ANALYSIS OF STRENGTH CHARACTERISTICS IN RAILROAD DOWELS PRODUCED BY VARIOUS MANUFACTURERS

The article describes operating conditions of the railroad dowel used in ZhBR 65 resilient rail fasteners. Requirements for railroad dowel tests in terms of their expediency, possibility to perform such tests and conformity with the actual operating conditions are analyzed. The initiative of the authors, arisen during an analysis of regulatory documents, served as a basis for the studies. Stresses in a dowel and its safety factor in operation and tests were determined analytically by the finite element method, using the APM FEM library, the system of strength analysis for KOMPAS-3D, certified within the GOST-R system. Railroad dowels manufactured by OOO NTT, ZAO Polimer ZAO and Vossloh Fastening Systems GmbH were used as study objects. For the purposes of simulation, 3D models of the corresponding dowels and their mating parts (sleeper, railroad screw, tension clamp, etc.) were built. According to the studies, in tensile tests of dowels, conducted according to Clause 4.6 of Specifications TsP 369 ТU-7, stresses of 85...100 MPa occur in the bodies of all dowels under consideration, which considerably exceed stresses appearing in dowels during operation, and the nature and distribution of such stresses do not correspond to those of operating stresses, the maximum value of which does not exceed 10 MPa. The analysis of stresses arising in sleepers with dowels by the manufacturers under consideration has shown that their limit value is 75 MPa. Besides, in sleepers with dowels by OOO NTT and Vossloh Fastening Systems GmbH, the maximum stresses are in the sleeper body, which allows for their redistribution and prevents dowel pulling-out from a sleeper. Sleepers with dowels made by ZAO Polimer have maximum stresses in the upper face of a sleeper coaxially with the dowel axis, which significantly increases the probability of dowel pulling-out in case of extreme loads

SURFACE ACTIVATION OF THE REINFORCING FILLER AND POLYMER MATRIX MODIFICATION AS EFFICIENT WAYS TO UPGRADE PROPERTIES OF POLYMER-MATRIX COMPOSITES BASED ON EPOXY MATRICES

The article is devoted to issues of interaction rise in the system "polymer matrix — reinforcing filler," which provides an increase in the complex of composite properties. Both surface activation of the reinforcing filler and polymer matrix modification are considered as options. It has been demonstrated that the number of functional groups available for interaction at the surface of basalt fibers increases due to desizing and surface activation of the fibers, which provides an increase in the complex of basalt fiber reinforced polymer properties. It has been found that the use of different methods of surface activation allows providing high strength characteristics of carbon-, glass-, and basalt fiber reinforced polymers, exceeding similar characteristics of materials in which surface activation of the reinforcing filler was not performed. Experiments have proved that the use of unidirectional carbon fibers for reinforcement leads to a significant increase in the entire complex of mechanical properties, due to the possibility to realize stress-strain properties of the reinforcing filler to the limit

Analytical Model for Information Flow Management in Intelligent Transport Systems

The performance of this study involves the use of the zoning method based on the principle of the hierarchical relationship between probabilities. This paper proposes an analytical model allowing for the design of information and analysis platforms in intelligent transport systems. The proposed model uses a synthesis of methods for managing complex systems’ structural dynamics and solves the problem of achieving the optimal balance between the information situations existing for the object and the subject under analysis. A series of principles are formulated that govern the mathematical modeling of information and analysis platforms. Specifically, these include the use of an object-oriented approach to forming the information space of possible decisions and the division into levels and subsystems based on the principles of technology homogeneity and information state heterogeneity. Using the proposed approach, an information and analysis platform is developed for sustainable transportation system management, that allows for the objective, multivariate forecasting-based record of changes in the system’s variables over time for a particular process, and where decision-making simulation models can be adjusted in relation to a particular process based on an information situation existing for a particular process within a complex transport system. The study demonstrates a mathematical model that solves the optimal balance problem in organizationally and technically complex management systems and is based on vector optimization techniques for the most optimal decision-making management. The analysis involves classical mathematical functions with an unlimited number of variables including traffic volume, cargo turnover, safety status, environmental performance, and related variables associated with the movement of objects within a transport network. The study has produced a routing protocol prescribing the optimal vehicle trajectories within an organizationally and technically complex system exposed to a substantial number of external factors of uncertain nature

DEVELOPMENT OF MATHEMATICAL MODELS THE INJECTION PUMP ENGINE KAMAZ-740.11.240 TO DESIGN AND CALCULATE OF HYDRAULIC SYSTEMS

Рассматривается вопрос оптимизации расчётов топливной аппаратуры дизеля. Исследуется степень количественного влияния параметров математических моделей дизельного топлива, показатели и функции чувствительности изменения параметров математических моделей на результаты моделирования.На основании экспериментальных табличных данных различных авторов построены регрессионные модели процессов, происходящих в топливном насосе высокого давления дизеля (ТНВД). Интерполяция табличных зависимостей была получена кубической сплайн интерполяцией.Представлена математическая модель процессов сжимаемости топлива в плунжерной паре ТНВД дизеля, с возможностью количественной оценки влияния значений коэффициента сжимаемости, коэффициента кинематической вязкости дизельного топлива, величины зазора в плунжерной паре, изменения скорости движения плунжера, изменения объёма над плунжером на результаты моделирования.The question of optimization calculations of diesel fuel equipment. We investigate the degree of influence of the quantitative parameters of mathematical models of diesel fuel performance and sensitivity function of parameters of mathematical models for the simulation results. Based on the experimental data of different authors table constructed regression models of the processes occurring in the high-pressure fuel pump diesel (fuel pump). Interpolation table dependence was obtained cubic spline interpolation. A mathematical model of the processes in the compressibility of the fuel injection pump diesel pump element, with the ability to quantify the effect of the compressibility factor, coefficient of kinematic viscosity of diesel fuel, the gap in the pump element, change the speed of movement of the plunger, changes in the volume of the plunger on the simulation results