scholarly journals The Mathematical Support of Machine Surfacing for the Railway Track

2020 ◽  
Vol 13 (3) ◽  
pp. 246-267
Author(s):  
Dmytro Kurhan ◽  
Maksym Havrylov
Keyword(s):  
Mathematical Model ◽  
Software Package ◽  
Geometric Shape ◽  
Railway Track ◽  
Mathematical Tool ◽  
Information Base ◽  
Automation Systems ◽  
Maintenance Personnel ◽  
The Mathematical Model

The condition of a railway track is characterized by many indices, including its geometric shape, both in the horizontal and vertical planes. The purpose of this paper is to create a mathematical tool to ensure the operation of track machines for surfacing, tamping, and alignment, which are equipped with automation systems. The developed mathematical model will be integrated into the AS "Strela" software package which is currently installed on machines. Scientific approaches used in the mathematical model allowed to reduce the operation of machines in "window", to simplify the work of maintenance personnel, to create an information base of track parameters, to establish rational parameters of curves during surfacing.

Mathematical Modeling for Longitudinal Displacement of a Straight Continuously Welded Railway Track and its Numerical Implementation

2011 ◽  
Vol 462-463 ◽  
pp. 801-806 ◽  
Author(s):  
Abreeza Manap
Keyword(s):  
Mathematical Model ◽  
Computer Software ◽  
Railway Track ◽  
Track Length ◽  
Longitudinal Displacement ◽  
Track System ◽  
Displacement Pattern ◽  
Longitudinal Flexibility ◽  
Displacement Patterns ◽  
The Mathematical Model

A mathematical model of the longitudinal flexibility of a continuously welded railway track and the methodology for the analysis of the longitudinal displacement of rails under the effects of passing trains is developed to investigate the longitudinal behavior of rails. The purpose of this analysis is to explore the changes of longitudinal stress distribution in the rails due to mechanical loading applied by a travelling train. A half track system is used to derive the equations required to obtain the magnitude of deflection and force of rails and these values are scaled to produce the displacement pattern using the method of superposition. The mathematical model is translated into MATLAB and validation of the program is verified through comparisons of displacement patterns generated by a computer software LONGIN. Analysis of a straight track due to train braking was performed over a track length of 1000 m. The longitudinal displacement obtained showed that maximum longitudinal displacement occur in the middle of the track at the distance of 570 m which is in direct agreement with the published result.

scholarly journals MATHEMATICAL MODEL OF RAILWAY DYNAMICS AUTONOMOUS TRACTION MODULE

2021 ◽  
pp. 119-120
Author(s):  
Frantisek Bures
Keyword(s):  
Complex System ◽  
Mathematical Model ◽  
Mathematical Description ◽  
Railway Track ◽  
Railway Transport ◽  
Railway Dynamics ◽  
The Mathematical Model

In the report the author offers a mathematical description of the model of the dynamics of the railway autonomous traction module. The autonomous traction module is a multi-mass complex system moving on a railway track. The mathematical model takes into account the parameters and types of connections between the solids of the system, as well as takes into account the sliding forces between the wheels and rails. The mathematical model developed by the author can be applied at theoretical researches of innovative designs of autonomous traction means on railway transport.

NUMERICAL AND PROGRAM IMPLEMENTATION OF A ONE-DIMENSIONAL MATHEMATICAL MODEL OF HYDRAULIC FRACTURING

2021 ◽  
Vol 7 (1) ◽  
pp. 126-145
Author(s):  
Alexey S. SHLYAPKIN ◽  
Alexey V. TATOSOV
Keyword(s):  
Mathematical Model ◽  
Hydraulic Fracturing ◽  
Program Implementation ◽  
Software Package ◽  
Import Substitution ◽  
Point Of View ◽  
Growth Potential ◽  
Design Problems ◽  
Software Market ◽  
The Mathematical Model

At present, an active policy of import substitution is being pursued, dictated by the imposed international sanctions, which creates a need for finding optimal engineering solutions, in particular, in the field of creating Russian software. In the study and design of hydraulic fracturing, they often rely on the results of modeling in specialized simulators. The appearance of the Russian products on the software market, surely, sets the correct vector of development; however, some aspects are not implemented in the existing mathematical models. The authors of this article present a model that allows considering in detail the process of movement of proppant particles in a hydraulic fracture. The chosen direction is important from the point of view of calculating the fracture cavity and refining its productivity, since the behavior of the particles has a significant effect on both the growth potential of the crack and its shape. The research methodology includes a theoretical justification of the mathematical model presented by the authors in their previous works; a description of the basic principles of selecting and constructing a numerical calculation scheme and creating a software package. The main methods of research are the methods of mathematical modeling, formed from practical problems on the estimation of geometric parameters of the crack, including the areas of continuum mechanics and fracture of solids, underground hydrodynamics. The proposed and implemented numerically mathematical model forms the basis of the authors’ software package, which allows solving the main design problems when performing hydraulic fracturing operations.

