TY  - JOUR
AU  - Lukić, Nebojša
AU  - Ivanov, Toni
AU  - Svorcan, Jelena
AU  - Simonović, Aleksandar
PY  - 2024
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7771
AB  - A novel concept of morphing airfoils, capable of changing camber and thickness, is proposed. A variable airfoil shape, defined by six input parameters, is achieved by allowing the three spinal points (at fixed axial positions) to slide vertically, while the upper and lower surfaces are determined by the lengths of the three corresponding ribs that are perpendicular to the spine. Thus, it is possible to find the most appropriate geometric configuration for a wide range of possible operating conditions often present with contemporary unmanned aerial vehicles. Shape optimizations for different Reynolds numbers and different cost functions are performed by coupling a genetic algorithm with simple panel method flow calculations. The obtained airfoils are presented and compared, whereas the proposed concept is validated by more advanced flow simulations. It appears that improvements in aerodynamic performance of nearly 20% can be expected at Re ranging from 0.05 × 106 to 0.1 × 106. The proposed methodology shows promise and can be applied to different types of lifting surfaces, including wing, tail or propeller blade segments. To check the viability of this method for producing airfoils that can be used in a practical sense, structural analysis of one of the obtained geometries using a simplified 1D finite element method as well as a more detailed 3D analysis are performed. The model is then 3D-printed on a fused deposition modeling (FDM) printer with a polyethylene terephthalate glycol (PETG) filament, and the capability of the airfoil to adequately morph between the two desired geometries is experimentally shown.
PB  - MDPI
T2  - Aerospace
T1  - Numerical Investigation and Optimization of a Morphing Airfoil Designed for Lower Reynolds Number
IS  - 4
SP  - 252
VL  - 11
DO  - 10.3390/aerospace11040252
ER  - 

@article{
author = "Lukić, Nebojša and Ivanov, Toni and Svorcan, Jelena and Simonović, Aleksandar",
year = "2024",
abstract = "A novel concept of morphing airfoils, capable of changing camber and thickness, is proposed. A variable airfoil shape, defined by six input parameters, is achieved by allowing the three spinal points (at fixed axial positions) to slide vertically, while the upper and lower surfaces are determined by the lengths of the three corresponding ribs that are perpendicular to the spine. Thus, it is possible to find the most appropriate geometric configuration for a wide range of possible operating conditions often present with contemporary unmanned aerial vehicles. Shape optimizations for different Reynolds numbers and different cost functions are performed by coupling a genetic algorithm with simple panel method flow calculations. The obtained airfoils are presented and compared, whereas the proposed concept is validated by more advanced flow simulations. It appears that improvements in aerodynamic performance of nearly 20% can be expected at Re ranging from 0.05 × 106 to 0.1 × 106. The proposed methodology shows promise and can be applied to different types of lifting surfaces, including wing, tail or propeller blade segments. To check the viability of this method for producing airfoils that can be used in a practical sense, structural analysis of one of the obtained geometries using a simplified 1D finite element method as well as a more detailed 3D analysis are performed. The model is then 3D-printed on a fused deposition modeling (FDM) printer with a polyethylene terephthalate glycol (PETG) filament, and the capability of the airfoil to adequately morph between the two desired geometries is experimentally shown.",
publisher = "MDPI",
journal = "Aerospace",
title = "Numerical Investigation and Optimization of a Morphing Airfoil Designed for Lower Reynolds Number",
number = "4",
pages = "252",
volume = "11",
doi = "10.3390/aerospace11040252"
}

Lukić, N., Ivanov, T., Svorcan, J.,& Simonović, A.. (2024). Numerical Investigation and Optimization of a Morphing Airfoil Designed for Lower Reynolds Number. in Aerospace
MDPI., 11(4), 252.
https://doi.org/10.3390/aerospace11040252

Lukić N, Ivanov T, Svorcan J, Simonović A. Numerical Investigation and Optimization of a Morphing Airfoil Designed for Lower Reynolds Number. in Aerospace. 2024;11(4):252.
doi:10.3390/aerospace11040252 .

Lukić, Nebojša, Ivanov, Toni, Svorcan, Jelena, Simonović, Aleksandar, "Numerical Investigation and Optimization of a Morphing Airfoil Designed for Lower Reynolds Number" in Aerospace, 11, no. 4 (2024):252,
https://doi.org/10.3390/aerospace11040252 . .

TY  - JOUR
AU  - Vorkapić, Miloš
AU  - Živojinović, Danijela
AU  - Kreculj, Dragan
AU  - Ivanov, Toni
AU  - Baltić, Marija
AU  - Simonović, Aleksandar
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/5419
AB  - Reverse engineering (RE) aims to design a new replacement part based on the existing part. The goal is to perform a quality reproduction of the physical part with the best possible mechanical characteristics aiming to find optimal solutions regarding the shape and dimensions of the part. The
procedure is implemented through a series of steps: creating a digital 3D model, improving model parameters, and realizing products using additive technologies. In this paper, a review and 
implementation of the fundamental methodologies of RE were carried out on the example of a damaged protective cover with an unknown geometry and material essential for the function of a discontinued device with no technical documentation and spare parts. An optical scanning method, 3D CAD, FEA, and additive manufacturing were used to realize the reproduced part. It was shown that by utilizing RE the lifecycle of the device could be significantly extended with minimal cost.
PB  - Faculty of Mechanical Engineering, Belgrade
T2  - FME Transactions
T1  - Application of Additive Technology and Reverse Engineering in the Realization of Damaged Obsolete Parts
EP  - 38
IS  - 1
SP  - 31
VL  - 51
DO  - 10.5937/fme2301031V
ER  - 

@article{
author = "Vorkapić, Miloš and Živojinović, Danijela and Kreculj, Dragan and Ivanov, Toni and Baltić, Marija and Simonović, Aleksandar",
year = "2023",
abstract = "Reverse engineering (RE) aims to design a new replacement part based on the existing part. The goal is to perform a quality reproduction of the physical part with the best possible mechanical characteristics aiming to find optimal solutions regarding the shape and dimensions of the part. The
procedure is implemented through a series of steps: creating a digital 3D model, improving model parameters, and realizing products using additive technologies. In this paper, a review and 
implementation of the fundamental methodologies of RE were carried out on the example of a damaged protective cover with an unknown geometry and material essential for the function of a discontinued device with no technical documentation and spare parts. An optical scanning method, 3D CAD, FEA, and additive manufacturing were used to realize the reproduced part. It was shown that by utilizing RE the lifecycle of the device could be significantly extended with minimal cost.",
publisher = "Faculty of Mechanical Engineering, Belgrade",
journal = "FME Transactions",
title = "Application of Additive Technology and Reverse Engineering in the Realization of Damaged Obsolete Parts",
pages = "38-31",
number = "1",
volume = "51",
doi = "10.5937/fme2301031V"
}

Vorkapić, M., Živojinović, D., Kreculj, D., Ivanov, T., Baltić, M.,& Simonović, A.. (2023). Application of Additive Technology and Reverse Engineering in the Realization of Damaged Obsolete Parts. in FME Transactions
Faculty of Mechanical Engineering, Belgrade., 51(1), 31-38.
https://doi.org/10.5937/fme2301031V

Vorkapić M, Živojinović D, Kreculj D, Ivanov T, Baltić M, Simonović A. Application of Additive Technology and Reverse Engineering in the Realization of Damaged Obsolete Parts. in FME Transactions. 2023;51(1):31-38.
doi:10.5937/fme2301031V .

Vorkapić, Miloš, Živojinović, Danijela, Kreculj, Dragan, Ivanov, Toni, Baltić, Marija, Simonović, Aleksandar, "Application of Additive Technology and Reverse Engineering in the Realization of Damaged Obsolete Parts" in FME Transactions, 51, no. 1 (2023):31-38,
https://doi.org/10.5937/fme2301031V . .

TY  - CONF
AU  - Svorcan, Jelena
AU  - Ivanov, Toni
AU  - Simonović, Aleksandar
PY  - 2023
UR  - http://www.ssm.kg.ac.rs/congress_2023/papers/
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/6979
AB  - Modern trends in the development of urban air vehicles and small-scale unmanned air vehicles require them to be as efficient as possible. One option is to improve their aerodynamic performance by semi-active boundary layer control (BLC) techniques, that are more economic and accessible through 3D printing, such as injection/blowing. Flow control generally serves to reduce BL thickness and friction drag, as well as to delay transition and separation. This computational study investigates and quantifies the change in lift and drag coefficients of NACA 23012 airfoil at the critical angle-of-attack (AoA) at M = 0.18 and Re = 1.8 million. Flow simulations are performed using the finite volume method in ANSYS Fluent. Clean and controlled flows are considered steady, incompressible, and viscous. Equations governing the flow are closed by k-ω SST turbulence model. The adopted numerical set-up is validated by available experimental data. Main observations on the possible improvements of aerodynamic performance at a higher angle-of-attack are presented and discussed.
PB  - Српско друштво за механику
C3  - 9th International Congress of the Serbian Society of Mechanics (ICSSM)
T1  - Improving airfoil performance by designed blowing
SP  - 91
UR  - https://hdl.handle.net/21.15107/rcub_machinery_6979
ER  - 

@conference{
author = "Svorcan, Jelena and Ivanov, Toni and Simonović, Aleksandar",
year = "2023",
abstract = "Modern trends in the development of urban air vehicles and small-scale unmanned air vehicles require them to be as efficient as possible. One option is to improve their aerodynamic performance by semi-active boundary layer control (BLC) techniques, that are more economic and accessible through 3D printing, such as injection/blowing. Flow control generally serves to reduce BL thickness and friction drag, as well as to delay transition and separation. This computational study investigates and quantifies the change in lift and drag coefficients of NACA 23012 airfoil at the critical angle-of-attack (AoA) at M = 0.18 and Re = 1.8 million. Flow simulations are performed using the finite volume method in ANSYS Fluent. Clean and controlled flows are considered steady, incompressible, and viscous. Equations governing the flow are closed by k-ω SST turbulence model. The adopted numerical set-up is validated by available experimental data. Main observations on the possible improvements of aerodynamic performance at a higher angle-of-attack are presented and discussed.",
publisher = "Српско друштво за механику",
journal = "9th International Congress of the Serbian Society of Mechanics (ICSSM)",
title = "Improving airfoil performance by designed blowing",
pages = "91",
url = "https://hdl.handle.net/21.15107/rcub_machinery_6979"
}

Svorcan, J., Ivanov, T.,& Simonović, A.. (2023). Improving airfoil performance by designed blowing. in 9th International Congress of the Serbian Society of Mechanics (ICSSM)
Српско друштво за механику., 91.
https://hdl.handle.net/21.15107/rcub_machinery_6979

Svorcan J, Ivanov T, Simonović A. Improving airfoil performance by designed blowing. in 9th International Congress of the Serbian Society of Mechanics (ICSSM). 2023;:91.
https://hdl.handle.net/21.15107/rcub_machinery_6979 .

Svorcan, Jelena, Ivanov, Toni, Simonović, Aleksandar, "Improving airfoil performance by designed blowing" in 9th International Congress of the Serbian Society of Mechanics (ICSSM) (2023):91,
https://hdl.handle.net/21.15107/rcub_machinery_6979 .

TY  - CONF
AU  - Ivanov, Toni
AU  - Ivanović, Milica
AU  - Zubić, Miloš
AU  - Simonović, Aleksandar
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7290
AB  - Jedan od ključnih elemenata za proces dekarbonizacije mogla bi biti upotreba vodonika u energetskim sektorima. Potencijal zamene fosilnih goriva održivo proizvedenim vodonikom odav-no je prepoznat. Zbog porasta troškova energije poslednjih godina, uticaja  konvencionalnih  goriva  na  životnu  sredinu  i  postignutog/predviđenog tehnološkog napretka u skladištenju i transportu, vo-donik postaje sve više izvodljivo rešenje u smislu primarnog izvora energije. Evropske zemlje su postavile ambiciozne planove za koriš-ćenje vodonika kao obnovljivog izvora energije. Mnogi istraživački projekti finansirani su iz grantova EU, dok je Evropska komisija po-stavila u martu 2022. godine plan za što veću nezavisnost od uvo-za fosilnih goriva, koji između ostalog za cilj ima proizvodnju 10 miliona tona vodonika, dok je 10 miliona tona planirano za uvoz do 2030. godine.Korišćenje vodonika kao izvora goriva u sektoru vazduhoplov-stva se takođe dosta razmatra poslednjih godina. Prednosti vodonika kao avionskog goriva su očigledne. Vodonik je održiv, ne proizvodi emisije štetnih gasova, ima veliku gustinu energije itd. Međutim, još uvek postoje velike tehničke poteškoće koje bi trebalo prevazići, što predstavlja izazov pri postavljanju vodonika kao održivog goriva za vazduhoplovstvo. U radu su predstavljeni i diskutovani najznačajniji izazovi, neka moguća rešenja i mogućnosti koje proizilaze iz upotre-be vodonika za vazduhoplovne propulzore.
C3  - Zbornik Međunarodnog kongresa o procesnoj industriji – Procesing, [S.l.]
T1  - Izazovi i prilike vodonika kao održivog vazduhoplovnog goriva budućnosti
EP  - 44
IS  - 1
SP  - 39
VL  - 36
DO  - 10.24094/ptk.023.039
ER  - 

