scholarly journals Evaluation of reliability of quickly repairable components of transshipment machines and mechanisms

2021 ◽  
Vol 2061 (1) ◽  
pp. 012085
Author(s):  
E K Ablyazov ◽  
G V Deruzhinsky ◽  
K A Ablyazov
Keyword(s):  
Initial Data ◽  
Spare Parts ◽  
Reliability Estimate ◽  
Reliability Indicators ◽  
Distribution Laws ◽  
Methodological Aspects ◽  
Laws Of Distribution ◽  
Complex Distribution ◽  
Repairable Components ◽  
Ship Handling

Abstract When calculating the reliability indicators of transshipment machines and mechanisms, the required values are not always obtained explicitly due to systematic difficulties (complex distribution laws) or limited initial data. The optimal stock of spare parts for transshipment machines and mechanisms depends on the reliability indicators, and the nature and intensity of their use. Downtime due to the failure of transshipment machines and mechanisms used for ship handling leads to greater losses than downtime of these machines in the warehouse. Failures of transshipment machines and mechanisms can be due to the failure of non-repairable and quickly repairable components, and those with a long repair time. To calculate the main reliability indicators of quickly repairable components, the most common laws of distribution of random variables were employed. The paper considers the methodological aspects of the probabilistic reliability estimate of quickly repairable components of transshipment machines and mechanisms.

scholarly journals Application of diffusion-non-monoton distribution to model the radio-electronic equipment operation process

2019 ◽  
Vol 9 (6) ◽  
Author(s):  
Volodymyr Mirnenko ◽  
Petro Yablonsky ◽  
Sergii Kitik
Keyword(s):  
Technical Condition ◽  
Spare Parts ◽  
Theory And Practice ◽  
Electronic Equipment ◽  
Analytical Relationship ◽  
Physical Parameters ◽  
Degradation Processes ◽  
Reliability Indicators ◽  
Technical Systems ◽  
Quantitative Indicators

The emergence of reliability as an applied mathematical discipline is associated with the 50-60 years of the last century, when large and complex technical systems began to be created in various branches of technology. In this regard, an acute reliability problem arose, that is, ensuring the functioning and operability of these complex and expensive systems. The whole variety of reliability studies is aimed at solving the following three problems: assessment and prediction of product reliability at the design stages (a priori methods); experimental evaluation of reliability indicators, that is, confirmation of the projected level of reliability according to the results of tests or operation (posterior methods); taking measures to achieve and ensure a given level of reliability by optimizing the maintenance strategy, redundancy, spare parts, etc. (optimization problems) The traditional has developed a certain division in the areas of theory and practice of reliability of machines (mechanical objects, technical systems containing mechanical components) and equipment (electronic products, technical devices containing electronic and radio elements). The main tasks of reliability of machines and equipment - the establishment of patterns of failure and the assessment of quantitative indicators of reliability - can be solved in two different ways. To date, the direction based on the use of only probabilistic concepts (purely probabilistic theory) has received the greatest development in the theory and practice of reliability. The second way to establish quantitative indicators of reliability, in contrast to a purely probabilistic approach, is based on the study of mechano-physico-chemical properties and some physical parameters of products characterizing the technical condition of the latter using probabilistic methods. The methodology for establishing quantitative reliability indicators based on the study of certain physical parameters characterizing the technical condition of products consists in identifying the kinetic laws of degradation processes (building mathematical models of degradation processes) and determining the analytical relationship between these laws and reliability indicators. The article discusses the use of diffusion-nonmonotonic distribution for modeling the process of operation of electronic equipment. Particular attention is paid to the determination of point estimates of distribution parameters based on the results of operational observations.

scholarly journals Method for calculating the spectral density of the moment resistance on the working body of the road mill machine

