TY  - JOUR
AU  - Vukšić Popović, Marija
AU  - Momčilović, Dejan
AU  - Tanasković, Jovan
AU  - Sedmak, Aleksandar
PY  - 2024
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7789
AB  - This paper presents an analysis of train screw coupling used mainly in Europe as mechanical
connection of wagons in train. An analysis of train breaks apart incidents revealed that less than
30 % of the cases were caused by elements of the screw coupling, with coupling links accounting
for only 5 % of the failures. Therefore, the investigation focused on testing the coupling links,
which are safety elements of the screw coupling. The coupling links underwent various inspections,
including visual inspection, dimensional control, non-destructive testing, examination
of chemical composition, and mechanical tests. Dimensional control found longitudinal plastic
deformations of the links. Chemical examination revealed that the links were made of different
material than recommended, but their mechanical properties generally met the recommended
values. However, variations were observed among different links, likely due to different rates of
deformation during testing and operational conditions. Overall, the analysis and inspections
provided insights into the condition and performance of coupling links in the screw coupling
system, highlighting the importance of monitoring and maintaining these elements to ensure safe
and efficient railway operations.
PB  - Elsevier
T2  - Engineering Failure Analysis
T1  - Testing of the condition and performance of coupling links from screw couplings of train
SP  - 108331
VL  - 161
DO  - 10.1016/j.engfailanal.2024.108331
ER  - 

@article{
author = "Vukšić Popović, Marija and Momčilović, Dejan and Tanasković, Jovan and Sedmak, Aleksandar",
year = "2024",
abstract = "This paper presents an analysis of train screw coupling used mainly in Europe as mechanical
connection of wagons in train. An analysis of train breaks apart incidents revealed that less than
30 % of the cases were caused by elements of the screw coupling, with coupling links accounting
for only 5 % of the failures. Therefore, the investigation focused on testing the coupling links,
which are safety elements of the screw coupling. The coupling links underwent various inspections,
including visual inspection, dimensional control, non-destructive testing, examination
of chemical composition, and mechanical tests. Dimensional control found longitudinal plastic
deformations of the links. Chemical examination revealed that the links were made of different
material than recommended, but their mechanical properties generally met the recommended
values. However, variations were observed among different links, likely due to different rates of
deformation during testing and operational conditions. Overall, the analysis and inspections
provided insights into the condition and performance of coupling links in the screw coupling
system, highlighting the importance of monitoring and maintaining these elements to ensure safe
and efficient railway operations.",
publisher = "Elsevier",
journal = "Engineering Failure Analysis",
title = "Testing of the condition and performance of coupling links from screw couplings of train",
pages = "108331",
volume = "161",
doi = "10.1016/j.engfailanal.2024.108331"
}

Vukšić Popović, M., Momčilović, D., Tanasković, J.,& Sedmak, A.. (2024). Testing of the condition and performance of coupling links from screw couplings of train. in Engineering Failure Analysis
Elsevier., 161, 108331.
https://doi.org/10.1016/j.engfailanal.2024.108331

Vukšić Popović M, Momčilović D, Tanasković J, Sedmak A. Testing of the condition and performance of coupling links from screw couplings of train. in Engineering Failure Analysis. 2024;161:108331.
doi:10.1016/j.engfailanal.2024.108331 .

Vukšić Popović, Marija, Momčilović, Dejan, Tanasković, Jovan, Sedmak, Aleksandar, "Testing of the condition and performance of coupling links from screw couplings of train" in Engineering Failure Analysis, 161 (2024):108331,
https://doi.org/10.1016/j.engfailanal.2024.108331 . .

TY  - JOUR
AU  - Milovanović, Aleksa
AU  - Montanari, Matteo
AU  - Golubović, Zorana
AU  - Marghitas, Mihai
AU  - Spagnoli, Andrea
AU  - Brighenti, Roberto
AU  - Sedmak, Aleksandar
PY  - 2024
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7785
AB  - In recent years, Additive Manufacturing (AM) has become an increasingly popular method in industrial
applications for fabricating components with complex geometries, offering several benefits over traditional
(subtractive) manufacturing methods. Among all available AM technologies, ‘‘vat photopolymerization’’ is still
a reliable approach for manufacturing high-resolution components at relatively small costs. This particular
AM technology is based on the photopolymerization process where 3D objects are created by light-induced
solidification and it has been broadly developed and used in the past decades. Depending on the employed
light source there are three different subtypes of this technology, namely: SLA, DLP, and mSLA. Among all
three listed, the Masked Stereolithography Apparatus (mSLA) technology has emerged as a promising approach
due to the much simpler AM machine construction compared to the other two. However, the mechanical
properties of mSLA components have not been studied extensively, hence there is a lack of knowledge of
how AM process parameters and post-processing treatments affect the final mechanical properties of mSLA
components. This work presents an experimental investigation of the compressive and flexural mechanical
responses of components produced through this relatively new AM technology. A series of static and cyclic
tests were conducted with varying layer thickness and post-curing times. It is demonstrated that a thorough
optimization of the mentioned variables is required to obtain parts with the desired mechanical properties.
PB  - Elsevier
T2  - Theoretical and Applied Fracture Mechanics
T1  - Compressive and flexural mechanical responses of components obtained through mSLA vat photopolymerization technology
IS  - 104406
VL  - 131
DO  - 10.1016/j.tafmec.2024.104406
ER  - 

@article{
author = "Milovanović, Aleksa and Montanari, Matteo and Golubović, Zorana and Marghitas, Mihai and Spagnoli, Andrea and Brighenti, Roberto and Sedmak, Aleksandar",
year = "2024",
abstract = "In recent years, Additive Manufacturing (AM) has become an increasingly popular method in industrial
applications for fabricating components with complex geometries, offering several benefits over traditional
(subtractive) manufacturing methods. Among all available AM technologies, ‘‘vat photopolymerization’’ is still
a reliable approach for manufacturing high-resolution components at relatively small costs. This particular
AM technology is based on the photopolymerization process where 3D objects are created by light-induced
solidification and it has been broadly developed and used in the past decades. Depending on the employed
light source there are three different subtypes of this technology, namely: SLA, DLP, and mSLA. Among all
three listed, the Masked Stereolithography Apparatus (mSLA) technology has emerged as a promising approach
due to the much simpler AM machine construction compared to the other two. However, the mechanical
properties of mSLA components have not been studied extensively, hence there is a lack of knowledge of
how AM process parameters and post-processing treatments affect the final mechanical properties of mSLA
components. This work presents an experimental investigation of the compressive and flexural mechanical
responses of components produced through this relatively new AM technology. A series of static and cyclic
tests were conducted with varying layer thickness and post-curing times. It is demonstrated that a thorough
optimization of the mentioned variables is required to obtain parts with the desired mechanical properties.",
publisher = "Elsevier",
journal = "Theoretical and Applied Fracture Mechanics",
title = "Compressive and flexural mechanical responses of components obtained through mSLA vat photopolymerization technology",
number = "104406",
volume = "131",
doi = "10.1016/j.tafmec.2024.104406"
}

Milovanović, A., Montanari, M., Golubović, Z., Marghitas, M., Spagnoli, A., Brighenti, R.,& Sedmak, A.. (2024). Compressive and flexural mechanical responses of components obtained through mSLA vat photopolymerization technology. in Theoretical and Applied Fracture Mechanics
Elsevier., 131(104406).
https://doi.org/10.1016/j.tafmec.2024.104406

Milovanović A, Montanari M, Golubović Z, Marghitas M, Spagnoli A, Brighenti R, Sedmak A. Compressive and flexural mechanical responses of components obtained through mSLA vat photopolymerization technology. in Theoretical and Applied Fracture Mechanics. 2024;131(104406).
doi:10.1016/j.tafmec.2024.104406 .

Milovanović, Aleksa, Montanari, Matteo, Golubović, Zorana, Marghitas, Mihai, Spagnoli, Andrea, Brighenti, Roberto, Sedmak, Aleksandar, "Compressive and flexural mechanical responses of components obtained through mSLA vat photopolymerization technology" in Theoretical and Applied Fracture Mechanics, 131, no. 104406 (2024),
https://doi.org/10.1016/j.tafmec.2024.104406 . .

TY  - JOUR
AU  - Jelić, Mirjana
AU  - Sedmak, Aleksandar
AU  - Folić, Boris
AU  - Sedmak, Simon
AU  - Aranđelović, Mihajlo
AU  - Folić, Radomir
AU  - Radu, Dorin
PY  - 2024
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7779
AB  - Belgrade fair hall 1 is well known for its dome, which is still the world largest self-supported construction made of pre-stressed concrete, with its diameter of 106 m. In this paper the Finite Element Method (FEM) was performed to analyze different loading and supporting conditions. At the same time, crack growth in a support column was simulated by the extended FEM (XFEM). Results of numerical calculations indicate ingenious design of such a complex structure which was based on “hand” calculation decades ago, without computers. In addition to classical engineering and more advanced numerical calculations, risk based analysis was performed taking into account artificially introduced crack and Failure Analysis Diagram, obtained using stress intensity factor and net stress, as well as fracture toughness and critical stress. This analysis, made for the first time for Belgrade fair hall 1, proved that its structural integrity is jeopardized only when a crack reaches half the thickness of a steel bar.
T2  - Frattura ed Integrita Strutturale
T1  - Structural integrity analysis of the pre-stressed concrete dome of the Belgrade fair hall 1
EP  - 351
IS  - 67
SP  - 337
VL  - 18
DO  - 10.3221/IGF-ESIS.67.24
ER  - 

@article{
author = "Jelić, Mirjana and Sedmak, Aleksandar and Folić, Boris and Sedmak, Simon and Aranđelović, Mihajlo and Folić, Radomir and Radu, Dorin",
year = "2024",
abstract = "Belgrade fair hall 1 is well known for its dome, which is still the world largest self-supported construction made of pre-stressed concrete, with its diameter of 106 m. In this paper the Finite Element Method (FEM) was performed to analyze different loading and supporting conditions. At the same time, crack growth in a support column was simulated by the extended FEM (XFEM). Results of numerical calculations indicate ingenious design of such a complex structure which was based on “hand” calculation decades ago, without computers. In addition to classical engineering and more advanced numerical calculations, risk based analysis was performed taking into account artificially introduced crack and Failure Analysis Diagram, obtained using stress intensity factor and net stress, as well as fracture toughness and critical stress. This analysis, made for the first time for Belgrade fair hall 1, proved that its structural integrity is jeopardized only when a crack reaches half the thickness of a steel bar.",
journal = "Frattura ed Integrita Strutturale",
title = "Structural integrity analysis of the pre-stressed concrete dome of the Belgrade fair hall 1",
pages = "351-337",
number = "67",
volume = "18",
doi = "10.3221/IGF-ESIS.67.24"
}

Jelić, M., Sedmak, A., Folić, B., Sedmak, S., Aranđelović, M., Folić, R.,& Radu, D.. (2024). Structural integrity analysis of the pre-stressed concrete dome of the Belgrade fair hall 1. in Frattura ed Integrita Strutturale, 18(67), 337-351.
https://doi.org/10.3221/IGF-ESIS.67.24

Jelić M, Sedmak A, Folić B, Sedmak S, Aranđelović M, Folić R, Radu D. Structural integrity analysis of the pre-stressed concrete dome of the Belgrade fair hall 1. in Frattura ed Integrita Strutturale. 2024;18(67):337-351.
doi:10.3221/IGF-ESIS.67.24 .

Jelić, Mirjana, Sedmak, Aleksandar, Folić, Boris, Sedmak, Simon, Aranđelović, Mihajlo, Folić, Radomir, Radu, Dorin, "Structural integrity analysis of the pre-stressed concrete dome of the Belgrade fair hall 1" in Frattura ed Integrita Strutturale, 18, no. 67 (2024):337-351,
https://doi.org/10.3221/IGF-ESIS.67.24 . .

