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2837 items
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Fuzzy expert analysis of the severity of mining machinery failure
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 ...Dejan V. Petrović, Miloš Tanasijević, Saša Stojadinović, Jelena Ivaz, Pavle Stojković. "Fuzzy expert analysis of the severity of mining machinery failure" in Applied Soft Computing, Elsevier BV (2020). https://doi.org/10.1016/j.asoc.2020.106459
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Fuzzy Model for Risk Assessment of Machinery Failures
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 ...... class (for the impact of a failure on the environment) for a main computer failure. Min–Max Composition of Failure Severity Indicators A min–max composition was done for the three fuzzy sets of the failure severity indicators (St, Sw, and Se) in order to acquire the failure severity fuzzy set. The membership ...
... (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 ...
... shows the final form of the failure severity membership functions for the main computer. Symmetry 2020, 12, 525 17 of 26 Figure 9. The final form of the failure severity membership functions related to class for the main computer. 5.1.2. Fuzzification of the Frequency of Failure Another risk indicator ...Dejan V. Petrović, Miloš Tanasijević, Saša Stojadinović, Jelena Ivaz, Pavle Stojković. "Fuzzy Model for Risk Assessment of Machinery Failures" in Symmetry, MDPI AG (2020). https://doi.org/10.3390/sym12040525
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Rock slope stability analysis under Hoek–Brown failure criterion with different flow rules
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 analizaSvetlana Melentijević, Zoran Berisavljević, Dušan Berisavljević, Claudio Olalla Marañón . "Rock slope stability analysis under Hoek–Brown failure criterion with different flow rules" in Bulletin of Engineering Geology and the Environment , Springer (2024). https://doi.org/10.1007/s10064-024-03667-0
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Failure Estimation of the Majdanpek Open Pit East Face Based on Inverse Velocity Model
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 ...Miloš Marjanović, Stefan Milanović, Nikola Simić, Lazar Kričak. "Failure Estimation of the Majdanpek Open Pit East Face Based on Inverse Velocity Model" in Regional Symposium on Landslides in the Adriatic-Balkan Region, Belgrade, 15-18th May 2024, University of Belgrade, Faculty of Mining and Geology (2024). https://doi.org/10.18485/resylab.2024.6.ch46
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Probabilistic analysis of anisotropic rock slope with reinforcement measures
During the construction of E75 highway through Grdelica gorge in Serbia, a major failure occurred in the zone of reinforced rock slope. Excavation was performed in highly anisotropic Paleozoic schist rock formation. The reinforcement consisted of the two rows of micropile wall with pre-stressed anchors. Forces in anchors were monitored with load cells while benchmarks were installed for superficial displacement measurements. The aim of the study is to investigate possible causes of instability considering different probability distributions of the ...Zoran Berisavljević, Dušan Berisavljević, Miloš Marjanović, Svetlana Melentijević. "Probabilistic analysis of anisotropic rock slope with reinforcement measures" in Geomechanics and Engineering (2023). https://doi.org/10.12989/gae.2023.34.3.285
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Pre-failure deformation monitoring as rockfall prediction tool
... 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 ...Miloš Marjanović, Biljana Abolmasov, Zoran Berisavljević, Marko Pejić, Petko Vranić. "Pre-failure deformation monitoring as rockfall prediction tool" in IOP Conference Series: Earth and Environmental Science, IOP Publishing (2021). https://doi.org/10.1088/1755-1315/833/1/012197
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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 otpadDragana Nišić. "Preliminary Risk Assessment of Dam Failure at the Location of the Cukaru Peki Deposit, Bor (Serbia)" in Minerals, MDPI (2021). https://doi.org/10.3390/min11101126
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Load bearing steel structure diagnostics on bucket wheel excavator, for the purpose of failure prevention
Jovančić Predrag, Ignjatović Dragan, Tanasijević Miloš, Maneski Taško. "Load bearing steel structure diagnostics on bucket wheel excavator, for the purpose of failure prevention" in Journal of Engineering Failure Analysis 18 no. 4, :Elsevier (2011): 1203-1211. https://doi.org/10.1016/j.engfailanal.2011.03.
