Search results

The subject of the research is a sub-rail foundation containing a viscous element. The purpose of the study is to evaluate the effect of including a viscous element in the elastic system (rails, sleepers, ballast, etc.) on the overall rigidity of a railway track. The design of a sub-rail foundation with a viscous element is described by the generalized Maxwell model and contains a shell filled with a Newtonian fluid, in particular air. Pneumatic shells with different thicknesses were considered. The modeling was carried out in the finite element analysis environment. Mathematical models of a track section with a sub-rail device containing a pneumatic shell were constructed. The calculation results showed the absence of a sharp increase in internal force factors and stress concentration in typical track sections when laying a sub-rail foundation with a pneumatic element. A change in the overall rigidity in the vertical plane did not lead to a significant change in bending stresses in the edges of the rails. With a small shell thickness, the bending stresses in the upper area of the sleeper decrease to 35 %, and in the lower area by 15 %. The maximum increase of up to 8 % is observed with a sharp difference in the shell thicknesses. Compressive stresses on the sleeper in the under-rail zone increase with a small shell thickness of the device due to the redistribution of forces to a smaller number of under-rail supports when the overall rigidity of the structure changes. Increasing the shell thickness to 40 cm leads to an increase in mechanical stresses of up to 20 %, which is an acceptable value with a large margin. The use of under-rail foundations with a viscous element is recommended for temporary railway tracks when laying them instead of ballast and sleepers, which allows for the track to be quickly laid and also quickly dismantled.

The work is devoted to the consideration of the possibility of using composite materials with an aluminum matrix in the design of electric transport pantographs. Currently, there is a tendency to increase the speeds of electric transport. This fact requires reliable and high-quality current collection, which can be achieved by reducing the mass of the current collector design, including through the use of composite materials. The possibility of using composite materials in parts and assemblies of current collectors operating under conditions of increased current loads and at high speeds of movement and the mechanical characteristics of the traditional ones used in the carriage design and the composite materials proposed for use are analyzed. The design of a carriage of high-speed electric rolling stock has been developed, in which an aluminum matrix composite material was used as a structural material. Statistical modeling using the finite element method in the SOLIDWORKS Simulation software package was performed. Comparison of the strength characteristics of carriage assemblies made of traditional materials and aluminum matrix composite showed the possibility of reducing their weight in the case of composite use without reducing the strength of structural elements. The static characteristic of the carriage in which the composite material was used coincides with the static characteristic of the carriage made of traditional materials, which confirms the possibility of using an aluminum matrix composite without making significant changes to the carriage design. To evaluate the dynamic characteristics of the composite carriage and its effect on the dynamic characteristics of the pantograph, modeling was carried out using the methods of multibody modeling of SOLIDWORKS Motion. The obtained simulation results indicate an improvement in dynamic characteristics when using composite materials, which has a beneficial effect on the reliability and quality of current collection.