TY  - JOUR
AU  - Sedmak, Aleksandar
AU  - Petrovski, Blagoj
AU  - Grbović, Aleksandar
AU  - Sedmak, Simon
AU  - Milošević, Nenad
PY  - 2024
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7778
AB  - Experimental and numerical analysis of crack growth in integral skin-stringer panels, produced by Laser Beam Welding (LBW), was performed in the scope of WELDAIR project and later on. Experiment was performed on full-scale components (four stringers, three welded clips), made of AA 6156 T6. Digital Image Correlation (DIC) was used to measure strains and construct CTOD or J crack resistance curves. It was shown that J vs. Δa can have unusual shape, indicating real component crack resistance instead of critical J value commonly obtained by comparing J-R curves with calculated Crack Driving Forces (CDFs). The applied technique is simple, practical and has no limitation in respect to material and geometry
PB  - Elsevier
T2  - Procedia Structural Integrity
T1  - Crack Resistance of AA6156 Welded Stringer Panels
EP  - 380
SP  - 376
VL  - 54
DO  - 10.1016/j.prostr.2024.01.096
ER  - 

@article{
author = "Sedmak, Aleksandar and Petrovski, Blagoj and Grbović, Aleksandar and Sedmak, Simon and Milošević, Nenad",
year = "2024",
abstract = "Experimental and numerical analysis of crack growth in integral skin-stringer panels, produced by Laser Beam Welding (LBW), was performed in the scope of WELDAIR project and later on. Experiment was performed on full-scale components (four stringers, three welded clips), made of AA 6156 T6. Digital Image Correlation (DIC) was used to measure strains and construct CTOD or J crack resistance curves. It was shown that J vs. Δa can have unusual shape, indicating real component crack resistance instead of critical J value commonly obtained by comparing J-R curves with calculated Crack Driving Forces (CDFs). The applied technique is simple, practical and has no limitation in respect to material and geometry",
publisher = "Elsevier",
journal = "Procedia Structural Integrity",
title = "Crack Resistance of AA6156 Welded Stringer Panels",
pages = "380-376",
volume = "54",
doi = "10.1016/j.prostr.2024.01.096"
}

Sedmak, A., Petrovski, B., Grbović, A., Sedmak, S.,& Milošević, N.. (2024). Crack Resistance of AA6156 Welded Stringer Panels. in Procedia Structural Integrity
Elsevier., 54, 376-380.
https://doi.org/10.1016/j.prostr.2024.01.096

Sedmak A, Petrovski B, Grbović A, Sedmak S, Milošević N. Crack Resistance of AA6156 Welded Stringer Panels. in Procedia Structural Integrity. 2024;54:376-380.
doi:10.1016/j.prostr.2024.01.096 .

Sedmak, Aleksandar, Petrovski, Blagoj, Grbović, Aleksandar, Sedmak, Simon, Milošević, Nenad, "Crack Resistance of AA6156 Welded Stringer Panels" in Procedia Structural Integrity, 54 (2024):376-380,
https://doi.org/10.1016/j.prostr.2024.01.096 . .

TY  - CONF
AU  - Milovanović, Aleksa
AU  - Galațanu, Sergiu-Valentin
AU  - Sedmak, Aleksandar
AU  - Marsavina, Liviu
AU  - Trajković, Isaak
AU  - Popa, Cosmin-Florin
AU  - Milošević, Miloš
PY  - 2024
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7780
AB  - Polylactic Acid (PLA) is a widely used material in Fused Deposition Modeling (FDM) technology. Additive Manufacturing (AM) parameters are known to have an influence on the mechanical properties of final components. In FDM, the layer thickness is an influencing parameter providing overall better mechanical properties with lower layer thickness values. In that case, the air gaps created between layers and raster lines have a lower share in total volume. However, layer over-compression might be an issue when choosing the lowest layer thickness options. This research paper investigates the impact properties of PLA material with variations in layer thickness namely, 0.1, 0.2, and 0.3 mm are considered here. Charpy tests were used for the impact property assessment, and all specimens were prepared with 100% infill percentage and honeycomb infill structure. Worth mentioning is that specimens have AMed notches. The impact tests were carried out on 7 specimens per batch (a total of 21 specimens). Therefore, obtained impact results from an instrumented pendulum were observed between groups to have an insight into the beneficial influence of lower layer thickness on impact properties and lower result scatter that finer layer resolution should produce.
PB  - Elsevier
C3  - Procedia Structural Integrity
T1  - Layer thickness influence on impact properties of FDM printed PLA material
EP  - 197
SP  - 190
VL  - 56
DO  - 10.1016/j.prostr.2024.02.055
ER  - 

@conference{
author = "Milovanović, Aleksa and Galațanu, Sergiu-Valentin and Sedmak, Aleksandar and Marsavina, Liviu and Trajković, Isaak and Popa, Cosmin-Florin and Milošević, Miloš",
year = "2024",
abstract = "Polylactic Acid (PLA) is a widely used material in Fused Deposition Modeling (FDM) technology. Additive Manufacturing (AM) parameters are known to have an influence on the mechanical properties of final components. In FDM, the layer thickness is an influencing parameter providing overall better mechanical properties with lower layer thickness values. In that case, the air gaps created between layers and raster lines have a lower share in total volume. However, layer over-compression might be an issue when choosing the lowest layer thickness options. This research paper investigates the impact properties of PLA material with variations in layer thickness namely, 0.1, 0.2, and 0.3 mm are considered here. Charpy tests were used for the impact property assessment, and all specimens were prepared with 100% infill percentage and honeycomb infill structure. Worth mentioning is that specimens have AMed notches. The impact tests were carried out on 7 specimens per batch (a total of 21 specimens). Therefore, obtained impact results from an instrumented pendulum were observed between groups to have an insight into the beneficial influence of lower layer thickness on impact properties and lower result scatter that finer layer resolution should produce.",
publisher = "Elsevier",
journal = "Procedia Structural Integrity",
title = "Layer thickness influence on impact properties of FDM printed PLA material",
pages = "197-190",
volume = "56",
doi = "10.1016/j.prostr.2024.02.055"
}

Milovanović, A., Galațanu, S., Sedmak, A., Marsavina, L., Trajković, I., Popa, C.,& Milošević, M.. (2024). Layer thickness influence on impact properties of FDM printed PLA material. in Procedia Structural Integrity
Elsevier., 56, 190-197.
https://doi.org/10.1016/j.prostr.2024.02.055

Milovanović A, Galațanu S, Sedmak A, Marsavina L, Trajković I, Popa C, Milošević M. Layer thickness influence on impact properties of FDM printed PLA material. in Procedia Structural Integrity. 2024;56:190-197.
doi:10.1016/j.prostr.2024.02.055 .

Milovanović, Aleksa, Galațanu, Sergiu-Valentin, Sedmak, Aleksandar, Marsavina, Liviu, Trajković, Isaak, Popa, Cosmin-Florin, Milošević, Miloš, "Layer thickness influence on impact properties of FDM printed PLA material" in Procedia Structural Integrity, 56 (2024):190-197,
https://doi.org/10.1016/j.prostr.2024.02.055 . .

TY  - JOUR
AU  - Aranđelović, Mihajlo
AU  - Đorđević, Branislav R.
AU  - Sedmak, Simon
AU  - Radu, Dorin
AU  - Petrović, Ana
AU  - Dikić, Stefan
AU  - Sedmak, Aleksandar
PY  - 2024
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7776
AB  - Failure analysis of welded joint with multiple defects was performed taking into account the effect of all defects, not just a dominant one. Four cases of multiple defects in welded joint under the uniaxial tensile loading were investigated using extended Finite Element Method. Two-dimensional Finite Element Models were made according to the tensile specimens with initial crack located in a critical area of welded joint. For each multiple defects case, numerical simulation was performed with three initial crack depth. Engineering Critical Analysis was made using Failure Assessment Diagrams for each defect that was determined as critical for its welded joint case. Numerical simulation showed that the geometry of the most prominent one from a point of view of structural integrity. It was concluded that the vertical misalignment in combination with a secondary defect, had the most adverse effect which can lead to failure of welded structure.
PB  - Elsevier
T2  - Engineering Failure Analysis
T1  - Failure analysis of welded joint with multiple defects by extended Finite Element Method and Engineering Critical Analysis
SP  - 108176
VL  - 160
DO  - 10.1016/j.engfailanal.2024.108176
ER  - 

@article{
author = "Aranđelović, Mihajlo and Đorđević, Branislav R. and Sedmak, Simon and Radu, Dorin and Petrović, Ana and Dikić, Stefan and Sedmak, Aleksandar",
year = "2024",
abstract = "Failure analysis of welded joint with multiple defects was performed taking into account the effect of all defects, not just a dominant one. Four cases of multiple defects in welded joint under the uniaxial tensile loading were investigated using extended Finite Element Method. Two-dimensional Finite Element Models were made according to the tensile specimens with initial crack located in a critical area of welded joint. For each multiple defects case, numerical simulation was performed with three initial crack depth. Engineering Critical Analysis was made using Failure Assessment Diagrams for each defect that was determined as critical for its welded joint case. Numerical simulation showed that the geometry of the most prominent one from a point of view of structural integrity. It was concluded that the vertical misalignment in combination with a secondary defect, had the most adverse effect which can lead to failure of welded structure.",
publisher = "Elsevier",
journal = "Engineering Failure Analysis",
title = "Failure analysis of welded joint with multiple defects by extended Finite Element Method and Engineering Critical Analysis",
pages = "108176",
volume = "160",
doi = "10.1016/j.engfailanal.2024.108176"
}

Aranđelović, M., Đorđević, B. R., Sedmak, S., Radu, D., Petrović, A., Dikić, S.,& Sedmak, A.. (2024). Failure analysis of welded joint with multiple defects by extended Finite Element Method and Engineering Critical Analysis. in Engineering Failure Analysis
Elsevier., 160, 108176.
https://doi.org/10.1016/j.engfailanal.2024.108176

Aranđelović M, Đorđević BR, Sedmak S, Radu D, Petrović A, Dikić S, Sedmak A. Failure analysis of welded joint with multiple defects by extended Finite Element Method and Engineering Critical Analysis. in Engineering Failure Analysis. 2024;160:108176.
doi:10.1016/j.engfailanal.2024.108176 .

Aranđelović, Mihajlo, Đorđević, Branislav R., Sedmak, Simon, Radu, Dorin, Petrović, Ana, Dikić, Stefan, Sedmak, Aleksandar, "Failure analysis of welded joint with multiple defects by extended Finite Element Method and Engineering Critical Analysis" in Engineering Failure Analysis, 160 (2024):108176,
https://doi.org/10.1016/j.engfailanal.2024.108176 . .

TY  - JOUR
AU  - Sedmak, Aleksandar
AU  - Radu, Dorin
AU  - Aranđelović, Mihajlo
AU  - Sedmak, Simon
AU  - Bancila, Radu
PY  - 2024
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7777
AB  - Numerous roads and railways network steel bridges exist with more than 100 years in service, often of great historical value. The in-service safety assessment of these structures is a complex problem which requires interdisciplinary approaches – from civil engineering application of Eurocodes or European recommendation for fatigue life estimation, up to an in-depth assessment by means of fracture mechanics. This article emphasizes the importance of rehabilitating the structure of existing steel bridges, considering the historical monument character of these structures, as well as the reuse of existing structures. Toward this aim, the study case for a historical riveted steel bridge build in the beginning of the twentieth century is presented, with an assessment method considering the structural integrity by means of fracture mechanics. Based on this case study, the paper is proposing an algorithm to assess historical steel bridges. The results of in-depth XFEM analysis with different crack size in the area of a riveted joint are also presented, in order to validate the algorithm.
PB  - Elsevier
T2  - Engineering Fracture Mechanics
T1  - Residual life assessment of the historical road riveted bridges
SP  - 109960
VL  - 299
DO  - 10.1016/j.engfracmech.2024.109960
ER  - 

@article{
author = "Sedmak, Aleksandar and Radu, Dorin and Aranđelović, Mihajlo and Sedmak, Simon and Bancila, Radu",
year = "2024",
abstract = "Numerous roads and railways network steel bridges exist with more than 100 years in service, often of great historical value. The in-service safety assessment of these structures is a complex problem which requires interdisciplinary approaches – from civil engineering application of Eurocodes or European recommendation for fatigue life estimation, up to an in-depth assessment by means of fracture mechanics. This article emphasizes the importance of rehabilitating the structure of existing steel bridges, considering the historical monument character of these structures, as well as the reuse of existing structures. Toward this aim, the study case for a historical riveted steel bridge build in the beginning of the twentieth century is presented, with an assessment method considering the structural integrity by means of fracture mechanics. Based on this case study, the paper is proposing an algorithm to assess historical steel bridges. The results of in-depth XFEM analysis with different crack size in the area of a riveted joint are also presented, in order to validate the algorithm.",
publisher = "Elsevier",
journal = "Engineering Fracture Mechanics",
title = "Residual life assessment of the historical road riveted bridges",
pages = "109960",
volume = "299",
doi = "10.1016/j.engfracmech.2024.109960"
}

Sedmak, A., Radu, D., Aranđelović, M., Sedmak, S.,& Bancila, R.. (2024). Residual life assessment of the historical road riveted bridges. in Engineering Fracture Mechanics
Elsevier., 299, 109960.
https://doi.org/10.1016/j.engfracmech.2024.109960

Sedmak A, Radu D, Aranđelović M, Sedmak S, Bancila R. Residual life assessment of the historical road riveted bridges. in Engineering Fracture Mechanics. 2024;299:109960.
doi:10.1016/j.engfracmech.2024.109960 .

