessing the side frame strength theoretically. The strength evaluation of the side frame by the results of field tests only does not give a complete picture of the distribution of stress fields, as the provided sensor installation points do not cover most of the design elements with possible stress concentration. Originality . The loads applied to the side frame during theoretical and experimental studies were compared to the loads acting during operation. The impact of use of inclined surfaces in the pedestal box opening was evaluated. Practical value. The obtained results allow the more accurate assessment of the three-piece bogie side frame strength, as well as allow you to choose the more preferred method of side frame support in the axle box.

Determination of dynamic performance of freight cars taking into account technical condition of side bearers

Abstract: 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).