Nauka ta progres transportu (Dec 2019)
GONDOLA CARS DYNAMICS FROM THE ACTION OF LONGITUDINAL FORCES
Abstract
Purpose. The aim of the work is to study the influence of longitudinal quasistatic tensile and compressive forces in gondola cars arising at stationary and transient modes of train movement on their main dynamic indicators and interaction indicators of rolling stock with a rail track, taking into account the possibility of speed increasing. The relevance of this study is related with the need to control the longitudinal forces arising during stationary and transient modes of train movement, with increasing speeds, masses and lengths of trains, especially freight ones, increasing the locomotives` power. Methodology. The main method for studying the dynamic loading of a gondola car on typical three-element bogies is mathematical and computer modeling of the interaction of rolling stock and track structure based on the model of spatial vibrations of freight cars` couplings. In a theoretical study, the influence of quasistatic longitudinal tensile and compressive forces is considered depending on the change in speed and the force value on the tension of 1 MN; 0.5 MN; 0 and before compression of 0.5 MN; 1 MN. Findings. As a result of theoretical studies and after modeling, taking into account the processes of oscillation of gondola cars under the action of quasistatic longitudinal forces limited by norms to ± 1MN (100 tf), the dependencies of the main parameters normalized by technical documentation are obtained taking into account the value of the movement speed. Originality. The influence of longitudinal compressive and tensile forces on the dynamic loading of a freight car is studied in order to solve the problem of forecasting the dynamics of rolling stock, taking into account the value of the speed along curved track sections. Practical value. Application of the results obtained can increase the stability of freight rolling stock and the strength of the railway track, which in turn will remove some existing restrictions on permissible speeds and increase the technical speed of trains. The obtained dependencies of the main normalized indices on the longitudinal quasistatic force will make it possible to predict the development of deviations and prevent their transformation into the dangerous ones for train movement.
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