S. A. Kravtsov, A. P. Boldyrev, F. Yu. Lozbinev Computational and Experimental Evaluation of the Characteristics of Polymer Elements [more] [back]
Purpose: To study the job of polymer elements of coupler draft gear. To develop the models of polymer elements of draft gear retaining set given the use in a polymer element of parts that lose stability during an operation. To obtain force characteristics of the developed models of polymer elements with the help of computer simulation. To compare the parameters of obtained force characteristics with the experimental data of non-modernized polymer element. As an object of research, to use supporting polymer element of draft gear PMKP-110. Methods: Computer modeling based on finite element method (FEM) was used to determine optimal variant of polymer element geometry. Since polymer elements’ job involves significant deformation of the elements themselves, the simulation was carried out in software package, which specializes in solving highly nonlinear problems. To compare the effectiveness of the developed models, the polymer element experimental study was carried out. Results: The necessity to study and modernize polymeric suites of automatic coupler draft gears is shown. One of the directions for polymer elements modernization is considered and several variants for polymer element models designed within the studied trends are presented. The most promising variants from possible models was chosen. Further research recommendations are given. Practical significance: The considered approach in polymer element study and modernization makes it possible to obtain a polymer suite with force characteristic improved parameters – an energy intensity and completeness coefficients. Such polymer suites installed into draft gears can increase their reliability, increase the efficiency that in a whole can affect the safety of cars and goods they carry. Keywords: Polymer element, automatic coupler draft gear, finite element method, force characteristic, completeness coefficient, energy intensity, hyper-elastic material
N. S. Bushuev, D. O. Shulman, N. A. Rochev Mastering Results for Passenger Transportation on Moscow — St. Petersburg Direction in Crisis 2020-2021 [more] [back]
Purpose: To show mastering results for passenger transportation by rail and air kinds of transport on Moscow — St. Petersburg direction including ones at crisis 2020–2021, in particular: to analyze the dynamics of changes in passenger traffic of Sapsan trains and air traffic on Moscow — St. Petersburg route as well as of air passenger traffic of domestic air lines of Pulkovo Airport in pre-Covid, Covid and post-Covid periods; to develop mathematical model for passenger traffic forecast. Methods: Regression analysis. Results: The dynamics of passenger traffic changes of railway and air kinds of transport on Moscow-St. Petersburg direction for 2010 to 2019 period has been shown; mathematical model to forecast passenger traffic of being considered kinds of transport till 2022 has been developed; the tendencies for passenger traffic statistical data changes at Covid and post-Covid periods in comparison with expected (forecasted) values have been studied. Practical significance: Conclusion about the expediency of research continuation on passenger traffic forecast in unstable situation conditions in the country and the world as well as in the conditions of strong concurrence between being considered kinds of transport on Moscow — St. Petersburg direction has been made. The analysis results can be recommended for practical use. Keywords: Passenger traffic, Covid-19, rail transport, air transport, Moscow — St. Petersburg direction
M. A. Marchenko Mathematical Model and Approach to Calculate Throughput [more] [back]
Purpose: To propose methodology for calculating actual throughput on railway line with full consideration of racing and drag effect of trains along their way on resulting actual throughput. Methods: Methods of analytical review, simulation and dynamic modeling, mathematical modeling were applied. Results: Analytical transformations of well-known formula for calculating throughput were performed. Analytical formula has been obtained that allows calculating actual throughput with higher accuracy. Practical significance: The results of the study can be used in the dispatch centers of JSC "Russian Railways" transportation management for more complete analysis of the operation of the polygon of a road, railway lines or individual sections in order of more detailed analysis of work, performed on transportation. Keywords: Railway polygon, throughput, inter-train interval, traffic non-parallel schedule, motion speed