@conference{
author = "Ivanov, Toni and Ivanović, Milica and Zubić, Miloš and Simonović, Aleksandar",
year = "2023",
abstract = "Jedan od ključnih elemenata za proces dekarbonizacije mogla bi biti upotreba vodonika u energetskim sektorima. Potencijal zamene fosilnih goriva održivo proizvedenim vodonikom odav-no je prepoznat. Zbog porasta troškova energije poslednjih godina, uticaja  konvencionalnih  goriva  na  životnu  sredinu  i  postignutog/predviđenog tehnološkog napretka u skladištenju i transportu, vo-donik postaje sve više izvodljivo rešenje u smislu primarnog izvora energije. Evropske zemlje su postavile ambiciozne planove za koriš-ćenje vodonika kao obnovljivog izvora energije. Mnogi istraživački projekti finansirani su iz grantova EU, dok je Evropska komisija po-stavila u martu 2022. godine plan za što veću nezavisnost od uvo-za fosilnih goriva, koji između ostalog za cilj ima proizvodnju 10 miliona tona vodonika, dok je 10 miliona tona planirano za uvoz do 2030. godine.Korišćenje vodonika kao izvora goriva u sektoru vazduhoplov-stva se takođe dosta razmatra poslednjih godina. Prednosti vodonika kao avionskog goriva su očigledne. Vodonik je održiv, ne proizvodi emisije štetnih gasova, ima veliku gustinu energije itd. Međutim, još uvek postoje velike tehničke poteškoće koje bi trebalo prevazići, što predstavlja izazov pri postavljanju vodonika kao održivog goriva za vazduhoplovstvo. U radu su predstavljeni i diskutovani najznačajniji izazovi, neka moguća rešenja i mogućnosti koje proizilaze iz upotre-be vodonika za vazduhoplovne propulzore.",
journal = "Zbornik Međunarodnog kongresa o procesnoj industriji – Procesing, [S.l.]",
title = "Izazovi i prilike vodonika kao održivog vazduhoplovnog goriva budućnosti",
pages = "44-39",
number = "1",
volume = "36",
doi = "10.24094/ptk.023.039"
}

Ivanov, T., Ivanović, M., Zubić, M.,& Simonović, A.. (2023). Izazovi i prilike vodonika kao održivog vazduhoplovnog goriva budućnosti. in Zbornik Međunarodnog kongresa o procesnoj industriji – Procesing, [S.l.], 36(1), 39-44.
https://doi.org/10.24094/ptk.023.039

Ivanov T, Ivanović M, Zubić M, Simonović A. Izazovi i prilike vodonika kao održivog vazduhoplovnog goriva budućnosti. in Zbornik Međunarodnog kongresa o procesnoj industriji – Procesing, [S.l.]. 2023;36(1):39-44.
doi:10.24094/ptk.023.039 .

Ivanov, Toni, Ivanović, Milica, Zubić, Miloš, Simonović, Aleksandar, "Izazovi i prilike vodonika kao održivog vazduhoplovnog goriva budućnosti" in Zbornik Međunarodnog kongresa o procesnoj industriji – Procesing, [S.l.], 36, no. 1 (2023):39-44,
https://doi.org/10.24094/ptk.023.039 . .

TY  - JOUR
AU  - Milošević, Miloš
AU  - Trajković, Isaak
AU  - Golubović, Zorana
AU  - Ivanov, Toni
AU  - Mladenović, Goran
AU  - Milovanović, Aleksa
AU  - Mitrović, Nenad
PY  - 2022
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/5424
AB  - Martial arts and fight sports are mostly based on exchanging the punches and kicks that often result with injuries of face, skull bones, and neck vertebrae. One of possibilities to reduce number of injuries in athletes who deal with martial arts is development of new materials and improvement of designs for helmets used in sport fights. In order to experimentally analyze impact forces and simulate conditions during different fight punches mechanical installment was made. Aramis system is used to measure the displacement fields and the distribution of deformations which occur on the neck over the entire analyzed area based on the correlation of digital images. On this manner better understanding of behavior of both materials and structures during the action of the impact forces and loading is obtained. This information can further be used in researches related to the development of helmets used in martial arts which would influence reduction of values of neck deformations in athletes.
PB  - SAGE
T2  - Advances in Mechanical Engineering
T1  - Development of methodologies for experimental analysis of neck deformations caused by impact forces in martial arts
EP  - 14
EP  - M23
IS  - 8
SP  - 1
VL  - 14
DO  - 10.1177/16878132221121515
ER  - 

@article{
author = "Milošević, Miloš and Trajković, Isaak and Golubović, Zorana and Ivanov, Toni and Mladenović, Goran and Milovanović, Aleksa and Mitrović, Nenad",
year = "2022",
abstract = "Martial arts and fight sports are mostly based on exchanging the punches and kicks that often result with injuries of face, skull bones, and neck vertebrae. One of possibilities to reduce number of injuries in athletes who deal with martial arts is development of new materials and improvement of designs for helmets used in sport fights. In order to experimentally analyze impact forces and simulate conditions during different fight punches mechanical installment was made. Aramis system is used to measure the displacement fields and the distribution of deformations which occur on the neck over the entire analyzed area based on the correlation of digital images. On this manner better understanding of behavior of both materials and structures during the action of the impact forces and loading is obtained. This information can further be used in researches related to the development of helmets used in martial arts which would influence reduction of values of neck deformations in athletes.",
publisher = "SAGE",
journal = "Advances in Mechanical Engineering",
title = "Development of methodologies for experimental analysis of neck deformations caused by impact forces in martial arts",
pages = "14-M23-1",
number = "8",
volume = "14",
doi = "10.1177/16878132221121515"
}

Milošević, M., Trajković, I., Golubović, Z., Ivanov, T., Mladenović, G., Milovanović, A.,& Mitrović, N.. (2022). Development of methodologies for experimental analysis of neck deformations caused by impact forces in martial arts. in Advances in Mechanical Engineering
SAGE., 14(8), 1-14.
https://doi.org/10.1177/16878132221121515

Milošević M, Trajković I, Golubović Z, Ivanov T, Mladenović G, Milovanović A, Mitrović N. Development of methodologies for experimental analysis of neck deformations caused by impact forces in martial arts. in Advances in Mechanical Engineering. 2022;14(8):1-14.
doi:10.1177/16878132221121515 .

Milošević, Miloš, Trajković, Isaak, Golubović, Zorana, Ivanov, Toni, Mladenović, Goran, Milovanović, Aleksa, Mitrović, Nenad, "Development of methodologies for experimental analysis of neck deformations caused by impact forces in martial arts" in Advances in Mechanical Engineering, 14, no. 8 (2022):1-14,
https://doi.org/10.1177/16878132221121515 . .

TY  - CONF
AU  - Ivanović, Milica
AU  - Ivanov, Toni
AU  - Aleksandar, Kovačević
PY  - 2022
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/6408
AB  - The unique property of a very high heat transfer rate in heat pipes, which originates from the phase change of a high latent heat working fluid, has led to their use in a wide range of engineering applications such as electronics cooling, heat exchangers, spacecraft and satellites etc. The zero-power demand, low weight, compactness and reliability further the benefits of their use. A small amount of working fluid inside a sealed pipe is used to transport heat with a slight temperature difference between the evaporation and condensation segments. The recirculation of fluid is realized through a wick structure and driven by capillary forces. In order to investigate the influence of the shape of the heat pipe on the rate of heat transfer, a numerical test was performed on two types of flat geometry heat pipes – square and hexagonal shaped, as well as circular and ellipsoidal shaped. The parameters of interest were pressure and temperature distribution, velocity in condensation direction and thermal conductivity distribution. Results indicate that the difference in geometry causes differences in all observed parameters, and thus significantly affects the thermal properties of the heat pipe.
C3  - 1st International Conference on Mathematical Modelling in Mechanics and Engineering, Mathematical Institute SANU
T1  - Numerical investigation of the influence of geometry on the thermal properties of a heat pipe
UR  - https://hdl.handle.net/21.15107/rcub_machinery_6408
ER  - 

@conference{
author = "Ivanović, Milica and Ivanov, Toni and Aleksandar, Kovačević",
year = "2022",
abstract = "The unique property of a very high heat transfer rate in heat pipes, which originates from the phase change of a high latent heat working fluid, has led to their use in a wide range of engineering applications such as electronics cooling, heat exchangers, spacecraft and satellites etc. The zero-power demand, low weight, compactness and reliability further the benefits of their use. A small amount of working fluid inside a sealed pipe is used to transport heat with a slight temperature difference between the evaporation and condensation segments. The recirculation of fluid is realized through a wick structure and driven by capillary forces. In order to investigate the influence of the shape of the heat pipe on the rate of heat transfer, a numerical test was performed on two types of flat geometry heat pipes – square and hexagonal shaped, as well as circular and ellipsoidal shaped. The parameters of interest were pressure and temperature distribution, velocity in condensation direction and thermal conductivity distribution. Results indicate that the difference in geometry causes differences in all observed parameters, and thus significantly affects the thermal properties of the heat pipe.",
journal = "1st International Conference on Mathematical Modelling in Mechanics and Engineering, Mathematical Institute SANU",
title = "Numerical investigation of the influence of geometry on the thermal properties of a heat pipe",
url = "https://hdl.handle.net/21.15107/rcub_machinery_6408"
}

Ivanović, M., Ivanov, T.,& Aleksandar, K.. (2022). Numerical investigation of the influence of geometry on the thermal properties of a heat pipe. in 1st International Conference on Mathematical Modelling in Mechanics and Engineering, Mathematical Institute SANU.
https://hdl.handle.net/21.15107/rcub_machinery_6408

Ivanović M, Ivanov T, Aleksandar K. Numerical investigation of the influence of geometry on the thermal properties of a heat pipe. in 1st International Conference on Mathematical Modelling in Mechanics and Engineering, Mathematical Institute SANU. 2022;.
https://hdl.handle.net/21.15107/rcub_machinery_6408 .

Ivanović, Milica, Ivanov, Toni, Aleksandar, Kovačević, "Numerical investigation of the influence of geometry on the thermal properties of a heat pipe" in 1st International Conference on Mathematical Modelling in Mechanics and Engineering, Mathematical Institute SANU (2022),
https://hdl.handle.net/21.15107/rcub_machinery_6408 .

TY  - CONF
AU  - Kovačević, Aleksandar
AU  - Ivanov, Toni
AU  - Simonović, Aleksandar
AU  - Vorkapić, Miloš
PY  - 2022
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/5430
AB  - Veoma veliki porast upotrebe 3D štampe u poslednje dve decenije posledica je niza benefita koje ova proizvodna tehnologija nudi. U ovom radu analizirano je odstupanje geometrije štampanog modela u odnosu na CAD model. Izrada eksperimentalnog modela izvršena je metodom fuzionog taloženja filamenta (FDM) pri čemu je korišćen akrilonitril butadien stirol (ABS) materijal. Pokazano je kako se sa brojem iteracija odstupanje geometrije 3D štampanih modela u odnosu na CAD model smanjuje. U zaključku je dat pregled celokupnog procesa i preporuke u pogledu ograničenja upotrebe ove metode.
PB  - Uniiverzitet u Beogradu - Mašinski fakultet
C3  - Zbornik radova - 42. JUPITER konferencija / Proceedings - 42nd JUPITER Conference
T1  - Povećanje preciznosti izrade 3D štampanih delova primenom iterativne metode
UR  - https://hdl.handle.net/21.15107/rcub_machinery_5430
ER  - 

@conference{
author = "Kovačević, Aleksandar and Ivanov, Toni and Simonović, Aleksandar and Vorkapić, Miloš",
year = "2022",
abstract = "Veoma veliki porast upotrebe 3D štampe u poslednje dve decenije posledica je niza benefita koje ova proizvodna tehnologija nudi. U ovom radu analizirano je odstupanje geometrije štampanog modela u odnosu na CAD model. Izrada eksperimentalnog modela izvršena je metodom fuzionog taloženja filamenta (FDM) pri čemu je korišćen akrilonitril butadien stirol (ABS) materijal. Pokazano je kako se sa brojem iteracija odstupanje geometrije 3D štampanih modela u odnosu na CAD model smanjuje. U zaključku je dat pregled celokupnog procesa i preporuke u pogledu ograničenja upotrebe ove metode.",
publisher = "Uniiverzitet u Beogradu - Mašinski fakultet",
journal = "Zbornik radova - 42. JUPITER konferencija / Proceedings - 42nd JUPITER Conference",
title = "Povećanje preciznosti izrade 3D štampanih delova primenom iterativne metode",
url = "https://hdl.handle.net/21.15107/rcub_machinery_5430"
}

Kovačević, A., Ivanov, T., Simonović, A.,& Vorkapić, M.. (2022). Povećanje preciznosti izrade 3D štampanih delova primenom iterativne metode. in Zbornik radova - 42. JUPITER konferencija / Proceedings - 42nd JUPITER Conference
Uniiverzitet u Beogradu - Mašinski fakultet..
https://hdl.handle.net/21.15107/rcub_machinery_5430

Kovačević A, Ivanov T, Simonović A, Vorkapić M. Povećanje preciznosti izrade 3D štampanih delova primenom iterativne metode. in Zbornik radova - 42. JUPITER konferencija / Proceedings - 42nd JUPITER Conference. 2022;.
https://hdl.handle.net/21.15107/rcub_machinery_5430 .

Kovačević, Aleksandar, Ivanov, Toni, Simonović, Aleksandar, Vorkapić, Miloš, "Povećanje preciznosti izrade 3D štampanih delova primenom iterativne metode" in Zbornik radova - 42. JUPITER konferencija / Proceedings - 42nd JUPITER Conference (2022),
https://hdl.handle.net/21.15107/rcub_machinery_5430 .

