INVESTIGATION OF TEMPERATURE OF BRAKE PADS WITH DIFFERENT EXTENT OF WEAR IN FRICTIONAL BRAKING

2020 ◽  
pp. 27-34
Author(s):  
P. Yu. Ivanov ◽  
◽  
A. M. Khudonogov ◽  
E. Yu. Dulskiy ◽  
A. A. Korsun ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Flow Distribution ◽  
Rolling Stock ◽  
Finite Element Models ◽  
Brake Pads ◽  
Coefficient Increase ◽  
Engineering Drawings ◽  
Freight Car ◽  
Full Stop

The issue of railway rolling stock brake pad heating is examined under frictional braking within a freight car with unilateral push, equipped with castiron brake pads. Foreign and domestic experience of studies of heat cycles caused by friction has been examined, mechanism of heat release in the contact zone between a pad and wheel during braking with consideration of a heat flow distribution coefficient is described, mathematical modeling choice as a way to refine temperature measurements in the process of experimental studies is grounded, the results of estimated determination of the thermal flow affecting the pad in braking of a loaded freight car weighing 93 ts with 5 ts push upon the axle from 60 km/h to full stop are shown. Dynamics of thermal energy change emitting in frictional braking with consideration of wheel rotation decelerating speed and friction coefficient increase is emulated. Finite element models of pads with even wear, wedgelike wear and with no wear having geometry of relevant engineering drawings are described. The results of investigation of heating of brake pads with different wear types in the process of braking until full stop are given.

scholarly journals ACCOUNTING FOR THE ELASTIC COMPONENT OF THE STROKE OF THE ROD IN THE BRAKE SYSTEM OF A TRUCK OF A FREIGHT CAR WITH A CYLINDER 670B

2019 ◽  
Vol 2019 (8) ◽  
pp. 64-70
Author(s):  
Владимир Синицын ◽  
Vladimir Sinicyn ◽  
Владимир Кобищанов ◽  
Vladimir Kobishchanov
Keyword(s):  
Elastic Deformation ◽  
Brake System ◽  
Rolling Stock ◽  
Maximum Width ◽  
Brake Pads ◽  
Railway Freight ◽  
Freight Car ◽  
Definition Of ◽  
Executive Mechanism ◽  
Type 3

The application of braking systems with the lo-cation of the executive mechanism directly upon a bogie is a promising trend in domestic brake production and freight car manufacturing on the whole. In the paper a common circuit of a braking rod leverage with the location of cylinders 670V on the bogie of two-axle type 2 and type 3 (RSS 9246-2013) is considered. The investigation carried out in the work is a continuation of works connected with the updating of a braking system developed earlier. The aim of the work consists in the definition of cylinder rod outlet limits taking into account elastic deformation of all elements of leverage in accordance with the procedure developed and appraised earlier and also the definition of maximum possible thickness of a brake pad used for this circuit in operation. The rod outlet limits obtained will be standard as system transmission ratio is unified, and an elastic constituent will have minimum deviations from the value obtained and depend upon a specific execution of elements. In this investigation there is used a 3D brake system model developed thoroughly that allows obtaining an elastic deformation value precise enough. Furthermore, data obtained allow defining a maximum operation outlet of rod of the braking cylinder 670V in the system analyzed during car motion on a long steep slope. On the basis of the investigations carried out there are defined the limits of rod outlet (35…47mm) for the developed common brake system with cylinders 670V that allows using brake pads of maximum width (65+5mm) used in railway freight rolling-stock of the RF. The maximum operation value of rod outlet is obtained during car motion on a steep long slope (63mm) which does not exceed a working stroke of a cylinder (100mm).

Evaluation of РА-3 rail bus pneumatic brake effi ciency

Innotrans ◽  
2020 ◽  
pp. 54-56
Author(s):  
Yaroslav D. Podlesnikov ◽  
◽  
Anatoly G. Silyuta ◽  
Keyword(s):  
Path Length ◽  
Rolling Stock ◽  
Process Safety ◽  
Brake Pads ◽  
Braking System ◽  
Effi Ciency ◽  
Transportation Process ◽  
Full Stop ◽  
Efficiency And Reliability

Braking system is a very important element of any rolling stock unit, as transportation process safety depends on its efficiency and reliability. Rail buses represent development of diesel trains intended for passenger service on non-electrified track sections. A sudden obstacle on the track requires immediate full stop of the rolling stock, it is urgent to have effective braking which provides the least brake path length. The paper presents results of brake path length calculation for РА-3 rail bus in two-car version with iron and composite brake pads.

scholarly journals Scientific Substantiation of Thermal Leveling for Deformations in the Car Structure

