Mladenović, I., Vorkapić, M., Pergal, M., Ivanov, T., Baltić, M., Obradov, M.,& Vasiljević-Radović, D.. (2023). Primena metodologije odzivnih površina (RSM) u cilju optimizacije eksperimentalnih parametara 3D-štampe i postizanja boljih mehaničkih performansi štampanih elemenata. 
University of Belgrade - Institute of Chemistry, Technology and Metallurgy..
https://hdl.handle.net/21.15107/rcub_cer_6931

Mladenović I, Vorkapić M, Pergal M, Ivanov T, Baltić M, Obradov M, Vasiljević-Radović D. Primena metodologije odzivnih površina (RSM) u cilju optimizacije eksperimentalnih parametara 3D-štampe i postizanja boljih mehaničkih performansi štampanih elemenata. 2023;.
https://hdl.handle.net/21.15107/rcub_cer_6931 .

Mladenović, Ivana, Vorkapić, Miloš, Pergal, Marija, Ivanov, Toni, Baltić, Marija, Obradov, Marko, Vasiljević-Radović, Dana, "Primena metodologije odzivnih površina (RSM) u cilju optimizacije eksperimentalnih parametara 3D-štampe i postizanja boljih mehaničkih performansi štampanih elemenata" (2023),
https://hdl.handle.net/21.15107/rcub_cer_6931 .

TY  - CONF
AU  - Baltić, Marija
AU  - Vorkapić, Miloš
AU  - Simonović, Aleksandar
AU  - Ivanov, Toni
AU  - Tanović, Dragoljub
PY  - 2023
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/6364
AB  - The utilization of biomaterials with mycelia as a stabilizing agent is gaining popularity in the fields of construction and architecture, offering a sustainable solution aligned with the principles of the circular economy. Interdisciplinary research involving biologists, technologists, and engineers is necessary to advance this field where science, art and design converge. These biomaterials contribute to energy reduction and cost-effectiveness, utilizing readily available and recyclable raw materials. Mycelium-based blocks have shown to be more affordable than traditional cement and gypsum blocks while significantly reducing CO2 emissions. The mycelium network, formed by hyphae, can be cultivated into a solid material, providing a defined technological process. This study focusses on performing 3-point bending testing on moulded specimens using additive technology PLA material, following the ASTM D1037 standard. After the growth of mycelium and the formation of the test tube-shaped structure, the samples are dried and characterized to enchance their mechanical characteristics.
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  - Assembling biomaterial specimens in a mould made of thermoplastic polymer: 3-point bending test
SP  - 28
EP  - 28
UR  - https://hdl.handle.net/21.15107/rcub_cer_6364
ER  - 

@conference{
author = "Baltić, Marija and Vorkapić, Miloš and Simonović, Aleksandar and Ivanov, Toni and Tanović, Dragoljub",
year = "2023",
abstract = "The utilization of biomaterials with mycelia as a stabilizing agent is gaining popularity in the fields of construction and architecture, offering a sustainable solution aligned with the principles of the circular economy. Interdisciplinary research involving biologists, technologists, and engineers is necessary to advance this field where science, art and design converge. These biomaterials contribute to energy reduction and cost-effectiveness, utilizing readily available and recyclable raw materials. Mycelium-based blocks have shown to be more affordable than traditional cement and gypsum blocks while significantly reducing CO2 emissions. The mycelium network, formed by hyphae, can be cultivated into a solid material, providing a defined technological process. This study focusses on performing 3-point bending testing on moulded specimens using additive technology PLA material, following the ASTM D1037 standard. After the growth of mycelium and the formation of the test tube-shaped structure, the samples are dried and characterized to enchance their mechanical characteristics.",
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 = "Assembling biomaterial specimens in a mould made of thermoplastic polymer: 3-point bending test",
pages = "28-28",
url = "https://hdl.handle.net/21.15107/rcub_cer_6364"
}

Baltić, M., Vorkapić, M., Simonović, A., Ivanov, T.,& Tanović, D.. (2023). Assembling biomaterial specimens in a mould made of thermoplastic polymer: 3-point bending test. 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., 28-28.
https://hdl.handle.net/21.15107/rcub_cer_6364

Baltić M, Vorkapić M, Simonović A, Ivanov T, Tanović D. Assembling biomaterial specimens in a mould made of thermoplastic polymer: 3-point bending test. 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. 2023;:28-28.
https://hdl.handle.net/21.15107/rcub_cer_6364 .

Baltić, Marija, Vorkapić, Miloš, Simonović, Aleksandar, Ivanov, Toni, Tanović, Dragoljub, "Assembling biomaterial specimens in a mould made of thermoplastic polymer: 3-point bending test" 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 (2023):28-28,
https://hdl.handle.net/21.15107/rcub_cer_6364 .

Vorkapić, M., Mladenović, I., Popović, B., Ivanov, T., Baltić, M., Simonović, A.,& Ćoćkalo, D.. (2023). Primena aditivnih tehnologija u cirkularnoj proizvodnji za realizaciju prototipa kućišta elektronike od biorazgradivih materijala. 
Универзитет у Београду - Институт за хемију технологију и металургију – Институт од националног значаја за Републику Србију..
https://hdl.handle.net/21.15107/rcub_cer_6655

Vorkapić M, Mladenović I, Popović B, Ivanov T, Baltić M, Simonović A, Ćoćkalo D. Primena aditivnih tehnologija u cirkularnoj proizvodnji za realizaciju prototipa kućišta elektronike od biorazgradivih materijala. 2023;.
https://hdl.handle.net/21.15107/rcub_cer_6655 .

Vorkapić, Miloš, Mladenović, Ivana, Popović, Bogdan, Ivanov, Toni, Baltić, Marija, Simonović, Aleksandar, Ćoćkalo, Dragan, "Primena aditivnih tehnologija u cirkularnoj proizvodnji za realizaciju prototipa kućišta elektronike od biorazgradivih materijala" (2023),
https://hdl.handle.net/21.15107/rcub_cer_6655 .

TY  - JOUR
AU  - Vorkapić, Miloš
AU  - Živojinović, Danijela
AU  - Kreculj, Dragan
AU  - Ivanov, Toni
AU  - Baltić, Marija
AU  - Simonović, Aleksandar
PY  - 2023
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5887
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 funda–
mental 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.
AB  - Реверзбилни инжењеринг (РЕ) има за циљ да
пројектује нови заменски део на основу постојећег
дела. Поступак се спроводи кроз низ корака: израда
дигиталног 3Д модела, побољшање и оптимизација
параметара модела и реализација производа
применом адитивних технологија. Циљ је да се
изврши квалитетна репродукција физичког дела са
најбољим могућим механичким карактеристикама у
циљу проналажења оптималних решења у погледу
облика и димензија дела. У овом раду је извршен
преглед и имплементација основних методологија
РЕ на примеру оштећеног заштитног поклопца
непознате геометрије и материјала од суштинског
значаја за функционисање уређаја који се не
производи, а при томе нема расположиве техничке
документације и резервних делова. У реализацији
репродукованог дела коришћена је метода оптичког
скенирања, 3D CAD, FEA и адитивна производња.
Показало се да се коришћењем РE може значајно
продужити животни циклус уређаја уз минималне
трошкове.
PB  - Beograd : Mašinski fakultet
T2  - FME Transactions
T1  - Application of Additive Technology and Reverse Engineering in the Realization of Damaged Obsolete Parts
T1  - Примена адитивне технологије и реверзибилног инжењерства у реализацији оштећених застарелих делова
VL  - 51
IS  - 1
SP  - 31
EP  - 38
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 funda–
mental 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., Реверзбилни инжењеринг (РЕ) има за циљ да
пројектује нови заменски део на основу постојећег
дела. Поступак се спроводи кроз низ корака: израда
дигиталног 3Д модела, побољшање и оптимизација
параметара модела и реализација производа
применом адитивних технологија. Циљ је да се
изврши квалитетна репродукција физичког дела са
најбољим могућим механичким карактеристикама у
циљу проналажења оптималних решења у погледу
облика и димензија дела. У овом раду је извршен
преглед и имплементација основних методологија
РЕ на примеру оштећеног заштитног поклопца
непознате геометрије и материјала од суштинског
значаја за функционисање уређаја који се не
производи, а при томе нема расположиве техничке
документације и резервних делова. У реализацији
репродукованог дела коришћена је метода оптичког
скенирања, 3D CAD, FEA и адитивна производња.
Показало се да се коришћењем РE може значајно
продужити животни циклус уређаја уз минималне
трошкове.",
publisher = "Beograd : Mašinski fakultet",
journal = "FME Transactions",
title = "Application of Additive Technology and Reverse Engineering in the Realization of Damaged Obsolete Parts, Примена адитивне технологије и реверзибилног инжењерства у реализацији оштећених застарелих делова",
volume = "51",
number = "1",
pages = "31-38",
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
Beograd : Mašinski fakultet., 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  - CHAP
AU  - Vorkapić, Miloš
AU  - Ivanov, Toni
PY  - 2023
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5759
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
SP  - 44
EP  - 78
DO  - 10.1007/978-3-031-19499-3_3
ER  - 

@inbook{
author = "Vorkapić, Miloš and Ivanov, Toni",
year = "2023",
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",
pages = "44-78",
doi = "10.1007/978-3-031-19499-3_3"
}

Vorkapić, M.,& Ivanov, T.. (2023). 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, 44-78.
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. 2023;564:44-78.
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 (2023):44-78,
https://doi.org/10.1007/978-3-031-19499-3_3 . .

