Gintautas Bureika

A mathematical model of train continuous motion uphill

Abstract The determination problem of adhesion coefficient of locomotives’ wheels with rails is described in this paper. The use of methods of mathematical statistics and theory of probability provides wider possibilities for determining the most acceptable (suitable) value of the adhesion coefficient. The random factors influencing on this value are analysed. The use of the adhesion coefficient values based on reliable research results could help maintain uninterrupted (continuous) traffic of heavy freight trains and increase not only the carrying capacity, but also the volume of the transported goods. The paper considers a mathematical model of steady traffic of heavy freight trains pulled by upgraded locomotives of the series 2M62M on railway line with a gradient. The research results show that the actual values of the adhesion coefficient and the total resistance are distributed according to the normal distribution law. A mode of locomotive motion largely depends on the relationship between the total ...

Research on the compatibility of the calculation methods of rolling‐stock brakes

Abstract One of the main tasks approached by the European Union is the liberalisation of railway transport service market. The foremost problem solved in this paper is the interoperability of various railway systems in the countries of the European Union. Thus, the immediate goal is to solve the problem of the interoperability of different railway systems used in the European Union. A distinction between railway track gauges (from 1435 to 1668 mm), particular couples of wagons, various clearances of rolling stock, different systems of infrastructure etc. are the main impediments. One of the problems in the nearest future will be the evaluation of the brakes of different wagons produced in Western Europe and the former Soviet Union. Freight trains in Lithuania consist of these two types of wagons, and therefore some problems of correcting the results of calculating braking distances and brake force may arise. The main object of this research is to investigate the methods evaluating the brakes of rolling‐st...

Determination of the dynamic characteristics of freight wagons with various bogie

In most cases, dynamic characteristics determine the wagon maintenance cycle, traffic safety, reliability and durability performance. The main dynamic indicators include the vertical Kvd and horizontal Khd dynamic coefficients as well as the stability coefficient Ks, which determines the wheel flange resistance to derailment. The article compares dynamic indications for three different types of bogies. There were no tangible differences observed for all the three different types of bogies running at a speed of 40 to 120 km/h on a direct tangent rail section. Nevertheless, there is a realistic potential to improve the dynamic indicators of a freight wagon by rationalising suspension unit parameters.

An Analytical Mathematical Method for Calculation of the Dynamic Wheel–Rail Impact Force Caused by Wheel Flat

ABSTRACT The simplified method to determine a vertical impact force of wheel with flat and rail interaction is presented in this article. The presented simplified method can be used to identify maximum contact force and its distribution in the contact length between the damaged wheel and the rail. The vertical impact force depends on geometrical parameters of the rail and wheel with flat, speed of vehicle and the angle of deviation of rail. This article demonstrates the influence of wheel with flat geometrical parameters, speed of vehicle to maximum contact force and its distribution in the contact zone. The obtained values of the simplified method for determination of a vertical contact force are compared with the results obtained from field measurements.

Multicriteria evaluation of operational effectiveness of freight diesel locomotives on Lithuanian railways

Abstract The paper analyses and assesses the operating expenses of freight Diesel locomotives 2M62, 2M62K, 2M62M and ER20CF, suggesting the ways of their reduction. Given the damages of the old locomotive M62 and the structure of its operating expenses, some methods of Diesel locomotives’ upgrading are offered. Service life of new generation Diesel locomotives SIEMENS ER20CF and the locomotives 2M62K, 2M62M after the upgrade are determined. The taxes on air pollution by the exhaust gases of Diesel engines are calculated for the locomotives of each series. The effectiveness of operation of freight Diesel locomotives is calculated by three multicriteria evaluation methods and the most efficient freight Diesel locomotive for Lithuanian Railways is determined based on a set of criteria. Basic conclusions are also given.

Mathematical model of dynamic interaction between wheel-set and rail track

Abstract The main goal of this title is to show how the effects on maximum bending tensions at different locations in the track caused by simultaneous changes of the various parameters can be estimated in a rational manner The dynamic of vertical interaction between a moving rigid wheel and a flexible railway track is investigated. A round and smooth wheel tread and an initially straight and non-corrugated rail surface are assumed in the present optimisation study. Asymmetric linear three-dimensional beam structure model of a finite length of the track is suggested including rail, pads. sleepers and ballast with spatially non-proportional damping. Transient bending tensions in sleepers and rail are calculated. The influence of eight selected track parameters on the dynamic behaviour of the track is investigated. A two-level fractional factmial design method is used in the search for a combination of numerical levels of these parameters making the maximum bending tensions the minimum. Finally, the main con...

