TY  - JOUR
AU  - Čolić, Katarina
AU  - Sedmak, Simon
AU  - Sedmak, Aleksandar
AU  - Milovanović, Aleksa
AU  - Milošević, Miloš
PY  - 2024
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7801
AB  - Research presented here involves numerical analysis of stresses in partial hip implant subjected to static loads, for two cases of patient weight. The numerical analysis requires the development of 3D models that would accurately repre-sent real partial hip implant geometry, hence a reverse engineering approach via 3D scanning is also included. This combined approach provides reliable insight into the behaviour of partial hip implants under static load, while also exposing certain issues related to the application of this specific implant geometry at higher weight levels.
T2  - STRUCTURAL INTEGRITY AND LIFE
T1  - NUMERICAL ANALYSIS OF STATIC STRESSES IN PARTIAL HIP IMPLANT
EP  - 20
IS  - 1
SP  - 17
VL  - 24
UR  - https://hdl.handle.net/21.15107/rcub_machinery_7801
ER  - 

@article{
author = "Čolić, Katarina and Sedmak, Simon and Sedmak, Aleksandar and Milovanović, Aleksa and Milošević, Miloš",
year = "2024",
abstract = "Research presented here involves numerical analysis of stresses in partial hip implant subjected to static loads, for two cases of patient weight. The numerical analysis requires the development of 3D models that would accurately repre-sent real partial hip implant geometry, hence a reverse engineering approach via 3D scanning is also included. This combined approach provides reliable insight into the behaviour of partial hip implants under static load, while also exposing certain issues related to the application of this specific implant geometry at higher weight levels.",
journal = "STRUCTURAL INTEGRITY AND LIFE",
title = "NUMERICAL ANALYSIS OF STATIC STRESSES IN PARTIAL HIP IMPLANT",
pages = "20-17",
number = "1",
volume = "24",
url = "https://hdl.handle.net/21.15107/rcub_machinery_7801"
}

Čolić, K., Sedmak, S., Sedmak, A., Milovanović, A.,& Milošević, M.. (2024). NUMERICAL ANALYSIS OF STATIC STRESSES IN PARTIAL HIP IMPLANT. in STRUCTURAL INTEGRITY AND LIFE, 24(1), 17-20.
https://hdl.handle.net/21.15107/rcub_machinery_7801

Čolić K, Sedmak S, Sedmak A, Milovanović A, Milošević M. NUMERICAL ANALYSIS OF STATIC STRESSES IN PARTIAL HIP IMPLANT. in STRUCTURAL INTEGRITY AND LIFE. 2024;24(1):17-20.
https://hdl.handle.net/21.15107/rcub_machinery_7801 .

Čolić, Katarina, Sedmak, Simon, Sedmak, Aleksandar, Milovanović, Aleksa, Milošević, Miloš, "NUMERICAL ANALYSIS OF STATIC STRESSES IN PARTIAL HIP IMPLANT" in STRUCTURAL INTEGRITY AND LIFE, 24, no. 1 (2024):17-20,
https://hdl.handle.net/21.15107/rcub_machinery_7801 .

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  - 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  - 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  - 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  - CONF
AU  - Đorđević, Branislav
AU  - Sedmak, Aleksandar
AU  - Sedmak, Simon
PY  - 2023
UR  - https://www.sciencedirect.com/journal/procedia-structural-integrity/vol/48/suppl/C
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7097
AB  - The Second International Symposium on Risk Analysis and Safety of Complex Structures and Components (IRAS 2023) took place between 2-4 April 2023 at the Faculty of Mechanical Engineering of the University of Belgrade. The guest editors of the IRAS 2023 deeply acknowledge all members of the International Scientific Committee, Thematic Sessions Organizers, Keynote Speakers and authors that contributed to the success of this event, which gathered more than 90 participants presenting 88 papers on the spot or online. Sponsors are also fully acknowledged for their important contributions. The ESIS/TC12 2023 winners of the “Robert Moskovic” Award, Award of Merit TC12, and ESIS/TC12 Young Scientist Award were announced during the conference. Additionally, guest editors (conference chairs) sincerely thank the tireless efforts of the Organizing Committee members, as well as students and other staff involved in the organization. Finally, the guest editors are pleased to inform that the third edition of the IRAS event will be organized by Prof. Grzegorz Lesiuk (University of Wroclaw, Poland) and will take place in Wroclaw in Poland in 2025.
C3  - Procedia Structural Integrity
T1  - Editorial of the 2nd IRAS conference
EP  - 3
SP  - 1
VL  - 48
DO  - 10.1016/j.prostr.2023.07.102
ER  - 

