scholarly journals PECULIARITIES OF BENCH TESTS OF HYDRAULIC DAMPER OF RAILWAY PASSENGER CAR

2020 ◽  
Vol - (1(16)) ◽  
pp. 28-34
Author(s):  
K. Boriak ◽  
◽  
М. Manzaruk ◽  
Keyword(s):  
Test Bench ◽  
Mechanical Test ◽  
Experimental Studies ◽  
Technical Condition ◽  
Railway Track ◽  
Expert Assessment ◽  
Passenger Car ◽  
Hydraulic Damper ◽  
Curved Section ◽  
Piston Stroke

The studies are devoted to the scientific problem connected with the significant differences in the piston stroke values during testing of the same type of hydraulic damper by the use of different test benches and methods. The damper manufacturer uses the mechanical test bench ЛИИЖТ, the design of which was created back in Soviet times. This test bench has certain design limitations regarding the amplitude of harmonic vibrations of the drive mechanism, and therefore the dampers are tested at short piston strokes, which are 4 %; 8 %; 16 %, respectively, as a percentage of the maximum stroke of the piston. The passenger car depot, as a consumer of absorbers, conducts their tests at the more modern universal stand ИГK-90.1, which differs from the mechanical stand of the manufacturer of absorbers, both in design and in the method of testing absorbers. The purpose of the research is to confirm or deny the presence of influence of the value of the piston stroke on the expert assessment of the technical condition of the hydraulic damper. To solve this problem, the modern universal test bench ИГК-90.1 carried out experimental studies with different volumes of damping fluid in the slave cylinder of the КВЗ-ЛИИЖТ 45.30.045M type. A comparative analysis of the protocols showed that in the “compression” mode, the nature of the obtained dependences of the force and resistance parameters with an increase in the piston’s moving speed changes depending on the volume of the damping fluid in the damper’s working cylinder. The authors believe that testing the absorbers during the piston stroke of at least 80% of the maximum piston stroke allows the presence of deformations of the guide rod and the insufficient amount of damping fluid (the presence of air) in the absorber’s working cylinder. Deformation of the stem can lead to jamming in operation. The presence of air in the working cylinder of the damper is generally unacceptable since such damper is not able to absorb the vertical and horizontal vibrations of the car body in a curved section of the railway track with the height difference of the railheads 150 mm.

scholarly journals THE METHOD OF EXPERT ASSESSMENT OF THE TECHNICAL CONDITION OF AN AUTOMOBILE ENGINE AFTER OVERHEATING

2021 ◽  
pp. 5-16
Author(s):  
Alexander Khrulev ◽  
Olexii Saraiev
Keyword(s):  
Cylinder Head ◽  
Computational Models ◽  
Thermal State ◽  
Objective Assessment ◽  
Experimental Studies ◽  
Calculated Data ◽  
Technical Condition ◽  
Expert Assessment ◽  
Technical Ability ◽  
Loss Of Coolant

Problem. For expert studies of the technical condition of a car, a difficult task is to determine the causes and development of malfunction of engine mechanisms and systems. The paper proposes a model of engine malfunction during overheating, including in emergency mode caused by rapid loss of coolant. It has been established that thermal damage to the cylinder head is possible within 10 seconds after the cooling failure. The piston heats up more slowly and can only be damaged in the upper part and for a much longer time. According to the results of the study, it was found that in the event of an emergency loss of coolant, the driver does not have the technical ability to see the temperature rise, which may be important when investigating the causes of engine malfunctions associated with overheating. Goal. The goal is to investigate and reproduce the model of engine failure after overheating. Methodology. The theoretical calculated data are confirmed by real experimental studies of engine overheating failures. Results. It was calculated by calculation that in the absence of coolant, the temperature sensor, if it is located on the outlet pipe of the cylinder head, will not increase the temperature until the engine fails. A certain definite character of malfunction of parts of engine mechanisms during its sudden overheating is shown. Originality. On the basis of the developed models, a methodology was drawn up and the calculation of the thermal state of engine parts after overheating was performed. Practical value. The research carried out and the computational models compiled allow the expert to make a more objective assessment of the development of the engine malfunction mechanism when it overheats during the operation of the car.

