FLAT CARS COUPLING DYNAMICS WHEN TRANSPORTING LONG CARGO

Abstract

Purpose. In connection with the tendency to intensify the transportation process under conditions of increased axial loads and train speeds the article aims to investigate the dynamic loading of the coupling of two flat cars with a long load, as well as to determine the dynamic forces of interaction under the action of quasi-static longitudinal forces. Methodology. The research is based on the method of mathematical and computer modeling of dynamic loading of longitudinal-and-flexural vibrations of a 22 m long stack of cargo, located on the coupling of two flat cars of 13-4012 model. The kinetic and potential energies of the system are compiled taking into account the kinetic and potential energies of the load, which are calculated using the known fundamental functions. To determine the fundamental functions, the problem of flexural vibrations of a load as a beam on two elastic supports was solved. To determine the fundamental functions for longitudinal displacements, the differential equation of free longitudinal vibrations of a bar of constant cross section was used. Theoretical studies were carried out when moving of flat cars with typical bogies 18-100 at speeds in the range from 60 to 100 km/h on a straight section of the railway track. Findings. During the study it was taken into account the movement of flat car coupling along a sinusoidal irregularity with a length of 25 m and different depths under the action of longitudinal compressive or tensile forces, as well as during running out. In the course of theoretical studies and after the modeling, taking into account the oscillation processes of the flat car and long cargo, in the presence of quasi-static longitudinal forces, the dependences of the main dynamic indicators on the movement speed were obtained. Originality. To determine the dynamic loading of the flat car coupling, a mathematical model of longitudinal-and-flexural vibrations in the vertical plane of the cargo stack-platform car coupling system has been developed. The proposed mathematical model makes it possible to theoretically determine the dynamic parameters of the system and ensure the development of methods for transporting long cargo in accordance with the safety requirements of train traffic. Practical value. As a result of the theoretical studies, a relevant and practically important problem of determining the loading of flat car coupling during the transportation of long cargo was solved, which will allow developing technical conditions for the implementation of resource-saving technologies.