scholarly journals Parametric evaluation of the technical object suitability based on analyze the quality of its maintenance and use taking into account the initial conditions

2018 ◽  
Vol 182 ◽  
pp. 01006
Author(s):  
Rafał Grądzki
Keyword(s):  
Equations Of State ◽  
Initial Conditions ◽  
Technical Condition ◽  
Operation Condition ◽  
Technical Object ◽  
Coupled Equations ◽  
Reliability Parameters ◽  
Operation Conditions ◽  
Operational Data

In this paper, the comparison of three various technical objects (engines of public transport buses) exploitation research for different initial conditions are presented. Object researches were carried out in 2012 and then repeated in 2013. Gathered operational data is presented in three sets (1 – concerning object, 2 – concerning driving conditions, 3 – concerning driver, where set 1 is the collection of diagnostic information Dk, and sets 2 and 3 are the information about object environment U) in form of conventional points (experts numerical assessments). Relation between point information of object and point information of environment was described by coupled equations of state (describing relations between operation condition and technical condition including initial conditions for each analyzed exploitation period). That method allows to determine parameters of technical condition aT and operation condition aR and next, from the course of aT parameter, set of parametrical damage mT(t) and from course of parameter aR – set of momentary damage aR(t). Thus it is possible to evaluate exploitation, technical and operation conditions of each object (bus engine). Received reliability parameters allows to properly control exploitation and service of particular objects and set of objects (fleet of buses) and its elements.

ANALYSIS OF THE RELIABILITY OF PEAT MACHINES IN THE PROCESS OF DESIGN

2020 ◽  
pp. 32-38
Author(s):  
I.V. GORLOV ◽  
Keyword(s):  
Calculation Method ◽  
Preliminary Analysis ◽  
Statistical Data ◽  
Technical Condition ◽  
Design Stage ◽  
Reliability Parameters ◽  
Use Of Data

The article discusses the method of preliminary analysis of the reliability of the design of peat machines (PM) at the design stage. For the designed TM, it is possible to assess the reliability using generalized statistical data on similar peat machines, but significant errors arise that do not allow predicting the technical condition of the equipment under development with the required accuracy. The proposed technique makes it possible to evaluate the developed design of the machine in terms of reliability based on the analysis of the operation of similar units of existing PM. For this, the existing peats machines are divided into separate mechanisms, for which there are statistics on failure parameters. The division of the designed machines is carried out in a similar way; while in order to obtain the necessary reliability parameters, it is proposed to use the coefficient calculation method, taking into account the presence in the developed PM design of the number of the most critical parts and assemblies. Thus, the use of data from the operation of existing PM makes it possible to improve the quality of predicting changes in the reliability parameters of the machines being developed, and as a result, during their operation, a decrease in the number of downtime due to difficult-to-predict failures is achieved, which makes it possible to increase the seasonal productivity of PM.

Identification of Parametric and Momentary Damages on the Basis of Lindeberg-Levy’s Model

2017 ◽  
Vol 260 ◽  
pp. 249-257
Author(s):  
Paweł Lindstedt ◽  
Tomasz Sudakowski
Keyword(s):  
Standard Deviation ◽  
Threshold Value ◽  
Technical Condition ◽  
Technical Object ◽  
Reliability Parameters ◽  
Innovative Method ◽  
Condition Equation ◽  
Lévy’S Theorem ◽  
The Moment ◽  
Damage Map

Article presents the innovative method for the assessment of reliability condition of the exploited system, based on the appropriate analysis of changes in the current parameters of technical condition aRb and the regulation condition aRc, determined from the compressed condition equation (1 and 2). While analyzing the course of momentary parameters for technical condition aRb and the regulation condition aRc, it was observed that the parametric and momentary damages can be identified on the basis of quantitative relations between momentary threshold value dpr and corresponding momentary permissible value dprdop, which are calculated from equation (7, 8, 9) resulting from Lindeberg-Levy’s theorem. It is assumed that the damages are prevailing, when for the moment θi: dpri>dpr dopi. With the number of damages (damage map), reliability parameters for each moment of exploitation of technical object (before the catastrophic damages will occur) can be determined. Parametric damages (expected lifetime E(T) and standard deviation of expected lifetime σE(T) provides the reasonable information for the appropriate planning of the servicing of exploitative objects.

scholarly journals The New Approach to Identification of Parametric and Momentary Damages on the Basis of Lindeberg – Levy’s Model

2017 ◽  
Vol 43 (1) ◽  
pp. 5-21
Author(s):  
Paweł Lindstedt ◽  
Tomasz Sudakowski ◽  
Artur Kułaszka
Keyword(s):  
Standard Deviation ◽  
Threshold Value ◽  
Technical Condition ◽  
Technical Object ◽  
New Approach ◽  
Reliability Parameters ◽  
Condition Equation ◽  
Lévy’S Theorem ◽  
The Moment ◽  
Damage Map

Abstract The new approach for the assessment of reliability condition of the exploited system, based on the appropriate analysis of changes in the current parameters of technical condition aRb and the regulation condition aRc, determined from the compressed condition equation (1 and 2). While analyzing the course of momentary parameters for technical condition aRb and the regulation condition aRc, it was observed that the parametric and momentary damages can be identified on the basis of quantitative relations between momentary threshold value dpr and corresponding momentary permissible value dpr dop, which are calculated from equation (7, 8, 9) resulting from Lindeberg–Levy’s theorem. It is assumed that the damages are prevailing, when for the moment θi: >dpri> dpr dopi. With the number of damages (damage map), reliability parameters for each moment of exploitation of technical object (before the catastrophic damages will occur) can be determined. Parametric damages (expected lifetime E(T) and standard deviation of expected lifetime σE(T) provides the reasonable information for the appropriate planning of the servicing of exploitative objects.