Mathematical Modeling and Optimization of Fluidized Layer Carbonitriding Process for 1C 25 Steel

2017 ◽  
Vol 1143 ◽  
pp. 180-187
Author(s):  
Marian Iulian Neacsu ◽  
Sorin Dobrovici
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Software Package ◽  
Order Equation ◽  
Graphical Interface ◽  
Technological Parameters ◽  
Fluidized Layer ◽  
The Mathematical Model ◽  
Hardness Values ◽  
Temperature Depth

This paper presents the experiment-based mathematical modelling of fluidized bed carbonitriding process for 1C 25 steel meant to optimize this type of thermochemical processing.Based on experimental results, the mathematical model was developed, which is a second order equation with three unknown terms (parameters): temperature, depth of carbonitrided layer, the percentage of ammonia.The mathematical model allowed the simulation of the fluidized layer carbonitriding process according to its parameters and the thermal energy optimization for obtaining HV hardness values in the range 300-400 MPa.Using the software package Matlab a graphical interface was done, through which all the combinations of technological parameters of the carbonitriding process are determined, leading to obtaining values of microhardness between 300 and 400 MPa, as well as the amount of energy consumed for each variant. The variant consuming the lowest energy is considered optimal.

Dynamics of a Rolling Wheelset

1993 ◽  
Vol 46 (7) ◽  
pp. 438-444 ◽  
Author(s):  
Hans True
Keyword(s):  
Mathematical Model ◽  
Equilibrium Point ◽  
Chaotic Motion ◽  
Dynamical Behavior ◽  
Railway Track ◽  
Kinematics And Dynamics ◽  
Bifurcation Diagrams ◽  
Speed Range ◽  
Set Up ◽  
The Mathematical Model

We discuss the kinematics and dynamics of a wheelset rolling on a railway track. The mathematical model of a suspended wheelset rolling with constant speed on a straight track is set up and its dynamics is investigated numerically. The results are presented mainly on bifurcation diagrams. Several kinds of dynamical behavior is identified within the investigated speed range. We find a stationary equilibrium point at low speeds and at higher speeds symmetric and asymmetric oscillations are found and ranges with chaotic motion are identified. The bifurcations are described.

scholarly journals A software package for the simulation of fluid flows in discrete fracture networks with vugs

2018 ◽  
pp. 405-415
Author(s):  
А.В. Блонский
Keyword(s):  
Mathematical Model ◽  
Software Package ◽  
Fluid Flows ◽  
Software Implementation ◽  
Computational Algorithms ◽  
Fracture Networks ◽  
Software Packages ◽  
Discrete Fracture Networks ◽  
Discrete Fracture ◽  
The Mathematical Model

Представлен программный комплекс для математического моделирования течений в дискретных системах трещин. Описана математическая модель течения, приведено краткое изложение вычислительных алгоритмов и сформулированы особенности программной реализации. Рассмотрена структура разработанного программного комплекса, обсуждаются аналогичные программные комплексы и указаны их отличия от представленного в настоящей статье. На ряде задач продемонстрирована работоспособность предложенных в статье математической модели, алгоритмов и программного комплекса. A software package for the mathematical simulation of fluid flows in discrete fracture networks is proposed. The mathematical model of flows is analyzed, a brief description of the computational algorithms is given, and the features of software implementation are formulated. The structure of the developed software package is considered, a number of similar software packages are discussed, and their differences from the proposed one are shown. A number of model problems are solved to demonstrate the efficiency of the proposed mathematical model, algorithms, and software implementation.

Dynamics of Working Processes in Automatic Direct-Acting Pressure Regulators of Pneumatic Spacecraft Systems

2021 ◽  
pp. 65-76
Author(s):  
A.V. Lebedev ◽  
A.V. Chernyshev ◽  
Y.V. Kyurdzhiev ◽  
A.P. Mitrofanov ◽  
O.S. Ilicheva ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Software Package ◽  
Block Diagram ◽  
Working Fluid ◽  
Pressure Regulator ◽  
Conservation Of Energy ◽  
General Mathematical Model ◽  
Direct Acting ◽  
The Mathematical Model ◽  
Working Processes