TY  - CONF
AU  - Vorkapić, Miloš
AU  - Ivanov, Toni
AU  - Baltić, Marija
AU  - Živojinović, Danijela
PY  - 2022
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/5428
AB  - Da bi se na 3D štampaču izradio model sa složenim dizajnom odličnog kvaliteta, treba posebnu pažnju posvetiti njegovim elementima. U radu su razmatrana tri fundamentalna elementa: glava štampača, mlaznica i radna podloga. Upravo ovi elementi su odgovorni za ispravan rad uređaja i dalju realizaciju modela. Održavanje i zadavanje parametara štampe u mnogome zavise od stanja uređaja i kvaliteta pripreme elemenata za ukupnu proceduru štampe. Ako kvalitet materijala ne odgovara mogu da se pojave problemi u realizaciji 3D modela. U radu su razmotreni i opisani pomenuti elementi. Ovim radom pokušano je da se sa aspekta kompromisa cene i kvaliteta izrade razmotri uloga vitalnih elementata 3D štampe u realizaciji modela.
PB  - Beograd : JUSK - Jedinstveno Udruženje Srbije za Kvalitet
C3  - Zbornik radova sa konferencije JUSK - 2022, Beograd, Srbija
T1  - Značaj komponenti 3D štampača na ukupan kvalitet izrade modela
UR  - https://hdl.handle.net/21.15107/rcub_machinery_5428
ER  - 

@conference{
author = "Vorkapić, Miloš and Ivanov, Toni and Baltić, Marija and Živojinović, Danijela",
year = "2022",
abstract = "Da bi se na 3D štampaču izradio model sa složenim dizajnom odličnog kvaliteta, treba posebnu pažnju posvetiti njegovim elementima. U radu su razmatrana tri fundamentalna elementa: glava štampača, mlaznica i radna podloga. Upravo ovi elementi su odgovorni za ispravan rad uređaja i dalju realizaciju modela. Održavanje i zadavanje parametara štampe u mnogome zavise od stanja uređaja i kvaliteta pripreme elemenata za ukupnu proceduru štampe. Ako kvalitet materijala ne odgovara mogu da se pojave problemi u realizaciji 3D modela. U radu su razmotreni i opisani pomenuti elementi. Ovim radom pokušano je da se sa aspekta kompromisa cene i kvaliteta izrade razmotri uloga vitalnih elementata 3D štampe u realizaciji modela.",
publisher = "Beograd : JUSK - Jedinstveno Udruženje Srbije za Kvalitet",
journal = "Zbornik radova sa konferencije JUSK - 2022, Beograd, Srbija",
title = "Značaj komponenti 3D štampača na ukupan kvalitet izrade modela",
url = "https://hdl.handle.net/21.15107/rcub_machinery_5428"
}

Vorkapić, M., Ivanov, T., Baltić, M.,& Živojinović, D.. (2022). Značaj komponenti 3D štampača na ukupan kvalitet izrade modela. in Zbornik radova sa konferencije JUSK - 2022, Beograd, Srbija
Beograd : JUSK - Jedinstveno Udruženje Srbije za Kvalitet..
https://hdl.handle.net/21.15107/rcub_machinery_5428

Vorkapić M, Ivanov T, Baltić M, Živojinović D. Značaj komponenti 3D štampača na ukupan kvalitet izrade modela. in Zbornik radova sa konferencije JUSK - 2022, Beograd, Srbija. 2022;.
https://hdl.handle.net/21.15107/rcub_machinery_5428 .

Vorkapić, Miloš, Ivanov, Toni, Baltić, Marija, Živojinović, Danijela, "Značaj komponenti 3D štampača na ukupan kvalitet izrade modela" in Zbornik radova sa konferencije JUSK - 2022, Beograd, Srbija (2022),
https://hdl.handle.net/21.15107/rcub_machinery_5428 .

TY  - CONF
AU  - Vorkapić, Miloš
AU  - Baltić, Marija
AU  - Ivanov, Toni
AU  - Simonović, Aleksandar
PY  - 2022
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/5422
AB  - This paper presents the 3D printing technology for various textile materials. The application of this technology is vital in manufacturing various clothing items, primarily for specific purposes: hikers, firefighters, soldiers, and athletes. The installation of sensors, life function parameters monitoring and the usage of the new materials are the basis for the future development of the textile industry. Today, thermoplastic and textile materials are increasingly used in practice. Polylactic Acid (PLA) thermoplastic materials were used in the paper - in spool, Polyvinyl Chloride (PVC) and Nylon (in strips); while from textile materials, polyester, viscose and silk in the form of finished fabrics were considered. The technology of preparation of textile fibres for 3D printing using laser is shown. This technology makes it easier to combine textiles and molten filament. The pros and cons of joining different materials are discussed. Further research would go in the direction of making constructive solutions and testing the mechanical properties of various textile-polymer composites.
PB  - Belgrade : Innovation Center of Faculty of Mechanical Engineering
C3  - Program and the Book of Abstracts - International Conference of Experimental and Numerical Investigations and New Technologies, CNN TECH 2022, 05 – 08 July 2022, Zlatibor, Serbia
T1  - The significance of 3D printing in textile-polymer composite structures realization for special purpose
UR  - https://hdl.handle.net/21.15107/rcub_machinery_5422
ER  - 

@conference{
author = "Vorkapić, Miloš and Baltić, Marija and Ivanov, Toni and Simonović, Aleksandar",
year = "2022",
abstract = "This paper presents the 3D printing technology for various textile materials. The application of this technology is vital in manufacturing various clothing items, primarily for specific purposes: hikers, firefighters, soldiers, and athletes. The installation of sensors, life function parameters monitoring and the usage of the new materials are the basis for the future development of the textile industry. Today, thermoplastic and textile materials are increasingly used in practice. Polylactic Acid (PLA) thermoplastic materials were used in the paper - in spool, Polyvinyl Chloride (PVC) and Nylon (in strips); while from textile materials, polyester, viscose and silk in the form of finished fabrics were considered. The technology of preparation of textile fibres for 3D printing using laser is shown. This technology makes it easier to combine textiles and molten filament. The pros and cons of joining different materials are discussed. Further research would go in the direction of making constructive solutions and testing the mechanical properties of various textile-polymer composites.",
publisher = "Belgrade : Innovation Center of Faculty of Mechanical Engineering",
journal = "Program and the Book of Abstracts - International Conference of Experimental and Numerical Investigations and New Technologies, CNN TECH 2022, 05 – 08 July 2022, Zlatibor, Serbia",
title = "The significance of 3D printing in textile-polymer composite structures realization for special purpose",
url = "https://hdl.handle.net/21.15107/rcub_machinery_5422"
}

Vorkapić, M., Baltić, M., Ivanov, T.,& Simonović, A.. (2022). The significance of 3D printing in textile-polymer composite structures realization for special purpose. in Program and the Book of Abstracts - International Conference of Experimental and Numerical Investigations and New Technologies, CNN TECH 2022, 05 – 08 July 2022, Zlatibor, Serbia
Belgrade : Innovation Center of Faculty of Mechanical Engineering..
https://hdl.handle.net/21.15107/rcub_machinery_5422

Vorkapić M, Baltić M, Ivanov T, Simonović A. The significance of 3D printing in textile-polymer composite structures realization for special purpose. in Program and the Book of Abstracts - International Conference of Experimental and Numerical Investigations and New Technologies, CNN TECH 2022, 05 – 08 July 2022, Zlatibor, Serbia. 2022;.
https://hdl.handle.net/21.15107/rcub_machinery_5422 .

Vorkapić, Miloš, Baltić, Marija, Ivanov, Toni, Simonović, Aleksandar, "The significance of 3D printing in textile-polymer composite structures realization for special purpose" in Program and the Book of Abstracts - International Conference of Experimental and Numerical Investigations and New Technologies, CNN TECH 2022, 05 – 08 July 2022, Zlatibor, Serbia (2022),
https://hdl.handle.net/21.15107/rcub_machinery_5422 .

TY  - CONF
AU  - Ivanović, Milica
AU  - Vorkapić, Miloš
AU  - Simonović, Aleksandar
AU  - Ivanov, Toni
AU  - Stamenković, Igor
PY  - 2022
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/5420
AB  - The use of threaded inserts embedded in plastic parts is very common in variety of industries including electronics, automotive, aerospace, medical, transportation, defense etc., particularly where frequent assembly and disassembly are required. Performed technique of placement the inserts in specimens is heat staking - pressing the heated insert into the mounting hole to melt the material surrounding the insert. Specimens were made of PLA and obtained using a commercial Creality Ender-6 3D printer. The square-shaped samples have dimensions of 20 x 20 x 4 [mm] with a 4.6 [mm] diameter central hole for placing brass inserts with M3 thread.
PB  - SIRAMM H2020-WIDESPREAD-2018-03 Project No. 857124, Horizon 2020
C3  - Workshop Programme and the Book of Abstracts - 2nd International Workshop on Structural Integrity of Additively Manufactured Materials – SIAMM22, 4th - 5th February 2022, Brno, Czech Republic
T1  - Influence of wall layer number around brass inserts in 3D printed specimens subjected to axial pull-out force
UR  - https://hdl.handle.net/21.15107/rcub_machinery_5420
ER  - 

@conference{
author = "Ivanović, Milica and Vorkapić, Miloš and Simonović, Aleksandar and Ivanov, Toni and Stamenković, Igor",
year = "2022",
abstract = "The use of threaded inserts embedded in plastic parts is very common in variety of industries including electronics, automotive, aerospace, medical, transportation, defense etc., particularly where frequent assembly and disassembly are required. Performed technique of placement the inserts in specimens is heat staking - pressing the heated insert into the mounting hole to melt the material surrounding the insert. Specimens were made of PLA and obtained using a commercial Creality Ender-6 3D printer. The square-shaped samples have dimensions of 20 x 20 x 4 [mm] with a 4.6 [mm] diameter central hole for placing brass inserts with M3 thread.",
publisher = "SIRAMM H2020-WIDESPREAD-2018-03 Project No. 857124, Horizon 2020",
journal = "Workshop Programme and the Book of Abstracts - 2nd International Workshop on Structural Integrity of Additively Manufactured Materials – SIAMM22, 4th - 5th February 2022, Brno, Czech Republic",
title = "Influence of wall layer number around brass inserts in 3D printed specimens subjected to axial pull-out force",
url = "https://hdl.handle.net/21.15107/rcub_machinery_5420"
}

Ivanović, M., Vorkapić, M., Simonović, A., Ivanov, T.,& Stamenković, I.. (2022). Influence of wall layer number around brass inserts in 3D printed specimens subjected to axial pull-out force. in Workshop Programme and the Book of Abstracts - 2nd International Workshop on Structural Integrity of Additively Manufactured Materials – SIAMM22, 4th - 5th February 2022, Brno, Czech Republic
SIRAMM H2020-WIDESPREAD-2018-03 Project No. 857124, Horizon 2020..
https://hdl.handle.net/21.15107/rcub_machinery_5420

Ivanović M, Vorkapić M, Simonović A, Ivanov T, Stamenković I. Influence of wall layer number around brass inserts in 3D printed specimens subjected to axial pull-out force. in Workshop Programme and the Book of Abstracts - 2nd International Workshop on Structural Integrity of Additively Manufactured Materials – SIAMM22, 4th - 5th February 2022, Brno, Czech Republic. 2022;.
https://hdl.handle.net/21.15107/rcub_machinery_5420 .

Ivanović, Milica, Vorkapić, Miloš, Simonović, Aleksandar, Ivanov, Toni, Stamenković, Igor, "Influence of wall layer number around brass inserts in 3D printed specimens subjected to axial pull-out force" in Workshop Programme and the Book of Abstracts - 2nd International Workshop on Structural Integrity of Additively Manufactured Materials – SIAMM22, 4th - 5th February 2022, Brno, Czech Republic (2022),
https://hdl.handle.net/21.15107/rcub_machinery_5420 .