Sedmak, Aleksandar, Radu, Dorin, Aranđelović, Mihajlo, Sedmak, Simon, Bancila, Radu, "Residual life assessment of the historical road riveted bridges" in Engineering Fracture Mechanics, 299 (2024):109960,
https://doi.org/10.1016/j.engfracmech.2024.109960 . .

TY  - JOUR
AU  - Raičević, Nikola
AU  - Grbović, Aleksandar
AU  - Kastratović, Gordana
AU  - Vidanović, Nenad
AU  - Sedmak, Aleksandar
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7006
AB  - This paper deals with the damage growth in High-Pressure Turbine (HPT) cooling holes of the case assembly made of Inconel 718. Several marks (cuts) were made on cooling holes into parent material during the service due to the non-skilled use of Electrical Discharge Machining (EDM) in the workshop. After a certain time, the case assembly returned to the workshop with all EDM marks cracked. Since HPT case assembly is not repairable and the only method for fixing this issue is its replacement with the new or used one (which might be pretty expensive), it was decided to use numerical analysis to estimate Paris coefficients for used Inconel 718, since the number of cycles and crack growth from the initial position were known, based on data obtained from the workshop. Firstly, finite element method (FEM) based numerical analysis was conducted in order to simulate crack propagation to match the one observed in the workshop, and then a multi-objective genetic algorithm – The standard response surface type - full second order polynomials – was used to obtain required Paris coefficients. The objectives of this optimization were the crack length and the corresponding number of cycles of crack growth. Obtained Paris coefficients were then used to estimate the residual life of HPT case assembly.
PB  - ELSEVIER
T2  - Procedia Structural Integrity
T1  - Residual life estimation of damaged structures exposed to high pressures and temperatures
EP  - 347
SP  - 342
VL  - 48
DO  - 10.1016/j.prostr.2023.07.123
ER  - 

@article{
author = "Raičević, Nikola and Grbović, Aleksandar and Kastratović, Gordana and Vidanović, Nenad and Sedmak, Aleksandar",
year = "2023",
abstract = "This paper deals with the damage growth in High-Pressure Turbine (HPT) cooling holes of the case assembly made of Inconel 718. Several marks (cuts) were made on cooling holes into parent material during the service due to the non-skilled use of Electrical Discharge Machining (EDM) in the workshop. After a certain time, the case assembly returned to the workshop with all EDM marks cracked. Since HPT case assembly is not repairable and the only method for fixing this issue is its replacement with the new or used one (which might be pretty expensive), it was decided to use numerical analysis to estimate Paris coefficients for used Inconel 718, since the number of cycles and crack growth from the initial position were known, based on data obtained from the workshop. Firstly, finite element method (FEM) based numerical analysis was conducted in order to simulate crack propagation to match the one observed in the workshop, and then a multi-objective genetic algorithm – The standard response surface type - full second order polynomials – was used to obtain required Paris coefficients. The objectives of this optimization were the crack length and the corresponding number of cycles of crack growth. Obtained Paris coefficients were then used to estimate the residual life of HPT case assembly.",
publisher = "ELSEVIER",
journal = "Procedia Structural Integrity",
title = "Residual life estimation of damaged structures exposed to high pressures and temperatures",
pages = "347-342",
volume = "48",
doi = "10.1016/j.prostr.2023.07.123"
}

Raičević, N., Grbović, A., Kastratović, G., Vidanović, N.,& Sedmak, A.. (2023). Residual life estimation of damaged structures exposed to high pressures and temperatures. in Procedia Structural Integrity
ELSEVIER., 48, 342-347.
https://doi.org/10.1016/j.prostr.2023.07.123

Raičević N, Grbović A, Kastratović G, Vidanović N, Sedmak A. Residual life estimation of damaged structures exposed to high pressures and temperatures. in Procedia Structural Integrity. 2023;48:342-347.
doi:10.1016/j.prostr.2023.07.123 .

Raičević, Nikola, Grbović, Aleksandar, Kastratović, Gordana, Vidanović, Nenad, Sedmak, Aleksandar, "Residual life estimation of damaged structures exposed to high pressures and temperatures" in Procedia Structural Integrity, 48 (2023):342-347,
https://doi.org/10.1016/j.prostr.2023.07.123 . .

TY  - CONF
AU  - Sedmak, Simon
AU  - Aranđelović, Mihajlo
AU  - Sedmak, Aleksandar
AU  - Petrović, Ana
AU  - Đorđević, Branislav
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/6027
AB  - Simulation of crack initiation and propagation which occurred during the tensile
testing of real welded joint specimens made of low-alloyed low-carbon structural
steels is presented in this paper. Welded joints in questions were made with a
number of different defect combinations [1-3], such as excess weld metal, undercuts,
vertical misalignment and incomplete root penetration. Tensile tests were performed
on specimens divided into four groups according to their defect combinations, along
with numerical simulations using finite element method [4-6]. Once numerical models
which were valid in terms of stress and strain distribution were obtained, cracks were
introduced in the most critical locations, which corresponded to the real specimen
locations were failure of specimens initiated. The goal was to observe the behaviour
of models in the presence of these cracks, since in the case of experimental
specimens, fracture behaviour was often unconventional, due to complex geometry
which caused them to deform in unexpected manner. This geometry was influenced
by the presence of multiple different defects in the welded joint, and in some cases
even resulted in stress states that were not uniaxial, as is usually the case with
experiments and simulations like the one presented here
C3  - The 27th International Conference on Fracture and Structural Integrity
T1  - Numerical simulation of crack growth in welded joints in the presence of multiple defects
SP  - 178
UR  - https://hdl.handle.net/21.15107/rcub_machinery_6027
ER  - 

@conference{
author = "Sedmak, Simon and Aranđelović, Mihajlo and Sedmak, Aleksandar and Petrović, Ana and Đorđević, Branislav",
year = "2023",
abstract = "Simulation of crack initiation and propagation which occurred during the tensile
testing of real welded joint specimens made of low-alloyed low-carbon structural
steels is presented in this paper. Welded joints in questions were made with a
number of different defect combinations [1-3], such as excess weld metal, undercuts,
vertical misalignment and incomplete root penetration. Tensile tests were performed
on specimens divided into four groups according to their defect combinations, along
with numerical simulations using finite element method [4-6]. Once numerical models
which were valid in terms of stress and strain distribution were obtained, cracks were
introduced in the most critical locations, which corresponded to the real specimen
locations were failure of specimens initiated. The goal was to observe the behaviour
of models in the presence of these cracks, since in the case of experimental
specimens, fracture behaviour was often unconventional, due to complex geometry
which caused them to deform in unexpected manner. This geometry was influenced
by the presence of multiple different defects in the welded joint, and in some cases
even resulted in stress states that were not uniaxial, as is usually the case with
experiments and simulations like the one presented here",
journal = "The 27th International Conference on Fracture and Structural Integrity",
title = "Numerical simulation of crack growth in welded joints in the presence of multiple defects",
pages = "178",
url = "https://hdl.handle.net/21.15107/rcub_machinery_6027"
}

Sedmak, S., Aranđelović, M., Sedmak, A., Petrović, A.,& Đorđević, B.. (2023). Numerical simulation of crack growth in welded joints in the presence of multiple defects. in The 27th International Conference on Fracture and Structural Integrity, 178.
https://hdl.handle.net/21.15107/rcub_machinery_6027

Sedmak S, Aranđelović M, Sedmak A, Petrović A, Đorđević B. Numerical simulation of crack growth in welded joints in the presence of multiple defects. in The 27th International Conference on Fracture and Structural Integrity. 2023;:178.
https://hdl.handle.net/21.15107/rcub_machinery_6027 .

Sedmak, Simon, Aranđelović, Mihajlo, Sedmak, Aleksandar, Petrović, Ana, Đorđević, Branislav, "Numerical simulation of crack growth in welded joints in the presence of multiple defects" in The 27th International Conference on Fracture and Structural Integrity (2023):178,
https://hdl.handle.net/21.15107/rcub_machinery_6027 .

TY  - CONF
AU  - Trajković, Isaak
AU  - Milošević, Miloš
AU  - Mitrović, Nenad
AU  - Sedmak, Aleksandar
AU  - Rakin, Marko
AU  - Međo, Bojan
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7700
AB  - A global problem for industrial plants that contain process equipment operating under high pressure is the assessment of the integrity of the equipment, specifically the pipelines. Standard procedures for determining fracture mechanics parameters (ASTM E1820) for materials used in pressure piping construction cannot be applied to most thin-wall pressure components. One of the solutions to this problem is the introduction of new procedures and geometries of test specimens. In order to understand the nature of the behavior of the specimens and to determine the parameters whose critical values are important for integrity assessment of the pipeline under pressure, a detailed analysis of the model of the non-standard ring-shaped specimen is
necessary. This paper will present the results of the analysis of fracture mechanics parameters obtained by the finite element method using the Simulia Abaqus software package. The properties of the material used in the software correspond to the properties of the P235TR1 pipeline material obtained by tensile testing on cylindrical samples with initial crack. The ratio of crack length (a) to sample width (W) corresponds to standard sample geometries and varies from a/W = 0.4 to a/W = 0.6. The values obtained from SENT (Single Edge Notched Tension) models with the same cross-section and a/W ratio were taken as reference values in relation to which the comparison is made. As a result of this research, the ratio of fracture mechanics parameters of the ring-shaped model (Pipe Ring Notched Tension – PRNT specimen) with a crack and the SENT model was obtained. The values of the J-integral were also obtained, distribution of values along the crack front does not correspond to the profile obtained on the SENT model. As a result of this test, a procedure for determining the critical value of the J-integral for models corresponding to the tested P235TR1 pipe samples was established, which is an important step in establishing a new procedure for testing of pipeline materials.
PB  - University of Belgrade - Faculty of Mechanical Engineering
C3  - International Conference of Experimental and Numerical Investigations and New Technologies CNN TECH 2023
T1  - THE INFLUENCE OF CYLLINDRICAL SPECIMEN GEOMETRY ON THE VALUES OF FRACTURE MECHANICS PARAMETERS
SP  - 26
UR  - https://hdl.handle.net/21.15107/rcub_machinery_7700
ER  - 

@conference{
author = "Trajković, Isaak and Milošević, Miloš and Mitrović, Nenad and Sedmak, Aleksandar and Rakin, Marko and Međo, Bojan",
year = "2023",
abstract = "A global problem for industrial plants that contain process equipment operating under high pressure is the assessment of the integrity of the equipment, specifically the pipelines. Standard procedures for determining fracture mechanics parameters (ASTM E1820) for materials used in pressure piping construction cannot be applied to most thin-wall pressure components. One of the solutions to this problem is the introduction of new procedures and geometries of test specimens. In order to understand the nature of the behavior of the specimens and to determine the parameters whose critical values are important for integrity assessment of the pipeline under pressure, a detailed analysis of the model of the non-standard ring-shaped specimen is
necessary. This paper will present the results of the analysis of fracture mechanics parameters obtained by the finite element method using the Simulia Abaqus software package. The properties of the material used in the software correspond to the properties of the P235TR1 pipeline material obtained by tensile testing on cylindrical samples with initial crack. The ratio of crack length (a) to sample width (W) corresponds to standard sample geometries and varies from a/W = 0.4 to a/W = 0.6. The values obtained from SENT (Single Edge Notched Tension) models with the same cross-section and a/W ratio were taken as reference values in relation to which the comparison is made. As a result of this research, the ratio of fracture mechanics parameters of the ring-shaped model (Pipe Ring Notched Tension – PRNT specimen) with a crack and the SENT model was obtained. The values of the J-integral were also obtained, distribution of values along the crack front does not correspond to the profile obtained on the SENT model. As a result of this test, a procedure for determining the critical value of the J-integral for models corresponding to the tested P235TR1 pipe samples was established, which is an important step in establishing a new procedure for testing of pipeline materials.",
publisher = "University of Belgrade - Faculty of Mechanical Engineering",
journal = "International Conference of Experimental and Numerical Investigations and New Technologies CNN TECH 2023",
title = "THE INFLUENCE OF CYLLINDRICAL SPECIMEN GEOMETRY ON THE VALUES OF FRACTURE MECHANICS PARAMETERS",
pages = "26",
url = "https://hdl.handle.net/21.15107/rcub_machinery_7700"
}

