Претрага

Упит dcterms_subject_txt:Severity of failure assessment

2845 items

  • Fuzzy expert analysis of the severity of mining machinery failure

    Dejan V. Petrović, Miloš Tanasijević, Saša Stojadinović, Jelena Ivaz, Pavle Stojković (2020)
    Mining machinery failure is almost an everyday occurrence. Usually the failures bare certain consequences, which require additional financial costs to repair and restore the system to its operational state. The consequences are viewed through negative and damaging effects a failure has on the machine, health and safety of the employees, work environment, and on the environment. The removal of the consequences of the failure requires additional financial investment, which has a negative impact on the company’s business. In order ...
    Severity of failure, Severity of failure assessment, Mining machinery, Fuzzy sets, Fuzzy logic

  • Fuzzy Model for Risk Assessment of Machinery Failures

    Dejan V. Petrović, Miloš Tanasijević, Saša Stojadinović, Jelena Ivaz, Pavle Stojković (2020)
    The main goal of this research was the development of an algorithm for the implementation of negative risk parameters in a synthesis model for a risk level assessment for a specific machine used in the mining industry. Fuzzy sets and fuzzy logic theory, in combination with statistical methods, were applied to analyze the time picture state of the observed machine. Fuzzy logic is presented through fuzzy proposition and a fuzzy composition module. Using these tools, the symmetric position of the ...
    fazi teorija, rizik, otkaz rudarskih mašina
    ... (related to class) of severity of failure. For a risk level assessment of the failure of subsystem components, 10 classes were taken. Because of this, it was necessary to map the failure severity assessment, which had 30 classes, into 10 classes. This could be achieved by using the value of every third class ...
    ... the risk assessment of one element, subsystem, and technical system are presented in this paper. 5.1. Failure Risk Assessment of Elements in a Subsystem Using Min–Max Composition 5.1.1. Determination of Failure Severity Indicators Failure severity represents the negative impact a failure has on the ...
    ... component. The risk indicators for the component include failure severity, failure occurrence probability, and failure detectability. Figure 1. Algorithm for the risk of failure assessment for engineering systems. In the proposed algorithm, failure severity is expressed through the following: • A maintainability ...

  • Preliminary Risk Assessment of Dam Failure at the Location of the Cukaru Peki Deposit, Bor (Serbia)

    Dragana Nišić (2021)
    preliminarna procena rizika, rušenje brane, nesreća, matrica rizika, posledice udesa, industrijski otpad

  • Risk assessment model of mining equipment failure based on fuzzy logic

    D. Petrović, Tanasijević Miloš, V. Milić, Lilić Nikola, Stojadinović Saša, Igor Svrkota (2014)

  • A fuzzy-based decision support model for effectiveness evaluation - a case study of examination of bulldozers

    Miloš Tanasijević, Predrag Jovančić, Dejan Ivezić, Uglješa Bugarić, Radiša Đurić (2019)
    Effectiveness evaluation is one of the basic components of engineering asset management and maintenance engineering in general. Effectiveness is an overall concept representing a measurement of quality of service level for the analyzed engineering system. This concept contains a series of partial indicators relating to time in operation and time for maintenance activities, as well as functional properties of the system. This article describes the analysis and structuring of partial indicators, as well as the development of a model ...
    Efikasnost, Fazi zaključivanje, Prikupljanje podataka, Buldozer

  • Applicability of the risk ranking methodology designed for water reservoirs to tailings storage facilities

    Dragana Nišić, Dinko Knežević, Aleksandar Cvjetić, Neda Nišić, Vladimir Jovanović (2022)
    The risks associated with operating water reservoirs and tailings storage facilities (TSFs) are different because of their different purposes, methods of construction and operation, and characteristics of the materials impounded and their flow behaviour. Regardless of the differences, these two types of structures are often put in the same category when it comes to risk assessment and the application of relevant methodologies, which may result in unrealistic outcomes. In this paper we investigate whether it is possible to apply ...
    procena rizika, akumulacije za vodu, jalovište, TSF, ICOLD, FMEA

  • Development of the Availability Concept by Using Fuzzy Theory with AHP Correction, a Case Study: Bulldozers in the Open-Pit Lignite Mine