Qualitative assessment of equipment failure cause finding and removal

2018 ◽  
pp. 116-126
Author(s):  
E. A. Vakulin ◽  
A. I. Zayats ◽  
V. A. Beklemeshev ◽  
V. A. Ivashkevich ◽  
V. A. Khazhiev ◽  
...  
Keyword(s):  
Production Condition ◽  
Real Life ◽  
Open Pit Mine ◽  
Qualitative Assessment ◽  
Open Pit ◽  
Quality Level ◽  
Equipment Failure ◽  
Operation Conditions ◽  
Failure Investigation

Investigation of failures is one of the critical activities of mining and haulage equipment operability assurance in mining. Maintaining failure investigation at the required quality level, it is possible to identify provisions, rules and procedures that should be revised or changed, operation conditions that should be improved, additional personnel training, if required, etc. Investigation of failures in mines is under responsibility of machine men and electricians of maintenance and operation services. In reality, factory management and setup for production condition weak concernment of these workers in quality investigation aimed at finding of sources of equipment failures. This article describes real-life results achieved in development and use of maintenance service operation, technology and management monitoring. The requirements are substantiated for quality improvement in failure cause finding and removal in mining and haulage equipment at Chernogorsky open pit mine, SUEK-Khakassia. Causes of the present quality of failure investigation by machine men of Chernogorsky Repair and Engineering Works and Chernogorsky open pit mine are revealed. The proposed recommended practices will improve quality of mining and haulage equipment failure investigation.

Software suite for determining the tilts of tower-type structures according to terrestrial laser scanning

2020 ◽  
Vol 961 (7) ◽  
pp. 2-7
Author(s):  
A.V. Zubov ◽  
N.N. Eliseeva
Keyword(s):  
Laser Scanning ◽  
Optimization Problems ◽  
Optimization Methods ◽  
User Participation ◽  
Software Suite ◽  
Current State ◽  
Visual Basic For Applications ◽  
Operational Data ◽  
Theoretical Developments

The authors describe a software suite for determining tilt degrees of tower-type structures according to ground laser scanning indication. Defining the tilt of the pipe is carried out with a set of measured data through approximating the sections by circumferences. They are constructed using one of the simplest search engine optimization methods (evolutionary algorithm). Automatic filtering the scan of the current section from distorting data is performed by the method of assessing the quality of models constructed with that of least squares. The software was designed using Visual Basic for Applications. It contains several blocks (subprograms), with each of them performing a specific task. The developed complex enables obtaining operational data on the current state of the object with minimal user participation in the calculation process. The software suite is the result of practical implementing theoretical developments on the possibilities of using search methods at solving optimization problems in geodetic practice.

High-Speed Imaging to Study an Auto-Oscillating Vocal Fold Replica for Different Initial Conditions

2017 ◽  
Vol 09 (05) ◽  
pp. 1750064 ◽  
Author(s):  
A. Van Hirtum ◽  
X. Pelorson
Keyword(s):  
Vocal Fold ◽  
High Speed ◽  
Initial Conditions ◽  
Vocal Folds ◽  
High Speed Imaging ◽  
Human Voice ◽  
Manual Intervention ◽  
Geometrical Features ◽  
Upstream Pressure

Experiments on mechanical deformable vocal folds replicas are important in physical studies of human voice production to understand the underlying fluid–structure interaction. At current date, most experiments are performed for constant initial conditions with respect to structural as well as geometrical features. Varying those conditions requires manual intervention, which might affect reproducibility and hence the quality of experimental results. In this work, a setup is described which allows setting elastic and geometrical initial conditions in an automated way for a deformable vocal fold replica. High-speed imaging is integrated in the setup in order to decorrelate elastic and geometrical features. This way, reproducible, accurate and systematic measurements can be performed for prescribed initial conditions of glottal area, mean upstream pressure and vocal fold elasticity. Moreover, quantification of geometrical features during auto-oscillation is shown to contribute to the experimental characterization and understanding.

scholarly journals Stellar mass spectrum within massive collapsing clumps

2018 ◽  
Vol 611 ◽  
pp. A89 ◽  
Author(s):  
Yueh-Ning Lee ◽  
Patrick Hennebelle
Keyword(s):  
Large Scale ◽  
Equations Of State ◽  
Initial Conditions ◽  
Peak Position ◽  
Density Fluctuations ◽  
Initial Mass Function ◽  
Analytical Models ◽  
Numerical Resolution ◽  
Tidal Forces ◽  
The Imf

