Машински факултет [Научни радови] / Faculty of Mechanical Engineering [Scientific papers]

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https://repozitorijum.ues.rs.ba/handle/123456789/48

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Прегледај Машински факултет [Научни радови] / Faculty of Mechanical Engineering [Scientific papers] по Аутор "Antunović, Ranko"

Сада се приказује 1 - 8 од 8
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    ANALYSIS OF DYNAMIC BEHAVIOR OF ROTATING MACHINES
    (Faculty of Engineering Hunedoara, University Politehnica Timisoara, 2014) Antunović, Ranko; Veg, Aleksandar
    Operating supervision and the condition monitoring of the rotating machines, deploying exact diagnostic methods, can be considered as a good insight into the current state of a technical system and exact assessment of maintenance necessity. In this way, one can survey a large scale of machines and processes, without loss of reliability, as well reducing the costs of maintenance and increasing system profitability. This is the paramount demand of the modern production philosophy. The paper, consideres importance of data selection and implementation of appropriate  diagnostic techniques with particular emphasis on the analysis of the dynamic behavior of rotating machinery. Shown are some of the results of diagnostic analysis that have been conducted on machines in a real operation, applying advanced methods of technical diagnostics.
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    DIJAGNOSTIKA VJETROELEKTRANE
    (Mašinski fakultet, Univerzitet u Zenici, 2016) Antunović, Ranko; Halep, Amir
    Svaki sistem zahtijeva redovno održavanje pa tako i vjetroelektrane. Savremeno održavanje vjetroelektrana se temlji na dijagnostici stanja vjetroelektrane koji se realizira kroz mjerenje parametara stanja sistema vjetroelektrane te obradi rezultata etabliranim metodama. U ovome radu je dat prikaz savremenih metoda koje se primjenjuju u nadzoru stanja vjetroelektrane
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    ENERGETSKI INDEKS PROIZVODNJE DRVNOG ČIPSA
    (Mašinski fakultet Istočno Sarajevo, Univerzitet u Istočnom Sarajevu, 2016) Vasković, Srđan; Gvero, Petar; Medaković, Vlado; Halilović, Velid; Ikić, Marko; Ašonja, Goran; Marković, Biljana; Antunović, Ranko
    Proizvodnja čvrstih biogrova definisana je odgovarajućim energetskim lancem snabdijevanja. Proces proizvodnje čvrstih goriva iz drvne biomase počinje sa tehnologijama za skupljanje drvnog ostatka, počev od obaranja stabla pa sve do sistema za preradu (za usitnjavanje, drobljenje, sušenje, presovanje ukoliko se pravi briket ili pelet). Efikasnost proizvodnje drvnog čipsa je u relaciji sa ukupnom uloženom energijom po 1 kWh donje toplotne moći proizvedenog goriva. Ovaj rad će prikazati analizu ukupno uložene energije u snabdijevačkom lanacu proizvodnje drvnog čipsa u funkciji od transportnih distanci i vlage u drvetu. Model za analizu energetskog indeksa proizvodnje drvnog čipsa urađen je u softverskom paketu Mathcad.
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    EXPERIMENTAL VERIFICATION OF NUMERICAL GEARBOX DRIVE SHAFT MODAL ANALYSIS RESULTS
    (University of Novi Sad, Faculty of Technical Sciences, 2016) Vučetić, Nikola; Blagojević, Mirko; Košarac, Aleksandar; Antunović, Ranko
    This paper shows the experimental determination of drive shaft DMB. 6.80.325 natural frequencies using available equipment for data acquisition and processing on the Faculty of Mechanical Engineering in East Sarajevo. The results were compared with the values of natural frequencies determined numerically in software Ansys Workbench 12.1 in which the mentioned shaft was modeled previously. Experimental results were processed in software packages MatLab and OriginPro.
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    Further Investigation of the Repetitive Failure in an Aircraft Engine Cylinder Head - Mechanical properties of Aluminum alloy 242.0
    (2020) Vučetić, Nikola; Jovičić, Gordana; Krstić, Branimir; Živković, Miroslav; Milovanović, Vladimir; Kačmarčik, Josip; Antunović, Ranko
    Aluminum alloys are widely used in military and aviation industry due to their properties such as low density and high strength. During the aircraft operation there are mechanical failures of various structural components caused by numerous mechanisms such as corrosion, material defects, high cycle fatigue and the like. One of the frequent mechanical failures on air-cooled piston engines is the cylinder head cracking. This paper is the continuation a comprehensive research of the Lycoming IO-360-B1F aircraft cylinder head failure. The failure of this type has already occurred during flight and about 50 failures like this have been registered from around the world, some of them with a fatal outcome and therefore require detailed research. The paper consists of machining of the tested specimens and their testing at many different