    Stevan Đenadić, Dragan Ignjatović, Miloš Tanasijević, Uglješa Bugarić, Ivan Janković, Tomislav Šubaranović (2019)
    Availability is one of the most used terms in maintainability engineering. This concept is used to denote: The quality of service of an engineering system, i.e., machines, weak points’ analysis, asset management, as well as making decisions in the process of life cycle management. Availability is an overall indicator and contains partial indicators that are oriented towards reliability, maintenance, and logistical support. Availability presents a variable value and changes in time and space. Usually, availability is shown as the ...
    raspoloživost, fazi teorija, AHP višekriterijumska analiza, eksperska ocena, buldozer
    ... attracted great interest, and today methods of this type are widely used and have broad application. It relies on the theory of relative measurements of the severity of the impact factors in decision making. The subject of interest is not the accurate measurements of individual quantities, but the accent ...
    ... USA, 2004; pp. 91–120. 9. Cai, K.Y. System failure engineering and fuzzy methodology an introductory overview. Fuzzy Sets Syst. 1996, 83, 113–133. [CrossRef] 10. Miodragovic, R.; Tanasijevic, M.; Mileusnic, Z.; Jovancic, P. Effectiveness assessment of agricultural machinery based on fuzzy sets theory ...
    ... impact on the time state picture of the technical system. • ‘C’(R)—Failures occur. In most cases, they are expected, and therefore, in some way they can be planned. Failures can be eliminated on the spot. • ‘D’(R)—Occurrence of failure is frequent. The reliability of the machine is low. Efficiency ...

  • Determining the Availability of Continuous Systems at Open Pits Applying Fuzzy Logic

    Miljan Gomilanović, Miloš Tanasijević, Saša Stepanović (2022)
    This work presents a model for determining the availability of continuous systems at open pits by applying fuzzy logic and fuzzy inference systems. The applied model was formed by the synthesis of independent partial indicators of availability. The model is based on an expert system for assessing the availability of continuous mining systems. The availability of the system, as a complex state parameter, is decomposed into the partial indicators, reliability, and convenience of maintenance, and the fuzzy compositions, used ...
    системи, континуални систем експоатације, површински коп, рударство, расположивост, фази логика, max–min композиција, min–max композиција

  • Failure Estimation of the Majdanpek Open Pit East Face Based on Inverse Velocity Model

    Miloš Marjanović, Stefan Milanović, Nikola Simić, Lazar Kričak (2024)
    The Majdanpek open pit mine south district is currently active mining prospect of copper ore exploitation in eastern Serbia. Its depth is approaching the termination depth and occurrences of large-scale instabilities and global instability of the final pit slope is possible. These can generate catastrophic mass movement inside an area that encloses a regional road route and the Pek River bed which is channelled along the outer contour of the pit. The displacements that were noted in early 2023, in the ...
    displacement, survey, inverse velocity, open pit

  • Rock slope stability analysis under Hoek–Brown failure criterion with different flow rules

    Svetlana Melentijević, Zoran Berisavljević, Dušan Berisavljević, Claudio Olalla Marañón (2024)
    The stability analysis of homogeneous rock slope following the Hoek–Brown failure criterion under the hypothesis of different flow rules is performed based on limit equilibrium and finite element methods. The applied failure criterion is the generalized Hoek–Brown that can be introduced as a shear/normal function in analysis applying different flow rules. The results are compared with those obtained by the application of equivalent shear strength parameters of the Mohr–Coulomb criterion, considering that this is still the most widely used ...
    Kružna klizna površ, Huk-Braunov kriterijum loma, Kriterijum popuštanja, Smičuća/normalna funkcija, Nivo napona, Verovatnoća i parametarska analiza

  • Legal framework for recultivation of degraded areas caused by mining exploitation

    Radmila Gaćina (2023)
    Prilikom površinske i podzemne eksploatacije uglja eksploatacioni sistemi oštećuju veće ili manje površine zemljišta. Iskustva pokazuju da su oštećenja zemljišta znatno veća kod površinske eksploatacije, gde je prostora degradiran ne samo u konturi rudnika i okoline, već se promene takođe dešavaju u prirodnom okruženju. U članku su predstavljeni rezultati studije zakonskih okvira rekultivacije u nekim zemljama sveta i u Srbiji. Praktično iskustvo rekultivacije pokazalo je da iskorišćenje i devastacija tokom rudarske aktivnosti predstavljaju opasnost ne samo za pogođena ...
    rekultivacija, melioracija, otkopavanje uglja, zakonska regulativa
    ... restoration of the original use of arable land, acceptance of the main content should include: reclaimed land area, surface cover thickness, ground slope and drainage function, the physical and chemical properties of the soil are in line with the standards of arable land, and the failure to meet the ...
    ... execution of the project cannot be started, and it is based on the preparation of the Study on the assessment of the impact on the environment (scope and content is determined by special regulations adopted on the basis of the above of the law). Legal framework in the field of recultivation of degraded ...
    ... Environmental Impact Assessment, - _ Lawon Strategic Environmental Impact Assessment, - _ Lawon Integrated Prevention and Control of Environmental Pollution. Legal and physical entity who use natural resources are obliged to keep up to date during the execution of works and performance of activities, ...

