Mechanical Tests Performed on Rubber Plates Used on Railway Vehicles

In order to place a product on the market that is completely safe for users, the manufacturer must go through certain steps: design, prototyping, execution and prototype validation through experimental methods, obtaining documents that allow to sell the product from certain public or private companies (for example homologation certificate) and series production. One of the most important steps is the validation tests of the prototype because it will depend on them that the prototype corresponds to the design requirements.

Optimal design of the disc vents for high-speed railway vehicles using thermal-structural coupled analysis with genetic algorithm

Braking devices are devices that convert kinetic energy into thermal energy using frictional force. A disc-type brake uses the frictional force to brake and can be used in a wide range of applications, such as automobiles, railway vehicles, and aircraft. However, heat dissipation of the disc has been considered a major problem. High temperatures during the braking process cause thermal stress and deformation problems of the disc because the physical properties of metal composing the disc change drastically with temperature. In this study, vents were applied on the disc surface to increase their heat dissipation performance. In general, vents are structurally susceptible to stress and deformation. However, heat dissipation is essential because the disc surface rises to high temperatures. Therefore, a thermal-structural coupled analysis was performed using the computational fluid dynamics and finite element method methods. Five different rotational speeds and surface temperatures of the disc were considered. Design of experiments was used to determine an optimized design utilizing the data from the coupled analysis, and Latin hypercube sampling was used to generate samples from a set of N regions. And the genetic algorithm was used to conduct a sensitivity analysis of the design parameters. The optimized design was determined for harsh conditions. The diameters of vents were selected 6.87 mm, 6.12 mm, and 5.99 mm in a radial direction through the optimization. Thermal stress and deformation acting on the disc were reduced in the optimally designed disc. The optimized disc model experiences a 7.01% decrease in maximum equivalent stress when compared to the original disc. The model also decreased by 7.63% in maximum equivalent elastic strain. So, through enhanced convection-induced heat dissipation, the vents can be considered as a new way to prevent problems with the thermal stress and deformation that were apparent at high temperatures.

Improvement of technology of production of compensation copper and copper steel current ducts

The article describes the technology of manufacturing conductors for power supply systems for cranes, railway vehicles, powerful critical electric motors and power systems. The results of studies for copper-steel samples are shown; in these systems there is a decrease in material losses due to an increase in the strength and durability of products. The proposed technology can be used to use steel-copper wires in power supply loss compensation systems.

Refinement of the rail–wheel contact pair to improve rail–wheel interaction conditions for railway vehicles with an increased axle load

At present, one of the global trends in railway transport development, which becomes clearer and clearer, is increasing the axle load of freight cars, which gives a considerable economic benefit. In this connection, of importance is not only the car design, but also the car capacity utilization factor: the higher this factor, the more economically efficient the car use. Because of this, one of the priority global lines in increasing the volume of fright traffic and the railway operation efficiency is increasing the carrying capacity of freight cars. Preparing the railways for cars with increased axle loads calls for the development of measures to decrease the track deformability, in particular by choosing appropriate wheel and rail profiles. The aim of this work was to develop recommendations on refining the wheel?rail contact pair to improve curve negotiation by railway vehicles with an increased axle loads on the Ukrainian railways. This paper presents the proprietary R-ITM wear-resistant railhead profile. The effect of the new profile on wheel?rail interaction in negotiating a curve of radius 300 m at a constant speed was studied for different cars. In doing so, emphasis was on wheel?rail interaction for a new-generation freight car on 18-9817 trucks with an axle load increased to 36 tf. The studies conducted made it possible to formulate the following recommendations: to improve curve negotiation by railway vehicles with increased axle loads, reduce the adverse effect on the track and improve traffic safety, new proprietary contact pair profiles are recommended: the ITM-73-03 wheel profile for cars, and the R-ITM railhead profile for outer rails together with the standard R65 railhead profile for inner rails.