TY  - JOUR
AU  - Vorkapić, Miloš
AU  - Mladenović, Ivana
AU  - Ivanov, Toni
AU  - Kovačević, Aleksandar
AU  - Mohammad Sakib, Hasan
AU  - Aleksandar, Simonović
AU  - Trajković, Isaak
PY  - 2022
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5363
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
VL  - 14
IS  - 8
SP  - 1
EP  - 15
DO  - 10.1177/16878132221120737
ER  - 

@article{
author = "Vorkapić, Miloš and Mladenović, Ivana and Ivanov, Toni and Kovačević, Aleksandar and Mohammad Sakib, Hasan and Aleksandar, Simonović 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",
volume = "14",
number = "8",
pages = "1-15",
doi = "10.1177/16878132221120737"
}

Vorkapić, M., Mladenović, I., Ivanov, T., Kovačević, A., Mohammad Sakib, H., Aleksandar, S.,& 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, Aleksandar S, 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, Aleksandar, Simonović, 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://cer.ihtm.bg.ac.rs/handle/123456789/5379
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, Serbia : Balkan Scientific Centre
T2  - Tribology and Materials
T1  - Optimisation of tensile stress of poly(lactic acid) 3D printed materials using response surface methodology
VL  - 1
IS  - 2
SP  - 70
EP  - 80
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, Serbia : Balkan Scientific Centre",
journal = "Tribology and Materials",
title = "Optimisation of tensile stress of poly(lactic acid) 3D printed materials using response surface methodology",
volume = "1",
number = "2",
pages = "70-80",
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, Serbia : 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  - CONF
AU  - Vorkapić, Miloš
AU  - Ivanov, Toni
AU  - Baltić, Marija
AU  - Živojinović, Danijela
PY  - 2022
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5707
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
SP  - 54
EP  - 59
UR  - https://hdl.handle.net/21.15107/rcub_cer_5707
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",
pages = "54-59",
url = "https://hdl.handle.net/21.15107/rcub_cer_5707"
}

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., 54-59.
https://hdl.handle.net/21.15107/rcub_cer_5707

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;:54-59.
https://hdl.handle.net/21.15107/rcub_cer_5707 .

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):54-59,
https://hdl.handle.net/21.15107/rcub_cer_5707 .

TY  - CONF
AU  - Vorkapić, Miloš
AU  - Baltić, Marija
AU  - Ivanov, Toni
AU  - Simonović, Aleksandar
PY  - 2022
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5676
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
SP  - 66
EP  - 66
UR  - https://hdl.handle.net/21.15107/rcub_cer_5676
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",
pages = "66-66",
url = "https://hdl.handle.net/21.15107/rcub_cer_5676"
}

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., 66-66.
https://hdl.handle.net/21.15107/rcub_cer_5676

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;:66-66.
https://hdl.handle.net/21.15107/rcub_cer_5676 .

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):66-66,
https://hdl.handle.net/21.15107/rcub_cer_5676 .

TY  - CONF
AU  - Ivanović, Milica
AU  - Vorkapić, Miloš
AU  - Simonović, Aleksandar
AU  - Ivanov, Toni
AU  - Stamenković, Igor
PY  - 2022
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5675
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., particullary 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
SP  - 24
EP  - 24
UR  - https://hdl.handle.net/21.15107/rcub_cer_5675
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., particullary 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",
pages = "24-24",
url = "https://hdl.handle.net/21.15107/rcub_cer_5675"
}

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., 24-24.
https://hdl.handle.net/21.15107/rcub_cer_5675

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;:24-24.
https://hdl.handle.net/21.15107/rcub_cer_5675 .

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):24-24,
https://hdl.handle.net/21.15107/rcub_cer_5675 .

TY  - CONF
AU  - Baltić, Marija
AU  - Ivanov, Toni
AU  - Vorkapić, Miloš
PY  - 2021
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5658
AB  - The proper functioning of urban public transport is imperative in larger city areas. Thus the bus is still the most commonly used type of passenger transport. Taking into account the daily frequency of these vehicles, the emission and impact of harmful substances on the environment are very important. One of the most important factors when inspecting a vehicle is checking the emission of exhaust gases, which is a significant indicator of the regularity of the power group. If the emission is above the permitted limits, it is important to prevent further bus exploitation. Because of the aforementioned problems the advantage is given to electric vehicles, and as a representative of the propulsion, electric batteries with LTO (lithium titanium) capacity of 90.5 kWh that can be charched fast at the terminals are considered.
This paper analyses one city line where a comparison of technical features, energy efficiency and environmental effects between the existing diesel and new electric buses was made. Based on the set models, appropriate load simulations, and the obtained results, it was established that 12 electric buses replace 9 articulated buses according to the frequency of passenger transport.
In terms of energy efficiency, two modes of electric buses operation were analysed: the first without air conditioning and heating system, and the second at a temperature of -10 °C. Based on detailed research, it is recommended to introduce electric buses in public transportation, both in terms of cost-effectiveness and in environmental protection.
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  - Comparative analysis of conventional diesel and electric bus characteristics – Technical and environmental aspects
SP  - 61
EP  - 61
UR  - https://hdl.handle.net/21.15107/rcub_cer_5658
ER  - 

@conference{
author = "Baltić, Marija and Ivanov, Toni and Vorkapić, Miloš",
year = "2021",
abstract = "The proper functioning of urban public transport is imperative in larger city areas. Thus the bus is still the most commonly used type of passenger transport. Taking into account the daily frequency of these vehicles, the emission and impact of harmful substances on the environment are very important. One of the most important factors when inspecting a vehicle is checking the emission of exhaust gases, which is a significant indicator of the regularity of the power group. If the emission is above the permitted limits, it is important to prevent further bus exploitation. Because of the aforementioned problems the advantage is given to electric vehicles, and as a representative of the propulsion, electric batteries with LTO (lithium titanium) capacity of 90.5 kWh that can be charched fast at the terminals are considered.
This paper analyses one city line where a comparison of technical features, energy efficiency and environmental effects between the existing diesel and new electric buses was made. Based on the set models, appropriate load simulations, and the obtained results, it was established that 12 electric buses replace 9 articulated buses according to the frequency of passenger transport.
In terms of energy efficiency, two modes of electric buses operation were analysed: the first without air conditioning and heating system, and the second at a temperature of -10 °C. Based on detailed research, it is recommended to introduce electric buses in public transportation, both in terms of cost-effectiveness and in environmental protection.",
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 = "Comparative analysis of conventional diesel and electric bus characteristics – Technical and environmental aspects",
pages = "61-61",
url = "https://hdl.handle.net/21.15107/rcub_cer_5658"
}

Baltić, M., Ivanov, T.,& Vorkapić, M.. (2021). Comparative analysis of conventional diesel and electric bus characteristics – Technical and environmental aspects. 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., 61-61.
https://hdl.handle.net/21.15107/rcub_cer_5658

Baltić M, Ivanov T, Vorkapić M. Comparative analysis of conventional diesel and electric bus characteristics – Technical and environmental aspects. 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;:61-61.
https://hdl.handle.net/21.15107/rcub_cer_5658 .

Baltić, Marija, Ivanov, Toni, Vorkapić, Miloš, "Comparative analysis of conventional diesel and electric bus characteristics – Technical and environmental aspects" 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):61-61,
https://hdl.handle.net/21.15107/rcub_cer_5658 .

TY  - CONF
AU  - Hasan, Mohammad Sakib
AU  - Ivanov, Toni
AU  - Vorkapić, Miloš
PY  - 2021
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5659
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
SP  - 66
EP  - 66
UR  - https://hdl.handle.net/21.15107/rcub_cer_5659
ER  - 

@conference{
author = "Hasan, Mohammad Sakib 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",
pages = "66-66",
url = "https://hdl.handle.net/21.15107/rcub_cer_5659"
}

Hasan, M. S., 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., 66-66.
https://hdl.handle.net/21.15107/rcub_cer_5659

Hasan MS, 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;:66-66.
https://hdl.handle.net/21.15107/rcub_cer_5659 .

Hasan, Mohammad Sakib, 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):66-66,
https://hdl.handle.net/21.15107/rcub_cer_5659 .