scholarly journals Simplification of the procedure for testing common rail fuel injectors

2020 ◽  
Vol 180 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Tomasz STOECK
Keyword(s):  
Test Bench ◽  
Wide Spectrum ◽  
Characteristic Curve ◽  
Technical Condition ◽  
Common Rail ◽  
Microsoft Excel ◽  
Fuel Injectors ◽  
Active Experiment ◽  
Fuel Delivery ◽  
Problematic Situations

The paper presents a simplified methodology for generating the characteristic curve of fuel doses for common rail injectors, which consists in limiting the number of measurements on the test bench and calculating missing data using predefined (array) functions of the Microsoft Excel spreadsheet. This allows checking the method of fuel delivery in a wide spectrum of predefined pressures and atomiser opening times, while reducing the arduousness and time-consumption of the active experiment phase. The proposed solution is particularly useful in problematic situations when standard manufacturer's tests, referred only to selected work points, make it impossible to clearly assess the technical condition of the injector.

scholarly journals Definition of Set of diagnostic Parameters of System based on the Functional Spaces Theory

2019 ◽  
Vol 18 (4) ◽  
pp. 949-975 ◽  
Author(s):  
Valentin Senchenkov ◽  
Damir Absalyamov ◽  
Dmitriy Avsyukevich
Keyword(s):  
Fourier Series ◽  
Experimental Studies ◽  
Numerical Procedure ◽  
Physical Nature ◽  
Convergent Series ◽  
Technical Condition ◽  
Partial Sums ◽  
Diagnostic Tools ◽  
Diagnostic Parameters ◽  
Integrable Functions

The development of methodical and mathematical apparatus for formation of a set of diagnostic parameters of complex technical systems, the content of which consists of processing the trajectories of the output processes of the system using the theory of functional spaces, is  considered in this paper. The trajectories of the output variables are considered as Lebesgue measurable functions. It ensures a unified approach to obtaining diagnostic parameters regardless  a physical nature of these variables and a set of their jump-like changes (finite discontinuities of trajectories). It adequately takes into account a complexity of the construction, a variety of physical principles and algorithms of systems operation. A structure of factor-spaces of measurable square Lebesgue integrable functions, ( spaces) is defined on sets of trajectories. The properties of these spaces allow to decompose the trajectories by the countable set of mutually orthogonal directions and represent them in the form of a convergent series. The choice of a set of diagnostic parameters as an ordered sequence of coefficients of decomposition of trajectories into partial sums of Fourier series is substantiated. The procedure of formation of a set of diagnostic parameters of the system, improved in comparison with the initial variants, when the trajectory is decomposed into a partial sum of Fourier series by an orthonormal Legendre basis, is presented. A method for the numerical determination of the power of such a set is proposed. New aspects of obtaining diagnostic information from the vibration processes of the system are revealed. A structure of spaces of continuous square Riemann integrable functions ( spaces) is defined on the sets of vibrotrajectories. Since they are subspaces in the afore mentioned factor-spaces, the general methodological bases for the transformation of vibrotrajectories remain unchanged. However, the algorithmic component of the choice of diagnostic parameters becomes more specific and observable. It is demonstrated by implementing a numerical procedure for decomposing vibrotrajectories by an orthogonal trigonometric basis, which is contained in spaces. The processing of the results of experimental studies of the vibration process and the setting on this basis of a subset of diagnostic parameters in one of the control points of the system is provided. The materials of the article are a contribution to the theory of obtaining information about the technical condition of complex systems. The applied value of the proposed development is a possibility of their use for the synthesis of algorithmic support of automated diagnostic tools.

scholarly journals On the issue of inertial excitation of diagnostic low-frequency vibrations in pipelines of housing and communal services

2020 ◽  
Vol 216 ◽  
pp. 01079
Author(s):  
R Z Shakurova ◽  
S O. Gaponenko ◽  
A E. Kondratiev
Keyword(s):  
Experimental Studies ◽  
Low Frequency ◽  
Technical Condition ◽  
Main Attention ◽  
Pipeline Wall

The article discusses and analyzes issues related to the diagnosis of the technical condition of pipelines for housing and communal services. The main attention is paid to the inertial excitation of diagnostic low-frequency vibrations in the pipeline wall using the developed device. The results of experimental studies are presented.

