scholarly journals Aspects of design and calculation of a railway track intended for dedicated passenger lines

2021 ◽  
Vol 80 (6) ◽  
pp. 351-358
Author(s):  
D. V. Ovchinnikov ◽  
K. A. Kul’gin
Keyword(s):  
Complex Loading ◽  
Point Of View ◽  
Throughput Capacity ◽  
Railway Track ◽  
Infrastructure Development ◽  
Construction Costs ◽  
Element Analysis ◽  
Passenger Traffic ◽  
Margin Of Safety ◽  
Typical Design

The article considers issues of application of dedicated passenger lines for intertown and interregional transportation on the railways of the Russian Federation, which in the future will accelerate passenger traffic due to changes in transportation technology, increase the carrying and throughput capacity of railways, reduce construction costs and current maintenance, and optimize the need for infrastructure development. The structures of the track superstructure used for the transportation process at the present time were developed and implemented taking into account the mixed traffic — passenger and freight. Growth of axle loads in freight traffic, as well as the length of trains, presupposes the strengthening (weighting) of the standard structures of the railway track to possibly ensure the guaranteed safe passage of more than 1 billion gross tonnage. At the same time, exclusively for passenger traffic, the typical design of the railway track is redundant and can be optimized in terms of reducing the materials of the track superstructure with a simultaneous change in the configuration of repair schemes and current maintenance conditions. The article presents an assessing the possibility of using a “passenger” track structure on dedicated passenger lines for intertown and interregional transportation according to the criteria of the allowable margin of safety in the environment of fnite element analysis — the most progressive method for calculating structures undergoing complex loading. The article presents the results of calculations of the stress-strain state of a railway track of various confgurations, including promising lightweight versions with R50 rails and reinforced concrete sleepers with under sleeper pads. Based on the calculations performed, recommendations are given for the areas of application of the considered track confgurations from the point of view of permissible stresses in its elements.

scholarly journals Mitigating the seismic pounding of multi-story buildings in series using linear and nonlinear fluid viscous dampers

2021 ◽  
Vol 21 (4) ◽  
Author(s):  
Hytham Elwardany ◽  
Robert Jankowski ◽  
Ayman Seleemah
Keyword(s):  
Substantial Improvement ◽  
Point Of View ◽  
Steel Buildings ◽  
Viscous Dampers ◽  
Element Analysis ◽  
Fluid Viscous Dampers ◽  
Adjacent Buildings ◽  
In Series ◽  
Linear And Nonlinear ◽  
Nonlinear Fluid

AbstractSeismic-induced pounding between adjacent buildings may have serious consequences, ranging from minor damage up to total collapse. Therefore, researchers try to mitigate the pounding problem using different methods, such as coupling the adjacent buildings with stiff beams, connecting them using viscoelastic links, and installing damping devices in each building individually. In the current paper, the effect of using linear and nonlinear fluid viscous dampers to mitigate the mutual pounding between a series of structures is investigated. Nonlinear finite-element analysis of a series of adjacent steel buildings equipped with damping devices was conducted. Contact surfaces with both contactor and target were used to model the mutual pounding. The results indicate that the use of linear or nonlinear dampers leads to the significant reduction in the response of adjacent buildings in series. Moreover, the substantial improvement of the performance of buildings has been observed for almost all stories. From the design point of view, it is concluded that dampers implemented in adjacent buildings should be designed to resist maximum force of 6.20 or 1.90 times the design independent force in the case of using linear or nonlinear fluid viscous dampers, respectively. Also, designers should pay attention to the design of the structural elements surrounding dampers, because considerable forces due to pounding may occur in the dampers at the maximum displaced position of the structure.

Heat Transfer and Thermal Stress Analysis of an Optoelectronic Package

1991 ◽  
Vol 113 (3) ◽  
pp. 258-262 ◽  
Author(s):  
J. G. Stack ◽  
M. S. Acarlar
Keyword(s):  
Heat Transfer ◽  
Thermal Management ◽  
Power Dissipation ◽  
Point Of View ◽  
Optical Data ◽  
Data Link ◽  
Element Analysis ◽  
Thermally Induced ◽  
Temperature Changes ◽  
Induced Stresses

The reliability and life of an Optical Data Link transmitter are inversely related to the temperature of the LED. It is therefore critical to have efficient packaging from the point of view of thermal management. For the ODL® 200H devices, it is also necessary to ensure that all package seals remain hermetic throughout the stringent military temperature range requirements of −65 to +150°C. For these devices, finite element analysis was used to study both the thermal paths due to LED power dissipation and the thermally induced stresses in the hermetic joints due to ambient temperature changes

scholarly journals Infrastructure development in Africa’s regions: investment trends and challenges

2021 ◽  
Vol 295 ◽  
pp. 01029
Author(s):  
Alina Ibragimova ◽  
Yan Wang ◽  
Michail Ivanov
Keyword(s):  
Empirical Evidence ◽  
Production Function ◽  
Global Economy ◽  
Point Of View ◽  
Economic Downturn ◽  
Infrastructure Development ◽  
Social Infrastructure ◽  
Economic Point ◽  
Industrial Sectors

