scholarly journals Experimental determination of longitudinal forces in front of braking train

2020 ◽  
Vol 78 (6) ◽  
pp. 358-365
Author(s):  
V. I. Matvetsov
Keyword(s):  
Thermal Stresses ◽  
Climatic Conditions ◽  
Axial Displacement ◽  
Operating Conditions ◽  
Normal Operation ◽  
Rolling Stock ◽  
Rail Track ◽  
Axial Forces ◽  
Continuously Welded Rail

The number of regularities detected in the experiments described by the author confirms that, despite of the differences in operating conditions between the middle of the 20th century and the present days, the methods of research and assessment of obtained results are still relevant.Features of the superstructure and track operation at the initial stage of introduction of the welded rails and continuously welded rail strings on the railways of the USSR are examined. It is demonstrated that axial displacement forces are occurred during the train movement, which are one of the most dangerous processes taking place in the track during the rolling stock movement. Axial displacement forces are manifested in the axial displacement of rails on the sleepers or displacement of rails with sleepers on the ballast. Knowledge of axial forces resulted from displacement of one rail line or the entire track is required for competent planning of installation and operation of the jointed rail track and continuously welded rail track, especially in the conditions of the Urals and Siberia. Methods and experimental results are provided for determination of additional axial forces acting in the track at the spike fastening and the individual intermediate fastening in front of braking train at the experimental sections of the continuously welded rail track in severe climatic conditions of the West-Siberian railway, where the annual fluctuations of therail temperature amount to 110°C.The following conclusions are made based on the analysis of the experiment results and experience of operation of the continuously welded rail strings: • no additional axial forces in front of braking train were detected in the continuously welded rail strings of the thermalstressed type without any release of thermal stresses on the independent fixation; • experiment confirmed possibility of installation and normal operation of continuously welded rail track on the entire network of railways of the Ministry of Transportation of the USSR; • recent wide introduction of trains of 7,100 t, combined trains of 12,600 and 14,200 tons require special attention to parameters of interaction of track and trains.

An Extended Model of Light Railway System Used in Analysis of Normal Operation and Fault Conditions

2014 ◽  
Author(s):  
Sorin Deleanu ◽  
Keith Forman ◽  
David C. Carpenter ◽  
Calin Munteanu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Short Circuit ◽  
Operating Conditions ◽  
Normal Operation ◽  
Dc Power ◽  
Railway System ◽  
Analytical Approaches ◽  
Element Method

The paper provides a description of the analysis of a Light Railway System for two configurations: - Rails above the ground and catenary supply - Track in a tunnel and power rail supply. Finite Element Method (FEM) analysis is compared to classical analytical approaches by Carson, Pollaczek, Bickford and Tylavsky. Reviews of methods to determine self and mutual impedance for electrified railroads are provided. The solution of finite element method (FEM) applied for the determination of impedance for the two traction rail and catenary configuration, modeled and examined, consists of computational analysis based upon minimizing the energy of electromagnetic field. The analytic impedance models are built on Carson-Pollaczek–Bickford equations, adjusted by Tylavsky, for two situations: when the ground is perfectly insulated and when considering the earth return current. The railway track – catenary is integrated in a system containing the model for traction substation(s) with DC power output and moving vehicle with induction motors, controlled using voltage inverters with pulse width modulation. The light transit train, supplied with a rectified DC power, is subjected to a significant harmonic content, which may affect the signal and control circuits. It is then shown that the power and signaling characteristics of the modelled system can predict the magnitude of the perturbation current for different frequencies, in normal operating conditions and in presence of faults as well. In many of the light transportation systems, from all types of faults, the DC short-circuit at the output of the power rectifiers used for energizing the power rail and/or catenary presents a special interest. This is because of two main reasons: the positions of the vehicle-loads are in continuous changing and, even if they operate from DC sources, the parent network is still of AC type. A key issue was the determination of the distributed parameters (resistances, inductances) of the running track and catenary, from experimental data and preliminary analytical and numerical calculations, followed by the analysis of their dependencies with the current magnitude and frequency response. A specific short-circuit study case is simulated when using a model of the traction system for the purpose of the DC fault current prediction. The paper concludes with a discussion of future developments and further work.

scholarly journals Determination of engine oil change interval for patrol engines based on actual operating time

2021 ◽  
Vol 18 (3) ◽  
pp. 274-285
Author(s):  
A. A. Abakarov ◽  
Sh. M. Igitov ◽  
Ali A. Abakarov
Keyword(s):  
Operating Time ◽  
Chemical Properties ◽  
The United States ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Engine Oil ◽  
Rolling Stock ◽  
Passenger Cars ◽  
Gasoline Engines ◽  
On The Road