Trajković, I., Milošević, M., Mitrović, N., Sedmak, A., Rakin, M.,& Međo, B.. (2023). THE INFLUENCE OF CYLLINDRICAL SPECIMEN GEOMETRY ON THE VALUES OF FRACTURE MECHANICS PARAMETERS. in International Conference of Experimental and Numerical Investigations and New Technologies CNN TECH 2023
University of Belgrade - Faculty of Mechanical Engineering., 26.
https://hdl.handle.net/21.15107/rcub_machinery_7700

Trajković I, Milošević M, Mitrović N, Sedmak A, Rakin M, Međo B. THE INFLUENCE OF CYLLINDRICAL SPECIMEN GEOMETRY ON THE VALUES OF FRACTURE MECHANICS PARAMETERS. in International Conference of Experimental and Numerical Investigations and New Technologies CNN TECH 2023. 2023;:26.
https://hdl.handle.net/21.15107/rcub_machinery_7700 .

Trajković, Isaak, Milošević, Miloš, Mitrović, Nenad, Sedmak, Aleksandar, Rakin, Marko, Međo, Bojan, "THE INFLUENCE OF CYLLINDRICAL SPECIMEN GEOMETRY ON THE VALUES OF FRACTURE MECHANICS PARAMETERS" in International Conference of Experimental and Numerical Investigations and New Technologies CNN TECH 2023 (2023):26,
https://hdl.handle.net/21.15107/rcub_machinery_7700 .

TY  - JOUR
AU  - Perković, Srđa
AU  - Sedmak, Aleksandar
AU  - Radaković, Zoran
AU  - Burzić, Zijah
AU  - Sedmak, Simon
AU  - Radović, Ljubica
AU  - Mandić, Ivana
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/6886
AB  - The search for alternative materials that can be used for parts of aircraft hydraulic systems has led to the idea of applying S32750 duplex steel for this purpose. This steel is mainly used in the oil and gas, chemical, and food industries. The reasons for this lie in this material’s exceptional welding, mechanical, and corrosion resistance properties. In order to verify this material’s suitability for aircraft engineering applications, it is necessary to investigate its behaviour at various temperatures, since aircrafts operate at a wide range of temperatures. For this reason, the effect of temperatures in the range from +20 °C to −80 °C on impact toughness was investigated in the case of S32750 duplex steel and its welded joints. Testing was performed using an instrumented pendulum to obtain force-time and energy-time diagrams, which allowed for more detailed assessment of the effect of testing temperature on total impact energy and its components of crack initiation energy and crack propagation energy. Testing was performed on standard Charpy specimens extracted from base metal (BM), welded metal (WM), and the heat-affected zone (HAZ). The results of these tests indicated high values of both crack initiation and propagation energies at room temperature for all the zones (BM, WM, and HAZ) and sufficient levels of crack propagation and total impact energies above −50 °C. In addition, fractography was conducted through optical microscopy (OM) and scanning electron microscopy (SEM), indicating ductile vs. cleavage fracture surface areas, which corresponded well with the impact toughness values. The results of this research confirm that the use of S32750 duplex steel in the manufacturing of aircraft hydraulic systems has considerable potential, and future work should confirm this.
PB  - MDPI
T2  - Materials
T1  - Effect of temperature on S32750 duplex steel welded joint impact toughness
IS  - 12
VL  - 16
DO  - 10.3390/ma16124432
ER  - 

@article{
author = "Perković, Srđa and Sedmak, Aleksandar and Radaković, Zoran and Burzić, Zijah and Sedmak, Simon and Radović, Ljubica and Mandić, Ivana",
year = "2023",
abstract = "The search for alternative materials that can be used for parts of aircraft hydraulic systems has led to the idea of applying S32750 duplex steel for this purpose. This steel is mainly used in the oil and gas, chemical, and food industries. The reasons for this lie in this material’s exceptional welding, mechanical, and corrosion resistance properties. In order to verify this material’s suitability for aircraft engineering applications, it is necessary to investigate its behaviour at various temperatures, since aircrafts operate at a wide range of temperatures. For this reason, the effect of temperatures in the range from +20 °C to −80 °C on impact toughness was investigated in the case of S32750 duplex steel and its welded joints. Testing was performed using an instrumented pendulum to obtain force-time and energy-time diagrams, which allowed for more detailed assessment of the effect of testing temperature on total impact energy and its components of crack initiation energy and crack propagation energy. Testing was performed on standard Charpy specimens extracted from base metal (BM), welded metal (WM), and the heat-affected zone (HAZ). The results of these tests indicated high values of both crack initiation and propagation energies at room temperature for all the zones (BM, WM, and HAZ) and sufficient levels of crack propagation and total impact energies above −50 °C. In addition, fractography was conducted through optical microscopy (OM) and scanning electron microscopy (SEM), indicating ductile vs. cleavage fracture surface areas, which corresponded well with the impact toughness values. The results of this research confirm that the use of S32750 duplex steel in the manufacturing of aircraft hydraulic systems has considerable potential, and future work should confirm this.",
publisher = "MDPI",
journal = "Materials",
title = "Effect of temperature on S32750 duplex steel welded joint impact toughness",
number = "12",
volume = "16",
doi = "10.3390/ma16124432"
}

Perković, S., Sedmak, A., Radaković, Z., Burzić, Z., Sedmak, S., Radović, L.,& Mandić, I.. (2023). Effect of temperature on S32750 duplex steel welded joint impact toughness. in Materials
MDPI., 16(12).
https://doi.org/10.3390/ma16124432

Perković S, Sedmak A, Radaković Z, Burzić Z, Sedmak S, Radović L, Mandić I. Effect of temperature on S32750 duplex steel welded joint impact toughness. in Materials. 2023;16(12).
doi:10.3390/ma16124432 .

Perković, Srđa, Sedmak, Aleksandar, Radaković, Zoran, Burzić, Zijah, Sedmak, Simon, Radović, Ljubica, Mandić, Ivana, "Effect of temperature on S32750 duplex steel welded joint impact toughness" in Materials, 16, no. 12 (2023),
https://doi.org/10.3390/ma16124432 . .

TY  - JOUR
AU  - Perković, Srđa
AU  - Radaković, Zoran
AU  - Burzić, Zijah
AU  - Sedmak, Simon
AU  - Sedmak, Aleksandar
AU  - Radović, Ljubica
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/6885
AB  - The paper presents the effect of stress concentration on duplex steel S32750 (according to UNS standards or W.Nr. 1.4410 according to EN standards) behaviour under impact loading. This analysis is based on the results obtained by experimental testing, with particular focus on the influence of crack-like defects on material behaviour under impact load.
AB  - Predmet rada je analiza uticaja koncentracije napona na ponašanje dupleks čelika S32750 (prema UNS standardu ili W.Nr. 1.4410 prema EN standard) pri udarnom opterećenju. Na osnovu dobijenih rezultata ispitivanja, analiziran je uticaj prisustva greške tipa prsline na ponašanje materijala predviđenog za udarno opterećenje.
PB  - Society for Structural Integrity and Life - DIVK (Društvo za integritet i vek konstrukcija - DIVK)
PB  - Institute for Materials Testing - IMS (Institut za ispitivanje materijala - IMS)
T2  - Structural Integrity and Life (Integritet i vek konstrukcija)
T1  - Stress concentration effects on toughness value of duplex steel S32750
T1  - Uticaj koncentracije napona na vrednost žilavosti dupleks čelika S32750
EP  - 7
IS  - 1
SP  - 3
VL  - 23
UR  - https://hdl.handle.net/21.15107/rcub_machinery_6885
ER  - 

@article{
author = "Perković, Srđa and Radaković, Zoran and Burzić, Zijah and Sedmak, Simon and Sedmak, Aleksandar and Radović, Ljubica",
year = "2023",
abstract = "The paper presents the effect of stress concentration on duplex steel S32750 (according to UNS standards or W.Nr. 1.4410 according to EN standards) behaviour under impact loading. This analysis is based on the results obtained by experimental testing, with particular focus on the influence of crack-like defects on material behaviour under impact load., Predmet rada je analiza uticaja koncentracije napona na ponašanje dupleks čelika S32750 (prema UNS standardu ili W.Nr. 1.4410 prema EN standard) pri udarnom opterećenju. Na osnovu dobijenih rezultata ispitivanja, analiziran je uticaj prisustva greške tipa prsline na ponašanje materijala predviđenog za udarno opterećenje.",
publisher = "Society for Structural Integrity and Life - DIVK (Društvo za integritet i vek konstrukcija - DIVK), Institute for Materials Testing - IMS (Institut za ispitivanje materijala - IMS)",
journal = "Structural Integrity and Life (Integritet i vek konstrukcija)",
title = "Stress concentration effects on toughness value of duplex steel S32750, Uticaj koncentracije napona na vrednost žilavosti dupleks čelika S32750",
pages = "7-3",
number = "1",
volume = "23",
url = "https://hdl.handle.net/21.15107/rcub_machinery_6885"
}

Perković, S., Radaković, Z., Burzić, Z., Sedmak, S., Sedmak, A.,& Radović, L.. (2023). Stress concentration effects on toughness value of duplex steel S32750. in Structural Integrity and Life (Integritet i vek konstrukcija)
Society for Structural Integrity and Life - DIVK (Društvo za integritet i vek konstrukcija - DIVK)., 23(1), 3-7.
https://hdl.handle.net/21.15107/rcub_machinery_6885

Perković S, Radaković Z, Burzić Z, Sedmak S, Sedmak A, Radović L. Stress concentration effects on toughness value of duplex steel S32750. in Structural Integrity and Life (Integritet i vek konstrukcija). 2023;23(1):3-7.
https://hdl.handle.net/21.15107/rcub_machinery_6885 .

Perković, Srđa, Radaković, Zoran, Burzić, Zijah, Sedmak, Simon, Sedmak, Aleksandar, Radović, Ljubica, "Stress concentration effects on toughness value of duplex steel S32750" in Structural Integrity and Life (Integritet i vek konstrukcija), 23, no. 1 (2023):3-7,
https://hdl.handle.net/21.15107/rcub_machinery_6885 .