2018 ◽  
Vol 7 (4.3) ◽  
pp. 125 ◽  
Author(s):  
Oleksiy Fomin ◽  
Oleksandr Logvinenko ◽  
Oleksiy Burlutsky ◽  
Andriy Rybin
Keyword(s):  
Rolling Stock ◽  
Railway Transport ◽  
Significant Deterioration ◽  
Rail Industry ◽  
Scientific Substantiation ◽  
Freight Car ◽  
The One ◽  
Welding Procedure ◽  
Transport Complex

Railway transport is the foundation of the transport complex and part of the transport network of logistics chains. However, significant deterioration of rolling stock units (especially freight cars accounting for the greater part of all transportation) is an urgent problem of the rail industry. Therefore, the problems of renovation of the existing freight car fleet by developing and introducing domestic models which can effectively compete in terms of the technical and economic and operational indexes are of crucial importance. But the car structure suffers from various deformations at all service stages (production, maintenance and operation). The main type of these deformations is residual ones developing during the welding procedure, due to the thermal effect. Therefore, the issues concerning elimination of these deformations in production and maintenance are becoming ever more urgent. In particular, the most recognized and economy-oriented approach in the field is the one based on the thermal leveling of welded structures. The implementation of this approach requires some research aimed at scientific substantiation of the thermal leveling, as well as, specification of forms and heating temperatures, determination of heating form sizes, thermal leveling simulation and experimental verification of the results, optical microscopy and determination of mechanical characteristics.  

Experimental investigation of the near-bit jet pump

2019 ◽  
Vol 6 (2) ◽  
pp. 35-40
Author(s):  
Ye. I. Kryzhanivskyi ◽  
D. O. Panevnyk
Keyword(s):  
Experimental Studies ◽  
Flow Distribution ◽  
Relative Pressure ◽  
Jet Pump ◽  
Mixed Flow ◽  
Theoretical Determination ◽  
Proposed Model ◽  
The Cost ◽  
The Mathematical Model

The nature of the flow distribution in the hydraulic system of the near-bit jet pump has been analyzed. The peculiarities of searching the pumping station operating point have been shown and the equation for determining hydraulic losses in the elements of the ejection system has been given. Based on experimental studies, an error in the theoretical determination of the relative pressure of a jet pump has been established when using a known and advanced model of its working process. In contrast to the known method, the proposed model provides for the determination of the hydraulic resistance of the chisel flushing system,which is located in the area of mixed flow at the cost of working, not mixed flow. Improving the mathematical model of the ejection system allows to reduce the error of theoretical determination of the relative pressure of the jet pump.

Improvement Of Curvilinear Diagrams Of Concrete Deformation

2019 ◽  
pp. 99-104
Keyword(s):  
Reinforced Concrete ◽  
Peak Load ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
Significant Difference ◽  
Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

Energetic properties of peat saturated with petroleum products

2020 ◽  
Vol 13 (2) ◽  
pp. 105-109
Author(s):  
E. S. Dremicheva
Keyword(s):  
Crude Oil ◽  
Diesel Fuel ◽  
Energy Use ◽  
Experimental Studies ◽  
Calorific Value ◽  
Petroleum Products ◽  
Ash Content ◽  
Motor Oil ◽  
Initial Sample

This paper presents a method of sorption using peat for elimination of emergency spills of crude oil and petroleum products and the possibility of energy use of oil-saturated peat. The results of assessment of the sorbent capacity of peat are presented, with waste motor oil and diesel fuel chosen as petroleum products. Natural peat has been found to possess sorption properties in relation to petroleum products. The sorbent capacity of peat can be observed from the first minutes of contact with motor oil and diesel fuel, and significantly depends on their viscosity. For the evaluation of thermal properties of peat saturated with petroleum products, experimental studies have been conducted on determination of moisture and ash content of as-fired fuel. It is shown that adsorbed oil increases the moisture and ash content of peat in comparison with the initial sample. Therefore, when intended for energy use, peat saturated with petroleum products is to be subjected to additional drying. Simulation of net calorific value has been performed based on the calorific values of peat and petroleum products with different ratios of petroleum product content in peat and for a saturated peat sample. The obtained results are compared with those of experiments conducted in a calorimetric bomb and recalculated for net calorific value. A satisfactory discrepancy is obtained, which amounts to about 12%. Options have been considered providing for combustion of saturated peat as fuel (burnt per se and combined with a solid fuel) and processing it to produce liquid, gaseous and solid fuels. Peat can be used to solve environmental problems of elimination of emergency spills of crude oil and petroleum products and as an additional resource in solving the problem of finding affordable energy.