The purpose of this work is to provide information on the development of the infrastructure of the African economy. The study provides statistics on African regions and industries. This article focuses on the forms of economic and social infrastructure, and directs to determine the share development infrastructural in Africa. The Africa has entered an era of devastating change this study shows that with the unfolding economic downturn in the northern economies that have traditionally dominated the global economy. The article provides empirical evidence on how the industrial sectors developed from an economic point of view. The authors believe that infrastructure affects output and productivity directly as a contribution to the production function of other sectors and as part of GDP formation. The article discusses the development of infrastructure for the period 1999-2019 without more detailed dynamics. It also does not explain the main topics developed by the authors. The work provides knowledge on how investments are developing in Africa, how industries have developed, and what is the role of each infrastructure sector in this development. It also shows how different areas of infrastructure work with different successes in creating new paths in the African economy.

SUSTAINABLE DEVELOPMENT AND QUALITY OF LIFE IN LITHUANIA COMPARED TO OTHER COUNTRIES

2012 ◽  
Vol 18 (4) ◽  
pp. 588-607 ◽  
Author(s):  
Dalia Štreimikienė ◽  
Neringa Barakauskaitė-Jakubauskienė
Keyword(s):  
Quality Of Life ◽  
Sustainable Development ◽  
Positive Impact ◽  
Life Quality ◽  
Point Of View ◽  
Infrastructure Development ◽  
New Approach ◽  
Definition Of ◽  
Objective Indicators

The paper presents the definition of quality of life and its relationship with sustainable development. The paper analyses and compares the indicators of quality of life in Lithuania with other countries. A quality of life is an explicit or implicit policy goal. Various measurements and indicators to evaluate a quality of life were proposed during the recent years however there are no widely accepted objective indicators of quality of life able to compare countries. Sustainable development concept proposes new approach to measure quality of life. Therefore the aim of sustainable development is to increase quality of life. Quality of life can be addressed in terms of people health, the state of economy, employment, infrastructure development, crime and environment. All these indicators are interrelated as economic development creates preconditions to maintain public health, develop social and technical infrastructure, to increase employment, to ensure quality of environment, to tackle with crime etc. From the other point of view healthy and satisfied with the quality of life nation have positive impact on stable economic growth.

Analysis and Design of Offshore Pile Foundation

2014 ◽  
Vol 891-892 ◽  
pp. 17-23 ◽  
Author(s):  
Sudip Basack
Keyword(s):  
Pile Foundation ◽  
Complex Loading ◽  
Offshore Structures ◽  
Laboratory Model ◽  
Element Analysis ◽  
Analysis And Design ◽  
Theoretical Investigations ◽  
Experimental Laboratory ◽  
Combined Action ◽  
Ocean Environment

The ocean environment necessitates the pile foundation supporting the offshore structures to be designed against cyclic load, moments and torques initiated by a combined action of waves, wind, tides, currents, etc. Such a complex loading condition induces progressive degradation in the pile-soil interactive performance introducing significant reduction in bearing capacity with increased settlement and displacements. The Author has carried out extensive experimental (laboratory model tests) and theoretical investigations (boundary element analysis) to study the salient features of this degradation and developed a design methodology for offshore pile foundation. The works conducted and the major conclusions drawn are highlighted in this paper.

Non-Linear Kinematic Hardening Identification for Anisotropic Sheet-Metals With Bending-Unbending Tests

2000 ◽  
Author(s):  
M. Brunet ◽  
F. Morestin ◽  
S. Godereaux
Keyword(s):  
Kinematic Hardening ◽  
Bending Moment ◽  
Complex Loading ◽  
Sheet Metals ◽  
Element Analysis ◽  
Initial Anisotropy ◽  
Non Linear ◽  
Identification Technique ◽  
Stress Behaviour ◽  
Constitutive Parameters

Abstract An inverse identification technique is proposed based on bending-unbending experiments on anisotropic sheet-metal strips. The initial anisotropy theory of plasticity is extended to include the concept of combined isotropic and non-linear kinematic hardening. This theory is adopted to characterise the anisotropic hardening due to loading-unloading which occurs in sheet-metals forming processes. To this end, a specific bending-unbending apparatus has been built to provide experimental moment-curvature curves. The constant bending moment applied over the length of the specimen allows to determined numerically the strain-stress behaviour but without Finite Element Analysis Four constitutive parameters have to be identified by an inverse approach. Our identification results show that bending-unbending tests are suitable to model quite accurately the constitutive behaviour of sheet metals under complex loading paths.

