Browsing by Author "Vaičiūnas, Gediminas"

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Determination of the Dynamic Characteristics of Freight Wagons with Various Bogie
(Taylor & Francis, 2015) Myamlin, Serhiy V.; Lingaitis, Leonas P.; Dailydka, Stasys; Vaičiūnas, Gediminas; Bogdevičius, Marijonas; Bureika, Gintautas
EN: 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.
Methods of Calculation Line Optimum Travel of Trains with Consideration of Longitudinal Dynamic Efforts
(Wydawnictwo Politechniki Śląskiej Gliwice, 2013) Lingaitis, Leonas Povilas; Vaičiūnas, Gediminas; Liudvinavičius, Lionginas; Jevdomacha, Grigorij; Evdomakha, Grigory V.
EN: The paper examines the main provisions of the methods used for optimization of station-to-station travel time taken (according to the criteria of minimum fuel consumption for haulage) for freight long train timing with consideration of longitudinal dynamic efforts. A hybrid mathematical model of long train travel is developed, where in one case of travel the train is considered as a flexible non-extensible line with a variable running weight, in other cases the train is considered as a system of weights connected by nonlinear deformable elements with a consideration of gap clearance in a draft. The model allows essentially reducing the time of solving the problem. The problem of selecting an optimum mode of train operation with consideration of longitudinal dynamic efforts and use of method of dynamic programming in a discrete form was set.
Research of Mathematical Model of Movement of Six-Axle Locomotives with Controllable Wheelsets Installation
(Springer, Cham, 2020) Kliuiev, Serhii; Bobyr, Dmytro V.; Vaičiūnas, Gediminas; Steišūnas, Stasys
ENG: Research of mathematical model of movement of six-axial locomotive with controllable wheelsets installation. Based on the general system of nonlinear variable coefficient differential equations of the vehicle movement in a rail track with inequalities in plan, the mathematical model of movement dynamics of locomotive of improved design with the axial formula 30-30 as an object of automatic control of the wheelsets position in the rail track is considered. Movement simulation is performed on the example of a six-axle locomotive at the speeds of movement and parameters of the curvilinear track sections, which coincide with the conditions of the experiment presented in the thesis work of V. N. Yazykov. The article presents research results of the mathematical model of movement of the improved locomotive bogie with controllable wheelsets installation in the curvilinear track sections using the Matlab/Simulink software package. The results of experimental studies of the All-Russian Scientific-Research and Design Technological Institute of Rolling Stock and the performed theoretical studies show that the efficiency of the improved system for controlling the wheelset position is higher than that of the serial design, in all modes of movement. The improved system of automatic control of wheelsets position makes it possible to reduce guiding forces by 35%. The possibility of using the mathematical model of locomotive movement of the axial formula 30-30 of improved bogie design with axle-box links of adjustable length, taking into account the dynamics of the automatic control system of the wheelsets installation in the rail track, is theoretically substantiated. The theoretical research found out the reduction of lateral forces in the improved bogie design during the passage of curvilinear track sections. The use of the explored mathematical model of locomotive movement reduces the volume and complexity of research works, as well as increases the reliability of engineering calculations when designing new and improving existing designs of the locomotive underframe.