Прегледај по Аутор "Jovičić, Gordana"
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- СтавкаEXPERIMENTAL AND NUMERICAL STRENGTH ANALYSIS OF WAGON FOR CONTAINERS TRANSPORTATION(Mašinski fakultet Istočno Sarajevo, Univerzitet u Istočnom Sarajevu, 2016) Milovanović, Vladimir; Živković, Miroslav; Jovičić, Gordana; Dišić, Aleksandar; Milutinović, Miroslav; Marković, Biljana; Antunović, RankoThis paper presents comparative experimental and numerical strength analysis of wagon for containers transportation according to the TSI standard and norm EN 12663-2:2010. The aim of this analysis is to show that results of stresses obtained by measuring with strain gauges and stresses obtained by FEM calculation gives good agreement. Based on the results and their good match, it can be concluded that the numerical FEM analysis can be reliably used for structural analysis. According to this fact, FEM analysis can reduce number of the testing new products. This leads to great savings in the design of new prototypes, in order to immediately start the process of mass production. This would lead to significantly less cost of products.
- СтавкаFurther 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, RankoAluminum 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.
- СтавкаINTEGRITY ASSESSMENT OF AN AIRCRAFT CYLINDER ASSEMBLY WITH A CRACK(Associated Publishers, 2022) Vučetić, Nikola; Jovičić, Gordana; Antunović, Ranko; Sovilj-Nikić, Sandra; Košarac, Aleksandar; Jeremić, DejanThe 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
- СтавкаISPITIVANJE ZAMORNIH KARAKTERISTIKA LEGURE ALUMINIJUMA 242.0 S CILJEM PROCJENE INTEGRITETA AVIONSKOG CILIDARSKOG SKLOPA SA PRSLINOM(Mašinski fakultet Istočno Sarajevo, Univerzitet u Istočnom Sarajevu, 2022) Vučetić, Nikola; Jovičić, Gordana; Antunović, Ranko; Milovanović, Vladimir; Krstić, Branimir; Jeremić, Dejan; Golubović, Dušan; Milutinović, Miroslav; Prodanović, SašaU cilju procjene integriteta cilindarskog sklopa avionskog motora Lycoming IO-360-B1F usljed pojave prsline na glavi cilindra potrebno je izvršiti niz eksperimentalnih ispitivanja legure aluminijuma 242.0 kao sastavnog materijala glave cilindra, među kojima je ispitivanje zamornih karakteristika na sobnoj i na povišenoj temperaturi. Dobijeni rezultati korišćeni su kao ulazni podaci u numeričkoj strukturnoj analizi razmatranog cilindarskog sklopa. Cilj ispitivanja materijala na zamor jeste odrediti dinamičku čvrstoću, odnosno najveći dinamički napon koji materijal pri određenom broju promjena opterećenja može da izdrži, a da pri tome ne dođe do loma.
- СтавкаKvantitativne metode izbora materijala električnih uređaja(Elektrotehnički fakultet, Univerzitet u Istočnom Sarajevu, 2016-03) Vučetić, Nikola; Adamović, Dragan; Jovičić, GordanaU radu je prikazan postupak izbora optimalnog materijala sastavnih elemenata električne pegle: kućišta, grijača i grijuće ploče, a pomenuti postupak se može primijeniti i za ostale slične električne uređaje. Predstavljene su dvije kvantitativne metode za izbor materijala: metoda uticajnosti karakteristika (digitalno-logička metoda) i metoda najmanjih odstupanja karakteristika od traženih (algebarski pristup). Definisani su osnovni kriterijumi, odnosno zahtjevi koje potencijalni materijali moraju da ispune, te je, na osnovu pomenutih metoda i softwarea Cambridge Engineering Selection (CES) izvršen pravilan izbor materijala.
- СтавкаPOČETNA ISTRAŽIVANJA S CILJEM RAZVOJA METODOLOGIJE ZA PROCJENU INTEGRITETA CILINDARSKOG SKLOPA AVIONSKOG KLIPNOG MOTORA(Mašinski fakultet Istočno Sarajevo, Univerzitet u Istočnom Sarajevu, 2018) Vučetić, Nikola; Jovičić, Gordana; Milovanović, Vladimir; Krstić, Branimir; Rakić, Dragan; Tomović, Radoslav; Antunović, Ranko; Golubović, Dušan; Košarac, Aleksandar; Jeremić, DejanU radu je dat pregled istraživanja mehaničkih otkaza različitih strukturnih elemenata vazduhoplova, kao u učestalost pojedinih mehanizama otkaza. Naveden je konkretan problem pucanja glave cilindra avionskog vazdušno hlađenog klipnog motora, te je predstavljen plan i cilj istraživanja u cilju razvoja metodologije za procjenu integriteta cilindarskog sklopa. U okviru planiranih istraživanja neophodno bi bilo izvršiti eksperimentalnu analizu mehaničkih karakteristika legure aluminijuma 242.0 na sobnoj i povišenoj temperaturi, kao i numeričku analizu cilindarskog sklopa. Prikazani su očekivani rezultati istraživanja, kao i zaključna razmatranja vezana za značaj samog istraživanja.