TY  - CONF
AU  - Ilić, Stefan
AU  - Vorkapić, Miloš
AU  - Ivanov, Toni
AU  - Svorcan, Jelena
PY  - 2021
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5661
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
SP  - 29
EP  - 30
UR  - https://hdl.handle.net/21.15107/rcub_cer_5661
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",
pages = "29-30",
url = "https://hdl.handle.net/21.15107/rcub_cer_5661"
}

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., 29-30.
https://hdl.handle.net/21.15107/rcub_cer_5661

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;:29-30.
https://hdl.handle.net/21.15107/rcub_cer_5661 .

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):29-30,
https://hdl.handle.net/21.15107/rcub_cer_5661 .

TY  - CONF
AU  - Vorkapić, Miloš
AU  - Stajčić, Aleksandar
AU  - Mladenović, Ivana
AU  - Ivanov, Toni
PY  - 2021
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5667
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
SP  - 102
EP  - 107
UR  - https://hdl.handle.net/21.15107/rcub_cer_5667
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",
pages = "102-107",
url = "https://hdl.handle.net/21.15107/rcub_cer_5667"
}

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., 102-107.
https://hdl.handle.net/21.15107/rcub_cer_5667

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;:102-107.
https://hdl.handle.net/21.15107/rcub_cer_5667 .

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):102-107,
https://hdl.handle.net/21.15107/rcub_cer_5667 .

TY  - JOUR
AU  - Vorkapić, Miloš
AU  - Ivanov, Toni
AU  - Baltić, Marija
AU  - Kreculj, Dragan
AU  - Tanović, Dragoljub Lj.
AU  - Kovačević, Aleksandar M.
PY  - 2020
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3925
AB  - Aditivna proizvodnja uključuje izradu proizvoda složene geometrije u relativno malim količinama, kao i izradu alata i kalupa za masovnu proizvodnju. Aditivnom proizovnjom realizuju se modeli prema digitalnom prikazu, a primena je ogromna u različitim industrijskim sektorima. U poređenju sa tradicionalnom proizvodnjom, glavni parametri u odabiru aditivne tehnologije su: ušteda energije, smanjenje otpada, smanjenje upotrebe većeg broja alata, kao i optimizacija dizajna. Aditivna proizvodnja ili tehnologija 3D štampe rade na principu dodavanja materijala u slojevima, tj. model se formira od slojeva rastopljenog materijala koji se odmah hladi i očvršćava. 3D štampa omogućava čestu i jednostavnu modifikaciju modela na zahtev kupca, a pre ulaska modela u samu proizvodnju. Ovo čini komunikaciju na relaciji proizvođač-kupac dosta jednostavnom. Polazni materijal za izradu modela je polilaktična kiselina (PLA). To je ekološki termoplastični poliester koji se prirodno razgrađuje u prirodi. Na mehaničke karakteristike realizovanog modela od PLA značajno utiču različite tehnološke promenljive kao što su: prečnik brizgaljke, debljina definisanog sloja, procentualna vrednost ispune, veličina uzorka koji se puni, brzina punjenja i temperatura proizvodnje. Cilj ovog rada je da se prikaže postupak realizacije kutije elektronike za malogabaritni transmiter pritiska na 3D štampaču. Time se projektantu daje mogućnost da ispravi postojeće greške, modifikuje proizvod prema zahterima krajnjih korisnika i na kraju daje polazna osnova za realizaciju prototipa novog proizvoda.
AB  - Additive manufacturing involves manufacturing of products with complex geometry in relatively small quantities, as well as the tools and molds manufacturing for mass production. With additive manufacturing, digital models are being realized and implementation is huge in various industrial sectors. Compared to traditional manufacturing, the main parameters in the choice of additive technology are: energy savings, waste reduction, reduced use of more tools and optimization of design. Additive manufacturing or 3D printing technology works on the principle of adding material in layers, i.e. the model is formed from layers of molten material that is immediately cooled and solidified. 3D printing allows to work with customers to solve design problems before embarking on a launch production. The starting material for the model is polyactic acid (PLA). It is an eco-friendly thermoplastic polyester, that breaks down naturally. The mechanical characteristics of the realized PLA model are significantly influenced by various technological variables, such as following: nozzle diameter, thickness of defined layer, percentage of fill,
sample size to be filled, filling rate and production temperature. The aim of this paper is to present the process of realization of an electronics enclosure for a compact pressure transmitter on a 3D printer. This gives the designer the possibility to correct existing errors, modify the product according to the wishes of the end users and finally provides a starting point for the prototype of new product.
PB  - Savez inženjera i tehničara Srbije, Beograd, Srbija
T2  - Tehnika
T1  - Upotreba 3D štampe u analizi dizajna realizovanog proizvoda: Slučaj - kutija malogabaritnog transmitera pritiska
T1  - The usage of 3D printing in the analysis of the product design: Case – Electronic enclosure of compact pressure transmitter
VL  - 75
IS  - 2
SP  - 179
EP  - 186
DO  - 10.5937/tehnika2002179V
ER  - 

@article{
author = "Vorkapić, Miloš and Ivanov, Toni and Baltić, Marija and Kreculj, Dragan and Tanović, Dragoljub Lj. and Kovačević, Aleksandar M.",
year = "2020",
abstract = "Aditivna proizvodnja uključuje izradu proizvoda složene geometrije u relativno malim količinama, kao i izradu alata i kalupa za masovnu proizvodnju. Aditivnom proizovnjom realizuju se modeli prema digitalnom prikazu, a primena je ogromna u različitim industrijskim sektorima. U poređenju sa tradicionalnom proizvodnjom, glavni parametri u odabiru aditivne tehnologije su: ušteda energije, smanjenje otpada, smanjenje upotrebe većeg broja alata, kao i optimizacija dizajna. Aditivna proizvodnja ili tehnologija 3D štampe rade na principu dodavanja materijala u slojevima, tj. model se formira od slojeva rastopljenog materijala koji se odmah hladi i očvršćava. 3D štampa omogućava čestu i jednostavnu modifikaciju modela na zahtev kupca, a pre ulaska modela u samu proizvodnju. Ovo čini komunikaciju na relaciji proizvođač-kupac dosta jednostavnom. Polazni materijal za izradu modela je polilaktična kiselina (PLA). To je ekološki termoplastični poliester koji se prirodno razgrađuje u prirodi. Na mehaničke karakteristike realizovanog modela od PLA značajno utiču različite tehnološke promenljive kao što su: prečnik brizgaljke, debljina definisanog sloja, procentualna vrednost ispune, veličina uzorka koji se puni, brzina punjenja i temperatura proizvodnje. Cilj ovog rada je da se prikaže postupak realizacije kutije elektronike za malogabaritni transmiter pritiska na 3D štampaču. Time se projektantu daje mogućnost da ispravi postojeće greške, modifikuje proizvod prema zahterima krajnjih korisnika i na kraju daje polazna osnova za realizaciju prototipa novog proizvoda., Additive manufacturing involves manufacturing of products with complex geometry in relatively small quantities, as well as the tools and molds manufacturing for mass production. With additive manufacturing, digital models are being realized and implementation is huge in various industrial sectors. Compared to traditional manufacturing, the main parameters in the choice of additive technology are: energy savings, waste reduction, reduced use of more tools and optimization of design. Additive manufacturing or 3D printing technology works on the principle of adding material in layers, i.e. the model is formed from layers of molten material that is immediately cooled and solidified. 3D printing allows to work with customers to solve design problems before embarking on a launch production. The starting material for the model is polyactic acid (PLA). It is an eco-friendly thermoplastic polyester, that breaks down naturally. The mechanical characteristics of the realized PLA model are significantly influenced by various technological variables, such as following: nozzle diameter, thickness of defined layer, percentage of fill,
sample size to be filled, filling rate and production temperature. The aim of this paper is to present the process of realization of an electronics enclosure for a compact pressure transmitter on a 3D printer. This gives the designer the possibility to correct existing errors, modify the product according to the wishes of the end users and finally provides a starting point for the prototype of new product.",
publisher = "Savez inženjera i tehničara Srbije, Beograd, Srbija",
journal = "Tehnika",
title = "Upotreba 3D štampe u analizi dizajna realizovanog proizvoda: Slučaj - kutija malogabaritnog transmitera pritiska, The usage of 3D printing in the analysis of the product design: Case – Electronic enclosure of compact pressure transmitter",
volume = "75",
number = "2",
pages = "179-186",
doi = "10.5937/tehnika2002179V"
}

Vorkapić, M., Ivanov, T., Baltić, M., Kreculj, D., Tanović, D. Lj.,& Kovačević, A. M.. (2020). Upotreba 3D štampe u analizi dizajna realizovanog proizvoda: Slučaj - kutija malogabaritnog transmitera pritiska. in Tehnika
Savez inženjera i tehničara Srbije, Beograd, Srbija., 75(2), 179-186.
https://doi.org/10.5937/tehnika2002179V

Vorkapić M, Ivanov T, Baltić M, Kreculj D, Tanović DL, Kovačević AM. Upotreba 3D štampe u analizi dizajna realizovanog proizvoda: Slučaj - kutija malogabaritnog transmitera pritiska. in Tehnika. 2020;75(2):179-186.
doi:10.5937/tehnika2002179V .