2020 ◽  
Vol 6 (4) ◽  
pp. 518-528
Author(s):  
K.V. Fomin ◽  
Keyword(s):  
Initial Data ◽  
Spectral Density ◽  
Design Stage ◽  
High Productivity ◽  
The Road ◽  
Reliability Indicators ◽  
Unit Structure ◽  
Characteristic Features ◽  
The Moment

Milling units are widely used in the construction and repair of roads. They guarantee high quality of work, have high productivity and make it possible to provide comprehensive mechanization of technological operations. During operation, significant dynamic loads occur in the drive elements and the design of the units, which leads to a deterioration in reliability indicators and a decrease in the technical and economic characteristics of their operation. Improving the reliability and efficiency of milling units is an problem, the solution of which is associated with the opportunity to predict the character and magnitude of the operating loads in the structural elements. The main source of these loads is the working body. At the same time, the forces of external resistance that arise during operation are sharply variable, random in nature. The article presents a method for calculating the spectral density and moment dispersion at the design stage. It takes into consideration the periodic character of the interaction of the cutters with the road surface, as well as random conditions and modes of operation of the milling unit. The article focuses on determining the initial data required for the calculation. The obtained expressions are analyzed and the main characteristic features of the mill loads are considered. The considered characteristics are the initial data for the dynamic analysis of the drive elements and the unit structure, as well as for strength calculations.

scholarly journals Composition and superposition failures probability distribution laws for assessing military electrical products reliability

2021 ◽  
Vol 25 ◽  
pp. 131-137
Author(s):  
V.V. Alekseev ◽  
◽  
Yu.P. Batyrev ◽  
M.A. Boldyrev ◽  
P.S. Vorontsov ◽  
...  
Keyword(s):  
Probability Distribution ◽  
Standard Test ◽  
Structural Method ◽  
Reliability Indices ◽  
Transformer Type ◽  
Distribution Laws ◽  
Laws Of Distribution

An implementation of the developed computational structural method for assessing the reliability of complex electrical products. The basis of this method is the use of combinations of composition and superposition laws of distribution of probabilities of failures. The estimation of reliability of a rotating transformer type ВT-5. The calculated reliability indices are compared with results of standard test ВT-5 for reliability. Received high convergence of the results.

Application of the Bayesian approach to the construction of statistical estimates of the parameters of the distribution laws of random variables

2020 ◽  
pp. 14-21
Author(s):  
R. Z. Khayrullin ◽  
A. A. Zakutin
Keyword(s):  
Bayesian Approach ◽  
Measurement Errors ◽  
Random Variables ◽  
Likelihood Method ◽  
Statistical Estimates ◽  
Point Estimates ◽  
Distribution Laws ◽  
Uniform Law ◽  
Laws Of Distribution ◽  
The Bayesian Approach

The proposed article is devoted to the application of the Bayesian approach to the construction of statistical estimates of the parameters of the laws of distribution of random variables. Four distribution laws are considered: the Poisson law, the exponential law, the uniform law, and the Pareto law are presented. The results of constructing point estimates and interval estimates for the parameters of these laws. The results of comparison with the corresponding statistical estimates constructed by the classical maximum likelihood method are presented too. The proposed algorithm can be effectively applied in the development of measurement methods, in solving measurement problems, in the development of practical methods for identifying systematic measurement errors.

ENSURING RELIABILITY FOR COMPLEX TECHNICAL SYSTEMS LIKE MOVABLE MOUNTINGS OF SPECIAL PURPOSE

2020 ◽  
pp. 42-47
Author(s):  
V. M. Trukhanov ◽  
N. V. Fedorova ◽  
G. V. Trukhanov
Keyword(s):  
Service Life ◽  
Complex Systems ◽  
Qualitative Analysis ◽  
Spare Parts ◽  
Failure Recovery ◽  
Recovery Times ◽  
Distribution Laws ◽  
Complex Technical Systems ◽  
Technical Systems