Monitoring the technical condition of the railway track using the method of continuous recording of dynamic processes occurring due to the interaction between rolling stock and railway track

2021 ◽  
pp. 66-82
Author(s):  
Yuriy P. BORONENKO ◽  
◽  
Aleksandr V. TRET’YAKOV ◽  
Rustam V. RAKHIMOV ◽  
Mariya V. ZIMAKOVA ◽  
...  
Keyword(s):  
Practical Importance ◽  
Stability Margin ◽  
Technical Condition ◽  
Continuous Recording ◽  
Railway Track ◽  
Lateral Interaction ◽  
Rolling Stock ◽  
Monitoring Method ◽  
Wheel Pair ◽  
Interaction Forces

Objective: To develop the method to monitor the technical condition of the railway track. Me-thods: A strain-gauge wheel pair is used for continuous recording of vertical and lateral interaction forces in a dynamic wheel–rail system. Results: Stability margin factors of a wagon relative to de-railment have been determined and the defective (prone to derailment) sections of a railway track have been identified with the exact identification of their location (GPS coordinates) on the map using navigation devices. Practical importance: The developed monitoring method makes it possi-ble to promptly re¬gister and eliminate railway track defects

scholarly journals Analysis of Wheel Squeal and Flanging on Curved Railway Tracks

2019 ◽  
Vol 20 (12) ◽  
pp. 2077-2087 ◽  
Author(s):  
Jae Chul Kim ◽  
Yang Soo Yun ◽  
Hee-Min Noh
Keyword(s):  
Frequency Analysis ◽  
High Frequency ◽  
Railway Track ◽  
Railway Vehicle ◽  
Vertical Force ◽  
Railway Tracks ◽  
Noise Characteristics ◽  
Experimental Approaches ◽  
Curved Section ◽  
Natural Frequency Analysis

Abstract When a railway vehicle moves over a sharply curved section of track, intense high-frequency noises sometimes occur. These are potentially a source of annoyance to those living adjacent to railway tracks. To efficiently identify measures appropriate to reduce curve squeal, it is important to determine the dominant noise type. However, it is difficult to analyze the various noises made over curved sections of railway using general noise measurements. In this study, we analyzed squealing and flange noises using various experimental approaches. We first investigated the noise characteristics of the railway vehicle via structural analysis of the wheel. It was confirmed that a wheel has various natural frequencies and eigenmodes in the high frequency range, i.e. over 1000 Hz. A roller rig test was performed to measure and investigate the characteristics of the noise generated when an actual wheel and the curved section of the railway track come in contact with each other. In this experiment the squeal and the flange noises, in particular, were reproduced by adjustments made to the lateral angle and vertical force, respectively. Results confirmed that the squealing noise occurs in the high frequency region and the flange noise occurs in various modes. A study was also conducted to measure and analyze the noise in the actual curved section of an urban railway. By comparing the frequency analysis and the natural frequency analysis of the noise that was actually measured, the mode by which the wheel caused the squealing noise was confirmed. Furthermore, the influence of the noise generated inside and outside the curved section of the track was investigated based on velocity, and the influence of the former on the noise generated was also examined. This study provides information on the squeal and flange noises generated when a railway vehicle moves over a curved section of a railway using various experimental approaches.

scholarly journals The use of thermography in the diagnosis of ship piston internal combustion engines

2018 ◽  
Vol 182 ◽  
pp. 01027
Author(s):  
Jan Monieta
Keyword(s):  
Infrared Thermography ◽  
Internal Combustion Engines ◽  
Experimental Studies ◽  
Internal Combustion ◽  
Technical Condition ◽  
Operating Conditions ◽  
Combustion Engines ◽  
Destructive Testing ◽  
Fault State ◽  
Floating Objects

