Прегледај по Аутор "Živković, Miroslav"
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- СтавкаA Comparison Study of Fatigue Behavior of S355J2+N, S690QL and X37CrMoV5-1 Steel(MDPI, 2022) Milovanović, Vladimir; Arsić, Dušan; Milutinović, Miroslav; Živković, Miroslav; Topalović, MarkoSteel of the mild-strength S355J2+N steel grade is the most often used steel for manufacturing carrying sections of constructions exposed to fatigue loads. The use of high-strength steels, such as S690QL, allows for the creation of structures that are light and simple to construct. However, increasing the yield strength of high-strength steels does not result in a corresponding increase in fatigue resistance. As a result, using high-strength steels for constructions subjected to fatigue loading can be a major design concern, raising the question of whether high-strength steels should be used at all. Most of the experimental investigations regarding the hot work tool steel X37CrMoV5-1 found in the literature are focused on its machining and wear resistance, with insufficient attention paid to the cyclic loads. This article evaluates the fatigue properties of mild-strength S355J2+N, high-strength S690QL, and X37CrMoV5-1 steel grades. A SHIMADZU servo-hydraulic testing machine is used to perform uniaxial tensile tests under uniaxial fatigue stress-controlled, fully reversed conditions (tensile–compression testing with R = 1 stress ratio) in accordance with EN ISO and ASTM standards. The aim of this paper is to highlight the fatigue characteristics of these three steels that are among the most used in their respective groups. Steel S355J2+N belongs to the group of hot-rolled normalized steels, S690QL belongs to the group of improved (quenched + tempered) steels with increased strength, and X37CrMoV5-1 belongs to the group of high-alloyed tool steels for hot work. This choice was made as the tested steels can be considered typical representatives of their groups. Based on the test results of these three steels, which are organized in S–N curves, the fatigue behavior of the entire mentioned groups of steels can be foreseen.
- СтавкаANALYSIS OF HEAT TRANSFER THROUGH THE BEAM SUPPORT OF THE WAGON STRUCTURE CALCULATED BY SOFTWARE PAK MULTYPHISICS(Mašinski fakultet, Univerzitet Istočno Sarajevo, 2012) Nikolić, Aleksandar; Blagojević, Milan; Milovanović, Vladimir; Živković, Miroslav; Milutinović, Miroslav; Antunović, RankoPaper deals with heat transfer through beam supports of wagon structure for transportation of hot steel ingots. It is well known that changing of the material properties at high temperatures leading to reduced carrying capacity of structures. Therefore, it is necessary to know the temperature distribution in the carrying element to avoid disturbing the integrity of construction. Basic equations which governs the problem of heat transfer in terms of finite element method (FEM) are presented taking into account the initial and boundary conditions. Heat transfer through beam supports of wagon structure for transportation of hot steel ingots is solved by software PAK Multyphisics. It is shown that the temperature of carrying elements is slightly elevated, which does not affect the normal operation of wagon construction.
- 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.
- СтавкаTHERMO-MECHANIC ANALYSIS OF CEMENT TRANSPORT WAGON - IDENTIFICATION OF THE CAUSE OF CRACKS(University Politehnica Timisoara, Faculty of Engineering Hunedoara, 2013) Milovanović, Vladimir; Rakić, Dragan; Živković, Miroslav; Vulović, Snežana; Milutinović, MiroslavThe paper represents a solution example of a specific engineering problem using thermomechanical analysis. The paper provides theoretical basis of numerical solving the problem of heat conducting through continuum using the finite element method. Calculation of heat conducting using the finite element method determines the temperature field used as an input for thermo-mechanical calculation. The basic task of thermo-mechanical calculation was the identification of the cause of cracks on the powder material transport wagon. After the analysis of the wagon crack causes, repair of the cracks is suggested. Repeating of the FEM analysis on the reconstructed model confirms that the wagon satisfies the criteria of static and fatigue strength appointed by the standards.