The article is devoted to the question of ensuring the reliability of complex technical systems such as special purpose mobile units for extended service life. The features of maintainability of complex systems as one of the properties of mobile units, which must be taken into account in the development of structures, provide them in the manufacture and maintain during operation at a given level of quantitative reliability. The qualitative analysis of design solutions to ensure accessibility to places of control and maintenance, meet the requirements for interchangeability, unification and structural and technological continuity is described. Mathematical dependences for assessing the maintainability of special-purpose mobile installations in the form of distribution laws and failure recovery times are presented, as well as mathematical dependencies on the determination of spare parts and materials necessary for timely ensuring reliability, in particular maintainability, during operation.

scholarly journals Reliability Analysis of Technical Means of Transport

2020 ◽  
Vol 10 (9) ◽  
pp. 3016 ◽  
Author(s):  
Józef Żurek ◽  
Jerzy Małachowski ◽  
Jarosław Ziółkowski ◽  
Joanna Szkutnik-Rogoż
Keyword(s):  
System Reliability ◽  
Spare Parts ◽  
Special Role ◽  
Original Solution ◽  
Military Logistics ◽  
Reliability Indicators ◽  
Military Unit ◽  
Vehicle Fleet ◽  
Expected Fitness

The importance of system reliability within military logistics should be considered in terms of the ability to ensure the readiness of all available resources, e.g., means of transport, which are necessary during the realization of operational tasks. A special role is played by technical security, which enables the performance of all the specific tasks by the realization of the process supporting the subsystem in the area of providing the necessary assemblies, subassemblies and spare parts. The objective of the work was to define reliability in relation to technical means of transport and to illustrate an original solution leading to the determination of the expected fitness time of the available vehicle fleet, using the example of a selected military unit. The GNU Octave software—designed to conduct, among other things, advanced numerical computations—was used for the study. The daily operational mileage for a selected group of means of transport and the moments of failures were recorded during the tests, for the period from 31 December 2013 until 30 June 2015. The conducted analysis enabled the determination of the fundamental reliability indicators. The presented model has been supported with numerical examples, along with the interpretation of the obtained results.

scholarly journals Method for testing modern common rail piezoelectric fuel injectors

2021 ◽  
Author(s):  
Tomasz Stoeck
Keyword(s):  
Measuring Equipment ◽  
Test Bench ◽  
Spare Parts ◽  
Common Rail ◽  
Fuel Injectors ◽  
Reference Models ◽  
Regeneration Procedure ◽  
Repairable Components

The paper presents the author's own method for testing piezoelectric common rail fuel injectors, which for many years were considered non-repairable components. This was mainly due to the lack of availability of spare parts and dedicated measuring equipment, enabling full diagnostics under test bench conditions. As a result, their workshop and laboratory servicing was very limited, as effective disassembly concerned basicaly only the plunger and barrel assembly (needle with nozzle) for selected reference models. The situation has now improved to such an extent that an author’s own regeneration procedure has been proposed with the replacement of the most important controls and actuators. The tests were carried out on the example of Siemens VDO Continental PCR 2.3 fuel injectors from one engine, listing the most important stages of this process, including the correction of fuel dosage and returns.

scholarly journals SELECTION OF THE OPTIMUM ROUTE IN AN EXTENDED TRANSPORTATION NETWORK UNDER UNCERTAINTY

2021 ◽  
Vol 5 (1) ◽  
pp. 62-68
Author(s):  
Lev Raskin ◽  
Oksana Sira ◽  
Yurii Parfeniuk
Keyword(s):  
Approximate Solution ◽  
Initial Data ◽  
Transportation Network ◽  
Random Variables ◽  
Computational Procedure ◽  
Theoretical Description ◽  
Exact Method ◽  
Arbitrary Distribution ◽  
Random Initial Data ◽  
Distribution Laws