  • Развој алгоритма процене ефеката ризика рада рударских машина на бази фази алгебре

    Dejan V. Petrović (2014-12-30)
    Појава изненадних отказа елемената техничких система у рударству је свакодневна појава...
    ризик, поузданост, технички систем, рударске машине, отказ, фази скупови, фази логика

  • Pre-failure deformation monitoring as rockfall prediction tool

    Miloš Marjanović, Biljana Abolmasov, Zoran Berisavljević, Marko Pejić, Petko Vranić (2021)
    General Engineering
    ... the pre-failure deformations preceding a series of rockfalls, reaching 0.3 m3 in volume with 0.5 annual reoccurrence probability. Monitoring enabled identification of subtle displacements of about 1 cm after the first event in 2014 and keeping track of its progression. After a series of events in ...
    ... Pre-failure deformation monitoring as rockfall prediction tool Miloš Marjanović1, Biljana Abolmasov1, Zoran Berisavljević1, Marko Pejić2, and Petko Vranić2 1University of Belgrade, Faculty of Mining and Geology, Đušina 7, Belgrade, Serbia 2University of Belgrade, Faculty of Civil Engineering ...
    ... investigations that frequency and rate of deformation of small events accelerates as the larger failure onsets. In addition, it is confirmed that the small events are spatially clustering around the future large failure scarp. They emphasize the importance of LiDAR scanning in further research and ...

  • A Model for Determining Fuzzy Evaluations of Partial Indicators of Availability for High-Capacity Continuous Systems at Coal Open Pits Using a Neuro-Fuzzy Inference System

    Miljan Gomilanović, Miloš Tanasijević, Saša Stepanović, Filip Miletić (2023)
    This paper presents a model for determining fuzzy evaluations of partial indicators of the availability of continuous systems at coal open pits using a neuro-fuzzy inference system. The system itself is a combination of fuzzy logic and artificial neural networks. The system availability is divided into partial indicators. By combining the fuzzy logic and artificial neural networks, a model is obtained that has the ability to learn and uses expert judgment for that learning. This paper deals with the ...
    системи, континуални системи експлоатације (роторни багер-транспортер-дробилично постројење), рударство, расположивост, меко рачунарство, фази логика, ANN, ANFIS

  • A Model for Determining the Dependability of Continuous Subsystems in Coal Mines Using the Fuzzy Logic Approach

    Nikola Stanić, Miljan Gomilanović, Petar Marković, Daniel Krzanović, Aleksandar Doderović, Saša Stepanović (2024)
    This study presents a unique model for assessing the dependability of continuous parts of combined systems in open-pit mining through the application of fuzzy logic. Continuous sub-systems as part of the combined system of coal exploitation in surface mines have the basic function of ensuring safe operation, high capacity with high reliability, and low costs. These subsystems are usually part of the thermal power plant’s coal supply system and ensure stable fuel supply. The model integrates various independent partial ...
    fuzzy logic, max-min composition, continuous part of combined system (CCS), open pit, mining, dependability