The purpose of the study was by means of modern software to explore working processes taking place in automatic direct-acting pressure regulators of pneumatic spacecraft systems. As a result, we developed a general mathematical model of the pressure regulator. The design of the regulator is shown in the form of a block diagram, composed of a set of channels, cavities, and stages. The elements of the block diagram are interconnected by the basic laws of conservation of energy and mass. The mathematical model was evaluated in the Amesim software package. Findings of the full-scale and computational experiments led to the conclusions about the effect the heat exchange between the working fluid and the environment produces on the parameters of the pressure regulator, and about the use of the Amesim software package for further research of working processes in the valve units of pneumatic systems.

scholarly journals DETERMINATION OF SUSTAINABLE LEVELS OF DESIGN ALTERNATIVES SELECTION IN THE WORKFLOW CAP SYSTEM

2021 ◽  
pp. 48-56
Author(s):  
S. G. Mitin ◽  
◽  
P. Yu. Bochkarev ◽  
V. V. Shalunov ◽  
I. A. Razmanov ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Fast Response ◽  
Design Solution ◽  
Design Activity ◽  
Mathematical Tool ◽  
Process Implementation ◽  
Design Alternatives ◽  
Level Of Selection ◽  
The Mathematical Model ◽  
Production Situation

The development of the mechanical treatment workflow CAP system is aimed at the solution of a crucial task of reduction of terms and the improvement of quality of multiproduct machining manufactures work preparation, as the existing workflow CAP systems have not got the possibility of fast response to changes in a production situation often arising within the multiproduct manufacture. The authors of this paper developed the workflow CAP system, which contains the requirements of the design activity full automation, design solution multivariance, and the feedback with the engineering process implementation subsystem. The paper deals with the development of a mathematical model and the technique of searching for sustainable levels of selecting design alternatives depending on the production situation for the whole design procedures of the workflow CAP system. The authors prove the application of a mathematical tool of genetic algorithms; describe the mathematical model using its terms. As a gene, the level of selection in a separate project procedure is specified. A chromosome is a set of genes according to the project procedures. The objective function determines the minimum total time of processing of the specified nomenclature of parts based on the ranges of gene aggregates resulting from crossing and mutation operations. The result of the work is the mathematical model and the technique for identifying the sustainable levels of selection in each project procedure ensuring the possibility of self-adjustment of the workflow CAP system depending on the production situation.

scholarly journals A software package for modeling the propagation of dynamic wave disturbances in heterogeneous multi-scale media

2021 ◽  
Vol 2056 (1) ◽  
pp. 012012
Author(s):  
N. Khokhlov
Keyword(s):  
Mathematical Model ◽  
Software Package ◽  
Heterogeneous Media ◽  
Numerical Algorithms ◽  
Theory Of Elasticity ◽  
Multi Scale ◽  
Wave Disturbances ◽  
The Mathematical Model ◽  
Selection Of ◽  
Dynamic Wave

Abstract The paper considers a software package designed to simulate the propagation of dynamic wave disturbances in heterogeneous media. One of the main features of the considered software package is numerical algorithms with an explicit selection of inhomogeneities. Within the framework of the work, such inhomogeneities as pores, fractures and interfaces between media (contact boundaries) are considered. The considered algorithms make it possible to perform calculations in different scale settings in micro and macro sizes. The mathematical model is based on the equations of the linear theory of elasticity. For the calculation, block structural meshes are used. The software package is parallelized using MPI and OpenMP technologies. Separate parts of the algorithm are parallelized using graphics accelerators such as GPGPU. The paper describes the features of the algorithms under consideration and provides examples of calculations that demonstrate the capabilities of the algorithm.

JOURNAL BEARING WITH VARIABLE DYNAMIC CHARACTERISTICS: SIMULATION RESULTS AND VERIFICATION

2021 ◽  
Vol 2 ◽  
pp. 140-145
Author(s):  
A.S. FETISOV ◽  
A.V. KORNAEV
Keyword(s):  
Fluid Dynamics ◽  
Mathematical Model ◽  
Software Package ◽  
Computational Experiment ◽  
Journal Bearing ◽  
Dynamic Parameters ◽  
Plain Bearing ◽  
Ansys Software ◽  
Simulation Results ◽  
The Mathematical Model

The article presents the results of a computational experiment on modeling a smooth plain bearing with a controlled axial supply of lubricant. The basic relations of the mathematical model, boundary conditions and parameters of modeling the fluid flow in the gap region of the sliding support are presented. The description of the calculation of the sliding support in the Ansys software package is given. The results of modeling and the results of calculating the static and dynamic parameters of the simulated bearing are presented. Conclusions are drawn on the applicability of computational fluid dynamics programs for calculating sliding supports

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