TY  - JOUR
AU  - Đorđević, Branislav
AU  - Mastilović, Sreten
AU  - Sedmak, Aleksandar
AU  - Dimić, Aleksandar
AU  - Kljajin, Milan
PY  - 2023
UR  - https://www.sciencedirect.com/science/article/pii/S0013794423006744
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7107
AB  - The phenomenon of ductile-to-brittle transition in ferritic steels has been a ubiquitous research challenge for the last 50 years. The characterization of this problem using the fracture mechanics concept, from the earliest studies based on the linear-elastic fracture mechanics to the application of the elastic–plastic fracture mechanics, has become inevitable over time. The fracture toughness is not an intrinsic material property but depends on geometrical factors (such as the specimen shape, thickness, and surface roughness), defect type and distribution, loading mode, and environmental conditions. The pronounced scatter of experimental data on fracture toughness, characteristic of all ferritic steels in the ductile-to-brittle transition temperature region, necessitated the use of statistical methods for data processing. That approach, which emerged in the 1970 s, can still be found today as the basis for interpreting fracture toughness data in ductile-to-brittle transition problems. This paper presents a brief historical overview of such studies along with the problems that have arisen as a consequence of using fracture mechanics concepts, such as constraint effects, as an example. In the time-honored research tradition, all the proposed methods and models, as well as their criticisms, provided the basis for the development of new approaches to the ductile-to-brittle characterization of ferritic steels. Specifically, these include size effects and scaling of geometrically similar samples, with the aim of predicting material behavior beyond experimental limits. Brief outlines of two new approaches are provided in this succinct review. The criticisms of all presented methods are oriented mostly on the application domain, as well as their capability to predict fracture toughness, with short overview of their most conspicuous advantages and disadvantages.
T2  - Engineering Fracture Mechanics
T1  - Ductile-to-brittle transition of ferritic steels: A historical sketch and some recent trends
SP  - 109716
VL  - 293
DO  - 10.1016/j.engfracmech.2023.109716
ER  - 

@article{
author = "Đorđević, Branislav and Mastilović, Sreten and Sedmak, Aleksandar and Dimić, Aleksandar and Kljajin, Milan",
year = "2023",
abstract = "The phenomenon of ductile-to-brittle transition in ferritic steels has been a ubiquitous research challenge for the last 50 years. The characterization of this problem using the fracture mechanics concept, from the earliest studies based on the linear-elastic fracture mechanics to the application of the elastic–plastic fracture mechanics, has become inevitable over time. The fracture toughness is not an intrinsic material property but depends on geometrical factors (such as the specimen shape, thickness, and surface roughness), defect type and distribution, loading mode, and environmental conditions. The pronounced scatter of experimental data on fracture toughness, characteristic of all ferritic steels in the ductile-to-brittle transition temperature region, necessitated the use of statistical methods for data processing. That approach, which emerged in the 1970 s, can still be found today as the basis for interpreting fracture toughness data in ductile-to-brittle transition problems. This paper presents a brief historical overview of such studies along with the problems that have arisen as a consequence of using fracture mechanics concepts, such as constraint effects, as an example. In the time-honored research tradition, all the proposed methods and models, as well as their criticisms, provided the basis for the development of new approaches to the ductile-to-brittle characterization of ferritic steels. Specifically, these include size effects and scaling of geometrically similar samples, with the aim of predicting material behavior beyond experimental limits. Brief outlines of two new approaches are provided in this succinct review. The criticisms of all presented methods are oriented mostly on the application domain, as well as their capability to predict fracture toughness, with short overview of their most conspicuous advantages and disadvantages.",
journal = "Engineering Fracture Mechanics",
title = "Ductile-to-brittle transition of ferritic steels: A historical sketch and some recent trends",
pages = "109716",
volume = "293",
doi = "10.1016/j.engfracmech.2023.109716"
}

Đorđević, B., Mastilović, S., Sedmak, A., Dimić, A.,& Kljajin, M.. (2023). Ductile-to-brittle transition of ferritic steels: A historical sketch and some recent trends. in Engineering Fracture Mechanics, 293, 109716.
https://doi.org/10.1016/j.engfracmech.2023.109716

Đorđević B, Mastilović S, Sedmak A, Dimić A, Kljajin M. Ductile-to-brittle transition of ferritic steels: A historical sketch and some recent trends. in Engineering Fracture Mechanics. 2023;293:109716.
doi:10.1016/j.engfracmech.2023.109716 .

Đorđević, Branislav, Mastilović, Sreten, Sedmak, Aleksandar, Dimić, Aleksandar, Kljajin, Milan, "Ductile-to-brittle transition of ferritic steels: A historical sketch and some recent trends" in Engineering Fracture Mechanics, 293 (2023):109716,
https://doi.org/10.1016/j.engfracmech.2023.109716 . .

TY  - JOUR
AU  - Adžiev, Gorgi
AU  - Sedmak, Aleksandar
AU  - Sedmak, Simon
AU  - Adžiev, Todor
AU  - Radaković, Zoran
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7108
AB  - The mismatching constraint effect on crack propagation through the heat-affected zone (HAZ) in a welded joint is presented in this paper. It is shown that due to this effect, the fracture behavior of an overmatched welded joint depends on the mechanical properties and the size of the region of the crack tip location, as well as on the properties and the size of surrounding regions. The finite element analysis of high-strength low-alloyed (HSLA) steel welded joints with crack tips in the heat-affected zone is performed based on previous experimental work. Two locations of the crack tip are analyzed: fine-grained HAZ (FGHAZ) and coarse-grained HAZ (CGHAZ). In both cases, after the initial propagation of the crack in FGHAZ or CGHAZ, its propagation is directed toward more ductile base metal, thus increasing the fracture resistance of a welded joint. Some new observations about the reasons for such behavior due to crack tip strain fields are presented as well.
T1  - Crack tip fields effects on crack propagation through the heat affected zone in an overmatched welded joint
IS  - 8
VL  - 46
DO  - 10.1111/ffe.14030
ER  - 

@article{
author = "Adžiev, Gorgi and Sedmak, Aleksandar and Sedmak, Simon and Adžiev, Todor and Radaković, Zoran",
year = "2023",
abstract = "The mismatching constraint effect on crack propagation through the heat-affected zone (HAZ) in a welded joint is presented in this paper. It is shown that due to this effect, the fracture behavior of an overmatched welded joint depends on the mechanical properties and the size of the region of the crack tip location, as well as on the properties and the size of surrounding regions. The finite element analysis of high-strength low-alloyed (HSLA) steel welded joints with crack tips in the heat-affected zone is performed based on previous experimental work. Two locations of the crack tip are analyzed: fine-grained HAZ (FGHAZ) and coarse-grained HAZ (CGHAZ). In both cases, after the initial propagation of the crack in FGHAZ or CGHAZ, its propagation is directed toward more ductile base metal, thus increasing the fracture resistance of a welded joint. Some new observations about the reasons for such behavior due to crack tip strain fields are presented as well.",
title = "Crack tip fields effects on crack propagation through the heat affected zone in an overmatched welded joint",
number = "8",
volume = "46",
doi = "10.1111/ffe.14030"
}

Adžiev, G., Sedmak, A., Sedmak, S., Adžiev, T.,& Radaković, Z.. (2023). Crack tip fields effects on crack propagation through the heat affected zone in an overmatched welded joint. , 46(8).
https://doi.org/10.1111/ffe.14030

Adžiev G, Sedmak A, Sedmak S, Adžiev T, Radaković Z. Crack tip fields effects on crack propagation through the heat affected zone in an overmatched welded joint. 2023;46(8).
doi:10.1111/ffe.14030 .

Adžiev, Gorgi, Sedmak, Aleksandar, Sedmak, Simon, Adžiev, Todor, Radaković, Zoran, "Crack tip fields effects on crack propagation through the heat affected zone in an overmatched welded joint", 46, no. 8 (2023),
https://doi.org/10.1111/ffe.14030 . .

TY  - JOUR
AU  - Petrov, Ljubiša
AU  - Bojović, Božica
AU  - Golubović, Zorana
AU  - Sedmak, Aleksandar
AU  - Mišković, Žarko
AU  - Trajković, Isaak
AU  - Milošević, Miloš
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7149
AB  - Since the beginnings of additive manufacturing (AM) in the 1980s, vat polymerization was the first and most intensively developing technology that enabled the production of very precise parts from photosensitive polymer resins. One of the most studied polymer materials is acrylonitrile butadiene styrene (ABS), but mostly in the form of filaments for the FDM (Fused Deposition Modelling) process. The objective of this research was to investigate in detail the mechanical properties of ABS resin specimens fabricated by stereolithography (SLA) and digital light processing (DLP). Specimen geometries were based on standards for tensile, threepoint bending, and compression tests. By combining deformation and mechanical tests with optical microscopic analyses of the morphology and fracture surface structures, as well as Shore A hardness measurements, a deeper insight into the behaviour of commercially available ABS resins was gained.
T2  - Structural Integrity and Life
T1  - Experimental Mechanical Characterization of Parts Manufactured by SLA and DLP Technologies
EP  - 121
IS  - 2
SP  - 117
VL  - 23
UR  - https://hdl.handle.net/21.15107/rcub_machinery_7149
ER  - 

@article{
author = "Petrov, Ljubiša and Bojović, Božica and Golubović, Zorana and Sedmak, Aleksandar and Mišković, Žarko and Trajković, Isaak and Milošević, Miloš",
year = "2023",
abstract = "Since the beginnings of additive manufacturing (AM) in the 1980s, vat polymerization was the first and most intensively developing technology that enabled the production of very precise parts from photosensitive polymer resins. One of the most studied polymer materials is acrylonitrile butadiene styrene (ABS), but mostly in the form of filaments for the FDM (Fused Deposition Modelling) process. The objective of this research was to investigate in detail the mechanical properties of ABS resin specimens fabricated by stereolithography (SLA) and digital light processing (DLP). Specimen geometries were based on standards for tensile, threepoint bending, and compression tests. By combining deformation and mechanical tests with optical microscopic analyses of the morphology and fracture surface structures, as well as Shore A hardness measurements, a deeper insight into the behaviour of commercially available ABS resins was gained.",
journal = "Structural Integrity and Life",
title = "Experimental Mechanical Characterization of Parts Manufactured by SLA and DLP Technologies",
pages = "121-117",
number = "2",
volume = "23",
url = "https://hdl.handle.net/21.15107/rcub_machinery_7149"
}

Petrov, L., Bojović, B., Golubović, Z., Sedmak, A., Mišković, Ž., Trajković, I.,& Milošević, M.. (2023). Experimental Mechanical Characterization of Parts Manufactured by SLA and DLP Technologies. in Structural Integrity and Life, 23(2), 117-121.
https://hdl.handle.net/21.15107/rcub_machinery_7149

Petrov L, Bojović B, Golubović Z, Sedmak A, Mišković Ž, Trajković I, Milošević M. Experimental Mechanical Characterization of Parts Manufactured by SLA and DLP Technologies. in Structural Integrity and Life. 2023;23(2):117-121.
https://hdl.handle.net/21.15107/rcub_machinery_7149 .

Petrov, Ljubiša, Bojović, Božica, Golubović, Zorana, Sedmak, Aleksandar, Mišković, Žarko, Trajković, Isaak, Milošević, Miloš, "Experimental Mechanical Characterization of Parts Manufactured by SLA and DLP Technologies" in Structural Integrity and Life, 23, no. 2 (2023):117-121,
https://hdl.handle.net/21.15107/rcub_machinery_7149 .

TY  - JOUR
AU  - Trajković, Isaak
AU  - Rakin, Marko
AU  - Milošević, Miloš
AU  - Mitrović, Nenad
AU  - Travica, Milan
AU  - Sedmak, Aleksandar
AU  - Međo, Bojan
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7231
AB  - In order to develop a non-standard method for determining the resistance to fracture and damage of pipeline materials, a new geometry of ring-shaped specimens with sharp notches or cracks has been defined. The need to develop a new method for testing of the specimens cut from the pipes arises due to the difficulties in determination of fracture mechanics parameters on thin-walled pressure pipelines, especially those with a smaller cross-section, by application of the standard procedures/specimens. Previous studies dealing with the topic of pipeline testing by non-standard methods are presented in the introductory part of the paper. In the experimental part of the research, tests on PRNT (Pipe Ring Notched Tension) and SENT (Single Edge Notched Tension) specimens are performed. Samples of these specimens were produced by SLS (Selective Laser Sintering) technique of additive production from PA12 (polyamide PA 2200) material. For the purpose of this study, a tool that is protected at the national level (in Serbia) as intellectual property is used for testing of the ring-shaped PRNT specimens. Tensile testing of both types of specimens is monitored by Aramis GOM 2M system; its operation is based on the method of digital image correlation, DIC. Additionally, finite element analyses are conducted on the PRNT and SENT geometries, enabling the calculation of the fracture mechanics parameter – Stress intensity factor K. It is concluded that the presented procedure based on the PRNT specimen has a good potential for use as a non-standard method for fracture resistance examination of pipeline materials. It can be performed on the specimens cut directly from the pipes (new or from exploitation). The dependence of the fracture resistance on the stress concentrator size is not pronounced, which means that the results depend dominantly on the material properties, rather than on geometry.
PB  - Engineering Fracture Mechanics
T2  - Engineering Fracture Mechanics
T1  - Selective laser sintered Pipe Ring Notched Tension specimens for examination of fracture properties of pipeline materials
IS  - 109573
VL  - 292
DO  - 10.1016/j.engfracmech.2023.109573
ER  - 

