Leibuk Y. Investigation of the influence of track inertial characteristics on the processes of interaction with rolling stock

The dissertation is devoted to the research of the influence of the reduced mass of the track on the level of forces of interaction of the railway track and passenger rolling stock in the vertical plane in the operating conditions of the main railways. The analysis of mathematical models for determination of forces of interaction of a railway track and a rolling stock for various operating conditions is carried out. He showed that it is possible to use combinations of models that are based on flat calculation schemes of static equilibrium, or spatial systems based on calculation schemes of dynamic equilibrium based on the principle of Lagrange-d'Alembert. Also, one of the conclusions of the analysis can be attributed to the gradual departure from the use in mathematical models of the calculation scheme of the railway track in the form of a beam on a solid elastic basis. The complex of mathematical models of the spatial dynamic system "vehicle-track", which was developed for the conditions of non-public railways, has been modified to take into account the design of passenger electric trains EKr1, HRCS2, EJ675, as well as forced railway track oscillations, taking into account its lead, in the vertical plane under the action of external loads. Based on the dynamic problem of the theory of elasticity, the value of the reduced mass of the railway track is theoretically determined taking into account the geometry of stress propagation (corresponding dynamic deformations) in the half-space involved in the interaction with the rolling stock. It is established that the main factors influencing the reduced mass of the sleeper base (in particular and the reduced mass of the railway track as a whole) are: the thickness of the ballast layer, modulus of deformation and density of ballast and subgrade. The speed of movement has an effect only starting from high levels (from 240 km / h and above) for structures with a low modulus of elasticity of the subrail base. For a railway track with R65 rails on reinforced concrete sleepers, depending on the values of other characteristics, the value of the reduced mass of the railway track is in the range of 11–15 kN. Verification of the theoretically obtained values of the reduced mass of the railway track on the existing sections of the main railways is carried out. Comparison of the data of experimental works with the results of theoretical research showed satisfactory convergence (discrepancy up to 5-8%). The force of interaction of passenger electric trains EKr1, HRCS2, EJ675 and the railway track in the vertical plane has been investigated by numerical methods. The values of the vertical forces of interaction for the selected mobile units in the speed range from 100 to 160 km/h were obtained, both taking into account the reduced mass of the railway track and without it. It is established that taking into account the reduced mass of the railway track, the magnitude of the vertical forces is reduced by 4-17%.