TY  - CONF
AU  - Kovačević, Aleksandar
AU  - Svorcan, Jelena
AU  - Ivanov, Toni
PY  - 2022
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/4264
AB  - Various algorithms are used to control modern unmanned aerial systems. However, thanks
to the simplicity of application, the most commonly used control algorithm for aircraft but also
for other dynamic systems in various industries is the PID (Proportional, Integral, Derivative)
controller. For the proper response of the system and fast stabilization during the action of
certain disturbances during its operation, it is necessary to precisely adjust the parameters of
the PID controller. This paper presents a mathematical model of a seesaw system for which a
PID control simulation was performed for different asymmetric geometries. Asymmetric
geometry implies different positions of the rotor relative to the axis of system rotation, as well
as when the rotor disks do not lie in the same plane, which simulates the influence of inaccuracy
in the construction of multi-rotor UAVs. The control simulation shows the possibility of
compensating for the mentioned geometric irregularities to ensure the appropriate behavior of
the system. The limit values of this influence are also shown, at which the PID control
algorithm cannot adequately perform the correction and ensure the correct response of the
system. The obtained simulation results would be verified by making an adequate physical
model and obtaining experimental results for the same input parameters, which may be the
subject of future research work.
PB  - University of Belgrade, Faculty of Mechanical Engineering
C3  - Booklet of Abstracts - 1st International Conference on Mathematical Modelling in Mechanics and Engineering
T1  - Modeling, simulation and control of propeller driven seesaw system with asymmetric geometry using PID controller
SP  - 111
UR  - https://hdl.handle.net/21.15107/rcub_machinery_4264
ER  - 

@conference{
author = "Kovačević, Aleksandar and Svorcan, Jelena and Ivanov, Toni",
year = "2022",
abstract = "Various algorithms are used to control modern unmanned aerial systems. However, thanks
to the simplicity of application, the most commonly used control algorithm for aircraft but also
for other dynamic systems in various industries is the PID (Proportional, Integral, Derivative)
controller. For the proper response of the system and fast stabilization during the action of
certain disturbances during its operation, it is necessary to precisely adjust the parameters of
the PID controller. This paper presents a mathematical model of a seesaw system for which a
PID control simulation was performed for different asymmetric geometries. Asymmetric
geometry implies different positions of the rotor relative to the axis of system rotation, as well
as when the rotor disks do not lie in the same plane, which simulates the influence of inaccuracy
in the construction of multi-rotor UAVs. The control simulation shows the possibility of
compensating for the mentioned geometric irregularities to ensure the appropriate behavior of
the system. The limit values of this influence are also shown, at which the PID control
algorithm cannot adequately perform the correction and ensure the correct response of the
system. The obtained simulation results would be verified by making an adequate physical
model and obtaining experimental results for the same input parameters, which may be the
subject of future research work.",
publisher = "University of Belgrade, Faculty of Mechanical Engineering",
journal = "Booklet of Abstracts - 1st International Conference on Mathematical Modelling in Mechanics and Engineering",
title = "Modeling, simulation and control of propeller driven seesaw system with asymmetric geometry using PID controller",
pages = "111",
url = "https://hdl.handle.net/21.15107/rcub_machinery_4264"
}

Kovačević, A., Svorcan, J.,& Ivanov, T.. (2022). Modeling, simulation and control of propeller driven seesaw system with asymmetric geometry using PID controller. in Booklet of Abstracts - 1st International Conference on Mathematical Modelling in Mechanics and Engineering
University of Belgrade, Faculty of Mechanical Engineering., 111.
https://hdl.handle.net/21.15107/rcub_machinery_4264

Kovačević A, Svorcan J, Ivanov T. Modeling, simulation and control of propeller driven seesaw system with asymmetric geometry using PID controller. in Booklet of Abstracts - 1st International Conference on Mathematical Modelling in Mechanics and Engineering. 2022;:111.
https://hdl.handle.net/21.15107/rcub_machinery_4264 .

Kovačević, Aleksandar, Svorcan, Jelena, Ivanov, Toni, "Modeling, simulation and control of propeller driven seesaw system with asymmetric geometry using PID controller" in Booklet of Abstracts - 1st International Conference on Mathematical Modelling in Mechanics and Engineering (2022):111,
https://hdl.handle.net/21.15107/rcub_machinery_4264 .

TY  - JOUR
AU  - Svorcan, Jelena
AU  - Andrić, Jelena
AU  - Čantrak, Đorđe
AU  - Ivanov, Toni
PY  - 2022
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/4173
T2  - Advances in Mechanical Engineering
T1  - Special Collection on advanced practices in aerospace and energy engineering
EP  - 3
IS  - 10
SP  - 1
VL  - 14
DO  - 10.1177/16878132221125578
ER  - 

@article{
author = "Svorcan, Jelena and Andrić, Jelena and Čantrak, Đorđe and Ivanov, Toni",
year = "2022",
journal = "Advances in Mechanical Engineering",
title = "Special Collection on advanced practices in aerospace and energy engineering",
pages = "3-1",
number = "10",
volume = "14",
doi = "10.1177/16878132221125578"
}

Svorcan, J., Andrić, J., Čantrak, Đ.,& Ivanov, T.. (2022). Special Collection on advanced practices in aerospace and energy engineering. in Advances in Mechanical Engineering, 14(10), 1-3.
https://doi.org/10.1177/16878132221125578

Svorcan J, Andrić J, Čantrak Đ, Ivanov T. Special Collection on advanced practices in aerospace and energy engineering. in Advances in Mechanical Engineering. 2022;14(10):1-3.
doi:10.1177/16878132221125578 .

Svorcan, Jelena, Andrić, Jelena, Čantrak, Đorđe, Ivanov, Toni, "Special Collection on advanced practices in aerospace and energy engineering" in Advances in Mechanical Engineering, 14, no. 10 (2022):1-3,
https://doi.org/10.1177/16878132221125578 . .

TY  - JOUR
AU  - Vorkapić, Miloš
AU  - Mladenović, Ivana
AU  - Ivanov, Toni
AU  - Kovačević, Aleksandar
AU  - Mohammad Sakib, Hasan
AU  - Simonović, Aleksandar
AU  - Trajković, Isaak
PY  - 2022
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/5423
AB  - Five series of specimens with two different print orientations (−45/45 and 0/90) and two print layer thicknesses (0.1 and 0.2 mm) were made. In total 60 specimens with 100% filament infill were made. One specimen series (20 pieces) was isolated as a reference or thermally untreated. Before the thermal treatment (annealing), two specimen moulding methods were used: NaCl powder (granulation 63 mm: 20 pieces) and Calcium Sulphate (Gypsum: 20 pieces). During the annealing, specimens immersed in NaCl powder were heated in a drying oven to the filament melting point (for PLA: 200°C, with a duration interval of 30 min), while the treatment of the heated specimens in gypsum was performed at a temperature of around 190°C, with duration interval of 3 h with the observed temperature inside the mould of about 100°C. An ultrasonic bath and a drying oven were used in the gypsum treatment. Temperature measurement and control during both annealing treatments were performed using a thermal imaging camera, while the temperature control inside the drying oven was performed using a digital thermometer. After treatment, the specimens in the moulds were cooled at room temperature, and the dimensions of annealing and untreated specimens were controlled. Surface morphology was characterised using scanning electron microscopy (SEM). The SEM analysis reveals improved internal structure after heat treatment of the PLA specimens. These results show that the investigated specimens after heat treatments had better structural properties than the referent specimens. Tensile testing on a universal testing machine in compliance with the ASTM D638 standard was also performed. The referent PLA specimen with −45/45 and layer thickness of 0.1 mm had the highest tensile stress value (64.08 MPa) while the specimen with minimal tensile stress value before fracture was 0/90, 0.2 mm (54.81 MPa). Heat treatment in gypsum showed the most significant increase in strength with −45/45 (0.1 mm) being the strongest (71.66 MPa) while the strongest specimen treated in sodium chloride was −45/45 (0.1 mm) with maximum tensile stress of 70.08 MPa. The mechanical characteristics of the PLA were characterised using the Vickers microhardness tester. The PLA microhardness value was calculated according to standards ASTM E384 and ISO 6507. The referent PLA specimen with −45/45 (0.2 mm) orientation shows the maximal microhardness value (125 MPa), and the minimal microhardness value was observed for the 0/90 (0.1 mm) orientation specimens (108 MPa). The heat treatment specimens in gypsum have a better hardness (185 MPa) than those treated in gypsum (165 MPa), with microhardness increasing by about 12%. The essence of the work is reflected in the additional filament processing to achieve a better structural and mechanical performance of the materials and reduce the anisotropy that is characteristic of 3D printing.
PB  - SAGE
T2  - Advances in Mechanical Engineering
T1  - Enhancing mechanical properties of 3D printed thermoplastic polymers by annealing in moulds
EP  - 15
IS  - 8
SP  - 1
VL  - 14
DO  - 10.1177/16878132221120737
ER  - 

@article{
author = "Vorkapić, Miloš and Mladenović, Ivana and Ivanov, Toni and Kovačević, Aleksandar and Mohammad Sakib, Hasan and Simonović, Aleksandar and Trajković, Isaak",
year = "2022",
abstract = "Five series of specimens with two different print orientations (−45/45 and 0/90) and two print layer thicknesses (0.1 and 0.2 mm) were made. In total 60 specimens with 100% filament infill were made. One specimen series (20 pieces) was isolated as a reference or thermally untreated. Before the thermal treatment (annealing), two specimen moulding methods were used: NaCl powder (granulation 63 mm: 20 pieces) and Calcium Sulphate (Gypsum: 20 pieces). During the annealing, specimens immersed in NaCl powder were heated in a drying oven to the filament melting point (for PLA: 200°C, with a duration interval of 30 min), while the treatment of the heated specimens in gypsum was performed at a temperature of around 190°C, with duration interval of 3 h with the observed temperature inside the mould of about 100°C. An ultrasonic bath and a drying oven were used in the gypsum treatment. Temperature measurement and control during both annealing treatments were performed using a thermal imaging camera, while the temperature control inside the drying oven was performed using a digital thermometer. After treatment, the specimens in the moulds were cooled at room temperature, and the dimensions of annealing and untreated specimens were controlled. Surface morphology was characterised using scanning electron microscopy (SEM). The SEM analysis reveals improved internal structure after heat treatment of the PLA specimens. These results show that the investigated specimens after heat treatments had better structural properties than the referent specimens. Tensile testing on a universal testing machine in compliance with the ASTM D638 standard was also performed. The referent PLA specimen with −45/45 and layer thickness of 0.1 mm had the highest tensile stress value (64.08 MPa) while the specimen with minimal tensile stress value before fracture was 0/90, 0.2 mm (54.81 MPa). Heat treatment in gypsum showed the most significant increase in strength with −45/45 (0.1 mm) being the strongest (71.66 MPa) while the strongest specimen treated in sodium chloride was −45/45 (0.1 mm) with maximum tensile stress of 70.08 MPa. The mechanical characteristics of the PLA were characterised using the Vickers microhardness tester. The PLA microhardness value was calculated according to standards ASTM E384 and ISO 6507. The referent PLA specimen with −45/45 (0.2 mm) orientation shows the maximal microhardness value (125 MPa), and the minimal microhardness value was observed for the 0/90 (0.1 mm) orientation specimens (108 MPa). The heat treatment specimens in gypsum have a better hardness (185 MPa) than those treated in gypsum (165 MPa), with microhardness increasing by about 12%. The essence of the work is reflected in the additional filament processing to achieve a better structural and mechanical performance of the materials and reduce the anisotropy that is characteristic of 3D printing.",
publisher = "SAGE",
journal = "Advances in Mechanical Engineering",
title = "Enhancing mechanical properties of 3D printed thermoplastic polymers by annealing in moulds",
pages = "15-1",
number = "8",
volume = "14",
doi = "10.1177/16878132221120737"
}

Vorkapić, M., Mladenović, I., Ivanov, T., Kovačević, A., Mohammad Sakib, H., Simonović, A.,& Trajković, I.. (2022). Enhancing mechanical properties of 3D printed thermoplastic polymers by annealing in moulds. in Advances in Mechanical Engineering
SAGE., 14(8), 1-15.
https://doi.org/10.1177/16878132221120737

Vorkapić M, Mladenović I, Ivanov T, Kovačević A, Mohammad Sakib H, Simonović A, Trajković I. Enhancing mechanical properties of 3D printed thermoplastic polymers by annealing in moulds. in Advances in Mechanical Engineering. 2022;14(8):1-15.
doi:10.1177/16878132221120737 .

Vorkapić, Miloš, Mladenović, Ivana, Ivanov, Toni, Kovačević, Aleksandar, Mohammad Sakib, Hasan, Simonović, Aleksandar, Trajković, Isaak, "Enhancing mechanical properties of 3D printed thermoplastic polymers by annealing in moulds" in Advances in Mechanical Engineering, 14, no. 8 (2022):1-15,
https://doi.org/10.1177/16878132221120737 . .

TY  - JOUR
AU  - Vorkapić, Miloš
AU  - Mladenović, Ivana
AU  - Pergal, Marija
AU  - Ivanov, Toni
AU  - Baltić, Marija
PY  - 2022
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/5421
AB  - Three-dimensional printed plastic products developed through fused deposition modelling (FDM) take long-term mechanical loading in most industrial prototypes. This article focuses on the impact of the 3D printing parameters, type of thermal treatment and variation of characteristic dimensions of standard specimens on the tensile properties of poly(lactic acid) (PLA) material. Two mediums were used for thermal treatment: NaCl powder and plaster. The specimens immersed in NaCl powder were heated to the melting temperature of the filament (200 °C), while the processing of the plastered specimens was performed at a temperature of 100 °C. After treatment, the specimens were cooled at room temperature (25 °C), and the dimensions of the annealed and untreated specimens were controlled. The tensile test of the specimens was performed on the universal test machine. The response surface methodology (RSM) is employed to predict the tensile stress by undertaking input parameters. The analysis of variance (ANOVA) results revealed that the untreated specimens, orientation –45/45 and layer thickness of 0.1 mm had the highest tensile stress value. Thermal treatment in plaster showed a significant increase in tensile strength, while the best specimens were obtained after treatment in NaCl, and all refer to the –45/45 (0.1 mm) orientation.
PB  - Belgrade : Balkan Scientific Centre
T2  - Tribology and Materials
T1  - Optimisation of tensile stress of poly(lactic acid) 3D printed materials using response surface methodology
EP  - 80
IS  - 2
SP  - 70
VL  - 1
DO  - 10.46793/tribomat.2022.009
ER  - 

@article{
author = "Vorkapić, Miloš and Mladenović, Ivana and Pergal, Marija and Ivanov, Toni and Baltić, Marija",
year = "2022",
abstract = "Three-dimensional printed plastic products developed through fused deposition modelling (FDM) take long-term mechanical loading in most industrial prototypes. This article focuses on the impact of the 3D printing parameters, type of thermal treatment and variation of characteristic dimensions of standard specimens on the tensile properties of poly(lactic acid) (PLA) material. Two mediums were used for thermal treatment: NaCl powder and plaster. The specimens immersed in NaCl powder were heated to the melting temperature of the filament (200 °C), while the processing of the plastered specimens was performed at a temperature of 100 °C. After treatment, the specimens were cooled at room temperature (25 °C), and the dimensions of the annealed and untreated specimens were controlled. The tensile test of the specimens was performed on the universal test machine. The response surface methodology (RSM) is employed to predict the tensile stress by undertaking input parameters. The analysis of variance (ANOVA) results revealed that the untreated specimens, orientation –45/45 and layer thickness of 0.1 mm had the highest tensile stress value. Thermal treatment in plaster showed a significant increase in tensile strength, while the best specimens were obtained after treatment in NaCl, and all refer to the –45/45 (0.1 mm) orientation.",
publisher = "Belgrade : Balkan Scientific Centre",
journal = "Tribology and Materials",
title = "Optimisation of tensile stress of poly(lactic acid) 3D printed materials using response surface methodology",
pages = "80-70",
number = "2",
volume = "1",
doi = "10.46793/tribomat.2022.009"
}

Vorkapić, M., Mladenović, I., Pergal, M., Ivanov, T.,& Baltić, M.. (2022). Optimisation of tensile stress of poly(lactic acid) 3D printed materials using response surface methodology. in Tribology and Materials
Belgrade : Balkan Scientific Centre., 1(2), 70-80.
https://doi.org/10.46793/tribomat.2022.009

Vorkapić M, Mladenović I, Pergal M, Ivanov T, Baltić M. Optimisation of tensile stress of poly(lactic acid) 3D printed materials using response surface methodology. in Tribology and Materials. 2022;1(2):70-80.
doi:10.46793/tribomat.2022.009 .