Vorkapić, Miloš, Ivanov, Toni, Baltić, Marija, Kreculj, Dragan, Tanović, Dragoljub Lj., Kovačević, Aleksandar M., "Upotreba 3D štampe u analizi dizajna realizovanog proizvoda: Slučaj - kutija malogabaritnog transmitera pritiska" in Tehnika, 75, no. 2 (2020):179-186,
https://doi.org/10.5937/tehnika2002179V . .

TY  - CONF
AU  - Simonović, Aleksandar
AU  - Kovačević, Aleksandar
AU  - Ivanov, Toni
AU  - Vorkapić, Miloš
PY  - 2020
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3919
AB  - The trend of wind turbine development has a special significance in the exploitation of renewable
energy sources. At higher altitudes, we have better wind energy utilization higher speed and
their conversion are achieved in the best possible use of wind turbines. The development of new technologies
opens space for a new generation of wind turbines with a 20MW rated power. In recent
years, various feasibility studies have shown that wind turbines with large rotor diameter and high
towers give positive shifts in the analysis of structural and aerodynamic parameters, with a focus on
reducing overall mass and damping vibrations due to the use of new materials. In this paper, the
evolution of high power wind turbines and an overview of the technological development of the basic
components of the turbine will be presented. Perspectives in the further development of wind turbines
with rated power above 20MW will be also considered.
AB  - Trend razvoja vetroturbina ima poseban značaj u eksploataciji obnovljivih izvora energije. Vetroturbine velikog prečnika rotora i visokih tornjeva sve se više razmatraju u istraživačkim i razvojnim centrima širom sveta. Upotrebom vetroturbina na većim visinama gde je brzina vetra znatno veća ostvaruje se mogućnost boljeg iskorišćenja ovog obnovljivog izvora energije. Razvoj novih tehnologija otvara mogućnost za novu generaciju vetroturbina snage preko 20 MW. U poslednjih nekoliko godina razne studije izvodljivosti su pokazale da koncept vetroturbine velikog prečnika rotora koji se nalazi na visokim tornju daje pozitivne rezultate sa aspekta analize strukturalnih i aerodinamičkih parametara. Posebna pažnja posvećena je smanjenju ukupne mase i prigušenju vibracija korišćenjem novih materijala. U ovom radu prezentovan je razvoj vetroturbina velike snage, dat je pregled tehnoloških mogućnosti u proizvodnji osnovnih komponenti kao i perspektiva za realizaciju vetroturbina snage preko 20 MW.
PB  - Savez mašinskih i elektrotehničkih inženjera i tehničara Srbije - SMEITS, Beograd
C3  - 8th International Conference on Renewable Electrical Power Sources (8. Međunarodna konferencija o obnovljivim izvorima električne energije), ICREPS 2020, October 16, Belgrade, Serbia
T1  - Wind turbine beyond 20 MW – Technology perspective
SP  - 123
EP  - 134
UR  - https://hdl.handle.net/21.15107/rcub_cer_3919
ER  - 

@conference{
author = "Simonović, Aleksandar and Kovačević, Aleksandar and Ivanov, Toni and Vorkapić, Miloš",
year = "2020",
abstract = "The trend of wind turbine development has a special significance in the exploitation of renewable
energy sources. At higher altitudes, we have better wind energy utilization higher speed and
their conversion are achieved in the best possible use of wind turbines. The development of new technologies
opens space for a new generation of wind turbines with a 20MW rated power. In recent
years, various feasibility studies have shown that wind turbines with large rotor diameter and high
towers give positive shifts in the analysis of structural and aerodynamic parameters, with a focus on
reducing overall mass and damping vibrations due to the use of new materials. In this paper, the
evolution of high power wind turbines and an overview of the technological development of the basic
components of the turbine will be presented. Perspectives in the further development of wind turbines
with rated power above 20MW will be also considered., Trend razvoja vetroturbina ima poseban značaj u eksploataciji obnovljivih izvora energije. Vetroturbine velikog prečnika rotora i visokih tornjeva sve se više razmatraju u istraživačkim i razvojnim centrima širom sveta. Upotrebom vetroturbina na većim visinama gde je brzina vetra znatno veća ostvaruje se mogućnost boljeg iskorišćenja ovog obnovljivog izvora energije. Razvoj novih tehnologija otvara mogućnost za novu generaciju vetroturbina snage preko 20 MW. U poslednjih nekoliko godina razne studije izvodljivosti su pokazale da koncept vetroturbine velikog prečnika rotora koji se nalazi na visokim tornju daje pozitivne rezultate sa aspekta analize strukturalnih i aerodinamičkih parametara. Posebna pažnja posvećena je smanjenju ukupne mase i prigušenju vibracija korišćenjem novih materijala. U ovom radu prezentovan je razvoj vetroturbina velike snage, dat je pregled tehnoloških mogućnosti u proizvodnji osnovnih komponenti kao i perspektiva za realizaciju vetroturbina snage preko 20 MW.",
publisher = "Savez mašinskih i elektrotehničkih inženjera i tehničara Srbije - SMEITS, Beograd",
journal = "8th International Conference on Renewable Electrical Power Sources (8. Međunarodna konferencija o obnovljivim izvorima električne energije), ICREPS 2020, October 16, Belgrade, Serbia",
title = "Wind turbine beyond 20 MW – Technology perspective",
pages = "123-134",
url = "https://hdl.handle.net/21.15107/rcub_cer_3919"
}

Simonović, A., Kovačević, A., Ivanov, T.,& Vorkapić, M.. (2020). Wind turbine beyond 20 MW – Technology perspective. in 8th International Conference on Renewable Electrical Power Sources (8. Međunarodna konferencija o obnovljivim izvorima električne energije), ICREPS 2020, October 16, Belgrade, Serbia
Savez mašinskih i elektrotehničkih inženjera i tehničara Srbije - SMEITS, Beograd., 123-134.
https://hdl.handle.net/21.15107/rcub_cer_3919

Simonović A, Kovačević A, Ivanov T, Vorkapić M. Wind turbine beyond 20 MW – Technology perspective. in 8th International Conference on Renewable Electrical Power Sources (8. Međunarodna konferencija o obnovljivim izvorima električne energije), ICREPS 2020, October 16, Belgrade, Serbia. 2020;:123-134.
https://hdl.handle.net/21.15107/rcub_cer_3919 .

Simonović, Aleksandar, Kovačević, Aleksandar, Ivanov, Toni, Vorkapić, Miloš, "Wind turbine beyond 20 MW – Technology perspective" in 8th International Conference on Renewable Electrical Power Sources (8. Međunarodna konferencija o obnovljivim izvorima električne energije), ICREPS 2020, October 16, Belgrade, Serbia (2020):123-134,
https://hdl.handle.net/21.15107/rcub_cer_3919 .