@conference{
author = "Đorđević, Branislav and Sedmak, Aleksandar and Sedmak, Simon",
year = "2023",
abstract = "The Second International Symposium on Risk Analysis and Safety of Complex Structures and Components (IRAS 2023) took place between 2-4 April 2023 at the Faculty of Mechanical Engineering of the University of Belgrade. The guest editors of the IRAS 2023 deeply acknowledge all members of the International Scientific Committee, Thematic Sessions Organizers, Keynote Speakers and authors that contributed to the success of this event, which gathered more than 90 participants presenting 88 papers on the spot or online. Sponsors are also fully acknowledged for their important contributions. The ESIS/TC12 2023 winners of the “Robert Moskovic” Award, Award of Merit TC12, and ESIS/TC12 Young Scientist Award were announced during the conference. Additionally, guest editors (conference chairs) sincerely thank the tireless efforts of the Organizing Committee members, as well as students and other staff involved in the organization. Finally, the guest editors are pleased to inform that the third edition of the IRAS event will be organized by Prof. Grzegorz Lesiuk (University of Wroclaw, Poland) and will take place in Wroclaw in Poland in 2025.",
journal = "Procedia Structural Integrity",
title = "Editorial of the 2nd IRAS conference",
pages = "3-1",
volume = "48",
doi = "10.1016/j.prostr.2023.07.102"
}

Đorđević, B., Sedmak, A.,& Sedmak, S.. (2023). Editorial of the 2nd IRAS conference. in Procedia Structural Integrity, 48, 1-3.
https://doi.org/10.1016/j.prostr.2023.07.102

Đorđević B, Sedmak A, Sedmak S. Editorial of the 2nd IRAS conference. in Procedia Structural Integrity. 2023;48:1-3.
doi:10.1016/j.prostr.2023.07.102 .

Đorđević, Branislav, Sedmak, Aleksandar, Sedmak, Simon, "Editorial of the 2nd IRAS conference" in Procedia Structural Integrity, 48 (2023):1-3,
https://doi.org/10.1016/j.prostr.2023.07.102 . .

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  - JOUR
AU  - Golubović, Zorana
AU  - Danilov, Ivan
AU  - Bojović, Božica
AU  - Petrov, Ljubiša
AU  - Sedmak, Aleksandar
AU  - Mišković, Žarko
AU  - Mitrović, Nenad
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7077
AB  - Additive manufacturing technologies have developed rapidly in recent decades, pushing
the limits of known manufacturing processes. The need to study the properties of the different
materials used for these processes comprehensively and in detail has become a primary goal in order
to get the best out of the manufacturing itself. The widely used thermoplastic polymer material
acrylonitrile butadiene styrene (ABS) was selected in the form of both filaments and ABS-like resins
to investigate and compare the mechanical properties through a series of different tests. ABS-like
resin material is commercially available, but it is not a sufficiently mechanically studied form of
the material, which leads to the rather limited literature. Considering that ABS resin is a declared
material that behaves like the ABS filament but in a different form, the objective of this study was to
compare these two commercially available materials printed with three different 3D printers, namely
Fused Deposition Modelling (FDM), Stereolithography (SLA) and Digital Light Processing (DLP). A
total of 45 test specimens with geometries and test protocols conforming to the relevant standards
were subjected to a series of tensile, three-point bending and compression tests to determine their
mechanical properties. Characterization also included evaluation of morphology with 2D and 3D
microscopy, dimensional accuracy of 3D scans, and Shore A hardness of each material and 3D printing
process. Tensile testing results have shown that FDM toughness is 40% of the value for DLP. FDM
elongation at break is 37% of DLP, while ultimate tensile stress for SLA is 27% higher than FDM value.
Elastic modulus for FDM and SLA coincide. Flexure testing results indicate that value of DLP flexural
modulus is 54% of the FDM value. SLA strain value is 59% of FDM, and DLP ultimate flexure stress
is 77% of the value for FDM. Compression test results imply that FDM specimens absorb at least
twice as much energy as vat polymerized specimens. Strain at break for SLA is 72% and strain at
ultimate stress is 60% of FDM values. FDM yield stress is 32% higher than DLP value. SLA ultimate
compressive stress is half of FDM, while value for DLP compressive modulus is 69% of the FDM
value. The results obtained are beneficial and give a more comprehensive picture of the behavior of
the ABS polymers used in different forms and different AM processes
PB  - MDPI
T2  - Polymers
T1  - A Comprehensive Mechanical Examination of ABS and ABS-like Polymers Additively Manufactured by Material Extrusion and Vat Photopolymerization Processes
IS  - 21
SP  - 4197
VL  - 15
DO  - 10.3390/polym15214197
ER  - 