Vorkapić, Miloš, Mladenović, Ivana, Pergal, Marija, Ivanov, Toni, Baltić, Marija, "Optimisation of tensile stress of poly(lactic acid) 3D printed materials using response surface methodology" in Tribology and Materials, 1, no. 2 (2022):70-80,
https://doi.org/10.46793/tribomat.2022.009 . .

TY  - CHAP
AU  - Vorkapić, Miloš
AU  - Ivanov, Toni
PY  - 2022
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/5418
AB  - This paper investigates the implementation of additive manufacturing (AM) in circular production (CP) through the 6R strategy. The methodology allows designers to reconsider their decisions, correct mistakes or make specific changes to the model in all phases of the design process, from initial drawings to the finished product. CP enables the complete realisation of the model/prototype with a particular focus on environmental protection and the additional use of recycled waste. The proposed algorithm is tested through the design and manufacturing of an enclosure of an industrial temperature transmitter. Some of the weaknesses of additive manufacturing, such as mechanically damaged surfaces, surface roughness, and tearing of models on weak joints, have been investigated, and recommendations for mitigation are given.

The mechanical product finishing methods are described in detail in the paper as well, and in order to check the prototype functionality, some tensile, thermal stress and drop tests were performed, and the results were analysed and discussed. It was shown that significant savings in time, cost and material can be achieved by implementing AM in realising a fully functional prototype while simultaneously in line with the demands for CP and 6R.
PB  - Springer
T2  - Experimental Research and Numerical Simulation in Applied Sciences. Proceedings of the International Conference of Experimental and Numerical Investigations and New Technologies, CNNTech 2022. Lecture Notes in Networks and Systems
T1  - Algorithm for Applying 3D Printing in Prototype Realization in Accordance with Circular Production and the 6R Strategy: Case - Enclosure for Industrial Temperature Transmitter
VL  - 564
DO  - 10.1007/978-3-031-19499-3_3
ER  - 

@inbook{
author = "Vorkapić, Miloš and Ivanov, Toni",
year = "2022",
abstract = "This paper investigates the implementation of additive manufacturing (AM) in circular production (CP) through the 6R strategy. The methodology allows designers to reconsider their decisions, correct mistakes or make specific changes to the model in all phases of the design process, from initial drawings to the finished product. CP enables the complete realisation of the model/prototype with a particular focus on environmental protection and the additional use of recycled waste. The proposed algorithm is tested through the design and manufacturing of an enclosure of an industrial temperature transmitter. Some of the weaknesses of additive manufacturing, such as mechanically damaged surfaces, surface roughness, and tearing of models on weak joints, have been investigated, and recommendations for mitigation are given.

The mechanical product finishing methods are described in detail in the paper as well, and in order to check the prototype functionality, some tensile, thermal stress and drop tests were performed, and the results were analysed and discussed. It was shown that significant savings in time, cost and material can be achieved by implementing AM in realising a fully functional prototype while simultaneously in line with the demands for CP and 6R.",
publisher = "Springer",
journal = "Experimental Research and Numerical Simulation in Applied Sciences. Proceedings of the International Conference of Experimental and Numerical Investigations and New Technologies, CNNTech 2022. Lecture Notes in Networks and Systems",
booktitle = "Algorithm for Applying 3D Printing in Prototype Realization in Accordance with Circular Production and the 6R Strategy: Case - Enclosure for Industrial Temperature Transmitter",
volume = "564",
doi = "10.1007/978-3-031-19499-3_3"
}

Vorkapić, M.,& Ivanov, T.. (2022). Algorithm for Applying 3D Printing in Prototype Realization in Accordance with Circular Production and the 6R Strategy: Case - Enclosure for Industrial Temperature Transmitter. in Experimental Research and Numerical Simulation in Applied Sciences. Proceedings of the International Conference of Experimental and Numerical Investigations and New Technologies, CNNTech 2022. Lecture Notes in Networks and Systems
Springer., 564.
https://doi.org/10.1007/978-3-031-19499-3_3

Vorkapić M, Ivanov T. Algorithm for Applying 3D Printing in Prototype Realization in Accordance with Circular Production and the 6R Strategy: Case - Enclosure for Industrial Temperature Transmitter. in Experimental Research and Numerical Simulation in Applied Sciences. Proceedings of the International Conference of Experimental and Numerical Investigations and New Technologies, CNNTech 2022. Lecture Notes in Networks and Systems. 2022;564.
doi:10.1007/978-3-031-19499-3_3 .

Vorkapić, Miloš, Ivanov, Toni, "Algorithm for Applying 3D Printing in Prototype Realization in Accordance with Circular Production and the 6R Strategy: Case - Enclosure for Industrial Temperature Transmitter" in Experimental Research and Numerical Simulation in Applied Sciences. Proceedings of the International Conference of Experimental and Numerical Investigations and New Technologies, CNNTech 2022. Lecture Notes in Networks and Systems, 564 (2022),
https://doi.org/10.1007/978-3-031-19499-3_3 . .

TY  - JOUR
AU  - Svorcan, Jelena
AU  - Kovačević, Aleksandar
AU  - Ivanov, Toni
AU  - Simonović, Aleksandar
PY  - 2022
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/4210
AB  - Detailed studies of propeller flows are regaining both interest and significance worldwide, as the number of their different design and applications (particularly for futuristic urban air vehicles) continues to grow. An additional distinctive characteristic of small-scale unmanned air vehicles (UAV) propellers is that they are meant to operate in a wide range of (previously considered atypical) operating conditions, including backward flight, flight in the vicinity of obstacles,
hard/ground surfaces, etc. These specific requirements raise the issue of the effects of ground proximity on their aerodynamic performance. This paper computationally investigates flows around a small-scale, custom-made propeller in ground effect. Different ground distances are considered and novel thrust and power relations (dependencies) on them are proposed. In order to obtain sufficiently reliable and accurate results and capture the most significant flow features, Reynolds-averaged Navier-Stokes (RANS) equations are solved by finite volume method. In addition, interesting flow visualizations are presented. Although the obtained thrust trend correlates well with the conventionally used semi-empirical formula, more realistic estimations are obtained for small ground distances. Furthermore, the positive effects of ground vicinity on rotor aerodynamic performances are once again confirmed and quantified.
PB  - Belgrade :  Military Technical Institute - VTI
T2  - Scientific Technical Review
T1  - Numerical analysis of a propeller in ground effect
EP  - 13
IS  - 2
SP  - 8
VL  - 72
DO  - 10.5937/str2202008S
ER  - 

@article{
author = "Svorcan, Jelena and Kovačević, Aleksandar and Ivanov, Toni and Simonović, Aleksandar",
year = "2022",
abstract = "Detailed studies of propeller flows are regaining both interest and significance worldwide, as the number of their different design and applications (particularly for futuristic urban air vehicles) continues to grow. An additional distinctive characteristic of small-scale unmanned air vehicles (UAV) propellers is that they are meant to operate in a wide range of (previously considered atypical) operating conditions, including backward flight, flight in the vicinity of obstacles,
hard/ground surfaces, etc. These specific requirements raise the issue of the effects of ground proximity on their aerodynamic performance. This paper computationally investigates flows around a small-scale, custom-made propeller in ground effect. Different ground distances are considered and novel thrust and power relations (dependencies) on them are proposed. In order to obtain sufficiently reliable and accurate results and capture the most significant flow features, Reynolds-averaged Navier-Stokes (RANS) equations are solved by finite volume method. In addition, interesting flow visualizations are presented. Although the obtained thrust trend correlates well with the conventionally used semi-empirical formula, more realistic estimations are obtained for small ground distances. Furthermore, the positive effects of ground vicinity on rotor aerodynamic performances are once again confirmed and quantified.",
publisher = "Belgrade :  Military Technical Institute - VTI",
journal = "Scientific Technical Review",
title = "Numerical analysis of a propeller in ground effect",
pages = "13-8",
number = "2",
volume = "72",
doi = "10.5937/str2202008S"
}

Svorcan, J., Kovačević, A., Ivanov, T.,& Simonović, A.. (2022). Numerical analysis of a propeller in ground effect. in Scientific Technical Review
Belgrade :  Military Technical Institute - VTI., 72(2), 8-13.
https://doi.org/10.5937/str2202008S

Svorcan J, Kovačević A, Ivanov T, Simonović A. Numerical analysis of a propeller in ground effect. in Scientific Technical Review. 2022;72(2):8-13.
doi:10.5937/str2202008S .

Svorcan, Jelena, Kovačević, Aleksandar, Ivanov, Toni, Simonović, Aleksandar, "Numerical analysis of a propeller in ground effect" in Scientific Technical Review, 72, no. 2 (2022):8-13,
https://doi.org/10.5937/str2202008S . .

TY  - CONF
AU  - Vorkapić, Miloš
AU  - Stajčić, Aleksandar
AU  - Mladenović, Ivana
AU  - Ivanov, Toni
PY  - 2021
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/5427
AB  - Iako 3D štampa verovatno neće preuzeti mnoge konvencionalne metode proizvodnje, 3D štampač može brzo da isporuči složeni dizajn sa velikom tačnošću. Međutim, aditivna proizvodnja takođe pokazuje određene slabosti. Ako karakteristike materijala nisu definisane, mogu se pojaviti problemi u realizaciji 3D modela. U našem radu je razmotreno osam uzoraka sa različitim vrednostima parametara: visina sloja, orijentacija ispune i gustina ispune. U softveru Ultimaker Cura postavlјeni su svi parametri uzorka, dok vizualizaciju dizajna uzorka vrši putanja mlaznica. Mikroskopski pregled strukture ispune pokazao je da postoje određene nepravilnosti u cilјu ispitivanja realizacije i orijentacije slojeva. U našoj analizi upotrebljena je polinalektična kiselina (PLA). Spolјni uticaji su takođe važni poput: mehaničko oštećenje, temperatura na vrhu mlaznice i brzine hlađenja materijala u okruženju. Sve to utiče na kvalitet. Mikroskopskom analizom pokušali su da se utvrde korelacije, problemi unutar strukture materijala, ali i da se daju preporuke za pobolјšanje realizacije modela.
PB  - Beograd : JUSK - Jedinstveno Udruženje Srbije za Kvalitet / Belgrade : UASQ - United Association of Serbia for Quality
C3  - Zbornik radova JUSK ICQ - XVII Međunarodna konvencija o kvalitetu 2021, 09-11/06/2021, Beograd, Srbija
T1  - Primer realizacije uzorka pomoću 3D štampe i analiza problema u kvalitetu
UR  - https://hdl.handle.net/21.15107/rcub_machinery_5427
ER  - 

@conference{
author = "Vorkapić, Miloš and Stajčić, Aleksandar and Mladenović, Ivana and Ivanov, Toni",
year = "2021",
abstract = "Iako 3D štampa verovatno neće preuzeti mnoge konvencionalne metode proizvodnje, 3D štampač može brzo da isporuči složeni dizajn sa velikom tačnošću. Međutim, aditivna proizvodnja takođe pokazuje određene slabosti. Ako karakteristike materijala nisu definisane, mogu se pojaviti problemi u realizaciji 3D modela. U našem radu je razmotreno osam uzoraka sa različitim vrednostima parametara: visina sloja, orijentacija ispune i gustina ispune. U softveru Ultimaker Cura postavlјeni su svi parametri uzorka, dok vizualizaciju dizajna uzorka vrši putanja mlaznica. Mikroskopski pregled strukture ispune pokazao je da postoje određene nepravilnosti u cilјu ispitivanja realizacije i orijentacije slojeva. U našoj analizi upotrebljena je polinalektična kiselina (PLA). Spolјni uticaji su takođe važni poput: mehaničko oštećenje, temperatura na vrhu mlaznice i brzine hlađenja materijala u okruženju. Sve to utiče na kvalitet. Mikroskopskom analizom pokušali su da se utvrde korelacije, problemi unutar strukture materijala, ali i da se daju preporuke za pobolјšanje realizacije modela.",
publisher = "Beograd : JUSK - Jedinstveno Udruženje Srbije za Kvalitet / Belgrade : UASQ - United Association of Serbia for Quality",
journal = "Zbornik radova JUSK ICQ - XVII Međunarodna konvencija o kvalitetu 2021, 09-11/06/2021, Beograd, Srbija",
title = "Primer realizacije uzorka pomoću 3D štampe i analiza problema u kvalitetu",
url = "https://hdl.handle.net/21.15107/rcub_machinery_5427"
}

Vorkapić, M., Stajčić, A., Mladenović, I.,& Ivanov, T.. (2021). Primer realizacije uzorka pomoću 3D štampe i analiza problema u kvalitetu. in Zbornik radova JUSK ICQ - XVII Međunarodna konvencija o kvalitetu 2021, 09-11/06/2021, Beograd, Srbija
Beograd : JUSK - Jedinstveno Udruženje Srbije za Kvalitet / Belgrade : UASQ - United Association of Serbia for Quality..
https://hdl.handle.net/21.15107/rcub_machinery_5427

Vorkapić M, Stajčić A, Mladenović I, Ivanov T. Primer realizacije uzorka pomoću 3D štampe i analiza problema u kvalitetu. in Zbornik radova JUSK ICQ - XVII Međunarodna konvencija o kvalitetu 2021, 09-11/06/2021, Beograd, Srbija. 2021;.
https://hdl.handle.net/21.15107/rcub_machinery_5427 .