TY  - CONF
AU  - Svorcan, Jelena
AU  - Peković, Ognjen
AU  - Ivanov, Toni
AU  - Vorkapić, Miloš
PY  - 2020
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3918
AB  - With wind energy extraction constantly increasing, the interest in small-scale urban wind turbines
is also expanding. Given that these machines often work in adverse operating conditions
(Earth’s boundary layer, vortex trails of surrounding objects, small and changeable wind speeds),
additional elements that locally augment wind velocity and facilitate turbine start may be installed.
This paper investigates possible benefits of adding an optimized flow concentrator to a vertical-axis
wind turbine (VAWT) rotor. Three-dimensional, unsteady, turbulent, incompressible flow simulations
of both isolated rotor consisting of three straight blades and a rotor with flow concentrator have been
performed in ANSYS FLUENT by finite volume method for several different operational regimes. This
type of flow simulations is challenging since flow angles are high, numerous flow phenomena and
instabilities are present and the interaction between the blades and detached vortices can be significant.
The rotational motion of the blades is solved by the unsteady Sliding Mesh (SM) approach. Flow
field is modeled by Unsteady Reynolds Averaged Navier-Stokes (URANS) equations with k-ω SST
turbulence model used for closure. Both quantitative and qualitative examinations of the obtained
numerical results are presented. In particular, the two computed power coefficient curves are compared
and the advantages of installing a flow concentrator are accentuated.
AB  - Usled stalnog porasta iskorišćenja energije vetra, interesovanje za male vetroturbine za urbane sredine se takođe širi. Kako ovakve mašine često funkcionišu u nepovoljnim radnim uslovima (Zemljinom graničnom sloju, vrtložnom tragu okolnih objekata, pri maloj i promenljivoj brzini vetra), moguće je instalirati dodatne elemente čija uloga je da lokalno povećaju brzinu kroz rotor i olakšaju pokretanje vetroturbine. Ovaj rad istražuje prednosti dodavanja optimizovanog koncentratora struje vazduha rotoru vetroturbine sa vertikalnom osom obrtanja. Prostorne, nestacionarne simulacije turbulentnog, nestišljivog opstrujavanja izolovanog rotora koji sadrži tri prave lopatice kao i rotora sa koncentratorom izvedene su u softverskom paketu ANSYS FLUENT metodom konačnih zapremina za nekoliko različitih radnih režima. Ova vrsta proračuna je izazovna jer su napadni uglovi visoki, javljaju se brojni strujni fenomeni i nestabilnosti dok interakcija između lopatica i odvojenih vrtloga može biti značajna.Obrtno kretanje lopatica rešeno je pristupom klizajućih mreža. Strujno polje modelovano je nestacionarnim Navije-Stoksovim jednačinama osrednjenim Rejnoldsovom statistikom (URANS) koje su zatvorene k-ω SST turbulentnim modelom. Prikazane su i kvantitativne i kvalitativne analize dobijenih numeričkih rezultata. Naročito je izvršeno poređenje dve krive koeficijenta snage i naglašene su prednosti instaliranja koncentratora struje vazduha.
PB  - Savez mašinskih i elektrotehničkih inženjera i tehničara Srbije - SMEITS, Beograd
C3  - 8th International Conference on Renewable Electrical Power Sources (8. Međunarodna konferencija o obnovljivim izvorima električne energije), ICREPS 2020, October 16, Belgrade, Serbia
T1  - Numerical evaluation of aerodynamic performances of vertical-axis wind turbine rotor with flow concentrator
SP  - 135
EP  - 141
UR  - https://hdl.handle.net/21.15107/rcub_cer_3918
ER  - 

@conference{
author = "Svorcan, Jelena and Peković, Ognjen and Ivanov, Toni and Vorkapić, Miloš",
year = "2020",
abstract = "With wind energy extraction constantly increasing, the interest in small-scale urban wind turbines
is also expanding. Given that these machines often work in adverse operating conditions
(Earth’s boundary layer, vortex trails of surrounding objects, small and changeable wind speeds),
additional elements that locally augment wind velocity and facilitate turbine start may be installed.
This paper investigates possible benefits of adding an optimized flow concentrator to a vertical-axis
wind turbine (VAWT) rotor. Three-dimensional, unsteady, turbulent, incompressible flow simulations
of both isolated rotor consisting of three straight blades and a rotor with flow concentrator have been
performed in ANSYS FLUENT by finite volume method for several different operational regimes. This
type of flow simulations is challenging since flow angles are high, numerous flow phenomena and
instabilities are present and the interaction between the blades and detached vortices can be significant.
The rotational motion of the blades is solved by the unsteady Sliding Mesh (SM) approach. Flow
field is modeled by Unsteady Reynolds Averaged Navier-Stokes (URANS) equations with k-ω SST
turbulence model used for closure. Both quantitative and qualitative examinations of the obtained
numerical results are presented. In particular, the two computed power coefficient curves are compared
and the advantages of installing a flow concentrator are accentuated., Usled stalnog porasta iskorišćenja energije vetra, interesovanje za male vetroturbine za urbane sredine se takođe širi. Kako ovakve mašine često funkcionišu u nepovoljnim radnim uslovima (Zemljinom graničnom sloju, vrtložnom tragu okolnih objekata, pri maloj i promenljivoj brzini vetra), moguće je instalirati dodatne elemente čija uloga je da lokalno povećaju brzinu kroz rotor i olakšaju pokretanje vetroturbine. Ovaj rad istražuje prednosti dodavanja optimizovanog koncentratora struje vazduha rotoru vetroturbine sa vertikalnom osom obrtanja. Prostorne, nestacionarne simulacije turbulentnog, nestišljivog opstrujavanja izolovanog rotora koji sadrži tri prave lopatice kao i rotora sa koncentratorom izvedene su u softverskom paketu ANSYS FLUENT metodom konačnih zapremina za nekoliko različitih radnih režima. Ova vrsta proračuna je izazovna jer su napadni uglovi visoki, javljaju se brojni strujni fenomeni i nestabilnosti dok interakcija između lopatica i odvojenih vrtloga može biti značajna.Obrtno kretanje lopatica rešeno je pristupom klizajućih mreža. Strujno polje modelovano je nestacionarnim Navije-Stoksovim jednačinama osrednjenim Rejnoldsovom statistikom (URANS) koje su zatvorene k-ω SST turbulentnim modelom. Prikazane su i kvantitativne i kvalitativne analize dobijenih numeričkih rezultata. Naročito je izvršeno poređenje dve krive koeficijenta snage i naglašene su prednosti instaliranja koncentratora struje vazduha.",
publisher = "Savez mašinskih i elektrotehničkih inženjera i tehničara Srbije - SMEITS, Beograd",
journal = "8th International Conference on Renewable Electrical Power Sources (8. Međunarodna konferencija o obnovljivim izvorima električne energije), ICREPS 2020, October 16, Belgrade, Serbia",
title = "Numerical evaluation of aerodynamic performances of vertical-axis wind turbine rotor with flow concentrator",
pages = "135-141",
url = "https://hdl.handle.net/21.15107/rcub_cer_3918"
}

Svorcan, J., Peković, O., Ivanov, T.,& Vorkapić, M.. (2020). Numerical evaluation of aerodynamic performances of vertical-axis wind turbine rotor with flow concentrator. in 8th International Conference on Renewable Electrical Power Sources (8. Međunarodna konferencija o obnovljivim izvorima električne energije), ICREPS 2020, October 16, Belgrade, Serbia
Savez mašinskih i elektrotehničkih inženjera i tehničara Srbije - SMEITS, Beograd., 135-141.
https://hdl.handle.net/21.15107/rcub_cer_3918

Svorcan J, Peković O, Ivanov T, Vorkapić M. Numerical evaluation of aerodynamic performances of vertical-axis wind turbine rotor with flow concentrator. in 8th International Conference on Renewable Electrical Power Sources (8. Međunarodna konferencija o obnovljivim izvorima električne energije), ICREPS 2020, October 16, Belgrade, Serbia. 2020;:135-141.
https://hdl.handle.net/21.15107/rcub_cer_3918 .

Svorcan, Jelena, Peković, Ognjen, Ivanov, Toni, Vorkapić, Miloš, "Numerical evaluation of aerodynamic performances of vertical-axis wind turbine rotor with flow concentrator" in 8th International Conference on Renewable Electrical Power Sources (8. Međunarodna konferencija o obnovljivim izvorima električne energije), ICREPS 2020, October 16, Belgrade, Serbia (2020):135-141,
https://hdl.handle.net/21.15107/rcub_cer_3918 .

TY  - CONF
AU  - Kovačević, Aleksandar
AU  - Ivanov, Toni
AU  - Simonović, Aleksandar
AU  - Vorkapić, Miloš
PY  - 2020
UR  - http://cent.mas.bg.ac.rs/jupiter/index.htm
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3904
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.
AB  - Large increase in the use of 3D printing or rapid prototyping in the last two decades is due to the many
benefits that this manufacturing technology offers. In this article geometry accuracy of 3D printed parts is analyzed.
For printing of the analyzed model Fused Deposition Modeling (FDM) method was employed. ABS material was used
to create the specimens. The measurement results have shown that the dimensional accuracy of printed parts increases
with the number of iterations. The overview of analyze and some recommendations in the sense of limitation in the
application of this method are given as a conclusion of this paper.
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
SP  - 2.13
EP  - 2.19
UR  - https://hdl.handle.net/21.15107/rcub_cer_3904
ER  - 

@conference{
author = "Kovačević, Aleksandar and Ivanov, Toni and Simonović, Aleksandar and Vorkapić, Miloš",
year = "2020",
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., Large increase in the use of 3D printing or rapid prototyping in the last two decades is due to the many
benefits that this manufacturing technology offers. In this article geometry accuracy of 3D printed parts is analyzed.
For printing of the analyzed model Fused Deposition Modeling (FDM) method was employed. ABS material was used
to create the specimens. The measurement results have shown that the dimensional accuracy of printed parts increases
with the number of iterations. The overview of analyze and some recommendations in the sense of limitation in the
application of this method are given as a conclusion of this paper.",
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",
pages = "2.13-2.19",
url = "https://hdl.handle.net/21.15107/rcub_cer_3904"
}

Kovačević, A., Ivanov, T., Simonović, A.,& Vorkapić, M.. (2020). Povećanje preciznosti izrade 3D štampanih delova primenom iterativne metode. in Zbornik radova - 42. JUPITER konferencija / Proceedings - 42nd JUPITER Conference
Uniiverzitet u Beogradu - Mašinski fakultet., 2.13-2.19.
https://hdl.handle.net/21.15107/rcub_cer_3904

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. 2020;:2.13-2.19.
https://hdl.handle.net/21.15107/rcub_cer_3904 .