EXPERIMENTAL STUDIES OF REINFORCED CONCRETE STRUCTURES WITH CROSS-SHAPED SPATIAL CRACK UNDER TORSION WITH BENDING

2020 ◽  
Vol 92 (6) ◽  
pp. 13-25
Author(s):  
Vl.I. KOLCHUNOV ◽  
◽  
A.I. DEMYANOV ◽  
M.M. MIHAILOV ◽  
◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Experimental Determination ◽  
Calculation Method ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Design Parameters ◽  
Reinforced Concrete Structures ◽  
Experimental Scheme

The article offers a method and program for experimental studies of reinforced concrete structures with cross-shaped spatial crack under torsion with bending, the main purpose of which is to check the design assumptions and experimental determination of the design parameters of the proposed calculation method. The conducted experimental studies provide an opportunity to test the proposed calculation apparatus and clarify the regularities for determining deflections, angles of rotation of extreme sections, and stresses in the compressed zone of concrete. For analysis, the article presents a typical experimental scheme for the formation and development of cracks in the form of a sweep, as well as characteristic graphs of the dependence of the angles of rotation of end sections.

Tribology of rail bogie

2018 ◽  
Vol 77 (4) ◽  
pp. 230-240
Author(s):  
D. P. Markov
Keyword(s):  
Contact Fatigue ◽  
Basic Element ◽  
Difficult Problem ◽  
Railway Track ◽  
Rolling Stock ◽  
Kinematic Parameters ◽  
Approximate Estimation ◽  
Railway Bogie ◽  
Classical Calculation

Railway bogie is the basic element that determines the force, kinematic, power and other parameters of the rolling stock, and its movement in the railway track has not been studied enough. Classical calculation of the kinematic and dynamic parameters of the bogie's motion with the determination of the position of its center of rotation, the instantaneous axes of rotation of wheelsets, the magnitudes and directions of all forces present a difficult problem even in quasi-static theory. The paper shows a simplified method that allows one to explain, within the limits of one article, the main kinematic and force parameters of the bogie movement (installation angles, clearance between the wheel flanges and side surfaces of the rails), wear and contact damage to the wheels and rails. Tribology of the railway bogie is an important part of transport tribology, the foundation of the theory of wheel-rail tribosystem, without which it is impossible to understand the mechanisms of catastrophic wear, derailments, contact fatigue, cohesion of wheels and rails. In the article basic questions are considered, without which it is impossible to analyze the movement of the bogie: physical foundations of wheel movement along the rail, types of relative motion of contacting bodies, tribological characteristics linking the force and kinematic parameters of the bogie. Kinematics and dynamics of a two-wheeled bogie-rail bicycle are analyzed instead of a single wheel and a wheelset, which makes it clearer and easier to explain how and what forces act on the bogie and how they affect on its position in the rail track. To calculate the motion parameters of a four-wheeled bogie, it is represented as two two-wheeled, moving each on its own rail. Connections between them are replaced by moments with respect to the point of contact between the flange of the guide wheel and the rail. This approach made it possible to give an approximate estimation of the main kinematic and force parameters of the motion of an ideal bogie (without axes skewing) in curves, to understand how the corners of the bogie installation and the gaps between the flanges of the wheels and rails vary when moving with different speeds, how wear and contact injuries arise and to give recommendations for their assessment and elimination.

scholarly journals Identification of Sleeper Support Conditions Using Mechanical Model Supported Data-Driven Approach

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3609
Author(s):  
Mykola Sysyn ◽  
Michal Przybylowicz ◽  
Olga Nabochenko ◽  
Lei Kou
Keyword(s):  
High Speed ◽  
Experimental Studies ◽  
Dynamic Interaction ◽  
Theoretical Research ◽  
Rolling Stock ◽  
Monitoring Methods ◽  
Beam Dynamic ◽  
Track Geometry ◽  
Data Driven Approach ◽  
Support Conditions

The ballasted track superstructure is characterized by a relative quick deterioration of track geometry due to ballast settlements and the accumulation of sleeper voids. The track zones with the sleeper voids differ from the geometrical irregularities with increased dynamic loading, high vibration, and unfavorable ballast-bed and sleeper contact conditions. This causes the accelerated growth of the inhomogeneous settlements, resulting in maintenance-expensive local instabilities that influence transportation reliability and availability. The recent identification and evaluation of the sleeper support conditions using track-side and on-board monitoring methods can help planning prevention activities to avoid or delay the development of local instabilities such as ballast breakdown, white spots, subgrade defects, etc. The paper presents theoretical and experimental studies that are directed at the development of the methods for sleeper support identification. The distinctive features of the dynamic behavior in the void zone compared to the equivalent geometrical irregularity are identified by numeric simulation using a three-beam dynamic model, taking into account superstructure and rolling stock dynamic interaction. The spectral features in time domain in scalograms and scattergrams are analyzed. Additionally, the theoretical research enabled to determine the similarities and differences of the dynamic interaction from the viewpoint of track-side and on-board measurements. The method of experimental investigation is presented by multipoint track-side measurements of rail-dynamic displacements using high-speed video records and digital imaging correlation (DIC) methods. The method is used to collect the statistical information from different-extent voided zones and the corresponding reference zones without voids. The applied machine learning methods enable the exact recent void identification using the wavelet scattering feature extraction from track-side measurements. A case study of the method application for an on-board measurement shows the moderate results of the recent void identification as well as the potential ways of its improvement.

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