Vorkapić, Miloš, Stajčić, Aleksandar, Mladenović, Ivana, Ivanov, Toni, "Primer realizacije uzorka pomoću 3D štampe i analiza problema u kvalitetu" in Zbornik radova JUSK ICQ - XVII Međunarodna konvencija o kvalitetu 2021, 09-11/06/2021, Beograd, Srbija (2021),
https://hdl.handle.net/21.15107/rcub_machinery_5427 .

TY  - CONF
AU  - Hasan, Sakib Mohammad
AU  - Ivanov, Toni
AU  - Vorkapić, Miloš
PY  - 2021
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/5426
AB  - In this paper, bone-shaped samples (dogbone) made of thermoplastic polymer PLA were tested according to the ASTM D638 standard. All samples were made on a WANHAO duplicator i3 plus 3D printer. PLA is the most widely used polymer mainly due to its thermoplastic workability and good mechanical properties. The mechanical characteristics of the materials were compared after the realization of the samples on the 3D printer and after the remelting process. All samples were built in horizontal orientation. Remelting process involves stacking / packing samples in a mold and pressing them with sodium chloride (NaCl) powder. Since sodium chloride (NaCl) is a poor conductor of temperature, it takes some time for the experiment to be realized in order to equalize the temperatures throughout the volume of the mold. The mold thus formed was kept at 210°C for 30-45 minutes. The purpose of salt powder molding is to get even curing without deformation on the surfaces of the parts. The samples become rougher after this treatment and it is necessary to remove excess salt from the structure as well as additional surface treatment. The remelting process proved to be very cheap, but also quite unreliable due to the slow and uneven rise in temperature in the mold. The SHIMADZU AGS-X 100 kN tensile testing machine was used to test the tensile strength of the samples. During the experiment, it was found that the samples with remelting process have a much higher tensile strength compared to the untreated samples. Remelting procedure of PLA greatly improves the mechanical properties and gives better performance to complex parts printed on a 3D printer by reducing the anisotropic characteristics of the polymer. Further research would be related to the testing of other thermoplastic materials such as ABS, PET-G etc. It would be interesting to use other materials for molding and to perform a comparative analysis of the obtained results of the new molding methods with the described method of applying salt powder.
PB  - Belgrade : Innovation Center of Faculty of Mechanical Engineering
C3  - Program and the Book of Abstracts - International Conference of Experimental and Numerical Investigations and New Technologies, CNN TECH 2021, 29/06-02/07 2021, Zlatibor, Serbia
T1  - Improvement of mechanical characteristics of PLA by applying remelting process
UR  - https://hdl.handle.net/21.15107/rcub_machinery_5426
ER  - 

@conference{
author = "Hasan, Sakib Mohammad and Ivanov, Toni and Vorkapić, Miloš",
year = "2021",
abstract = "In this paper, bone-shaped samples (dogbone) made of thermoplastic polymer PLA were tested according to the ASTM D638 standard. All samples were made on a WANHAO duplicator i3 plus 3D printer. PLA is the most widely used polymer mainly due to its thermoplastic workability and good mechanical properties. The mechanical characteristics of the materials were compared after the realization of the samples on the 3D printer and after the remelting process. All samples were built in horizontal orientation. Remelting process involves stacking / packing samples in a mold and pressing them with sodium chloride (NaCl) powder. Since sodium chloride (NaCl) is a poor conductor of temperature, it takes some time for the experiment to be realized in order to equalize the temperatures throughout the volume of the mold. The mold thus formed was kept at 210°C for 30-45 minutes. The purpose of salt powder molding is to get even curing without deformation on the surfaces of the parts. The samples become rougher after this treatment and it is necessary to remove excess salt from the structure as well as additional surface treatment. The remelting process proved to be very cheap, but also quite unreliable due to the slow and uneven rise in temperature in the mold. The SHIMADZU AGS-X 100 kN tensile testing machine was used to test the tensile strength of the samples. During the experiment, it was found that the samples with remelting process have a much higher tensile strength compared to the untreated samples. Remelting procedure of PLA greatly improves the mechanical properties and gives better performance to complex parts printed on a 3D printer by reducing the anisotropic characteristics of the polymer. Further research would be related to the testing of other thermoplastic materials such as ABS, PET-G etc. It would be interesting to use other materials for molding and to perform a comparative analysis of the obtained results of the new molding methods with the described method of applying salt powder.",
publisher = "Belgrade : Innovation Center of Faculty of Mechanical Engineering",
journal = "Program and the Book of Abstracts - International Conference of Experimental and Numerical Investigations and New Technologies, CNN TECH 2021, 29/06-02/07 2021, Zlatibor, Serbia",
title = "Improvement of mechanical characteristics of PLA by applying remelting process",
url = "https://hdl.handle.net/21.15107/rcub_machinery_5426"
}

Hasan, S. M., Ivanov, T.,& Vorkapić, M.. (2021). Improvement of mechanical characteristics of PLA by applying remelting process. in Program and the Book of Abstracts - International Conference of Experimental and Numerical Investigations and New Technologies, CNN TECH 2021, 29/06-02/07 2021, Zlatibor, Serbia
Belgrade : Innovation Center of Faculty of Mechanical Engineering..
https://hdl.handle.net/21.15107/rcub_machinery_5426

Hasan SM, Ivanov T, Vorkapić M. Improvement of mechanical characteristics of PLA by applying remelting process. in Program and the Book of Abstracts - International Conference of Experimental and Numerical Investigations and New Technologies, CNN TECH 2021, 29/06-02/07 2021, Zlatibor, Serbia. 2021;.
https://hdl.handle.net/21.15107/rcub_machinery_5426 .

Hasan, Sakib Mohammad, Ivanov, Toni, Vorkapić, Miloš, "Improvement of mechanical characteristics of PLA by applying remelting process" in Program and the Book of Abstracts - International Conference of Experimental and Numerical Investigations and New Technologies, CNN TECH 2021, 29/06-02/07 2021, Zlatibor, Serbia (2021),
https://hdl.handle.net/21.15107/rcub_machinery_5426 .

TY  - CONF
AU  - Ilić, Stefan
AU  - Vorkapić, Miloš
AU  - Ivanov, Toni
AU  - Svorcan, Jelena
PY  - 2021
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/5425
AB  - The application of additive technology gives a designer more freedom in designing and defining the optimal product design. Also, it is possible to make a model with different materials that have different mechanical properties in order to meet different requirements in different places inside and outside of the part. In this paper, a 3D printer Wanhao Duplicator, type i3 plus, made in the People's Republic of China, was used for the realization of the elements of a mechanical mounting system. It is a desktop 3D printer with a maximum printable area of 200 x 200 x 180 mm3, nozzle diameter of 0.1-0.4 mm, and printing speed of 10-100 mm/s (see Figure 3). For the realization of the model, the chosen material was ABS (Acrylonitrile Butadiene Styrene) in the form of a filament (diameter 1.75 mm, manufacturer Wanhao). ABS is an amorphous polymer with the following features: excellent mechanical properties, resistance to elevated temperatures, and resistance to shocks. On the Wanhao printer, the prescribed distance between the nozzle and the plate is 0.1 mm. This is the minimum thickness of a single printed layer in the xy plane. The diameter of the melted thread is 0.1 mm, which is very thin, allowing for a very dense construction of the print along the z axis. All these parameters are essential for the quality of the print. 3D printing technology enabled the custom design and fabrication of a mechanical system intended to be placed in an irradiation room, in order to hold the component whose electric characteristics are being examined. The irradiation room may contain one or more sources of ionizing radiation. Each irradiation room may have a different way of mounting the component under test. Since it is necessary to study a specific electronic component with different ionizing radiation sources (gamma and X-ray), at different dose rates, and located in different irradiation rooms, designing a custom mounting system for each irradiation room is necessary. The cost of making a mechanical mounting system using 3D printing technology is significantly lower compared to other production methods. Thus, the creation of a system for each irradiation room individually becomes more economical. Creating such a system for each irradiation room allows much easier and more accurate positioning of the component, which reduces the error in calculating the dose that the component receives during irradiation. Each mechanical system should allow the installation of printed circuit boards of different sizes, on which the tested electronic components are located. Also, the material from which the mounting system is made must not affect the component during the experiment. Materials used in 3D printing have a negligible effect on the reflection or scattering of high-energy photons because they do not contain atoms with heavy nuclei.
PB  - SIRAMM project - H2020-WIDESPREAD-2018-03 Project No. 857124, Horizon 2020
C3  - Program and the Book of Abstracts - International Conference East Europe Conference on Additively Manufactured Materials – EECAM21, 2nd-4th September 2021, Belgrade, Serbia
T1  - The use of 3D printing for studying the influence of ionizing radiation on electronic components
UR  - https://hdl.handle.net/21.15107/rcub_machinery_5425
ER  - 

@conference{
author = "Ilić, Stefan and Vorkapić, Miloš and Ivanov, Toni and Svorcan, Jelena",
year = "2021",
abstract = "The application of additive technology gives a designer more freedom in designing and defining the optimal product design. Also, it is possible to make a model with different materials that have different mechanical properties in order to meet different requirements in different places inside and outside of the part. In this paper, a 3D printer Wanhao Duplicator, type i3 plus, made in the People's Republic of China, was used for the realization of the elements of a mechanical mounting system. It is a desktop 3D printer with a maximum printable area of 200 x 200 x 180 mm3, nozzle diameter of 0.1-0.4 mm, and printing speed of 10-100 mm/s (see Figure 3). For the realization of the model, the chosen material was ABS (Acrylonitrile Butadiene Styrene) in the form of a filament (diameter 1.75 mm, manufacturer Wanhao). ABS is an amorphous polymer with the following features: excellent mechanical properties, resistance to elevated temperatures, and resistance to shocks. On the Wanhao printer, the prescribed distance between the nozzle and the plate is 0.1 mm. This is the minimum thickness of a single printed layer in the xy plane. The diameter of the melted thread is 0.1 mm, which is very thin, allowing for a very dense construction of the print along the z axis. All these parameters are essential for the quality of the print. 3D printing technology enabled the custom design and fabrication of a mechanical system intended to be placed in an irradiation room, in order to hold the component whose electric characteristics are being examined. The irradiation room may contain one or more sources of ionizing radiation. Each irradiation room may have a different way of mounting the component under test. Since it is necessary to study a specific electronic component with different ionizing radiation sources (gamma and X-ray), at different dose rates, and located in different irradiation rooms, designing a custom mounting system for each irradiation room is necessary. The cost of making a mechanical mounting system using 3D printing technology is significantly lower compared to other production methods. Thus, the creation of a system for each irradiation room individually becomes more economical. Creating such a system for each irradiation room allows much easier and more accurate positioning of the component, which reduces the error in calculating the dose that the component receives during irradiation. Each mechanical system should allow the installation of printed circuit boards of different sizes, on which the tested electronic components are located. Also, the material from which the mounting system is made must not affect the component during the experiment. Materials used in 3D printing have a negligible effect on the reflection or scattering of high-energy photons because they do not contain atoms with heavy nuclei.",
publisher = "SIRAMM project - H2020-WIDESPREAD-2018-03 Project No. 857124, Horizon 2020",
journal = "Program and the Book of Abstracts - International Conference East Europe Conference on Additively Manufactured Materials – EECAM21, 2nd-4th September 2021, Belgrade, Serbia",
title = "The use of 3D printing for studying the influence of ionizing radiation on electronic components",
url = "https://hdl.handle.net/21.15107/rcub_machinery_5425"
}

Ilić, S., Vorkapić, M., Ivanov, T.,& Svorcan, J.. (2021). The use of 3D printing for studying the influence of ionizing radiation on electronic components. in Program and the Book of Abstracts - International Conference East Europe Conference on Additively Manufactured Materials – EECAM21, 2nd-4th September 2021, Belgrade, Serbia
SIRAMM project - H2020-WIDESPREAD-2018-03 Project No. 857124, Horizon 2020..
https://hdl.handle.net/21.15107/rcub_machinery_5425

Ilić S, Vorkapić M, Ivanov T, Svorcan J. The use of 3D printing for studying the influence of ionizing radiation on electronic components. in Program and the Book of Abstracts - International Conference East Europe Conference on Additively Manufactured Materials – EECAM21, 2nd-4th September 2021, Belgrade, Serbia. 2021;.
https://hdl.handle.net/21.15107/rcub_machinery_5425 .