Introduction. This paper shows the results of a study of the frequency of maintenance of passenger cars in various operating conditions, and provides recommendations for replacing the engine oil of gasoline engines (category SN classification according to API) according to the actual engine operating time (moto-hours). The service book of passenger cars contains the regulations for car maintenance with a list of operations that must be performed. The oil change intervals specified in the Regulations on Maintenance and Repair of Rolling Stock of motor Transport and the factory instructions do not take into account the specifics of the operation of vehicles. Depending on the road and climatic conditions and the operating mode, the standard maintenance schedule can be adjusted, in particular, the frequency of engine oil changes. The scientific novelty of the work is to determine the intervals of car maintenance for specific operating conditions.Materials and methods. The paper presents an analysis of Russian and foreign car maintenance systems, in particular, the oil change intervals of gasoline engines in European countries, the United States and Japan.The results of operational and resource tests of motor oils of gasoline engines carried out by methods of measuring their physical and chemical properties are presented.Results. In this paper, based on the analysis of the problem, recommendations for changing oil in gasoline engines by motorcycle hours for the conditions of the Republic of Dagestan (RD) are developed.The use of external and built-in technical means for calculating the motor hours allows you to determine the recommended oil change interval.Discussion and conclusion. In this paper, on the basis of research on a certain number of vehicles operating in various (including difficult) conditions, recommendations are developed that allow you to determine the rules of car maintenance for various operating conditions.

scholarly journals Determination of the maximum dangerous width of a rail track on a reinforced concrete base with fasteners of the КБ type, taking into account all influencing factors

2021 ◽  
pp. 113-120
Author(s):  
Vadym Novikov ◽  
Andriy Babenko ◽  
Oleksandr Kharkivskyi ◽  
Olena Olexandrivna Tkachenko
Keyword(s):  
Reinforced Concrete ◽  
High Speed ◽  
Railway Track ◽  
Rolling Stock ◽  
Lateral Direction ◽  
Maximum Width ◽  
Rail Track ◽  
Emergency Braking ◽  
Simultaneous Influence

Railway track retention standards in Ukraine do not take into account theconstruction of the subrail base, but regulate one for all types maximum dangerous value of the trackwidth, which was changed from 1546 mm to 1548 mm without any justification of scientific researchor explanations of the effects of tolerances the width of the rail track and the wheel track, which ingeneral at that time were not fully investigated but taking into account the emergence anddevelopment of new scientific problems associated with the emergence of intensive lateral wear ofrails and ridges of locomotive and wagon wheels. The deterministic dependences of lateralimpressions of the P65 type rail thread head on the simultaneous influence of vertical and horizontalforces for the newly installed repair profiles of UZ rolling stock on the basis of previously performedexperimental and theoretical studies were investigated. The results allow at this stage of research todetermine and calculate the practical values of the maximum dangerous width of the track, in whichthe subrail base consists of reinforced concrete sleepers and separate rail fasteners, which are usedboth on conventional highways with mixed traffic and on high-speed lines UZ.The article establishes the need to take into account new factors influencing the dangerouswidth of the rail track with intermediate rail fasteners of separate type depending on the load stress of sections and new repair profiles of rolling stock, as well as wear processes of intermediate railfasteners type KБ and its elements on the appearance of elastic backlash in the lateral direction fromthe influence of the guide wheels of the rolling stock. The recommended value of the maximum widthof the rail track for areas where service or emergency braking is applied - 1550 mm, taking intoaccount that the contact of the wheel and the rail is not at a point, but on an ellipse. The establishednorm of the maximum width of a rail track allows to define economic efficiency of introduction in theconditions of operation of a track in curved sections of a track of small radii with limited use of themaximum admissible lateral wear (15 mm) of a head of a rail thread provided that the normal-forcedentry of rolling stock carts.

scholarly journals ЕНЕРГОСПОЖИВАННЯ НАВЧАЛЬНИХ КОРПУСІВ УНІВЕРСИТЕТУ В УМОВАХ КАРАНТИННИХ ОБМЕЖЕНЬ УКРАЇНИ

2021 ◽  
pp. 9-19
Author(s):  
VALERII DESHKO ◽  
INNA BILOUS ◽  
IRYNA SUKHODUB ◽  
TETYANA BOIKO
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Integrated Approach ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Normal Operation ◽  
Software Environment ◽  
Depth Analysis ◽  
Educational Buildings ◽  
Academic Building