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 (2020):2.13-2.19,
https://hdl.handle.net/21.15107/rcub_cer_3904 .

TY  - CONF
AU  - Hasan, Mohammad Sakib
AU  - Vorkapić, Miloš
AU  - Ivanov, Toni
AU  - Kovačević, Aleksandar
PY  - 2020
UR  - http://cent.mas.bg.ac.rs/jupiter/index.htm
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3903
AB  - U ovom radu, izvršena je analiza i predikcija brzina štampe u eksploatacionim uslovima. Postoje
odstupanja zadane brzine na štampaču od proračunate stvarne vrednosti. S tim u vezi, postoji i razlika u
vremenima izrade. Ovde je posmatrana brzina kao ravnomerno pravolinijsko kretanja brizgaljke. Zato, VNM je
poslužila za predikciju Vsr, sa promenom ulaznih parametara. Za rezultate predikcije brzine dobili smo
zadovoljavajuću vrednost regresionog koeficijenta 0.9999 sa ukupnom MAPE greškom koja iznosi 1,84%. Mreža bi
se mogla koristiti za obradu, predviđanje i optimizaciju prosečne brzine mlaznice i ostalih procesnih parametara.
AB  - In this paper, an analysis and printing speed prediction in exploitation conditions performed. There are set speed deviations of the on the printer from the calculated actual value. In this regard, there is also a difference in manufacturing times. Here, speed viewed as a uniform perpendicular nozzle motion. Therefore, the VNM used the Vsr prediction, with the input parameters changing. For the speed prediction results, we received a satisfactory regression coefficient value of 0.9999 with a total MAPE error of 1.84%. The network could be use for processing, prediction and, nozzle average speed optimization and other process parameters.
PB  - Uniiverzitet u Beogradu - Mašinski fakultet
C3  - Zbornik radova - 42. JUPITER konferencija / Proceedings - 42nd JUPITER Conference
T1  - Predikcija brzine na 3D štampaču primenom veštačkih neuronskih mreža
SP  - 2.7
EP  - 2.12
UR  - https://hdl.handle.net/21.15107/rcub_cer_3903
ER  - 

@conference{
author = "Hasan, Mohammad Sakib and Vorkapić, Miloš and Ivanov, Toni and Kovačević, Aleksandar",
year = "2020",
abstract = "U ovom radu, izvršena je analiza i predikcija brzina štampe u eksploatacionim uslovima. Postoje
odstupanja zadane brzine na štampaču od proračunate stvarne vrednosti. S tim u vezi, postoji i razlika u
vremenima izrade. Ovde je posmatrana brzina kao ravnomerno pravolinijsko kretanja brizgaljke. Zato, VNM je
poslužila za predikciju Vsr, sa promenom ulaznih parametara. Za rezultate predikcije brzine dobili smo
zadovoljavajuću vrednost regresionog koeficijenta 0.9999 sa ukupnom MAPE greškom koja iznosi 1,84%. Mreža bi
se mogla koristiti za obradu, predviđanje i optimizaciju prosečne brzine mlaznice i ostalih procesnih parametara., In this paper, an analysis and printing speed prediction in exploitation conditions performed. There are set speed deviations of the on the printer from the calculated actual value. In this regard, there is also a difference in manufacturing times. Here, speed viewed as a uniform perpendicular nozzle motion. Therefore, the VNM used the Vsr prediction, with the input parameters changing. For the speed prediction results, we received a satisfactory regression coefficient value of 0.9999 with a total MAPE error of 1.84%. The network could be use for processing, prediction and, nozzle average speed optimization and other process parameters.",
publisher = "Uniiverzitet u Beogradu - Mašinski fakultet",
journal = "Zbornik radova - 42. JUPITER konferencija / Proceedings - 42nd JUPITER Conference",
title = "Predikcija brzine na 3D štampaču primenom veštačkih neuronskih mreža",
pages = "2.7-2.12",
url = "https://hdl.handle.net/21.15107/rcub_cer_3903"
}

Hasan, M. S., Vorkapić, M., Ivanov, T.,& Kovačević, A.. (2020). Predikcija brzine na 3D štampaču primenom veštačkih neuronskih mreža. in Zbornik radova - 42. JUPITER konferencija / Proceedings - 42nd JUPITER Conference
Uniiverzitet u Beogradu - Mašinski fakultet., 2.7-2.12.
https://hdl.handle.net/21.15107/rcub_cer_3903

Hasan MS, Vorkapić M, Ivanov T, Kovačević A. Predikcija brzine na 3D štampaču primenom veštačkih neuronskih mreža. in Zbornik radova - 42. JUPITER konferencija / Proceedings - 42nd JUPITER Conference. 2020;:2.7-2.12.
https://hdl.handle.net/21.15107/rcub_cer_3903 .

Hasan, Mohammad Sakib, Vorkapić, Miloš, Ivanov, Toni, Kovačević, Aleksandar, "Predikcija brzine na 3D štampaču primenom veštačkih neuronskih mreža" in Zbornik radova - 42. JUPITER konferencija / Proceedings - 42nd JUPITER Conference (2020):2.7-2.12,
https://hdl.handle.net/21.15107/rcub_cer_3903 .

TY  - CHAP
AU  - Vorkapić, Miloš
AU  - Simonović, Aleksandar
AU  - Ivanov, Toni
PY  - 2020
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3972
AB  - Additive manufacturing technology helped many organizations to save
money in the product design process by reducing prototype costs, and also by providing a means for early evaluation and decision making. The idea of this paper is
to design an electronics enclosure for an intelligent industrial pressure transmitter,
using the additive technology. All enclosure elements are made on a 3D printer
WANHAO duplicator i3 plus, using PLA materials. The enclosure realization,
from CAD drawings to the finished model, enables a designer to correct existing errors, or make certain modifications as required by end-users. A process is
described that enables designers to review their decisions at any stage of product
realization, thus providing much more freedom in rapid prototyping. In this example, the advantages and disadvantages of additive manufacturing over conventional
manufacturing are outlined. Some deficiencies have also been observed, such as
mechanical damage to surfaces, burning of surfaces, tearing of prints, and surface
roughness. To mitigate such irregularities, both mechanical and chemical finishing
methods were used. The example confirmed that the finishing methods can affect
the final enclosure dimensions and shape. Further prototype development should
focus more on print quality, which depends on the shape of surfaces, the accuracy
of the geometry, the uniformity of structure and shape, material density, and the
resolution of details.
PB  - Springer
T2  - Lecture Notes in Networks and Systems - Experimental and Computational Investigations in Engineering
T1  - Algorithm for Applying 3D Printing in Prototype Realization – Case: Enclosure for an Industrial Pressure Transmitter
VL  - 153
SP  - 112
EP  - 129
DO  - 10.1007/978-3-030-58362-0_8
ER  - 

@inbook{
author = "Vorkapić, Miloš and Simonović, Aleksandar and Ivanov, Toni",
year = "2020",
abstract = "Additive manufacturing technology helped many organizations to save
money in the product design process by reducing prototype costs, and also by providing a means for early evaluation and decision making. The idea of this paper is
to design an electronics enclosure for an intelligent industrial pressure transmitter,
using the additive technology. All enclosure elements are made on a 3D printer
WANHAO duplicator i3 plus, using PLA materials. The enclosure realization,
from CAD drawings to the finished model, enables a designer to correct existing errors, or make certain modifications as required by end-users. A process is
described that enables designers to review their decisions at any stage of product
realization, thus providing much more freedom in rapid prototyping. In this example, the advantages and disadvantages of additive manufacturing over conventional
manufacturing are outlined. Some deficiencies have also been observed, such as
mechanical damage to surfaces, burning of surfaces, tearing of prints, and surface
roughness. To mitigate such irregularities, both mechanical and chemical finishing
methods were used. The example confirmed that the finishing methods can affect
the final enclosure dimensions and shape. Further prototype development should
focus more on print quality, which depends on the shape of surfaces, the accuracy
of the geometry, the uniformity of structure and shape, material density, and the
resolution of details.",
publisher = "Springer",
journal = "Lecture Notes in Networks and Systems - Experimental and Computational Investigations in Engineering",
booktitle = "Algorithm for Applying 3D Printing in Prototype Realization – Case: Enclosure for an Industrial Pressure Transmitter",
volume = "153",
pages = "112-129",
doi = "10.1007/978-3-030-58362-0_8"
}

Vorkapić, M., Simonović, A.,& Ivanov, T.. (2020). Algorithm for Applying 3D Printing in Prototype Realization – Case: Enclosure for an Industrial Pressure Transmitter. in Lecture Notes in Networks and Systems - Experimental and Computational Investigations in Engineering
Springer., 153, 112-129.
https://doi.org/10.1007/978-3-030-58362-0_8

Vorkapić M, Simonović A, Ivanov T. Algorithm for Applying 3D Printing in Prototype Realization – Case: Enclosure for an Industrial Pressure Transmitter. in Lecture Notes in Networks and Systems - Experimental and Computational Investigations in Engineering. 2020;153:112-129.
doi:10.1007/978-3-030-58362-0_8 .