@article{
author = "Trajković, Isaak and Rakin, Marko and Milošević, Miloš and Mitrović, Nenad and Travica, Milan and Sedmak, Aleksandar and Međo, Bojan",
year = "2023",
abstract = "In order to develop a non-standard method for determining the resistance to fracture and damage of pipeline materials, a new geometry of ring-shaped specimens with sharp notches or cracks has been defined. The need to develop a new method for testing of the specimens cut from the pipes arises due to the difficulties in determination of fracture mechanics parameters on thin-walled pressure pipelines, especially those with a smaller cross-section, by application of the standard procedures/specimens. Previous studies dealing with the topic of pipeline testing by non-standard methods are presented in the introductory part of the paper. In the experimental part of the research, tests on PRNT (Pipe Ring Notched Tension) and SENT (Single Edge Notched Tension) specimens are performed. Samples of these specimens were produced by SLS (Selective Laser Sintering) technique of additive production from PA12 (polyamide PA 2200) material. For the purpose of this study, a tool that is protected at the national level (in Serbia) as intellectual property is used for testing of the ring-shaped PRNT specimens. Tensile testing of both types of specimens is monitored by Aramis GOM 2M system; its operation is based on the method of digital image correlation, DIC. Additionally, finite element analyses are conducted on the PRNT and SENT geometries, enabling the calculation of the fracture mechanics parameter – Stress intensity factor K. It is concluded that the presented procedure based on the PRNT specimen has a good potential for use as a non-standard method for fracture resistance examination of pipeline materials. It can be performed on the specimens cut directly from the pipes (new or from exploitation). The dependence of the fracture resistance on the stress concentrator size is not pronounced, which means that the results depend dominantly on the material properties, rather than on geometry.",
publisher = "Engineering Fracture Mechanics",
journal = "Engineering Fracture Mechanics",
title = "Selective laser sintered Pipe Ring Notched Tension specimens for examination of fracture properties of pipeline materials",
number = "109573",
volume = "292",
doi = "10.1016/j.engfracmech.2023.109573"
}

Trajković, I., Rakin, M., Milošević, M., Mitrović, N., Travica, M., Sedmak, A.,& Međo, B.. (2023). Selective laser sintered Pipe Ring Notched Tension specimens for examination of fracture properties of pipeline materials. in Engineering Fracture Mechanics
Engineering Fracture Mechanics., 292(109573).
https://doi.org/10.1016/j.engfracmech.2023.109573

Trajković I, Rakin M, Milošević M, Mitrović N, Travica M, Sedmak A, Međo B. Selective laser sintered Pipe Ring Notched Tension specimens for examination of fracture properties of pipeline materials. in Engineering Fracture Mechanics. 2023;292(109573).
doi:10.1016/j.engfracmech.2023.109573 .

Trajković, Isaak, Rakin, Marko, Milošević, Miloš, Mitrović, Nenad, Travica, Milan, Sedmak, Aleksandar, Međo, Bojan, "Selective laser sintered Pipe Ring Notched Tension specimens for examination of fracture properties of pipeline materials" in Engineering Fracture Mechanics, 292, no. 109573 (2023),
https://doi.org/10.1016/j.engfracmech.2023.109573 . .

TY  - JOUR
AU  - Aranđelović, Mihajlo
AU  - Petrović, Ana
AU  - Đorđević, Branislav
AU  - Sedmak, Simon
AU  - Sedmak, Aleksandar
AU  - Dikić, Stefan
AU  - Radu, Dorin
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/6010
AB  - The research represents the ongoing investigation of the welded joints behavior made
of low-carbon low-alloyed steel in the presence of different multiple defects. Following the initial
experimental and numerical analyses performed on low-grade steel, a set of experiments were
performed with specimens made of steel EN 1.0044 (commercial designation S275JR), along with
development of new numerical models. Four combinations were made, including defects like
undercuts, excess weld metal, misalignment, weld face sagging and incomplete root penetration,
considering that these defects are often encountered in practice, and can appear simultaneously. The finite element method (FEM) was used to simulate the experiments. Tensile properties of the HAZ and weld metal were calculated using strain measurements by the digital image correlation (DIC) method. The finite element method (FEM) results were in good agreement with the experimental ones.
PB  - MDPI
T2  - Sustainability
T1  - Effects of Multiple Defects on Welded Joint Behaviour under the Uniaxial Tensile Loading: Fem and Experimental Approach
IS  - 1
VL  - 15
DO  - doi.org/10.3390/su15010761
ER  - 

@article{
author = "Aranđelović, Mihajlo and Petrović, Ana and Đorđević, Branislav and Sedmak, Simon and Sedmak, Aleksandar and Dikić, Stefan and Radu, Dorin",
year = "2023",
abstract = "The research represents the ongoing investigation of the welded joints behavior made
of low-carbon low-alloyed steel in the presence of different multiple defects. Following the initial
experimental and numerical analyses performed on low-grade steel, a set of experiments were
performed with specimens made of steel EN 1.0044 (commercial designation S275JR), along with
development of new numerical models. Four combinations were made, including defects like
undercuts, excess weld metal, misalignment, weld face sagging and incomplete root penetration,
considering that these defects are often encountered in practice, and can appear simultaneously. The finite element method (FEM) was used to simulate the experiments. Tensile properties of the HAZ and weld metal were calculated using strain measurements by the digital image correlation (DIC) method. The finite element method (FEM) results were in good agreement with the experimental ones.",
publisher = "MDPI",
journal = "Sustainability",
title = "Effects of Multiple Defects on Welded Joint Behaviour under the Uniaxial Tensile Loading: Fem and Experimental Approach",
number = "1",
volume = "15",
doi = "doi.org/10.3390/su15010761"
}

Aranđelović, M., Petrović, A., Đorđević, B., Sedmak, S., Sedmak, A., Dikić, S.,& Radu, D.. (2023). Effects of Multiple Defects on Welded Joint Behaviour under the Uniaxial Tensile Loading: Fem and Experimental Approach. in Sustainability
MDPI., 15(1).
https://doi.org/doi.org/10.3390/su15010761

Aranđelović M, Petrović A, Đorđević B, Sedmak S, Sedmak A, Dikić S, Radu D. Effects of Multiple Defects on Welded Joint Behaviour under the Uniaxial Tensile Loading: Fem and Experimental Approach. in Sustainability. 2023;15(1).
doi:doi.org/10.3390/su15010761 .

Aranđelović, Mihajlo, Petrović, Ana, Đorđević, Branislav, Sedmak, Simon, Sedmak, Aleksandar, Dikić, Stefan, Radu, Dorin, "Effects of Multiple Defects on Welded Joint Behaviour under the Uniaxial Tensile Loading: Fem and Experimental Approach" in Sustainability, 15, no. 1 (2023),
https://doi.org/doi.org/10.3390/su15010761 . .

TY  - JOUR
AU  - Milovanović, Aleksa
AU  - Golubović, Zorana
AU  - Kirin, Snežana
AU  - Babinsky, Tomas
AU  - Šulak, Ivo
AU  - Milošević, Miloš
AU  - Sedmak, Aleksandar
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7147
AB  - Polypropylene (PP) is a relatively new material in fused deposition modeling
(FDM) technology. The main feature of this material is its ability to significantly elongate under
applied load, unlike any other thermoplastic material used in FDM technology. Not much research has been conducted on this FDM material so far, hence, the subject of this paper is the
investigation of printing parameters’ influence on PP tensile properties. Targeted parameters are
layer height, infill density, and the orientation of raster lines, resulting in four different manufacturing regimes. To have a better insight into the experimental results, the data are analysed using ANOVA statistical method with Tukey HSD post hoc test. Obtained statistical results have proven the printing parameter’s influence on tensile results, emphasizing the influence on elastic modulus. Here, Tukey test results show the maximal number of homogeneous subsets evidencing that all printing parameters have an influence on elastic modulus values.
T2  - Journal of Mechanical Science and Technology
T1  - Manufacturing parameter influence on FDM polypropylene tensile properties
VL  - 37
DO  - 10.1007/s12206-023-2305-5
ER  - 

@article{
author = "Milovanović, Aleksa and Golubović, Zorana and Kirin, Snežana and Babinsky, Tomas and Šulak, Ivo and Milošević, Miloš and Sedmak, Aleksandar",
year = "2023",
abstract = "Polypropylene (PP) is a relatively new material in fused deposition modeling
(FDM) technology. The main feature of this material is its ability to significantly elongate under
applied load, unlike any other thermoplastic material used in FDM technology. Not much research has been conducted on this FDM material so far, hence, the subject of this paper is the
investigation of printing parameters’ influence on PP tensile properties. Targeted parameters are
layer height, infill density, and the orientation of raster lines, resulting in four different manufacturing regimes. To have a better insight into the experimental results, the data are analysed using ANOVA statistical method with Tukey HSD post hoc test. Obtained statistical results have proven the printing parameter’s influence on tensile results, emphasizing the influence on elastic modulus. Here, Tukey test results show the maximal number of homogeneous subsets evidencing that all printing parameters have an influence on elastic modulus values.",
journal = "Journal of Mechanical Science and Technology",
title = "Manufacturing parameter influence on FDM polypropylene tensile properties",
volume = "37",
doi = "10.1007/s12206-023-2305-5"
}

Milovanović, A., Golubović, Z., Kirin, S., Babinsky, T., Šulak, I., Milošević, M.,& Sedmak, A.. (2023). Manufacturing parameter influence on FDM polypropylene tensile properties. in Journal of Mechanical Science and Technology, 37.
https://doi.org/10.1007/s12206-023-2305-5

Milovanović A, Golubović Z, Kirin S, Babinsky T, Šulak I, Milošević M, Sedmak A. Manufacturing parameter influence on FDM polypropylene tensile properties. in Journal of Mechanical Science and Technology. 2023;37.
doi:10.1007/s12206-023-2305-5 .

Milovanović, Aleksa, Golubović, Zorana, Kirin, Snežana, Babinsky, Tomas, Šulak, Ivo, Milošević, Miloš, Sedmak, Aleksandar, "Manufacturing parameter influence on FDM polypropylene tensile properties" in Journal of Mechanical Science and Technology, 37 (2023),
https://doi.org/10.1007/s12206-023-2305-5 . .

TY  - JOUR
AU  - Smoljanić, Tamara
AU  - Milovanović, Aleksa
AU  - Sedmak, Simon
AU  - Milović, Ljubica
AU  - Sedmak, Aleksandar
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7428
AB  - This paper presents development of numerical models for simulation of the behaviour of titanium alloy hip implants under static and dynamic loads, which is a part of extensive research involving the structural integrity of such implants under various loading conditions, as well as under exposure to aggressive environments. Numerical models were created in ABAQUS and ANSYS software packages, in order to determine the stress/strain distribution, the number of cycles to failure and stress intensity factors, for two different hip implant geometries. The ABAQUS models were used for static and ANSYS models for dynamic loads. The next stage in this analysis involved comparing these two cases, to determine the one with the better behaviour, depending on the exploitation conditions, which can greatly vary between different groups of patients. The targeted patient weight for all numerical simulations was 90 kg, while failure assessment diagrams were made for both implant geometries, assuming a crack length of 1 mm.
T2  - HEMIJSKA INDUSTRIJA (Chemical Industry)
T1  - Numerical simulation of titanium alloy hip replacement implants behaviour under static and dynamic loads
DO  - 10.2298/HEMIND221118026S
ER  - 

@article{
author = "Smoljanić, Tamara and Milovanović, Aleksa and Sedmak, Simon and Milović, Ljubica and Sedmak, Aleksandar",
year = "2023",
abstract = "This paper presents development of numerical models for simulation of the behaviour of titanium alloy hip implants under static and dynamic loads, which is a part of extensive research involving the structural integrity of such implants under various loading conditions, as well as under exposure to aggressive environments. Numerical models were created in ABAQUS and ANSYS software packages, in order to determine the stress/strain distribution, the number of cycles to failure and stress intensity factors, for two different hip implant geometries. The ABAQUS models were used for static and ANSYS models for dynamic loads. The next stage in this analysis involved comparing these two cases, to determine the one with the better behaviour, depending on the exploitation conditions, which can greatly vary between different groups of patients. The targeted patient weight for all numerical simulations was 90 kg, while failure assessment diagrams were made for both implant geometries, assuming a crack length of 1 mm.",
journal = "HEMIJSKA INDUSTRIJA (Chemical Industry)",
title = "Numerical simulation of titanium alloy hip replacement implants behaviour under static and dynamic loads",
doi = "10.2298/HEMIND221118026S"
}

Smoljanić, T., Milovanović, A., Sedmak, S., Milović, L.,& Sedmak, A.. (2023). Numerical simulation of titanium alloy hip replacement implants behaviour under static and dynamic loads. in HEMIJSKA INDUSTRIJA (Chemical Industry).
https://doi.org/10.2298/HEMIND221118026S

Smoljanić T, Milovanović A, Sedmak S, Milović L, Sedmak A. Numerical simulation of titanium alloy hip replacement implants behaviour under static and dynamic loads. in HEMIJSKA INDUSTRIJA (Chemical Industry). 2023;.
doi:10.2298/HEMIND221118026S .