Ilić, Stefan, Vorkapić, Miloš, Ivanov, Toni, Svorcan, Jelena, "The use of 3D printing for studying the influence of ionizing radiation on electronic components" in Program and the Book of Abstracts - International Conference East Europe Conference on Additively Manufactured Materials – EECAM21, 2nd-4th September 2021, Belgrade, Serbia (2021),
https://hdl.handle.net/21.15107/rcub_machinery_5425 .

TY  - CONF
AU  - Svorcan, Jelena
AU  - Hasan, Mohammad Sakib
AU  - Kovačević, A.
AU  - Ivanov, Toni
PY  - 2021
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/3648
AB  - HALE (high-altitude long-endurance) aircrafts, relatively novel, unmanned air vehicles specifically designed to fly at high altitudes for extended periods of time, require state-of-theart technological solutions in order to operate properly. Likewise, their propulsion system (that usually implies propelled flight) should be optimized with respect to both aerodynamic and structural aspects. This paper presents a conceptual design of a HALE propeller realized through multi-objective and multidisciplinary optimization procedure. A tightly coupled aerostructural two-criteria optimization by genetic algorithm is performed to define a laminated blade of best aerodynamic performance (expressed through maximal aerodynamic efficiency) and minimal mass that is both statically and dynamically reliable when subjected to conjugate aerodynamic, inertial and gravitational loads while cruising at the altitude of 20 km. Numerous geometric, aerodynamic and structural constraints are introduced, and different materials and laminate lay-up sequences are considered. Obtained Pareto sets (of optimal solutions) and Pareto fronts are presented and analyzed in detail. In the end, some recommendations and further research possibilities are given.
PB  - American Institute of Aeronautics and Astronautics Inc, AIAA
C3  - AIAA Propulsion and Energy Forum, 2021
T1  - Design of HALE Propeller through Multi-objective Optimization
DO  - 10.2514/6.2021-3730
ER  - 

@conference{
author = "Svorcan, Jelena and Hasan, Mohammad Sakib and Kovačević, A. and Ivanov, Toni",
year = "2021",
abstract = "HALE (high-altitude long-endurance) aircrafts, relatively novel, unmanned air vehicles specifically designed to fly at high altitudes for extended periods of time, require state-of-theart technological solutions in order to operate properly. Likewise, their propulsion system (that usually implies propelled flight) should be optimized with respect to both aerodynamic and structural aspects. This paper presents a conceptual design of a HALE propeller realized through multi-objective and multidisciplinary optimization procedure. A tightly coupled aerostructural two-criteria optimization by genetic algorithm is performed to define a laminated blade of best aerodynamic performance (expressed through maximal aerodynamic efficiency) and minimal mass that is both statically and dynamically reliable when subjected to conjugate aerodynamic, inertial and gravitational loads while cruising at the altitude of 20 km. Numerous geometric, aerodynamic and structural constraints are introduced, and different materials and laminate lay-up sequences are considered. Obtained Pareto sets (of optimal solutions) and Pareto fronts are presented and analyzed in detail. In the end, some recommendations and further research possibilities are given.",
publisher = "American Institute of Aeronautics and Astronautics Inc, AIAA",
journal = "AIAA Propulsion and Energy Forum, 2021",
title = "Design of HALE Propeller through Multi-objective Optimization",
doi = "10.2514/6.2021-3730"
}

Svorcan, J., Hasan, M. S., Kovačević, A.,& Ivanov, T.. (2021). Design of HALE Propeller through Multi-objective Optimization. in AIAA Propulsion and Energy Forum, 2021
American Institute of Aeronautics and Astronautics Inc, AIAA..
https://doi.org/10.2514/6.2021-3730

Svorcan J, Hasan MS, Kovačević A, Ivanov T. Design of HALE Propeller through Multi-objective Optimization. in AIAA Propulsion and Energy Forum, 2021. 2021;.
doi:10.2514/6.2021-3730 .

Svorcan, Jelena, Hasan, Mohammad Sakib, Kovačević, A., Ivanov, Toni, "Design of HALE Propeller through Multi-objective Optimization" in AIAA Propulsion and Energy Forum, 2021 (2021),
https://doi.org/10.2514/6.2021-3730 . .

TY  - CONF
AU  - Svorcan, Jelena
AU  - Peković, Ognjen
AU  - Ivanov, Toni
AU  - Baltić, Marija
AU  - Simonović, Aleksandar
PY  - 2021
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/4257
AB  - Open systems, that include both water and air fractions, and whose behavior is highly dominated by the interaction between these two phases are particularly important and interesting for many industrial applications (e.g. energy production, maritime and aerial transport, food resources). Since the physics governing these flows is highly complex and incorporates many unexplained phenomena, novel physical models, as well as measurement techniques, are still being developed and tested in accordance with the particular problem that is being analyzed. Although real engineering cases often involve wind-wave interactions, stochastic waves, geometrically irregular boundaries, turbulence, wave interference etc, the main interests of this work are the effects of oncoming wind speed as well as adopted turbulence model on the initially still water surface and consequential wave formation. These aspects have to be considered in the development of amphibian aircrafts or ekranoplans since they take off from water surfaces while later aircrafts operate in the vicinity of water during the entire flight. Wave formation is also extremely important
for off-shore wind turbines. For the sake of simplicity, the conducted numerical simulations are planar. The fluids (air and water) are considered incompressible, while the flow is unsteady and turbulent. The unsteady Reynolds averaged Navier-Stokes equations are closed by one of the two two-equation turbulence models based on the Boussinesq hypothesis: realizable k-ε or k-ω SST model. The investigated wind speeds are 30 m/s, 50 m/s and 80 m/s, while the results are presented in the shape of water volume fractions. As expected, the increase in wind speed induces higher amplitude waves, when the effects of turbulence models also become important.
PB  - International Association for Hydro-Environment Engineering and Research (IAHR)
C3  - Abstract Book - 6th IAHR Europe Congress
T1  - The effects of wind speed and turbulence model on wave formation in open systems
EP  - 860
SP  - 859
UR  - https://hdl.handle.net/21.15107/rcub_machinery_4257
ER  - 

@conference{
author = "Svorcan, Jelena and Peković, Ognjen and Ivanov, Toni and Baltić, Marija and Simonović, Aleksandar",
year = "2021",
abstract = "Open systems, that include both water and air fractions, and whose behavior is highly dominated by the interaction between these two phases are particularly important and interesting for many industrial applications (e.g. energy production, maritime and aerial transport, food resources). Since the physics governing these flows is highly complex and incorporates many unexplained phenomena, novel physical models, as well as measurement techniques, are still being developed and tested in accordance with the particular problem that is being analyzed. Although real engineering cases often involve wind-wave interactions, stochastic waves, geometrically irregular boundaries, turbulence, wave interference etc, the main interests of this work are the effects of oncoming wind speed as well as adopted turbulence model on the initially still water surface and consequential wave formation. These aspects have to be considered in the development of amphibian aircrafts or ekranoplans since they take off from water surfaces while later aircrafts operate in the vicinity of water during the entire flight. Wave formation is also extremely important
for off-shore wind turbines. For the sake of simplicity, the conducted numerical simulations are planar. The fluids (air and water) are considered incompressible, while the flow is unsteady and turbulent. The unsteady Reynolds averaged Navier-Stokes equations are closed by one of the two two-equation turbulence models based on the Boussinesq hypothesis: realizable k-ε or k-ω SST model. The investigated wind speeds are 30 m/s, 50 m/s and 80 m/s, while the results are presented in the shape of water volume fractions. As expected, the increase in wind speed induces higher amplitude waves, when the effects of turbulence models also become important.",
publisher = "International Association for Hydro-Environment Engineering and Research (IAHR)",
journal = "Abstract Book - 6th IAHR Europe Congress",
title = "The effects of wind speed and turbulence model on wave formation in open systems",
pages = "860-859",
url = "https://hdl.handle.net/21.15107/rcub_machinery_4257"
}

Svorcan, J., Peković, O., Ivanov, T., Baltić, M.,& Simonović, A.. (2021). The effects of wind speed and turbulence model on wave formation in open systems. in Abstract Book - 6th IAHR Europe Congress
International Association for Hydro-Environment Engineering and Research (IAHR)., 859-860.
https://hdl.handle.net/21.15107/rcub_machinery_4257

Svorcan J, Peković O, Ivanov T, Baltić M, Simonović A. The effects of wind speed and turbulence model on wave formation in open systems. in Abstract Book - 6th IAHR Europe Congress. 2021;:859-860.
https://hdl.handle.net/21.15107/rcub_machinery_4257 .

Svorcan, Jelena, Peković, Ognjen, Ivanov, Toni, Baltić, Marija, Simonović, Aleksandar, "The effects of wind speed and turbulence model on wave formation in open systems" in Abstract Book - 6th IAHR Europe Congress (2021):859-860,
https://hdl.handle.net/21.15107/rcub_machinery_4257 .

TY  - CONF
AU  - Kovačević, Aleksandar
AU  - Svorcan, Jelena
AU  - Ivanov, Toni
PY  - 2021
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/4259
AB  - The application of composite materials in the aerospace industry has begun since the middle of the 20th century. Their use in various elements of aircraft constructions has extended over time. Primary load carrying elements of some aircraft constructions are made of composite materials due to their excellent mechanical properties as well as the good strength-to-weight ratio. Propellers and fan blades of jet engines are increasingly made of high-quality composite materials. Besides the mechanical properties of the material, production technology has a great impact on composite structure quality.
The production process of two-bladed composite propeller is presented in this paper. Manufacturing of composite propeller for multirotor UAV application with suitable technology and relatively cheap materials is the main motive of this work. According to this motive, both (upper and lower) shells of the propeller are made of balanced plain weave glass fiber with epoxy matrix. The vacuum infusion process is used for shell manufacturing. After the polymerization process of shells (24h, 25°C), unidirectional carbon fabric reinforcements in the root zone and expanding polyurethane core are added during the bonding process. Then, the bonded propeller was cured 4h at 70°C.
The high production process quality of the two-bladed propeller with the previously described technology is partly confirmed in this paper. Namely, the checking of propeller geometry and comparison with the CAD model was performed. Results of that comparison showed that a high degree of agreement between produced and CAD model was obtained. Comparison of static test and numerical structural analysis could be subjects of future work. That would provide the final validation of manufacturing technology quality which is described in this paper.
PB  - Belgrade : Innovation Center of Faculty of Mechanical Engineering
C3  - The Book of Abstracts - International Conference of Experimental and Numerical Investigations and New Technologies CNN TECH
T1  - Production process of composite propeller for multirotor UAV
SP  - 65
UR  - https://hdl.handle.net/21.15107/rcub_machinery_4259
ER  - 

@conference{
author = "Kovačević, Aleksandar and Svorcan, Jelena and Ivanov, Toni",
year = "2021",
abstract = "The application of composite materials in the aerospace industry has begun since the middle of the 20th century. Their use in various elements of aircraft constructions has extended over time. Primary load carrying elements of some aircraft constructions are made of composite materials due to their excellent mechanical properties as well as the good strength-to-weight ratio. Propellers and fan blades of jet engines are increasingly made of high-quality composite materials. Besides the mechanical properties of the material, production technology has a great impact on composite structure quality.
The production process of two-bladed composite propeller is presented in this paper. Manufacturing of composite propeller for multirotor UAV application with suitable technology and relatively cheap materials is the main motive of this work. According to this motive, both (upper and lower) shells of the propeller are made of balanced plain weave glass fiber with epoxy matrix. The vacuum infusion process is used for shell manufacturing. After the polymerization process of shells (24h, 25°C), unidirectional carbon fabric reinforcements in the root zone and expanding polyurethane core are added during the bonding process. Then, the bonded propeller was cured 4h at 70°C.
The high production process quality of the two-bladed propeller with the previously described technology is partly confirmed in this paper. Namely, the checking of propeller geometry and comparison with the CAD model was performed. Results of that comparison showed that a high degree of agreement between produced and CAD model was obtained. Comparison of static test and numerical structural analysis could be subjects of future work. That would provide the final validation of manufacturing technology quality which is described in this paper.",
publisher = "Belgrade : Innovation Center of Faculty of Mechanical Engineering",
journal = "The Book of Abstracts - International Conference of Experimental and Numerical Investigations and New Technologies CNN TECH",
title = "Production process of composite propeller for multirotor UAV",
pages = "65",
url = "https://hdl.handle.net/21.15107/rcub_machinery_4259"
}

Kovačević, A., Svorcan, J.,& Ivanov, T.. (2021). Production process of composite propeller for multirotor UAV. in The Book of Abstracts - International Conference of Experimental and Numerical Investigations and New Technologies CNN TECH
Belgrade : Innovation Center of Faculty of Mechanical Engineering., 65.
https://hdl.handle.net/21.15107/rcub_machinery_4259

Kovačević A, Svorcan J, Ivanov T. Production process of composite propeller for multirotor UAV. in The Book of Abstracts - International Conference of Experimental and Numerical Investigations and New Technologies CNN TECH. 2021;:65.
https://hdl.handle.net/21.15107/rcub_machinery_4259 .