Target. To analyze the features of energy consumption of the building of the educational building No. 17 of the National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute" in the conditions of quarantine restrictions in the implementation of energy-saving heating schemes.Methodology. Dynamic energetic modeling of a university academic building created in the DesignBuilder software environment under normal and quarantine modes.Results. Recommendations for the implementation of energy-saving modes of heating the building of the academic building of the university during the period of distance learning when introducing quarantine restrictions in Ukraine.Scientific novelty. An integrated approach has been developed to an in-depth analysis of energy consumption under conditions of partial use of the premises of educational buildings during the quarantine period. It is substantiated that the use of premises with partial operation of the building requires additional unit costs for heating needs.Practical significance. Simulation dynamic modeling of the building's energy consumption for heating for various modes of operation and employment / use of premises of educational buildings during the quarantine period in Ukraine, the results of the study will allow to obtain a set of energy characteristics of the building as a whole and its individual rooms / zones for hourly changes in internal operating conditions and external climatic conditions. The use of the proposed scheme of operation of the heating system of the building of the educational building allows to reduce energy consumption during the heating period by 8,5% compared to energy consumption during normal operation, which is economically feasible in conditions of partial occupancy of the building during quarantine restrictions (during lockdown) and an unpredictable macroeconomic situation on the energy market, causing a trend towards an increase in prices for basic energy resources.

scholarly journals MODEL FOR DETERMINATION OF CHARACTERISTICS OF RAILWAY TRAIN REGIME MAPS

2020 ◽  
pp. 132-142
Author(s):  
A. Falendysh ◽  
A. Gatchenko ◽  
O. Kletska ◽  
E. Kiritseva ◽  
M. Barybin
Keyword(s):  
Energy Efficient ◽  
Mechanical Energy ◽  
Technical Condition ◽  
Operating Conditions ◽  
Rolling Stock ◽  
Railway Transport ◽  
Ecological Requirements ◽  
Methods Of Calculation ◽  
Methods Of Operation

The article considers the issues of determining rational approaches to the creation of train maps, the rational use of diesel modes and the use of automated computer simulation system. Based on the obtained results, an energy-efficient mode of train driving is proposed and a mathematical model of the locomotive operation character is created. There is a need to review obsolete regime and train locomotive crews in the latest methods of operation. The basic values and methods of calculation for specific operating conditions on the basis of the law of conservation of mechanical energy are established. It is proposed to create a passport of each locomotive to determine the rational weight norms on the existing service shoulders. After all, overloading or underutilization of the locomotive's resource is associated with loss of profit or the emergence of emergencies. The necessity of the offered methods within the limits of ecological requirements to traction rolling stock is proved. The possibility of forming a rational system of mileage between technical inspections and repairs for each locomotive as a whole on the basis of forecasting and statistics is determined. It is recommended to further implement mathematical modeling and digital means of monitoring the technical condition after repairs to achieve economic efficiency of railway transport.

scholarly journals A study of the dependence between fuel consumption of a heat gas turbine and variation of heat loading of regional consumers having various climatic conditions taking into account determination of structural characteristics of heat exchanging equipment for grid water heating

2021 ◽  
Vol 25 (4) ◽  
pp. 478-487
Author(s):  
E. L. Stepanova ◽  
P. V. Zharkov
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Parametric Optimization ◽  
Waste Heat ◽  
Structural Characteristics ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Waste Heat Boiler ◽  
Heat Loading

The aim was to optimize the dependence between fuel consumption and heat loading of regional consumers varied due to climatic conditions, taking into account the determination of structural characteristics of heat exchanging equipment for grid water heating in a heat gas turbine. A heat gas turbine comprising two fuel combustion chambers, a waste-heat boiler and a contact heat exchanger to heat makeup grid water was investigated. Scheme and parametric optimization studies were carried out using a mathematic model of a gas turbine created using a software and hardware system developed at the Department of Heat Power Systems of the Melentiev Energy Systems Institute, Siberian Branch of the Russian Academy of Sciences. Th turbine operating conditions differing in heat loads in four suggested operating regions were studied. It was found that an increase in fuel consumption in the second combustion chamber was 29%– 84% compared to that in the first combustion chamber. This rise was recorded when the turbine heat loading was increasing in the considered regions. Data analysis of the scheme and parametric optimization studies showed that, for operating conditions with a higher heat loading, it seems reasonable to ensure the maximum possible heating of makeup grid water as the loading rises. It is also recommended to slightly increase the heat surface area of the makeup grid water heater whose structural materials are less expensive than in a waste-heat boiler. It was shown that the suggested technical solution slightly increases specific capital investments while fully providing electrical and heat power to consumers. The obtained results can be used to select optimal technical solutions ensuring competitiveness in the operation of a heat gas turbine in regions with various climatic characteristics.

scholarly journals DETERMINATION OF THE TECHNICAL CONDITION OF A RAILWAY BRIDGE

2020 ◽  
pp. 32-39
Author(s):  
I. Seryh ◽  
E. Chernyshova ◽  
A. Degtyar
Keyword(s):  
Technical Condition ◽  
Operating Conditions ◽  
Industrial Safety ◽  
Normal Operation ◽  
Bridge Structure ◽  
Structural Elements ◽  
Railway Bridge ◽  
Technical Examination ◽  
Second Category