Smoljanić, Tamara, Milovanović, Aleksa, Sedmak, Simon, Milović, Ljubica, Sedmak, Aleksandar, "Numerical simulation of titanium alloy hip replacement implants behaviour under static and dynamic loads" in HEMIJSKA INDUSTRIJA (Chemical Industry) (2023),
https://doi.org/10.2298/HEMIND221118026S . .

TY  - JOUR
AU  - Mastilović, Sreten
AU  - Đorđević, Branislav
AU  - Sedmak, Aleksandar
AU  - Kirin, Snežana
PY  - 2023
UR  - http://divk.inovacionicentar.rs/ivk/ivk23/OF2302-1.html
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7105
AB  - The phenomenon of ductile-to-brittle transition (DBT) in ferritic steels, widely used in design of nuclear reactor pressure vessels, has been a pervasive semi-centennial research topic. Due to the extremely pronounced experimental data scatter, the statistical approach to characterization of this problem has become inevitable from the earliest analyses. In the present study, the fracture toughness parameters derived from the EURO fracture toughness dataset for 22NiMoCr37 reactor steel are used with the aim to explore the utility of the recently proposed two-step-scaling method. Two widely different temperatures (-154 °C and -91 °C; belonging to the lower shelf and the DBT transition regions of fracture toughness, in respect) are selected to demonstrate the accuracy of extrapolation and interpolation of the fracture toughness CDF (cumulative distribution function) and the pertinent issues related to the method application. The fracture toughness measure used is the critical value of the stress intensity factor used in the master curve KJc (MPa√m). The obtained predictions are in good agreement with the experimental results and well within the inherent experimental data scatter. The prediction of the fracture toughness CDF obtained by extrapolation using the novel two-step-scaling method is reasonably conservative.
PB  - Društvo za integritet i vek konstrukcija „Prof. dr Stojan Sedmak“, Institut za ispitivanje materijala (IMS), Beograd
T2  - Structural Integrity and Life -
T1  - SIZE EFFECT ASSESSMENT OF KJc EXPERIMENTAL DATA USING THE TWO-STEP-SCALING METHOD
EP  - 110
IS  - 2
SP  - 105
VL  - 23
UR  - https://hdl.handle.net/21.15107/rcub_machinery_7105
ER  - 

@article{
author = "Mastilović, Sreten and Đorđević, Branislav and Sedmak, Aleksandar and Kirin, Snežana",
year = "2023",
abstract = "The phenomenon of ductile-to-brittle transition (DBT) in ferritic steels, widely used in design of nuclear reactor pressure vessels, has been a pervasive semi-centennial research topic. Due to the extremely pronounced experimental data scatter, the statistical approach to characterization of this problem has become inevitable from the earliest analyses. In the present study, the fracture toughness parameters derived from the EURO fracture toughness dataset for 22NiMoCr37 reactor steel are used with the aim to explore the utility of the recently proposed two-step-scaling method. Two widely different temperatures (-154 °C and -91 °C; belonging to the lower shelf and the DBT transition regions of fracture toughness, in respect) are selected to demonstrate the accuracy of extrapolation and interpolation of the fracture toughness CDF (cumulative distribution function) and the pertinent issues related to the method application. The fracture toughness measure used is the critical value of the stress intensity factor used in the master curve KJc (MPa√m). The obtained predictions are in good agreement with the experimental results and well within the inherent experimental data scatter. The prediction of the fracture toughness CDF obtained by extrapolation using the novel two-step-scaling method is reasonably conservative.",
publisher = "Društvo za integritet i vek konstrukcija „Prof. dr Stojan Sedmak“, Institut za ispitivanje materijala (IMS), Beograd",
journal = "Structural Integrity and Life -",
title = "SIZE EFFECT ASSESSMENT OF KJc EXPERIMENTAL DATA USING THE TWO-STEP-SCALING METHOD",
pages = "110-105",
number = "2",
volume = "23",
url = "https://hdl.handle.net/21.15107/rcub_machinery_7105"
}

Mastilović, S., Đorđević, B., Sedmak, A.,& Kirin, S.. (2023). SIZE EFFECT ASSESSMENT OF KJc EXPERIMENTAL DATA USING THE TWO-STEP-SCALING METHOD. in Structural Integrity and Life -
Društvo za integritet i vek konstrukcija „Prof. dr Stojan Sedmak“, Institut za ispitivanje materijala (IMS), Beograd., 23(2), 105-110.
https://hdl.handle.net/21.15107/rcub_machinery_7105

Mastilović S, Đorđević B, Sedmak A, Kirin S. SIZE EFFECT ASSESSMENT OF KJc EXPERIMENTAL DATA USING THE TWO-STEP-SCALING METHOD. in Structural Integrity and Life -. 2023;23(2):105-110.
https://hdl.handle.net/21.15107/rcub_machinery_7105 .

Mastilović, Sreten, Đorđević, Branislav, Sedmak, Aleksandar, Kirin, Snežana, "SIZE EFFECT ASSESSMENT OF KJc EXPERIMENTAL DATA USING THE TWO-STEP-SCALING METHOD" in Structural Integrity and Life -, 23, no. 2 (2023):105-110,
https://hdl.handle.net/21.15107/rcub_machinery_7105 .

TY  - JOUR
AU  - Raičević, Nikola
AU  - Grbović, Aleksandar
AU  - Kastratović, Gordana
AU  - Vidanović, Nenad
AU  - Sedmak, Aleksandar
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7007
AB  - The torque link is part of the nose landing gear of aircraft. It prevents the piston from turning inside the cylinder of the shock absorber, enabling its up and down motion during the landing and take-off. As such, its structural integrity and life are crucial for aircraft safe operation, but because of complex geometry and variable loading conditions, its fatigue life estimation represents a real challenge. In this paper, fatigue lives of two different designs of the torque links of the light aircraft are evaluated by a numerical approach based on the improved FEM. Firstly, the fatigue life of the damaged torque link was assessed for actual load conditions. Then, improved torque links, obtained through topological optimization, were analyzed and their fatigue life was calculated. Finally, the numerical simulations of the additive manufacturing (AM) process of optimized torque links were carried out, and the fatigue life of these torque links, including residual stresses from AM, were estimated too. The obtained numbers of cycles in all cases were compared and discussed for all torque links cases. This is an advanced approach to fatigue life assessment of optimized printed 3D parts based on numerical simulations of both crack growth and AM process.
PB  - Elsevier
T2  - International Journal of Fatigue
T1  - Fatigue life prediction of topologically optimized torque link adjusted for additive manufacturing
SP  - 107907
VL  - 176
DO  - 10.1016/j.ijfatigue.2023.107907
ER  - 

@article{
author = "Raičević, Nikola and Grbović, Aleksandar and Kastratović, Gordana and Vidanović, Nenad and Sedmak, Aleksandar",
year = "2023",
abstract = "The torque link is part of the nose landing gear of aircraft. It prevents the piston from turning inside the cylinder of the shock absorber, enabling its up and down motion during the landing and take-off. As such, its structural integrity and life are crucial for aircraft safe operation, but because of complex geometry and variable loading conditions, its fatigue life estimation represents a real challenge. In this paper, fatigue lives of two different designs of the torque links of the light aircraft are evaluated by a numerical approach based on the improved FEM. Firstly, the fatigue life of the damaged torque link was assessed for actual load conditions. Then, improved torque links, obtained through topological optimization, were analyzed and their fatigue life was calculated. Finally, the numerical simulations of the additive manufacturing (AM) process of optimized torque links were carried out, and the fatigue life of these torque links, including residual stresses from AM, were estimated too. The obtained numbers of cycles in all cases were compared and discussed for all torque links cases. This is an advanced approach to fatigue life assessment of optimized printed 3D parts based on numerical simulations of both crack growth and AM process.",
publisher = "Elsevier",
journal = "International Journal of Fatigue",
title = "Fatigue life prediction of topologically optimized torque link adjusted for additive manufacturing",
pages = "107907",
volume = "176",
doi = "10.1016/j.ijfatigue.2023.107907"
}

Raičević, N., Grbović, A., Kastratović, G., Vidanović, N.,& Sedmak, A.. (2023). Fatigue life prediction of topologically optimized torque link adjusted for additive manufacturing. in International Journal of Fatigue
Elsevier., 176, 107907.
https://doi.org/10.1016/j.ijfatigue.2023.107907

Raičević N, Grbović A, Kastratović G, Vidanović N, Sedmak A. Fatigue life prediction of topologically optimized torque link adjusted for additive manufacturing. in International Journal of Fatigue. 2023;176:107907.
doi:10.1016/j.ijfatigue.2023.107907 .

Raičević, Nikola, Grbović, Aleksandar, Kastratović, Gordana, Vidanović, Nenad, Sedmak, Aleksandar, "Fatigue life prediction of topologically optimized torque link adjusted for additive manufacturing" in International Journal of Fatigue, 176 (2023):107907,
https://doi.org/10.1016/j.ijfatigue.2023.107907 . .

TY  - JOUR
AU  - Milovanović, Aleksa
AU  - Golubović, Zorana
AU  - Kirin, Snežana
AU  - Babinský, Tomáš
AU  - Šulák, Ivo
AU  - Milošević, Miloš
AU  - Sedmak, Aleksandar
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7643
AB  - Polypropylene (PP) is a relatively new material in fused deposition modeling (FDM) technology. The main feature of this material is its ability to significantly elongate under applied load, unlike any other thermoplastic material used in FDM technology. Not much research has been conducted on this FDM material so far, hence, the subject of this paper is the investigation of printing parameters’ influence on PP tensile properties. Targeted parameters are layer height, infill density, and the orientation of raster lines, resulting in four different manufacturing regimes. To have a better insight into the experimental results, the data are analysed using ANOVA statistical method with Tukey HSD post hoc test. Obtained statistical results have proven the printing parameter’s influence on tensile results, emphasizing the influence on elastic modulus. Here, Tukey test results show the maximal number of homogeneous subsets evidencing that all printing parameters have an influence on elastic modulus values.
T2  - Journal of Mechanical Science and Technology
T1  - Manufacturing parameter influence on FDM polypropylene tensile properties
EP  - 7
IS  - 11
SP  - 1
VL  - 37
DO  - 10.1007/s12206-023-2305-5
ER  - 

@article{
author = "Milovanović, Aleksa and Golubović, Zorana and Kirin, Snežana and Babinský, Tomáš and Šulák, Ivo and Milošević, Miloš and Sedmak, Aleksandar",
year = "2023",
abstract = "Polypropylene (PP) is a relatively new material in fused deposition modeling (FDM) technology. The main feature of this material is its ability to significantly elongate under applied load, unlike any other thermoplastic material used in FDM technology. Not much research has been conducted on this FDM material so far, hence, the subject of this paper is the investigation of printing parameters’ influence on PP tensile properties. Targeted parameters are layer height, infill density, and the orientation of raster lines, resulting in four different manufacturing regimes. To have a better insight into the experimental results, the data are analysed using ANOVA statistical method with Tukey HSD post hoc test. Obtained statistical results have proven the printing parameter’s influence on tensile results, emphasizing the influence on elastic modulus. Here, Tukey test results show the maximal number of homogeneous subsets evidencing that all printing parameters have an influence on elastic modulus values.",
journal = "Journal of Mechanical Science and Technology",
title = "Manufacturing parameter influence on FDM polypropylene tensile properties",
pages = "7-1",
number = "11",
volume = "37",
doi = "10.1007/s12206-023-2305-5"
}

Milovanović, A., Golubović, Z., Kirin, S., Babinský, T., Šulák, I., Milošević, M.,& Sedmak, A.. (2023). Manufacturing parameter influence on FDM polypropylene tensile properties. in Journal of Mechanical Science and Technology, 37(11), 1-7.
https://doi.org/10.1007/s12206-023-2305-5

Milovanović A, Golubović Z, Kirin S, Babinský T, Šulák I, Milošević M, Sedmak A. Manufacturing parameter influence on FDM polypropylene tensile properties. in Journal of Mechanical Science and Technology. 2023;37(11):1-7.
doi:10.1007/s12206-023-2305-5 .