INVESTIGATION OF DYNAMIC MODELS OF INDEPENDENTLY ROTATING WHEELS OF WAGONS

Abstract The article deals with the modelling of independently rotating wheels (IRW) systems for wagons. The research work of the intensity of rolling stock wheels rims and flanges is observed. The main performance objectives of IRW are to reduce winding of wheel‐sets, to enable railway rolling stocks to achieve higher speeds, to decrease wear of rail and wheel rolling surface, to improve the performance on railway curves and to reduce lateral displacement on rails. IRW with profiled tread are examined and the mathematical model of these IRW is created. Finally, the peculiarities of the stability and wearing characteristics of such IRW systems are presented.

Modelling the assessment of traffic risk at level crossings of Lithuanian railways

AbstractThe article discusses the problem of railway safety management and the criteria for evaluating the traffic risk described in various scientific publications. The research aims to assess the risk posed to railway infrastructure objects and to create a model for safety risk evaluation. The research on the traffic safety risk with respect to the infrastructure of the rail transport system was divided into three stages. The Plan–Do–Check–Act (PDCA) model can be used for investigating the problem of managing railway traffic safety risks in the Lithuanian railways. The main threats to railway infrastructure objects are defined, and the catalogue of technical parameters of level crossings of the Lithuanian railways is presented. The maximum allowable train speed, the intensity of railway and road traffic, as well as the size (width) and visibility of level crossings from the train driver’s cab are chosen as the main criteria for evaluating the vulnerability of a level crossing. The logistic regression me...

The Research on Competitiveness of Road Transport Enterprises: Lithuanian Case

The Research on Competitiveness of Road Transport Enterprises: Lithuanian Case In the paper, various opinions of Lithuanian and foreign authors of scientific publications are reviewed and the criteria for assessing competitiveness of road transport are discussed upon. On assessment of competitiveness of services provided by Lithuanian road transport enterprises, not only technical options are taken into account. It is proposed to assess competitiveness of enterprises upon taking into consideration the total set of services provided as well as their quality and the marketing level of the enterprise. In the paper, the factors impacting competitiveness of road transport are discussed upon and the research works required for objective assessment of competitiveness of road transport are foreseen. A model for assessing competitiveness of road transport enterprises realized by the authors is provided. In the end of the paper, conclusions and recommendations are provided. Autotransporta uzņēmumu konkurētspējas izpēte: Lietuvas piemērs Autori rakstā parāda autotransporta konkurētspējas novērtēšanas kritērijus, pamatojoties uz lietuviešu un aizrobežu zinātnieku pētījumu rezultātiem. Pakalpojumu konkurētspējas novērtēšanā raksta autori iesaka neaprobežoties tikai ar tehniskām iespējām, bet gan analizēt visu piedāvāto pakalpojumu paketi, to kvalitāti un uzņēmuma mārketingu. Rakstā tiek parādīti faktori, kas ietekmē autotransporta konkurētspēju. Bez tam tiek pētīti faktori, kas ietekmē autotransporta pakalpojumu izvēli. Rakstā tiek piedāvāts modelis autotransporta uzņēmuma konkurētspējas novērtēšanai, ko ir aprobējuši Lietuvas autotransporta eksperti.

Theoretical and practical perspectives of diesel locomotive with DC traction motors wheel-sets’ slipping and sliding control

The causes of slipping and sliding of the locomotives driving wheel-sets are analysed from theoretical and practical perspectives. The main factors influencing wheel-sets’ slipping are described, and their correlation is determined. The specific methods of stopping the slipping of the Diesel locomotives and having a conventional electric drive system are described in the paper. The process of wheel-sets’ slipping and its control are simulated and shown graphically. Structural diagrams demonstrating the control of the dynamic locomotive wheel-sets’ slipping and sliding, based on the evaluation of the influence of the speed-torque characteristics of DC traction motors on these processes, are presented. Major parameters of the DC/DC and AC/DC systems used in the automatic control of the dynamic slipping and sliding of the locomotives wheel-sets are defined and new methods of controlling the dynamic slipping and sliding are suggested.