The reliability and durability of any structures, including in transportation, depend on operating conditions and on timely diagnostics of damages and defects arising during their normal operation. Proper diagnostics will allow to determine the degree of wear of the structures, as well as to identify causes of damages. This work will focus on industrial safety inspection, using railway bridge built in 1987 as an example. A comprehensive inspection included full technical examination of the bridge and all its structural elements. The outcome and all necessary repair recommendations are documented. Recommendations for reconstruction and restoration methods of the damaged elements and structures of the bridge are based on a scientifically accurate assessment of its technical condition to establish signs and causes of the damages. Based on the results of the comprehensive inspection of all the damages in the bridge structure, the technical condition of the bridge is assessed three points on a five-point scale. The identified failures in durability and safety are classified in the second category. The categories of defects found are mainly related to safety - B1, B2, durability - D2, D3, and repairability - P2, Р3.

On the Design Considerations of New Offloading Hose Applied on a Turret Moored FPSO

2017 ◽  
Author(s):  
Decao Yin ◽  
Ivar Fylling ◽  
Halvor Lie ◽  
Rolf J. Baarholm ◽  
Timothy E. Kendon
Keyword(s):  
Limit State ◽  
Petroleum Products ◽  
Operating Conditions ◽  
Normal Operation ◽  
Ultimate Limit State ◽  
Operation Condition ◽  
Utilization Factor ◽  
Offshore Production ◽  
Axial Forces ◽  
Production Platform

Offloading hoses are used to transfer crude oil or liquid petroleum products from a fixed offshore production platform/floating production, storage and offloading (FPSO) unit to shuttle tankers. The hoses are subjected to environmental loads that are mainly waves, current, and vessel motions from both FPSO and the shuttle tanker. New offloading hoses were planned to be applied in a FPSO in harsh environment, and a design analysis was done in this connection. Numerical simulations were performed on ultimate limit state (ULS), serviceability limit state (SLS) and accidental limit state (ALS) by using the software RIFLEX [2]. Critical responses such as curvature and axial forces are checked. The following conditions are checked: 1. Normal operation condition with oil filled hose 2. Connect operation condition, floating gas filled hose 3. Emergency disconnect condition A SIMA [3] workflow was established to calculate accumulated fatigue damage of all the elements of the offloading hose model. For the new offloading hose, it is important to have a combined bending-tension loading capacity check. A utilization factor is proposed that possibly may be generalized. The results show that the specified hose has ample capacity for the considered operating conditions for the shuttle tanker to stay in any position within the 2nd emergency shut down sector (ESD2).

Simulation and Contrast Analysis of tem Images of Cracks

1990 ◽  
Vol 48 (1) ◽  
pp. 578-579
Author(s):  
D. Goyal ◽  
A. H. King
Keyword(s):  
Displacement Vector ◽  
Crack Tip ◽  
Perfect Crystal ◽  
Operating Conditions ◽  
Displacement Fields ◽  
Fringe Contrast ◽  
Orthogonal Geometry ◽  
Moire Fringe ◽  
Moiré Fringe

TEM images of cracks have been found to give rise to a moiré fringe type of contrast. It is apparent that the moire fringe contrast is observed because of the presence of a fault in a perfect crystal, and is characteristic of the fault geometry and the diffracting conditions in the TEM. Various studies have reported that the moire fringe contrast observed due to the presence of a crack in an otherwise perfect crystal is distinctive of the mode of crack. This paper describes a technique to study the geometry and mode of the cracks by comparing the images they produce in the TEM because of the effect that their displacement fields have on the diffraction of electrons by the crystal (containing a crack) with the corresponding theoretical images. In order to formulate a means of matching experimental images with theoretical ones, displacement fields of dislocations present (if any) in the vicinity of the crack are not considered, only the effect of the displacement field of the crack is considered.The theoretical images are obtained using a computer program based on the two beam approximation of the dynamical theory of diffraction contrast for an imperfect crystal. The procedures for the determination of the various parameters involved in these computations have been well documented. There are three basic modes of crack. Preliminary studies were carried out considering the simplest form of crack geometries, i. e., mode I, II, III and the mixed modes, with orthogonal crack geometries. It was found that the contrast obtained from each mode is very distinct. The effect of variation of operating conditions such as diffracting vector (), the deviation parameter (ω), the electron beam direction () and the displacement vector were studied. It has been found that any small change in the above parameters can result in a drastic change in the contrast. The most important parameter for the matching of the theoretical and the experimental images was found to be the determination of the geometry of the crack under consideration. In order to be able to simulate the crack image shown in Figure 1, the crack geometry was modified from a orthogonal geometry to one with a crack tip inclined to the original crack front. The variation in the crack tip direction resulted in the variation of the displacement vector also. Figure 1 is a cross-sectional micrograph of a silicon wafer with a chromium film on top, showing a crack in the silicon.

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