Milovanović, Aleksa, Golubović, Zorana, Kirin, Snežana, Babinský, Tomáš, Šulák, Ivo, Milošević, Miloš, Sedmak, Aleksandar, "Manufacturing parameter influence on FDM polypropylene tensile properties" in Journal of Mechanical Science and Technology, 37, no. 11 (2023):1-7,
https://doi.org/10.1007/s12206-023-2305-5 . .

TY  - JOUR
AU  - Gorgi, Adziev
AU  - Sedmak, Aleksandar
AU  - Sedmak, Simon
AU  - Adžiev, Todor
AU  - Radaković, Zoran
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7758
AB  - The mismatching constraint effect on crack propagation through the heat‐affected zone (HAZ) in a welded joint is presented in this paper. It is shown that due to this effect, the fracture behavior of an overmatched welded joint depends on the mechanical properties and the size of the region of the crack tip location, as well as on the properties and the size of surrounding regions. The finite element analysis of high‐strength low‐alloyed (HSLA) steel welded joints with crack tips in the heat‐affected zone is performed based on previous experimental work. Two locations of the crack tip are analyzed: fine‐grained HAZ (FGHAZ) and coarse‐grained HAZ (CGHAZ). In both cases, after the initial propagation of the crack in FGHAZ or CGHAZ, its propagation is directed toward more ductile base metal, thus increasing the fracture resistance of a welded joint. Some new observations about the reasons for such behavior due to crack tip strain fields are presented as well.
PB  - John Wiley & Sons Ltd.
T2  - Fatigue & Fracture of Engineering Materials & Structures
T1  - Crack tip fields effects on crack propagation through the heat affected zone in an overmatched welded joint
EP  - 3028
IS  - 8
SP  - 3014
VL  - 46
DO  - 10.1111/ffe.14030
ER  - 

@article{
author = "Gorgi, Adziev and Sedmak, Aleksandar and Sedmak, Simon and Adžiev, Todor and Radaković, Zoran",
year = "2023",
abstract = "The mismatching constraint effect on crack propagation through the heat‐affected zone (HAZ) in a welded joint is presented in this paper. It is shown that due to this effect, the fracture behavior of an overmatched welded joint depends on the mechanical properties and the size of the region of the crack tip location, as well as on the properties and the size of surrounding regions. The finite element analysis of high‐strength low‐alloyed (HSLA) steel welded joints with crack tips in the heat‐affected zone is performed based on previous experimental work. Two locations of the crack tip are analyzed: fine‐grained HAZ (FGHAZ) and coarse‐grained HAZ (CGHAZ). In both cases, after the initial propagation of the crack in FGHAZ or CGHAZ, its propagation is directed toward more ductile base metal, thus increasing the fracture resistance of a welded joint. Some new observations about the reasons for such behavior due to crack tip strain fields are presented as well.",
publisher = "John Wiley & Sons Ltd.",
journal = "Fatigue & Fracture of Engineering Materials & Structures",
title = "Crack tip fields effects on crack propagation through the heat affected zone in an overmatched welded joint",
pages = "3028-3014",
number = "8",
volume = "46",
doi = "10.1111/ffe.14030"
}

Gorgi, A., Sedmak, A., Sedmak, S., Adžiev, T.,& Radaković, Z.. (2023). Crack tip fields effects on crack propagation through the heat affected zone in an overmatched welded joint. in Fatigue & Fracture of Engineering Materials & Structures
John Wiley & Sons Ltd.., 46(8), 3014-3028.
https://doi.org/10.1111/ffe.14030

Gorgi A, Sedmak A, Sedmak S, Adžiev T, Radaković Z. Crack tip fields effects on crack propagation through the heat affected zone in an overmatched welded joint. in Fatigue & Fracture of Engineering Materials & Structures. 2023;46(8):3014-3028.
doi:10.1111/ffe.14030 .

Gorgi, Adziev, Sedmak, Aleksandar, Sedmak, Simon, Adžiev, Todor, Radaković, Zoran, "Crack tip fields effects on crack propagation through the heat affected zone in an overmatched welded joint" in Fatigue & Fracture of Engineering Materials & Structures, 46, no. 8 (2023):3014-3028,
https://doi.org/10.1111/ffe.14030 . .

TY  - JOUR
AU  - Dojčinović, Marina
AU  - Prokić Cvetković, Radica
AU  - Sedmak, Aleksandar
AU  - Popović, Olivera
AU  - Cvetković, Ivana
AU  - Radu, Dorin
PY  - 2023
UR  - https://www.scopus.com/record/display.uri?eid=2-s2.0-85164814751&origin=resultslist
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7768
AB  - The effect of the shielding gas arc welding process on the cavitation resistance of the three-component aluminum alloy AlMg4.5Mn and its welded joints was investigated. Welding was performed using the GTAW and GMAW processes in a shielded atmosphere of pure argon. After the welding, metallographic tests were performed, and the hardness distribution in the welded joints was determined. The ultrasonic vibration method was used to evaluate the base metal’s and weld metal’s resistance to cavitation. The change in mass was monitored to determine the cavitation rates. The morphology of the surface damage of the base metal and weld metal due to cavitation was monitored using scanning electron microscopy to explain the effect of the shielding gas arc welding process on their resistance to cavitation. © 2023 by the authors.
T2  - Materials
T1  - Effect of Shielding Gas Arc Welding Process on Cavitation Resistance of Welded Joints of AlMg4.5Mn Alloy
SP  - 4781
VL  - 16
DO  - 10.3390/ma16134781
ER  - 

@article{
author = "Dojčinović, Marina and Prokić Cvetković, Radica and Sedmak, Aleksandar and Popović, Olivera and Cvetković, Ivana and Radu, Dorin",
year = "2023",
abstract = "The effect of the shielding gas arc welding process on the cavitation resistance of the three-component aluminum alloy AlMg4.5Mn and its welded joints was investigated. Welding was performed using the GTAW and GMAW processes in a shielded atmosphere of pure argon. After the welding, metallographic tests were performed, and the hardness distribution in the welded joints was determined. The ultrasonic vibration method was used to evaluate the base metal’s and weld metal’s resistance to cavitation. The change in mass was monitored to determine the cavitation rates. The morphology of the surface damage of the base metal and weld metal due to cavitation was monitored using scanning electron microscopy to explain the effect of the shielding gas arc welding process on their resistance to cavitation. © 2023 by the authors.",
journal = "Materials",
title = "Effect of Shielding Gas Arc Welding Process on Cavitation Resistance of Welded Joints of AlMg4.5Mn Alloy",
pages = "4781",
volume = "16",
doi = "10.3390/ma16134781"
}

Dojčinović, M., Prokić Cvetković, R., Sedmak, A., Popović, O., Cvetković, I.,& Radu, D.. (2023). Effect of Shielding Gas Arc Welding Process on Cavitation Resistance of Welded Joints of AlMg4.5Mn Alloy. in Materials, 16, 4781.
https://doi.org/10.3390/ma16134781

Dojčinović M, Prokić Cvetković R, Sedmak A, Popović O, Cvetković I, Radu D. Effect of Shielding Gas Arc Welding Process on Cavitation Resistance of Welded Joints of AlMg4.5Mn Alloy. in Materials. 2023;16:4781.
doi:10.3390/ma16134781 .

Dojčinović, Marina, Prokić Cvetković, Radica, Sedmak, Aleksandar, Popović, Olivera, Cvetković, Ivana, Radu, Dorin, "Effect of Shielding Gas Arc Welding Process on Cavitation Resistance of Welded Joints of AlMg4.5Mn Alloy" in Materials, 16 (2023):4781,
https://doi.org/10.3390/ma16134781 . .

TY  - CONF
AU  - Milovanović, Aleksa
AU  - Babinský, Tomáš
AU  - Sedmak, Aleksandar
AU  - Milošević, Miloš
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7634
AB  - The structural life of a functional component includes the period when the component has developed some sort of defect (e.g., crack). In such cases, damage-tolerant design utilizes fracture mechanics parameters for the assessment of the component’s structural capability to withstand loads expected in the exploitation. One of the most fundamental parameters is the stress intensity factor, which characterizes the stress state near the crack tip. The critical value of this parameter is called fracture toughness, and it is the most suitable failure criterion for brittle materials. One of the most used materials in fused deposition modeling (FDM) technology is PLA polymer, known for its brittle behaviour. Due to good mechanical properties in comparison with other FDM polymers and excellent biocompatibility, the PLA material is not just a material for prototyping purposes but may also serve as a material for functional applications in medicine, food packaging, etc. The FDM printing parameters influence the final component's mechanical properties. The aim of this paper is to assess the impact of printing parameters, such as layer height, infill density, and raster orientation, on fracture toughness values.
C3  - International scientific and professional conference POLITEHNIKA 2023 (Belgrade, 15th December 2023)
T1  - PRINTING PARAMETER IMPACT ON PLA MATERIAL FRACTURE TOUGHNESS RESULTS
EP  - 525
SP  - 520
UR  - https://hdl.handle.net/21.15107/rcub_machinery_7634
ER  - 

@conference{
author = "Milovanović, Aleksa and Babinský, Tomáš and Sedmak, Aleksandar and Milošević, Miloš",
year = "2023",
abstract = "The structural life of a functional component includes the period when the component has developed some sort of defect (e.g., crack). In such cases, damage-tolerant design utilizes fracture mechanics parameters for the assessment of the component’s structural capability to withstand loads expected in the exploitation. One of the most fundamental parameters is the stress intensity factor, which characterizes the stress state near the crack tip. The critical value of this parameter is called fracture toughness, and it is the most suitable failure criterion for brittle materials. One of the most used materials in fused deposition modeling (FDM) technology is PLA polymer, known for its brittle behaviour. Due to good mechanical properties in comparison with other FDM polymers and excellent biocompatibility, the PLA material is not just a material for prototyping purposes but may also serve as a material for functional applications in medicine, food packaging, etc. The FDM printing parameters influence the final component's mechanical properties. The aim of this paper is to assess the impact of printing parameters, such as layer height, infill density, and raster orientation, on fracture toughness values.",
journal = "International scientific and professional conference POLITEHNIKA 2023 (Belgrade, 15th December 2023)",
title = "PRINTING PARAMETER IMPACT ON PLA MATERIAL FRACTURE TOUGHNESS RESULTS",
pages = "525-520",
url = "https://hdl.handle.net/21.15107/rcub_machinery_7634"
}

Milovanović, A., Babinský, T., Sedmak, A.,& Milošević, M.. (2023). PRINTING PARAMETER IMPACT ON PLA MATERIAL FRACTURE TOUGHNESS RESULTS. in International scientific and professional conference POLITEHNIKA 2023 (Belgrade, 15th December 2023), 520-525.
https://hdl.handle.net/21.15107/rcub_machinery_7634

Milovanović A, Babinský T, Sedmak A, Milošević M. PRINTING PARAMETER IMPACT ON PLA MATERIAL FRACTURE TOUGHNESS RESULTS. in International scientific and professional conference POLITEHNIKA 2023 (Belgrade, 15th December 2023). 2023;:520-525.
https://hdl.handle.net/21.15107/rcub_machinery_7634 .

Milovanović, Aleksa, Babinský, Tomáš, Sedmak, Aleksandar, Milošević, Miloš, "PRINTING PARAMETER IMPACT ON PLA MATERIAL FRACTURE TOUGHNESS RESULTS" in International scientific and professional conference POLITEHNIKA 2023 (Belgrade, 15th December 2023) (2023):520-525,
https://hdl.handle.net/21.15107/rcub_machinery_7634 .