locations and in many different laboratories throughout Bosnia and Herzegovina, Serbia and Slovenia. This paper is based on a research that includes the experimental analysis of mechanical properties of Aluminum alloy 242.0 which is a constituent material of the cylinder head of the Lycoming IO-360-B1F aircraft engine on which a crack appeared. Based on chemical, metallographic, static and dynamic experimental tests of the material properties, Aluminum alloy 242.0 static and fatigue properties were obtained, S-N curve was formed and endurance limit was determined. Results of numerical simulations of experiments, confirmed by experimental results, were performed to make numerical procedures reliable due to further research. The results of the research are planned to be implemented in numerical modeling of the cylinder assembly stress-strain state under workload and in further numerical research of Lycoming IO-360-B1F cylinder assembly integrity assessment.
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    INTEGRITY ASSESSMENT OF AN AIRCRAFT CYLINDER ASSEMBLY WITH A CRACK
    (Associated Publishers, 2022) Vučetić, Nikola; Jovičić, Gordana; Antunović, Ranko; Sovilj-Nikić, Sandra; Košarac, Aleksandar; Jeremić, Dejan
    The repeatability of the air-cooled piston engine cylinder assembly failure due to a crack in the cylinder head, as well as its severity from the aspect of crew and passenger safety were the main motives for our research. In this paper an integrity assessment of a cylinder assembly with a crack was performed. By modeling cracks of different lengths in the cylinder head and considering the values of stress intensity factors and J-integral values at a given crack length on the one hand and determining the critical values of these fracture mechanics parameters on the other hand, the stability of the crack was examined. As part of the research, the dependence of the crack length on the stress intensity factor was established. The methodology proposed in this paper can be adapted to assess the integrity of other similar structural elements
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    MATHEMATICAL MODEL FOR TEMPERATURE CHANGE OF A JOURNAL BEARING
    (Vinča Nuclear Research Institute, Belgrade, Srbija, 2018) Antunović, Ranko; Halep, Amir; Bučko, Mihael M.; Perić, Sreten R.
    In this work, a representative mathematical model has been developed, which re-liably describes the heating and cooling of a journal bearing as a result of its malfunctioning, and the model has been further confirmed on a test bench. The bearing model was validated by using analytical modeling methods, i. e. the ex-perimental results were compared to the data obtained by analytical calculations. The regression and variance analysis techniques were applied to process the rec-orded data, to test the mathematical model and to define mathematical functions for the heating/cooling of the journal bearing. This investigation shows that a representative model may reliably indicate the change in the thermal field, which may be a consequence of journal bearing damage.
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    Vibration and Temperature Measurement Based Indicator of Journal Bearing Malfunction
    (Faculty of Mechanical Engineering in Slavonski Brod; Faculty of Electrical Engineering, Computing and Information Technologies Osijek; Faculty of Civil Engineering and Architecture Osijek, 2018) Antunović, Ranko; Halep, Amir; Bučko, Mihael; Perić, Sreten; Vučetić, Nikola
    This paper aims to present the development and implementation of the new malfunction indicator in journal bearings, based on vibrational and thermal records, called DFJB-Defect Factor Journal Bearing. Briefly, the indicator contains the specifically processed information about the bearing vibrations and temperature, on the basis of which the DFJB is calculated using fuzzy logic, and thus the state of the journal bearing may be determined. It should be pointed out that the DFJB is developed in a manner that besides the temperature and the total number of absolute vibrations, it may also integrate following parameters of monitoring: the parameters of rotating vibrations, vibrations spectrum, the thickness of oil film in the journal bearing, the intensity of the ultrasound emission of the bearing etc. These parameters may in certain cases offer more reliable malfunction identification. Experimental investigations conducted in this work, on real machine equipment and in real exploitation conditions, have shown this method to be reliable in the identification of malfunctions in journal bearings. As a result of implementation of DFJB, the time necessary to collect measuring data is significantly shortened, whereas the diagnosis procedure for journal bearings is highly simplified. This is particularly important in complex technical systems with a vast number of measuring points, which often result in the overload of the operator.