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Determination of Mechanical Properties of Altered Dacite by Laboratory Methods
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 ...... 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 ...Veljko Rupar, Vladimir Čebašek, Vladimir Milisavljević, Dejan Stevanović, Nikola Živanović. "Determination of Mechanical Properties of Altered Dacite by Laboratory Methods" in Minerals, MDPI AG (2021). https://doi.org/10.3390/min11080813
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Influence of Failure Mode Level of Complex Technical System with Serial Connection
Savković Snežana, Jovančić Predrag, Tanasijević Miloš. "Influence of Failure Mode Level of Complex Technical System with Serial Connection" in 21th Annual International Conference Composites/Nano Engineering ICCE-21 1, Tenerife, Spain:University of New Orleans (2013): 717-718
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Persistence and failure of mean-field approximations adapted to a class of systems of delay-coupled excitable units
Franović Igor, Todorović Kristina, Vasović Nebojša, Burić Nikola. "Persistence and failure of mean-field approximations adapted to a class of systems of delay-coupled excitable units" in Physical Review E 89 no. 2, Vašington:American Physical Society (2014): 022926-1-022926-10
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Lost production costs of the overburden excavation system caused by rubber belt failure
Bugarić Uglješa, Tanasijević Miloš, Polovina Dragan, Ignjatović Dragan, Jovančić Predrag. "Lost production costs of the overburden excavation system caused by rubber belt failure" in Journal of Maintenance and Reliability 14 no. 4, :Polish Maintenance Society (2012): 333-341
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Risk assessment model of mining equipment failure based on fuzzy logic
D. Petrović, Tanasijević Miloš, V. Milić, Lilić Nikola, Stojadinović Saša, Igor Svrkota. "Risk assessment model of mining equipment failure based on fuzzy logic" in Expert Systems with Applications 41 (2014): 8157-8164
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Impact of a failure zone above the underground roadway on rockbolting structure loading
Vladimir Milisavljević, Dragan Zlatanović, Simon Sedmak, Milenko Ljubojev. "Impact of a failure zone above the underground roadway on rockbolting structure loading" in Structural integrity and life/Integritet i vek konstrukcija 15 no. 2, Beograd:Society for Structural Integrity and Life / IMS Institute (2015): 85-94
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The shear strength evaluation of rough and infilled joints and its indications for stability of rock cutting in schist rock mass
Construction of E75 highway section through Grdelica gorge was one of the most demanding projects realized in recent Serbian history. The alignment approximately 25 km long consists of several tens of bridges, two tunnels, three galleries and cuts with total length of 6 km. The alignment passes through highly anisotropic Palaeozoic schist rock formation of different weathering grades. This study focuses on shear strength properties of discontinuities, which are found to be the critical feature contributing to the occurrence ...Dušan Berisavljević, Zoran Berisavljević, Svetlana Melentijević. "The shear strength evaluation of rough and infilled joints and its indications for stability of rock cutting in schist rock mass" in Bulletin of engineering geology and the environment, Springer (2022). https://doi.org/10.1007/s10064-022-02580-8
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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. "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" in Journal of Vibroengineering (2017). https://doi.org/10.21595/jve.2016.17321
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The optimization of auxiliary machinery in open-cast lignite mines: a case study of bulldozers
One of the most important prerequisites for the successful operation of the open-cast lignite mine is to carry out all the auxiliary works timely with the necessary quality. The most important and most commonly used auxiliary machines are bulldozers. Engaging time of bulldozers use is in direct relation with the coefficients of the time and capacity utilization of the continuous system for the excavation of coal and tailings, which indicates their importance. More than 100 bulldozers have been hired ...... . One of the most important reliability indicators is failure frequency, i.e. expected number of failures in certain time interval. Failure frequency distribution curve is afore mentioned "bath tub" curve, shown in Figure 5. Interpretation of this curve indicates that usually large number of failures ...
... after this initial period. As machine approaches to the end of its life, curve enters the worn-out period with increasing rate of failures. A о Area ог decreasing Area of constant Area ofincreased 3 failure rate , failure rate | failure rate G > » » д 1 ı — || ı о 1 || о || || — ı || ~ ...
... Year ог изе Figure 4. Diagram јог determination of Птите со515 value for САТ D8R апа Dressta TD25M dozers 3. AVAILABILITY Typical curve ог failures, known as "bath tub" curve, is evident regarding dozers ореганпр оп open-cast mines. Failure is a condition when the machine completely or partially ...Dragan Ignjatović, Predrag Jovančić, Stevan Đenadić, Ivan Janković, Ivica Ristović. "The optimization of auxiliary machinery in open-cast lignite mines: a case study of bulldozers" in 7th International Symposium Mining and Environmental Protection, University of Belgrade, Faculty of Mining and Geology, Belgrade, Serbia (2019)
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Development of the Cost-Based Model for Monitoring the Lifetime of the Earth Moving Machines
This paper presents the model for the identification of reference points on the lifetime curve of engineering systems. This curve commonly represents the increase and decline of failure in relation to time. A direct correlation between failure rate and costs is assumed in this paper, therefore, statistical and empirical analysis of costs provided reference points. This approach is used for positioning stages of the engineering system’s lifetime with a minimal number of failures and costs, regardless of whether these ...Electrical and Electronic Engineering,Industrial and Manufacturing Engineering, Control and Optimization, Mechanical Engineering, Computer Science (miscellaneous), Control and Systems EngineeringUgljesa Bugarić, Milos Tanasijević, Stevan Djenadić, Dragan Ignjatović, Ivan Janković. "Development of the Cost-Based Model for Monitoring the Lifetime of the Earth Moving Machines" in Machines, MDPI AG (2022). https://doi.org/10.3390/machines10110995
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A fuzzy-based decision support model for effectiveness evaluation - a case study of examination of bulldozers
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 ...Miloš Tanasijević, Predrag Jovančić, Dejan Ivezić, Uglješa Bugarić, Radiša Đurić. "A fuzzy-based decision support model for effectiveness evaluation - a case study of examination of bulldozers" in International Journal of Industrial Engineering: Theory, Applications and Practice (2019)
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Application of Thermal Imaging in Surface Mining
Milanka Negovanović (2022)Termalno snimanje se sve više koristi u rudarskoj industriji kao jedan od dijagnostičkih alata za praćenje određenih proizvodnih procesa, kao i stanja opreme i mašina. Predstavlja nedestruktivnu i beskontaktnu metodu ispitivanja koja omogućava rano otkrivanje problema, planiranje održavanja sa minimalnim kvarovima, sprečavanje neplaniranih poremećaja, posmatranje materijala u nepristupačnim ili opasnim područjima i poboljšanje bezbednosti i produktivnosti. Termalno snimanje koristi specijalizovane termalne kamere sa unutrašnjim detektorima koji identifikuju veoma male temperaturne varijacije i proizvode sliku tog nevidljivog infracrvenog ili toplotnog ...Termalno snimanje, nedestruktivne metode testiranja, površinska eksploatacija, termalne kamere, rudarske operacijeMilanka Negovanović. "Application of Thermal Imaging in Surface Mining" in 15th International Conference OMC 2022, Zlatibor, 12-15th October 2022, Jugoslovenski komitet za površinsku eksploataciju (2022)