Modeling of spatial distribution of passenger traffi c on interurban bus routes

Innotrans ◽  
2020 ◽  
pp. 31-36
Author(s):  
Alexander V. Martynenko ◽  
◽  
Alexander A. Shevtsov ◽  
Keyword(s):  
Spatial Distribution ◽  
Quantitative Description ◽  
Point Of View ◽  
Practical Point ◽  
Ticket Price ◽  
Passenger Traffic ◽  
Correlation And Regression Analysis ◽  
Classical Gravity ◽  
Bus Service

This paper is devoted to the quantitative description of the spatial distribution of passenger traffic based on the classical gravity model on the example of interurban bus service between Yekaterinburg and other cities of the Sverdlovsk region. The influence of factors such as population, distance between localities, and ticket price on the volume of passenger traffic was studied. As a result of the correlation and regression analysis, it was found that both the distance between localities and the ticket price can be used as a measure of the remoteness of localities. However, the quality of the resulting regression model does not change. The spatial distribution of interurban bus passenger traffic depends on the measure of distance of localities from each other and the size of their population. Moreover, the size of the population is a much more significant factor than the measure of distance. From a practical point of view, this means that when predicting passenger traffic, demographic factors must first be taken into account.

scholarly journals Optimization of ER8 and 42CrMo4 Steel Rail Wheel for Road–Rail Vehicles

2020 ◽  
Vol 10 (14) ◽  
pp. 4717
Author(s):  
Filip Lisowski ◽  
Edward Lisowski
Keyword(s):  
Geometry Optimization ◽  
High Strength ◽  
Railway Track ◽  
Hydraulic Motor ◽  
Steel Rail ◽  
Element Analysis ◽  
Track Maintenance ◽  
Rail Vehicles ◽  
First Order Method ◽  
Failure Site

Railway track maintenance services aim to shorten the time of removing failures on the railways. One of the most important element that shorten the repair time is the quick access to the failure site with an appropriate equipment. The use of road-rail vehicles is becoming increasingly important in this field. In this type of constructions, it is possible to use proven road vehicles such as self-propelled machines or trucks running on wheels with tires. Equipping these vehicles with a parallel rail drive system allows for quick access to the failure site using both roads and railways. Steel rail wheels of road-rail vehicles are designed for specific applications. Since the total weight of vehicle is a crucial parameter for roadworthiness, the effort is made to minimize the mass of rail wheels. The wheel under consideration is mounted directly on the hydraulic motor. This method of assembly is structurally convenient, as no shafts or intermediate couplings are required. On the other hand, it results in strict requirements for the wheel geometry and can cause significant stress concentration. Therefore, the problem of wheel geometry optimization is discussed. Consideration is given to the use of ER8 steel for railway application and 42CrMo4 high-strength steel. Finite element analysis within Ansys software and various optimization tools and methods, such as random tool, subproblem approximation method and first-order method are applied. The obtained results allow to minimize the rail wheel mass with respect to the used material. Moreover, computational demands and methods leading to the best results are compared.

Static and Dynamic Analysis of Motor Cycle Wheel Designs

2015 ◽  
Vol 813-814 ◽  
pp. 915-920 ◽  
Author(s):  
A. Eswara Kumar ◽  
M. Naga Raju ◽  
Navuri Karteek ◽  
Daggupati Prakash
Keyword(s):  
Vital Role ◽  
Point Of View ◽  
Al Alloy ◽  
Analysis Tool ◽  
Structural Stiffness ◽  
Element Analysis ◽  
Static And Dynamic Analysis ◽  
Wheel Rim ◽  
Strength And Stiffness ◽  
Von Mises

The wheel of a vehicle plays a vital role to bear the load applies on it. Generally spokes acts as the supports between the wheel rim and hub. These spokes must have sufficient strength and stiffness to avoid the failure of the wheel. In present days these wheels are made up of aluminum alloy, magnesium alloy and steel. To reduce the weight of the wheel many wheel designs are implemented and applied for different vehicles. In this paper three different wheel designs are chosen, those are inclined spokes, curved spokes and Y shaped spokes made up of Al alloy, Mg alloy and Steel. Static structural analysis subjected to pressure on the wheel rim and free vibrational analyses are performed by using finite element analysis tool Ansys 12. The objective of the present work is to observe the best design which contains higher structural stiffness, specific structural stiffness with lower von mises stresses under static load conditions. It is observed that curve shaped spoke designs are better in for manufacturing of wheel in both static and dynamic point of view.

Experimental and Numerical Study of Railway Ballast Compactness during Tamping Process

2013 ◽  
Vol 690-693 ◽  
pp. 2730-2733
Author(s):  
Tao Yong Zhou ◽  
Bin Hu ◽  
Bo Yan ◽  
Jun Feng Sun
Keyword(s):  
Discrete Element Method ◽  
Numerical Study ◽  
Discrete Element ◽  
Railway Track ◽  
Analysis Model ◽  
Railway Ballast ◽  
Element Analysis ◽  
Before And After ◽  
Filling Method ◽  
Element Method

Railway ballast tamping operations is employed in order to restore the geometry of railway track distorted by train traffics. The main goal is to compact the stone ballast under the sleepers supporting the railway squeezing and vibrations. The ballast compactness is the most direct index for evaluating the effect of tamping operation. This paper presents an experimental method used to detect the railway ballast compactness before and after tamping operation based on water-filling method, and creates a discrete element analysis model of railway ballast which analyzes the change of ballast compactness before and after tamping operation based on discrete element method. The simulation results are very similar with experimental results, which verify that the discrete element method is an effective method to evaluate the change of railway ballast compactness during tamping process.

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