Context. Understanding the origin of the initial mass function (IMF) of stars is a major problem for the star formation process and beyond. Aim. We investigate the dependence of the peak of the IMF on the physics of the so-called first Larson core, which corresponds to the point where the dust becomes opaque to its own radiation. Methods. We performed numerical simulations of collapsing clouds of 1000 M⊙ for various gas equations of state (eos), paying great attention to the numerical resolution and convergence. The initial conditions of these numerical experiments are varied in the companion paper. We also develop analytical models that we compare to our numerical results. Results. When an isothermal eos is used, we show that the peak of the IMF shifts to lower masses with improved numerical resolution. When an adiabatic eos is employed, numerical convergence is obtained. The peak position varies with the eos, and using an analytical model to infer the mass of the first Larson core, we find that the peak position is about ten times its value. By analyzing the stability of nonlinear density fluctuations in the vicinity of a point mass and then summing over a reasonable density distribution, we find that tidal forces exert a strong stabilizing effect and likely lead to a preferential mass several times higher than that of the first Larson core. Conclusions. We propose that in a sufficiently massive and cold cloud, the peak of the IMF is determined by the thermodynamics of the high-density adiabatic gas as well as the stabilizing influence of tidal forces. The resulting characteristic mass is about ten times the mass of the first Larson core, which altogether leads to a few tenths of solar masses. Since these processes are not related to the large-scale physical conditions and to the environment, our results suggest a possible explanation for the apparent universality of the peak of the IMF.

scholarly journals Simulation of rod vibrations process with an independent pendular suspension and vertical stabilization system

2018 ◽  
Vol 56 (4) ◽  
pp. 469-480
Author(s):  
I. S. Kruk ◽  
A. A. Tiunchik ◽  
V. Romanyuk
Keyword(s):  
Technological Process ◽  
Initial Conditions ◽  
Vertical Movement ◽  
Design Stage ◽  
Geometrical Parameters ◽  
Stabilization System ◽  
Special Approach ◽  
Rod Structures ◽  
Design And Testing

Continuous improvement of field sprayer design aimed at performance increase by increasing the working width, requires a special approach to ensure reliability of the supporting rod structure and quality of technological process. The question of rod vibrations, which arise when the driving systems copy field rough surface and abrupt changes in speed of the unit, remains topical. At the design stage of supporting structures of the rods, special attention is paid to the substantiation of its geometrical parameters in the longitudinal and transverse sections; studies of changes in the characteristics of vertical and horizontal vibrations, taking into account the method of the rod hanging and the system used for its stabilization. This allows to ensure the reliability of the rod design and the required quality of the technological process. The article proposes construction of the rod independent pendulum suspension on the sprayer frame and its stabilization system based on the use of damping elements. The analytical studies sequence system was developed for rod vibrations analysis, depending on initial conditions, parameters and characteristics of the used damping elements, under which they are effectively damped. It is shown that at certain numerical values of the geometrical parameters of the rod, the suspension and vibrations damping methods, not only the numerical values of the functions are changed, but also the functions themselves that describe the process of the rod's vertical movement, including cases of resonance. The obtained theoretical results can be used for design and testing of machines with rod working units and allow, at design stages, to simulate the process of movement of various rod structures from external excitatory forces, and to determine patterns of changes in the characteristics of damped vibrations using different damping elements and their installation parameters.

scholarly journals Comprehensive Downtime Prediction in Next-Generation Internet

1970 ◽  
Vol 5 (1) ◽  
Author(s):  
W. F. Al-Khateeb, S. Al-Irhayim, and K. A. Al-Khateeb
Keyword(s):  
Analytical Calculation ◽  
Multiprotocol Label Switching ◽  
Next Generation ◽  
Label Switching ◽  
Next Generation Internet ◽  
Reliability Parameters ◽  
Wide Range ◽  
The Individual ◽  
Single Figure

The benchmark for the reliability quality of networks depends mainly on the accuracy and comprehensiveness of the reliability parameters. Downtime prediction of a communication system is crucial for the quality of service (QoS) offered to the end-user. Markov model enables analytical calculation of average single figure cumulative downtime over one year. The single average approach, generally, does not adequately describe the wide range of service performance that is likely to be experienced in communications systems due to the random nature of the failure. Therefore, it would be more appropriate to add downtime distribution obtained from network availability models to predict the expected cumulative downtime and other performance parameters among a large number of system populations. The distribution approach provides more comprehensive information about the behavior of the individual systems. Laplace-Stieltjes transform enables analytical solutions for simple network architectures, i.e. the simplex system and the parallel system. This paper uses simulations to determine reliability parameters for complex architecture such as the Multiprotocol Label Switching (MPLS) backbone planned for next-generation Internet. In addition to the single figure downtime, simulations provide other reliability parameters such as probability of zero downtime. The paper also considers the downtime distribution among a population of equally designed systems.Key Words: Reliability, availability, downtime, Multiprotocol label switching

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