The intensity of infrared radiation emitted by objects depends mainly on their temperature. One of the diagnostic signals may be the temperature field. In infrared thermography, this quantity is used as an indicator of the technical condition of marine objects. The article presents an overview of the use of infrared thermography for the diagnosis mainly of marine piston floating objects and various types of reciprocating internal combustion engines as well as examples of own research results. A general introduction to infrared thermography and common procedures for temperature measurement and non-destructive testing are presented. Experimental research was carried out both in laboratory conditions and in the operating conditions of sea-going vessels. Experimental studies consisted of the presentation of photographs of the same objects made in visible light and the use of infrared thermography. The same objects were also compared, but for different cylinders of the tested internal combustion engines as well as for the up state and fault state. The characteristics of the temperature values at selected points were taken depending on the engine load along with the approximation mathematical models of these dependencies.

scholarly journals Results of theoretical and experimental studies on determining the coefficient of subgrade reaction of sleepers for the conditions of main railways with axial loads of 30-35 tons per axle

2018 ◽  
Vol 230 ◽  
pp. 01003
Author(s):  
Oleksandr Darenskiy ◽  
Eduard Bielikov ◽  
Olexii Dudin ◽  
Alina Zvierieva ◽  
Anatolii Oleshchenko
Keyword(s):  
Sustainable Development ◽  
Reinforced Concrete ◽  
Axial Load ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Railway Track ◽  
Rolling Stock ◽  
Subgrade Reaction ◽  
Axial Loads ◽  
Interaction Dynamics

The article considers obtaining numerical values of the coefficient of subgrade reaction of wooden and reinforced concrete sleepers with axial loads up to 30-35 tons per axle. It has been concluded that using the rolling stock with axial loads of up to 35 tons per axle is necessary in order to ensure sustainable development of the railway complex. The performance of the railway track thus should be investigated in order to predict its operation in such conditions. Generally, such studies are performed using numerical methods. One of the parameters that are required for such calculations is the parameter which is commonly called the coefficient of subgrade reaction. Empirical dependencies of the coefficient of subgrade reaction of wooden and reinforced concrete sleepers on the axial load and on the operating conditions of the track have been obtained. The obtained results can be used in studies of the interaction dynamics of the track of main railways with rolling stock with axial loads of 30-35 tons per axle, which will give an opportunity to provide well-grounded recommendations on the rules for the arrangement and maintenance of the track in such conditions.

Engineering Graphics Course Using Modern Software Systems for Students of Civil Engineering University

2015 ◽  
Vol 3 (1) ◽  
pp. 47-58 ◽  
Author(s):  
Петухова ◽  
Anna Petukhova
Keyword(s):  
Computer Aided Design ◽  
Civil Engineering ◽  
Integrated Approach ◽  
3D Models ◽  
Technical Condition ◽  
Railway Track ◽  
Software Systems ◽  
Gradual Transition ◽  
Engineering Graphics ◽  
Amount Of Knowledge

We should equip the graduates of technical universities with the most modern knowledge. It is one of the most impor - tant teaching aims. Civil engineer must be able to draw, read drawings, simulate parts, mechanisms, structures, buildings and sites on their computers. This is a great amount of knowledge and a huge range of skills, and their formation requires a gradual transition from drawings using pencil and ruler, through a standard drawing program (such Autodesk AutoCAD and Compass ASCON) to the more complex software systems (AutoCAD, Revit and AutoCAD Civil 3D). The article presents our experience in developing educational programs for undergraduate and specialties. The program is designed for "General construction", "Railway Construction", "Management of the technical condition of the railway track", "Bridges", "Tunnels and Subways", "Industrial and Civil Engineering", "Water supply and sanitation". The system of training is based on a modular principle. The first module "Descriptive Geometry" uses the classic teaching methods. Although it is supplemented by modern visualization tools (electronic posters, presentations, 3D models). The second module "Engineering Graphics" is built with a focus on computer way of doing drawings. At this stage, we form the basic skills of drawing and 3D-modeling. The main goal the next phase of training (course "Computer Graphics") is to form good skills in computer-aided design. In the last stage (course "Software"), we use the most modern software systems using BIM. An integrated approach can effectively reach both local and general educational purposes and creates a base for the formation of core professional competencies engineer.

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