Vorkapić, Miloš, Simonović, Aleksandar, Ivanov, Toni, "Algorithm for Applying 3D Printing in Prototype Realization – Case: Enclosure for an Industrial Pressure Transmitter" in Lecture Notes in Networks and Systems - Experimental and Computational Investigations in Engineering, 153 (2020):112-129,
https://doi.org/10.1007/978-3-030-58362-0_8 . .

TY  - CONF
AU  - Hasan, Sakib Mohammad
AU  - Ivanov, Toni
AU  - Tanović, Dragoljub
AU  - Simonović, Aleksandar
AU  - Vorkapić, Miloš
PY  - 2020
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3924
AB  - Additive manufacturing (AM) or 3D printing is becoming very popular in the aerospace and defense industry
because of its ability to manufacture complex parts at a low price. Fused deposition modeling (FDM) is one of the most
popular 3D printing techniques currently on the market. Acrylonitrile butadiene styrene (ABS) or poly (lactic acid)
(PLA) are the two most commonly used 3D printed materials. Dimensional accuracy of FDM processed 3D printed
materials (PLA, ABS, PETG, and HIPS) and experimental investigation of the tensile properties of those materials is
the main scope of this paper. Tensile testing machine SHIMADZU AGS-X 100 kN was used to carry out the
experimental study.
PB  - The Military Technical Institute, Belgrade, Serbia
C3  - 9th International Scientific Conference on Defensive Technologies, OTEH 2020, October 15-16, Belgrade, Serbia
T1  - Dimensional accuracy and experimental investigation on tensile behavior of various 3D printed materials
SP  - 400
EP  - 406
UR  - https://hdl.handle.net/21.15107/rcub_cer_3924
ER  - 

@conference{
author = "Hasan, Sakib Mohammad and Ivanov, Toni and Tanović, Dragoljub and Simonović, Aleksandar and Vorkapić, Miloš",
year = "2020",
abstract = "Additive manufacturing (AM) or 3D printing is becoming very popular in the aerospace and defense industry
because of its ability to manufacture complex parts at a low price. Fused deposition modeling (FDM) is one of the most
popular 3D printing techniques currently on the market. Acrylonitrile butadiene styrene (ABS) or poly (lactic acid)
(PLA) are the two most commonly used 3D printed materials. Dimensional accuracy of FDM processed 3D printed
materials (PLA, ABS, PETG, and HIPS) and experimental investigation of the tensile properties of those materials is
the main scope of this paper. Tensile testing machine SHIMADZU AGS-X 100 kN was used to carry out the
experimental study.",
publisher = "The Military Technical Institute, Belgrade, Serbia",
journal = "9th International Scientific Conference on Defensive Technologies, OTEH 2020, October 15-16, Belgrade, Serbia",
title = "Dimensional accuracy and experimental investigation on tensile behavior of various 3D printed materials",
pages = "400-406",
url = "https://hdl.handle.net/21.15107/rcub_cer_3924"
}

Hasan, S. M., Ivanov, T., Tanović, D., Simonović, A.,& Vorkapić, M.. (2020). Dimensional accuracy and experimental investigation on tensile behavior of various 3D printed materials. in 9th International Scientific Conference on Defensive Technologies, OTEH 2020, October 15-16, Belgrade, Serbia
The Military Technical Institute, Belgrade, Serbia., 400-406.
https://hdl.handle.net/21.15107/rcub_cer_3924

Hasan SM, Ivanov T, Tanović D, Simonović A, Vorkapić M. Dimensional accuracy and experimental investigation on tensile behavior of various 3D printed materials. in 9th International Scientific Conference on Defensive Technologies, OTEH 2020, October 15-16, Belgrade, Serbia. 2020;:400-406.
https://hdl.handle.net/21.15107/rcub_cer_3924 .

Hasan, Sakib Mohammad, Ivanov, Toni, Tanović, Dragoljub, Simonović, Aleksandar, Vorkapić, Miloš, "Dimensional accuracy and experimental investigation on tensile behavior of various 3D printed materials" in 9th International Scientific Conference on Defensive Technologies, OTEH 2020, October 15-16, Belgrade, Serbia (2020):400-406,
https://hdl.handle.net/21.15107/rcub_cer_3924 .

TY  - JOUR
AU  - Hasan, Mohammad Sakib
AU  - Ivanov, Toni
AU  - Vorkapić, Miloš
AU  - Simonović, Aleksandar
AU  - Daou, David
AU  - Kovačević, Aleksandar
AU  - Milovanović, Aleksa
PY  - 2020
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3722
AB  - Rapid innovations in 3D printing technology have allowed highly complex parts to be manufactured quickly and easily, particularly for prototyping purposes. Fused Deposition Modeling of thermoplastic materials is one of the most commonly used techniques in three-dimensional (3D) printing. The major aim of Fused Deposition Modeling (FDM) is to design and manufacture usable parts for fields such as engineering and medicine. Therefore, it is essential to investigate the mechanical properties of such FDM processed structures. One of the most commonly used materials currently on the market is Polylactic Acid (PLA). The main purpose of this paper is to investigate the effects of aging and heat treatment on the tensile properties of PLA printed test specimens. The tensile properties of parts manufactured by the 3D printer are influenced by various parameters such as extrusion temperature, infill density, building direction, layer height, etc. A total of 96 specimens were built by altering building orientation and layer height to estimate and compare the tensile properties of the printed parts. To investigate the aging effect, 30 of 96 specimens were printed 6 months before the tensile experiment. Half of both aged and new specimens were cured in an oven at 57.5 [˚C] for 3 hours while the other half endured no heat treatment. After the performed measurement, it can be concluded that heat treatment generally improves structural strength of the printed parts, while aging decreases it. However, these effects are highly dependent on the layer thickness and printing quality. The tensile test is conducted according to the ASTM D638 standard. The fractured samples were further characterized using an electron microscope.
PB  - Romania : Revista Chimie SRL
T2  - Materiale  Plastice
T1  - Impact of Aging Effect and Heat Treatment on the Tensile Properties of PLA (Poly Lactic Acid) Printed Parts
VL  - 57
IS  - 3
SP  - 147
EP  - 159
DO  - 10.37358/MP.20.3.5389
ER  - 

@article{
author = "Hasan, Mohammad Sakib and Ivanov, Toni and Vorkapić, Miloš and Simonović, Aleksandar and Daou, David and Kovačević, Aleksandar and Milovanović, Aleksa",
year = "2020",
abstract = "Rapid innovations in 3D printing technology have allowed highly complex parts to be manufactured quickly and easily, particularly for prototyping purposes. Fused Deposition Modeling of thermoplastic materials is one of the most commonly used techniques in three-dimensional (3D) printing. The major aim of Fused Deposition Modeling (FDM) is to design and manufacture usable parts for fields such as engineering and medicine. Therefore, it is essential to investigate the mechanical properties of such FDM processed structures. One of the most commonly used materials currently on the market is Polylactic Acid (PLA). The main purpose of this paper is to investigate the effects of aging and heat treatment on the tensile properties of PLA printed test specimens. The tensile properties of parts manufactured by the 3D printer are influenced by various parameters such as extrusion temperature, infill density, building direction, layer height, etc. A total of 96 specimens were built by altering building orientation and layer height to estimate and compare the tensile properties of the printed parts. To investigate the aging effect, 30 of 96 specimens were printed 6 months before the tensile experiment. Half of both aged and new specimens were cured in an oven at 57.5 [˚C] for 3 hours while the other half endured no heat treatment. After the performed measurement, it can be concluded that heat treatment generally improves structural strength of the printed parts, while aging decreases it. However, these effects are highly dependent on the layer thickness and printing quality. The tensile test is conducted according to the ASTM D638 standard. The fractured samples were further characterized using an electron microscope.",
publisher = "Romania : Revista Chimie SRL",
journal = "Materiale  Plastice",
title = "Impact of Aging Effect and Heat Treatment on the Tensile Properties of PLA (Poly Lactic Acid) Printed Parts",
volume = "57",
number = "3",
pages = "147-159",
doi = "10.37358/MP.20.3.5389"
}

Hasan, M. S., Ivanov, T., Vorkapić, M., Simonović, A., Daou, D., Kovačević, A.,& Milovanović, A.. (2020). Impact of Aging Effect and Heat Treatment on the Tensile Properties of PLA (Poly Lactic Acid) Printed Parts. in Materiale  Plastice
Romania : Revista Chimie SRL., 57(3), 147-159.
https://doi.org/10.37358/MP.20.3.5389

Hasan MS, Ivanov T, Vorkapić M, Simonović A, Daou D, Kovačević A, Milovanović A. Impact of Aging Effect and Heat Treatment on the Tensile Properties of PLA (Poly Lactic Acid) Printed Parts. in Materiale  Plastice. 2020;57(3):147-159.
doi:10.37358/MP.20.3.5389 .