Relevance. For a given values set of extensive transport network sections lengths an exact method has been developed for finding optimal routes. The method provides an approximate solution when the initial data - are random variables with known distribution laws, as well as if these data are not clearly specified. Fora special case with a normal distribution of the numerical characteristics of the network, solution is brought to the final results. Method. An exact method of deterministic routing is proposed, which gives an approximate solution in case of random initial data. The method is extended to the case when the initial data are described in theory of fuzzy sets terms. The problem of stability assessing of solutions to problems of control the theory under conditions of uncertainty of initial data is considered. Results. A method of optimal routes finding is proposed when the initial data are deterministic or random variables with known distribution densities. A particular case of a probabilistic - theoretical description of the initial data is considered when can be obtained a simple solution of problem. Proposed method for obtaining an approximate solution in the general case for arbitrary distribution densities of random initial data. The situation is common when the initial data are not clearly defined. A simple computational procedure proposed for obtaining a solution. A method for stability assessing of solutions to control problems adopted under conditions of uncertainty in the initial data, is considered.

scholarly journals EFFICIENCY OF COMPUTER NETWORKS WITH SDN IN THE CONDITIONS OF INCOMPLETE INFORMATION ON RELIABILITY

2021 ◽  
Vol 5 (2) ◽  
pp. 103-107
Author(s):  
Ольга Зінченко ◽  
Віктор Вишнівський ◽  
Юлія Березовська ◽  
Петер Седлачек
Keyword(s):  
Incomplete Information ◽  
Computer Networks ◽  
Computer Network ◽  
A Priori ◽  
Packet Transmission ◽  
Reliability Indicators ◽  
Distribution Laws ◽  
Priori Information ◽  
Management Functions ◽  
Time Reserve

The paper analyzes the effectiveness of computer networks with SDN in conditions of incomplete reliability information. In order to ensure the specified indicators of the reliability of the computer network, it is recommended to use their guaranteed estimates. To increase the level of security of information systems and introduce the concept of time reserve in the process of packet transmission, it is necessary to separate the functions of traffic transmission from management functions. This is the basic principle of SDN. When using SDN technology in computer networks, it is possible to enter a time reserve when transmitting messages. This makes it possible to more accurately determine the reliability. The evaluation of the data transmission system of the computer network takes into account the possibility of entering a time reserve and obtained the basic calculated ratios for reliability indicators in terms of incomplete information about their distribution laws. A priori information is limited by knowledge of the first initial moments of mathematical expectation and variance. These results are a justification for the structure of computer networks that are designed or upgraded. You can also use this information to build highly reliable networks or technical facilities that exist in a single implementation.

scholarly journals A Demand Prediction Model of Repairable Components based on Grey Birth and Death Process

2021 ◽  
Author(s):  
Yingjing Gu ◽  
Ching-Ter Chang
Keyword(s):  
Operating Cost ◽  
Demand Forecasting ◽  
Spare Parts ◽  
Death Process ◽  
Practical Case ◽  
Uncertain Information ◽  
Birth And Death Process ◽  
Demand Prediction ◽  
Spare Parts Inventory ◽  
Repairable Components

Abstract During the life cycle of equipment, the failure and repair rates of repairable components show uncertain characteristics. The birth and death process (BDP) based on the determined failure and repair rates may not meet the demand forecasting of spare parts. In order to resolve this problem, the grey state transition matrix is constructed by using interval grey numbers to appropriately represent the failure and repair rates of repairable components. In addition, the grey BDP model is built for the demand forecasting of spare parts. The memoryless and existence conditions of steady solution of the grey BDP are studied. To some extent, the spare parts demand law with the uncertain information of the failure and repair rates can easily be revealed. The practical case study is provided to verify the validity and practicability of the proposed model. Also, it provides a new perspective for the spare parts demand prediction problem under the condition of uncertain Markov Process. Accordingly, airlines can predict the maintenance resources demand more accurately and avoid two situations which are not allowed: (1) lower spare parts inventory will lead to the delay production; and (2) higher spare parts inventory will lead to the operating cost pressure.

Sign in / Sign up

Export Citation Format

Share Document