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.

The power factor improving of the motors in enterprises with repair of railway equipment

Abstract: In this article the following problem has been considered: ways of power factor increase for electric drives installed at the railway machinery repair enterprises with taking into account the specific conditions of technological processes.

The development prospects of ukrainian market of transport services

Abstract: The article gives a brief analysis to the state of transport services market in Ukraine and proposes measures of its improvement.

An Overview of the Etcs Braking Curves

Abstract: The purpose of the article is to present an overview of the ETCS braking curves according to the European specifications. Though the ETCS specifications lay down the basic principles for the braking curves and the associated information displayed to the driver, but there is still no harmonized method to compute them. In the absence of any requirement, the algorithms of the ETCS on-board suppliers lead to different braking distances for a given type of rolling stock. For cross border trains, the differences through national rules require the implementation in the ETCS on-board of several national braking curves. The main features of the braking curves have been reviewed in the article, including the following main aspects: basic principle to ensure of the train movement safety, the purpose and main types of ETCS braking curves, the input parameters for braking curve calculation, construction of the emergency brake deceleration curve, and guaranteed emergency brake deceleration. The basic principle to ensure the train movement safety is based on their separation in fixed block distance (for a conventional signalling system) or in moving block-sections (for ERTMS/ETCS level 3). To ensure these principles the ETCS onboard computer must predict the decrease of the train speed in the future, from a mathematical model of the train braking dynamics and of the track characteristics ahead. This prediction of the speed decrease versus distance is called a braking curve. The minimum interval between trains under automatic train protection system is defined by minimum movement authority that comprises odometer tolerance, driver allowance, ATP reaction times, brake application time. Braking curve predict of the train speed decrease versus distance by the ERTMS/ETCS on-board equipment, from a mathematical model of the train braking dynamics and the track characteristics ahead. ETCS supervises both the position and speed of the train to ensure they continuously remain within the allowed speed and distance limits, and if necessary it will command the intervention of the braking system to avoid any risk of the train exceeding those limits. There have been considered in the work the main ETCS braking curves and the supervision limits of the EBD braking curves, the movement authority, the end of authority, the most restrictive speed profile, the supervised location and others. Differences in braking on dry and wet rails are considered. The braking on dry rails is relatively easy to represent through a statistical model that take into account the dispersion of the braking performance. But on wet rails the physical phenomenon that occur when braking are still today extremely difficult to model. In order to overcome this difficulty, two distinct rolling stock correction factors have been considered in order to get the guaranteed emergency brake deceleration.

Strengthening of reinforced concrete road bridges composite materials

Abstract: У статті розглядаються питання проектування і технології посилення залізобетонних мостів з використанням композиційних матеріалів.

Analysis of influence of design characteristics of inclined bucket elevator on the power of its drive

Abstract: Purpose. One of the main elements of the inclined belt bucket elevators is their drive. To determine the drive power, it is necessary to carry out calculations according to standard methods, which are described in the modern literature. The basic design parameters are the productivity, lifting height, type and properties of the transported material, the angle of inclination. It is necessary to build a parametric dependence of the driving power of the elevator on its design parameters, which takes into account the standard sizes and types of buckets and belts . Methodology. Using the methodology of traction calculation of inclined belt bucket elevator there were built parametric dependences of efforts in specific points of the route of the elevator, as well as the parametric dependences of the drive power of high-speed elevators with deep and shallow buckets on their design parameters and characteristics . Findings. On the basis of constructed parametric dependencies, it was found that the function of changing the value of the elevator’s power from design capacity (at fixed lifting height, type of cargo, belt speed) is piecewise constant and monotonically increasing. It was built a graphical representation of elevator drive power on the angle of its inclination within acceptable limits of change. The resulting relationship is non-linear and monotonically decreasing. In general terms the intervals of project performance values, which provide a constant value of drive power of inclined elevator were defined. As an example of the obtained results it was observed the process of dependence construction of the drive power on design capacity and inclination angle of the elevator for transporting the fine coal . Originality. For the first time there were constructed the parametric dependences of drive power of inclined bucket elevator on its design parameters that take into account the standard sizes and types of buckets and belts . Practical value. Using the constructed dependencies enables relatively quick determination of the approximate value of the drive power of high-speed inclined elevators with deep and shallow buckets at the design stage and high-quality selection of its basic elements in the design of specific characteristics: type of cargo, productivity, lifting height, angle of inclination .