Hasan, Mohammad Sakib, Ivanov, Toni, Vorkapić, Miloš, Simonović, Aleksandar, Daou, David, Kovačević, Aleksandar, Milovanović, Aleksa, "Impact of Aging Effect and Heat Treatment on the Tensile Properties of PLA (Poly Lactic Acid) Printed Parts" in Materiale  Plastice, 57, no. 3 (2020):147-159,
https://doi.org/10.37358/MP.20.3.5389 . .

TY  - JOUR
AU  - Baltić, Marija
AU  - Svorcan, Jelena
AU  - Perić, Bojan
AU  - Vorkapić, Miloš
AU  - Ivanov, Toni
AU  - Peković, Ognjen
PY  - 2019
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2997
AB  - In order to investigate both static and dynamic characteristics of composite plates and validate a contemporary, non-invasive experimental technique a comparative experimental and numerical analysis was performed. Three, geometrically the same but different in ply orientation, carbon-epoxy laminates were tested in both healthy and damaged conditions. Damages were inflicted in a shape of horizontal crack. Experiments and numerical simulations were performed by digital image correlation (DIC) and finite element method (FEM), respectively. Obtained time-responses of the tested structures were fast Fourier transformed (FFT) to frequency domain for a clearer
understanding of natural frequencies and oscillation modes. Results are presented in tabular and graphical form. The overall correspondence of two sets of structural displacements is satisfactory. Some discrepancies might be contributed to the idealized geometry and restraint consideration. Also, due to the fast damping of higher tones, the errors in determining higher natural frequencies increase but still remain in 5 % range.
PB  - Springer
T2  - Journal of Mechanical Science and Technology
T1  - Comparative numerical and experimental investigation of static and dynamic characteristics of composite plates
VL  - 33
IS  - 6
SP  - 2597
EP  - 2603
DO  - 10.1007/s12206-019-0507-7
ER  - 

@article{
author = "Baltić, Marija and Svorcan, Jelena and Perić, Bojan and Vorkapić, Miloš and Ivanov, Toni and Peković, Ognjen",
year = "2019",
abstract = "In order to investigate both static and dynamic characteristics of composite plates and validate a contemporary, non-invasive experimental technique a comparative experimental and numerical analysis was performed. Three, geometrically the same but different in ply orientation, carbon-epoxy laminates were tested in both healthy and damaged conditions. Damages were inflicted in a shape of horizontal crack. Experiments and numerical simulations were performed by digital image correlation (DIC) and finite element method (FEM), respectively. Obtained time-responses of the tested structures were fast Fourier transformed (FFT) to frequency domain for a clearer
understanding of natural frequencies and oscillation modes. Results are presented in tabular and graphical form. The overall correspondence of two sets of structural displacements is satisfactory. Some discrepancies might be contributed to the idealized geometry and restraint consideration. Also, due to the fast damping of higher tones, the errors in determining higher natural frequencies increase but still remain in 5 % range.",
publisher = "Springer",
journal = "Journal of Mechanical Science and Technology",
title = "Comparative numerical and experimental investigation of static and dynamic characteristics of composite plates",
volume = "33",
number = "6",
pages = "2597-2603",
doi = "10.1007/s12206-019-0507-7"
}

Baltić, M., Svorcan, J., Perić, B., Vorkapić, M., Ivanov, T.,& Peković, O.. (2019). Comparative numerical and experimental investigation of static and dynamic characteristics of composite plates. in Journal of Mechanical Science and Technology
Springer., 33(6), 2597-2603.
https://doi.org/10.1007/s12206-019-0507-7

Baltić M, Svorcan J, Perić B, Vorkapić M, Ivanov T, Peković O. Comparative numerical and experimental investigation of static and dynamic characteristics of composite plates. in Journal of Mechanical Science and Technology. 2019;33(6):2597-2603.
doi:10.1007/s12206-019-0507-7 .

Baltić, Marija, Svorcan, Jelena, Perić, Bojan, Vorkapić, Miloš, Ivanov, Toni, Peković, Ognjen, "Comparative numerical and experimental investigation of static and dynamic characteristics of composite plates" in Journal of Mechanical Science and Technology, 33, no. 6 (2019):2597-2603,
https://doi.org/10.1007/s12206-019-0507-7 . .

TY  - CONF
AU  - Vorkapić, Miloš
AU  - Ivanov, Toni
AU  - Alsabri, Anwer
AU  - Simonović, Aleksandar
PY  - 2018
UR  - http://cent.mas.bg.ac.rs/jupiter/index.htm
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/3909
AB  - Libija je zemlja bogata naftom i prirodnim gasom čije učešće u proizvodnji električne energije je preko 90%.
Međutim, sve više su u upotrebi i obnovljivi izvori energije, kao što je energija vetra. U Libiji postoji ogromni
potencijal za upotrebu energije vetra, a on je najveći u priobalnom delu. Ovim radom analizirana je
brzina vetra radi upotrebe vetroturbina u ruralnim oblastima Libije.
AB  - Libya is a rich country with oil and natural gas which accounts for over 90% of the country's total electricity
production. However, renewable energy sources, such as wind energy, are increasingly being used. In Libya there is a
huge potential for the use of wind energy, which is largest in the coastal area. This paper analyzes wind velocity for the
use of wind turbines in the rural regions of Libya.
PB  - Univerzitet u Beogradu - Mašinski fakultet
C3  - Zbornik radova - 41. JUPITER konferencija / Proceedings - 41nd JUPITER Conference
T1  - Predikcija brzine vetra na teritoriji Libije primenom veštačkih neuronskih mreža
SP  - 3.54
EP  - 3.59
UR  - https://hdl.handle.net/21.15107/rcub_cer_3909
ER  - 

@conference{
author = "Vorkapić, Miloš and Ivanov, Toni and Alsabri, Anwer and Simonović, Aleksandar",
year = "2018",
abstract = "Libija je zemlja bogata naftom i prirodnim gasom čije učešće u proizvodnji električne energije je preko 90%.
Međutim, sve više su u upotrebi i obnovljivi izvori energije, kao što je energija vetra. U Libiji postoji ogromni
potencijal za upotrebu energije vetra, a on je najveći u priobalnom delu. Ovim radom analizirana je
brzina vetra radi upotrebe vetroturbina u ruralnim oblastima Libije., Libya is a rich country with oil and natural gas which accounts for over 90% of the country's total electricity
production. However, renewable energy sources, such as wind energy, are increasingly being used. In Libya there is a
huge potential for the use of wind energy, which is largest in the coastal area. This paper analyzes wind velocity for the
use of wind turbines in the rural regions of Libya.",
publisher = "Univerzitet u Beogradu - Mašinski fakultet",
journal = "Zbornik radova - 41. JUPITER konferencija / Proceedings - 41nd JUPITER Conference",
title = "Predikcija brzine vetra na teritoriji Libije primenom veštačkih neuronskih mreža",
pages = "3.54-3.59",
url = "https://hdl.handle.net/21.15107/rcub_cer_3909"
}

Vorkapić, M., Ivanov, T., Alsabri, A.,& Simonović, A.. (2018). Predikcija brzine vetra na teritoriji Libije primenom veštačkih neuronskih mreža. in Zbornik radova - 41. JUPITER konferencija / Proceedings - 41nd JUPITER Conference
Univerzitet u Beogradu - Mašinski fakultet., 3.54-3.59.
https://hdl.handle.net/21.15107/rcub_cer_3909

Vorkapić M, Ivanov T, Alsabri A, Simonović A. Predikcija brzine vetra na teritoriji Libije primenom veštačkih neuronskih mreža. in Zbornik radova - 41. JUPITER konferencija / Proceedings - 41nd JUPITER Conference. 2018;:3.54-3.59.
https://hdl.handle.net/21.15107/rcub_cer_3909 .

Vorkapić, Miloš, Ivanov, Toni, Alsabri, Anwer, Simonović, Aleksandar, "Predikcija brzine vetra na teritoriji Libije primenom veštačkih neuronskih mreža" in Zbornik radova - 41. JUPITER konferencija / Proceedings - 41nd JUPITER Conference (2018):3.54-3.59,
https://hdl.handle.net/21.15107/rcub_cer_3909 .