  • A Fuzzy Expert Model for Availability Evaluation

    Dejan Ivezić, Miloš Tanasijević, Predrag Jovančić, Radiša Đurić (2019)
    Each technical system within itself carries the great potential danger of possible occurrence of failure and damages. Mining machines are characteristic by great investment values, costs of unplanned shutdowns, complex working conditions, and environment and workers hazards. Systematic monitoring of the mining machinery is of great importance for the management of the mining companies. Availability is the overall concept of quality of service. Includes information regard to operating state, an idle state, a standby state and shut down. The ...
    raspoloživost, ekspertski sistem, fazi teorija, buldozeri
    ... model of availability assessment is practically summarized in two steps: fuzzy proposition of availability partial indicators - R, M and S and fuzzy composition of mentioned indicators into one A. The defining of linguistic variables for A, R, M and S is the first step in the creation of an expert ...
    ... For the introduction of operators’ and experts’ opinions and judgments in the availability assessment model, specific questioners are created. For each indicator of A, operators/experts distributed 100% of their confidence to five fuzzy sets. Average value of confidences of all operators/experts ...
    ... their values Ωc, namely the size of j. - Find the MAXimum between previously identified minimums for each group of outcomes. The maximum which corresponding the jth value is calculated following the equations: MAXj = max {MINo}, for every j (5) The assessment of engineering system finally is ...

  • Extensive vibrations of the belt conveyer drive electromotor of a bucket wheel excavator as a result of intesified wear-and-tear of its mount support

    Vesna Damnjanović, Predrag Jovančić, Snežana Aleksandrović (2017)

  • Determination of Mechanical Properties of Altered Dacite by Laboratory Methods

    Veljko Rupar, Vladimir Čebašek, Vladimir Milisavljević, Dejan Stevanović, Nikola Živanović (2021)
    This paper presents a methodology for determining the uniaxial and triaxial compressive strength of heterogeneous material composed of dacite (D) and altered dacite (AD). A zone of gradual transition from altered dacite to dacite was observed in the rock mass. The mechanical properties of the rock material in that zone were determined by laboratory tests of composite samples that consisted of rock material discs. However, the functional dependence on the strength parameter alteration of the rock material (UCS, intact ...
    Geology, Geotechnical Engineering, Engineering Geology
    ... in Figure 7b. The specimen of altered dacite (Figure 7f) has a laminar structure, and failure occurs in the direction of the lamination plane. The failure patterns and continuity of the failure surface indicate that bonding material at the interface zone between the discs of rock material is unnecessary ...
    ... AD, and the minimum value of σci UCS = 33.31 MPa was for 70.1% AD. Figure 7 shows specimens with characteristic failure patterns of monolithic and com- posite specimens for different participation of altered dacite. During the UCS testing of a dacite sample, brittle failure occurs, and the cracks are ...
    ... testing was no longer than 15 days. The values of horizontal σ3 and vertical σ1 stress were obtained based on the registered values of the confining and axial load that led the sample to failure along the known surface of the specimen. Analysis and calculation of rock material strength parameters were performed ...

  • Prioritization of strategic measures for strengthening the security of supply of the Serbian natural gas sector

    Boban Pavlović, Dejan Ivezić, Marija Živković (2020)
    To strengthen the security of supply of the Serbian gas sector, it is necessary to analyze the impact of planned strategic measures. The analysis involves the identification of the most influential threats to the security of natural gas supply and prioritization of the strategic measures for overcoming the consequences of threats. The proposed methodology is based on Fuzzy Analytic Hierarchy Process. The obtained weights for the identified threats and strategic measures are formed according to experts' judgments. The results ...
    Sigurnost snabdevanja, Donošenje odluka, Snabdevanje prirodnim gasom, Fazi AHP, Energetski indikatori

  • Classification of mining waste landfills according to legislation in Serbia

    Dragana Nišić, Uroš Pantelić, Nikoleta Aleksić, Neda Nišić (2021)
    rudarski otpad, jalovina, uredba, deponija, kategorija A, klasifikacija
    ... possibility of a potential failure and the character and composition of the waste disposed on it, while the process of classification according to the consequences of the failure runs thro- ugh three iterations, through which endangered humanity, source-path-recipient chain and significance of consequences ...
    ... od udesa, Službeni glasnik RS, br. 41/2019 [9] D. Nišić, D. Knežević, and N.Lilić: Assessment of risks associated with the operation of the tailings storage facility Veliki Krivelj, Bor (Serbia), Archives of Mining Sciences, vol. 63, no. 1, 2018 [10] L. N. Bowker: Potential risk index for any ...
    ... Teaney, B. T, Mount, B. J, Asunskis, D. J, Jordan, B. T., Barker, R. J, Santos, E. E. and Schaefer, C.E.G, Post-catastrophe analysis of the Fundão Tailings dam failure in the Doce River sy- stem, Southeast Brazil: potentially toxic elements in affected soils. Water, Air, & Soil Pollution, vol. 228 ...