Kovačević, Aleksandar, Svorcan, Jelena, Ivanov, Toni, "Production process of composite propeller for multirotor UAV" in The Book of Abstracts - International Conference of Experimental and Numerical Investigations and New Technologies CNN TECH (2021):65,
https://hdl.handle.net/21.15107/rcub_machinery_4259 .

TY  - CONF
AU  - Svorcan, Jelena
AU  - Kovačević, Aleksandar
AU  - Ivanov, Toni
AU  - Jovanović, Miroslav
PY  - 2021
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/4215
AB  - The main topic that is investigated in the present research is the turbulent flow around small-scale rotor blades in hovering flight condition. Small-scale rotorcraft imply somewhat specific operating conditions such as low Reynolds numbers, considerable viscous effects, degraded aerodynamic performances, flow separation, rotational flow, cyclic load cases, etc. It is therefore very important to perform as accurate as possible flow simulations that will enable obtaining practical aerodynamic data that can be used in subsequent structural and flight mechanics analyses. This paper provides the description of steps that are to be conducted when simulating hovering flow. Here, a quasi-steady approach, that combines RANS equations closed by k-ω SST turbulence model with the multiple reference frames, is adopted. Both quantitative and qualitative results are presented. Furthermore, the numerical model is validated against the obtained experimental data. The correspondence between the two sets of results can be considered satisfactory (relative differences for thrust coefficient amount to 15%, while they are even lower for the torque coefficient), while the effects of Reynolds number are not significant when throttle is above 40%.
PB  - Belgrade : Serbian Society of Mechanics
C3  - Proceedings / The 8th International Congress of Serbian Society of Mechanics, Kragujevac, Serbia, June 28-30, 2021
T1  - Numerical investigation of Reynolds number effects on rotor aerodynamic performances in hover
EP  - 534
SP  - 527
UR  - https://hdl.handle.net/21.15107/rcub_machinery_4215
ER  - 

@conference{
author = "Svorcan, Jelena and Kovačević, Aleksandar and Ivanov, Toni and Jovanović, Miroslav",
year = "2021",
abstract = "The main topic that is investigated in the present research is the turbulent flow around small-scale rotor blades in hovering flight condition. Small-scale rotorcraft imply somewhat specific operating conditions such as low Reynolds numbers, considerable viscous effects, degraded aerodynamic performances, flow separation, rotational flow, cyclic load cases, etc. It is therefore very important to perform as accurate as possible flow simulations that will enable obtaining practical aerodynamic data that can be used in subsequent structural and flight mechanics analyses. This paper provides the description of steps that are to be conducted when simulating hovering flow. Here, a quasi-steady approach, that combines RANS equations closed by k-ω SST turbulence model with the multiple reference frames, is adopted. Both quantitative and qualitative results are presented. Furthermore, the numerical model is validated against the obtained experimental data. The correspondence between the two sets of results can be considered satisfactory (relative differences for thrust coefficient amount to 15%, while they are even lower for the torque coefficient), while the effects of Reynolds number are not significant when throttle is above 40%.",
publisher = "Belgrade : Serbian Society of Mechanics",
journal = "Proceedings / The 8th International Congress of Serbian Society of Mechanics, Kragujevac, Serbia, June 28-30, 2021",
title = "Numerical investigation of Reynolds number effects on rotor aerodynamic performances in hover",
pages = "534-527",
url = "https://hdl.handle.net/21.15107/rcub_machinery_4215"
}

Svorcan, J., Kovačević, A., Ivanov, T.,& Jovanović, M.. (2021). Numerical investigation of Reynolds number effects on rotor aerodynamic performances in hover. in Proceedings / The 8th International Congress of Serbian Society of Mechanics, Kragujevac, Serbia, June 28-30, 2021
Belgrade : Serbian Society of Mechanics., 527-534.
https://hdl.handle.net/21.15107/rcub_machinery_4215

Svorcan J, Kovačević A, Ivanov T, Jovanović M. Numerical investigation of Reynolds number effects on rotor aerodynamic performances in hover. in Proceedings / The 8th International Congress of Serbian Society of Mechanics, Kragujevac, Serbia, June 28-30, 2021. 2021;:527-534.
https://hdl.handle.net/21.15107/rcub_machinery_4215 .

Svorcan, Jelena, Kovačević, Aleksandar, Ivanov, Toni, Jovanović, Miroslav, "Numerical investigation of Reynolds number effects on rotor aerodynamic performances in hover" in Proceedings / The 8th International Congress of Serbian Society of Mechanics, Kragujevac, Serbia, June 28-30, 2021 (2021):527-534,
https://hdl.handle.net/21.15107/rcub_machinery_4215 .

TY  - CHAP
AU  - Davidović, Nikola
AU  - Miloš, Predrag
AU  - Kolarević, Nenad
AU  - Ivanov, Toni
AU  - Jojić, Branislav
PY  - 2021
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/3675
AB  - Subsonic ramjets, due to its simplicity, nowadays could be very attractive for expendable unmanned applications. However, due to very low efficiency at low Mach numbers, practically there isn’t any important application at subsonic speed. In 50’s subsonic ramjet was used for tip jet applications. Later in 70’s there was a study of Fan Augmented Ramjet (FARJ) where a fan was in-tended to be powered by a piston engine, both in subsonic and supersonic regimes. Almost at the same time it was analyzed ejector augmented subsonic ramjet. Both of these studies did not find real application of such engines. Finally, there was an attempt for the use of an Electric Ducted Fan, used in RC models, with a combustor but exit fan pressure was almost at atmospheric pressure which results in very low efficiency. This paper presents a study of propulsion system which consists of a pitot intake, electrically powered compressor/fan, combustor and nozzle (Electrically Fan Augmented Ram Jet, EFARJ). The electric motor connection to the compressor/fan is direct, without gearbox, which implies usage of a high-speed brushless motor. Such propulsion system is compared to pure ramjet and finally it is compared to performances of small expendable turbojet. Comparison is made regarding costs, weight and thrust/consumption. The study shows that the proposed propulsion system could be competitive for expendable, low speed and short duration applications.
PB  - Springer
T2  - Lecture Notes in Networks and Systems
T1  - Study of innovative subsonic ramjet
EP  - 431
SP  - 413
VL  - 153
DO  - 10.1007/978-3-030-58362-0_24
ER  - 

@inbook{
author = "Davidović, Nikola and Miloš, Predrag and Kolarević, Nenad and Ivanov, Toni and Jojić, Branislav",
year = "2021",
abstract = "Subsonic ramjets, due to its simplicity, nowadays could be very attractive for expendable unmanned applications. However, due to very low efficiency at low Mach numbers, practically there isn’t any important application at subsonic speed. In 50’s subsonic ramjet was used for tip jet applications. Later in 70’s there was a study of Fan Augmented Ramjet (FARJ) where a fan was in-tended to be powered by a piston engine, both in subsonic and supersonic regimes. Almost at the same time it was analyzed ejector augmented subsonic ramjet. Both of these studies did not find real application of such engines. Finally, there was an attempt for the use of an Electric Ducted Fan, used in RC models, with a combustor but exit fan pressure was almost at atmospheric pressure which results in very low efficiency. This paper presents a study of propulsion system which consists of a pitot intake, electrically powered compressor/fan, combustor and nozzle (Electrically Fan Augmented Ram Jet, EFARJ). The electric motor connection to the compressor/fan is direct, without gearbox, which implies usage of a high-speed brushless motor. Such propulsion system is compared to pure ramjet and finally it is compared to performances of small expendable turbojet. Comparison is made regarding costs, weight and thrust/consumption. The study shows that the proposed propulsion system could be competitive for expendable, low speed and short duration applications.",
publisher = "Springer",
journal = "Lecture Notes in Networks and Systems",
booktitle = "Study of innovative subsonic ramjet",
pages = "431-413",
volume = "153",
doi = "10.1007/978-3-030-58362-0_24"
}

Davidović, N., Miloš, P., Kolarević, N., Ivanov, T.,& Jojić, B.. (2021). Study of innovative subsonic ramjet. in Lecture Notes in Networks and Systems
Springer., 153, 413-431.
https://doi.org/10.1007/978-3-030-58362-0_24

Davidović N, Miloš P, Kolarević N, Ivanov T, Jojić B. Study of innovative subsonic ramjet. in Lecture Notes in Networks and Systems. 2021;153:413-431.
doi:10.1007/978-3-030-58362-0_24 .

Davidović, Nikola, Miloš, Predrag, Kolarević, Nenad, Ivanov, Toni, Jojić, Branislav, "Study of innovative subsonic ramjet" in Lecture Notes in Networks and Systems, 153 (2021):413-431,
https://doi.org/10.1007/978-3-030-58362-0_24 . .

TY  - JOUR
AU  - Kovacević, Aleksandar
AU  - Svorcan, Jelena
AU  - Hasan, Mohammad Sakib
AU  - Ivanov, Toni
AU  - Jovanović, Miroslav
PY  - 2021
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/3503
AB  - Purpose Modern unmanned air vehicles (UAVs) are usually equipped with rotors connected to electric motors that enable them to hover and fly in all directions. The purpose of the paper is to design optimal composite rotor blades for such small UAVs and investigate their aerodynamic performances both computationally and experimentally. Design/methodology/approach Artificial intelligence method (genetic algorithm) is used to optimize the blade airfoil described by six input parameters. Furthermore, different computational methods, e.g. vortex methods and computational fluid dynamics, blade element momentum theory and finite element method, are used to predict the aerodynamic performances of the optimized airfoil and complete rotor as well the structural behaviour of the blade, respectively. Finally, composite blade is manufactured and the rotor performance is also determined experimentally by thrust and torque measurements. Findings Complete process of blade design (including geometry definition and optimization, estimation of aerodynamic performances, structural analysis and blade manufacturing) is conducted and explained in detail. The correspondence between computed and measured thrust and torque curves of the optimal rotor is satisfactory (differences mostly remain below 15%), which validates and justifies the used design approach formulated specifically for low-cost, small-scale propeller blades. Furthermore, the proposed techniques can easily be applied to any kind of rotating lifting surfaces including helicopter or wind turbine blades. Originality/value Blade design methodology is simplified, shortened and made more flexible thus enabling the fast and economic production of propeller blades optimized for specific working conditions.
PB  - Emerald Group Publishing Ltd, Bingley
T2  - Aircraft Engineering and Aerospace Technology
T1  - Optimal propeller blade design, computation, manufacturing and experimental testing
EP  - 1332
IS  - 8
SP  - 1323
VL  - 93
DO  - 10.1108/AEAT-03-2021-0091
ER  - 

@article{
author = "Kovacević, Aleksandar and Svorcan, Jelena and Hasan, Mohammad Sakib and Ivanov, Toni and Jovanović, Miroslav",
year = "2021",
abstract = "Purpose Modern unmanned air vehicles (UAVs) are usually equipped with rotors connected to electric motors that enable them to hover and fly in all directions. The purpose of the paper is to design optimal composite rotor blades for such small UAVs and investigate their aerodynamic performances both computationally and experimentally. Design/methodology/approach Artificial intelligence method (genetic algorithm) is used to optimize the blade airfoil described by six input parameters. Furthermore, different computational methods, e.g. vortex methods and computational fluid dynamics, blade element momentum theory and finite element method, are used to predict the aerodynamic performances of the optimized airfoil and complete rotor as well the structural behaviour of the blade, respectively. Finally, composite blade is manufactured and the rotor performance is also determined experimentally by thrust and torque measurements. Findings Complete process of blade design (including geometry definition and optimization, estimation of aerodynamic performances, structural analysis and blade manufacturing) is conducted and explained in detail. The correspondence between computed and measured thrust and torque curves of the optimal rotor is satisfactory (differences mostly remain below 15%), which validates and justifies the used design approach formulated specifically for low-cost, small-scale propeller blades. Furthermore, the proposed techniques can easily be applied to any kind of rotating lifting surfaces including helicopter or wind turbine blades. Originality/value Blade design methodology is simplified, shortened and made more flexible thus enabling the fast and economic production of propeller blades optimized for specific working conditions.",
publisher = "Emerald Group Publishing Ltd, Bingley",
journal = "Aircraft Engineering and Aerospace Technology",
title = "Optimal propeller blade design, computation, manufacturing and experimental testing",
pages = "1332-1323",
number = "8",
volume = "93",
doi = "10.1108/AEAT-03-2021-0091"
}

Kovacević, A., Svorcan, J., Hasan, M. S., Ivanov, T.,& Jovanović, M.. (2021). Optimal propeller blade design, computation, manufacturing and experimental testing. in Aircraft Engineering and Aerospace Technology
Emerald Group Publishing Ltd, Bingley., 93(8), 1323-1332.
https://doi.org/10.1108/AEAT-03-2021-0091

Kovacević A, Svorcan J, Hasan MS, Ivanov T, Jovanović M. Optimal propeller blade design, computation, manufacturing and experimental testing. in Aircraft Engineering and Aerospace Technology. 2021;93(8):1323-1332.
doi:10.1108/AEAT-03-2021-0091 .

Kovacević, Aleksandar, Svorcan, Jelena, Hasan, Mohammad Sakib, Ivanov, Toni, Jovanović, Miroslav, "Optimal propeller blade design, computation, manufacturing and experimental testing" in Aircraft Engineering and Aerospace Technology, 93, no. 8 (2021):1323-1332,
https://doi.org/10.1108/AEAT-03-2021-0091 . .