@article{
author = "Golubović, Zorana and Danilov, Ivan and Bojović, Božica and Petrov, Ljubiša and Sedmak, Aleksandar and Mišković, Žarko and Mitrović, Nenad",
year = "2023",
abstract = "Additive manufacturing technologies have developed rapidly in recent decades, pushing
the limits of known manufacturing processes. The need to study the properties of the different
materials used for these processes comprehensively and in detail has become a primary goal in order
to get the best out of the manufacturing itself. The widely used thermoplastic polymer material
acrylonitrile butadiene styrene (ABS) was selected in the form of both filaments and ABS-like resins
to investigate and compare the mechanical properties through a series of different tests. ABS-like
resin material is commercially available, but it is not a sufficiently mechanically studied form of
the material, which leads to the rather limited literature. Considering that ABS resin is a declared
material that behaves like the ABS filament but in a different form, the objective of this study was to
compare these two commercially available materials printed with three different 3D printers, namely
Fused Deposition Modelling (FDM), Stereolithography (SLA) and Digital Light Processing (DLP). A
total of 45 test specimens with geometries and test protocols conforming to the relevant standards
were subjected to a series of tensile, three-point bending and compression tests to determine their
mechanical properties. Characterization also included evaluation of morphology with 2D and 3D
microscopy, dimensional accuracy of 3D scans, and Shore A hardness of each material and 3D printing
process. Tensile testing results have shown that FDM toughness is 40% of the value for DLP. FDM
elongation at break is 37% of DLP, while ultimate tensile stress for SLA is 27% higher than FDM value.
Elastic modulus for FDM and SLA coincide. Flexure testing results indicate that value of DLP flexural
modulus is 54% of the FDM value. SLA strain value is 59% of FDM, and DLP ultimate flexure stress
is 77% of the value for FDM. Compression test results imply that FDM specimens absorb at least
twice as much energy as vat polymerized specimens. Strain at break for SLA is 72% and strain at
ultimate stress is 60% of FDM values. FDM yield stress is 32% higher than DLP value. SLA ultimate
compressive stress is half of FDM, while value for DLP compressive modulus is 69% of the FDM
value. The results obtained are beneficial and give a more comprehensive picture of the behavior of
the ABS polymers used in different forms and different AM processes",
publisher = "MDPI",
journal = "Polymers",
title = "A Comprehensive Mechanical Examination of ABS and ABS-like Polymers Additively Manufactured by Material Extrusion and Vat Photopolymerization Processes",
number = "21",
pages = "4197",
volume = "15",
doi = "10.3390/polym15214197"
}

Golubović, Z., Danilov, I., Bojović, B., Petrov, L., Sedmak, A., Mišković, Ž.,& Mitrović, N.. (2023). A Comprehensive Mechanical Examination of ABS and ABS-like Polymers Additively Manufactured by Material Extrusion and Vat Photopolymerization Processes. in Polymers
MDPI., 15(21), 4197.
https://doi.org/10.3390/polym15214197

Golubović Z, Danilov I, Bojović B, Petrov L, Sedmak A, Mišković Ž, Mitrović N. A Comprehensive Mechanical Examination of ABS and ABS-like Polymers Additively Manufactured by Material Extrusion and Vat Photopolymerization Processes. in Polymers. 2023;15(21):4197.
doi:10.3390/polym15214197 .

Golubović, Zorana, Danilov, Ivan, Bojović, Božica, Petrov, Ljubiša, Sedmak, Aleksandar, Mišković, Žarko, Mitrović, Nenad, "A Comprehensive Mechanical Examination of ABS and ABS-like Polymers Additively Manufactured by Material Extrusion and Vat Photopolymerization Processes" in Polymers, 15, no. 21 (2023):4197,
https://doi.org/10.3390/polym15214197 . .

TY  - CONF
AU  - Miladinov, Milan
AU  - Sedmak, Simon
AU  - Đorđević, Branislav
AU  - Sedmak, Aleksandar
AU  - Vučetić, Filip
AU  - Milivojević, Aleksandar
PY  - 2023
UR  - https://www.sciencedirect.com/journal/procedia-structural-integrity/vol/48/suppl/C
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7101
AB  - Bucket-wheel excavators are continuously working machines for removal of waste and useful materials in open-pit mines, mainly used for mining of lignite. The purpose of a tooth gear ring is to rotate the excavator using two reducers. Due to this, the structural integrity of such elements is of great importance for the safe and reliable operation of the bucket-wheel excavator as a whole. In order to ensure its proper function, non-destructive testing (NDT) methods (namely magnetic particles testing) was performed after casting of gears. NDT revealed the presence of cracks with varying lengths (10-110 mm), which were located in the gear teeth, its main body and the openings used for connections between segments. For this reason, it was necessary to adopt a repair welding technology which would eliminate the cracks. Since the tooth gear ring was made of GS-40MnCrSi3V low-alloyed cast steel, electrode 42 4 B 42 H5 (designation according to EN 499E) was selected as filler material, due to its exceptional mechanical properties, suitability for welding of low-carbon low-alloyed steels and low hydrogen content. Manual arc welding was the procedure used in this case. Since these repairs were all performed on the surface of the tooth gear ring segments, final NDT included only magnetic particle and penetrant testing, both of which had shown that the repair technology was successfully applied, i.e. not new defects were detected in the repaired gear ring elements.
PB  - Elsevier B.V.
C3  - Second International Symposium on Risk Analysis and Safety of Complex Structures and Components (IRAS 2023)
T1  - Repairing of cracks on tooth gear ring of a bucket-wheel excavator
EP  - 32
SP  - 27
VL  - 48
DO  - 10.1016/j.prostr.2023.07.106
ER  - 

@conference{
author = "Miladinov, Milan and Sedmak, Simon and Đorđević, Branislav and Sedmak, Aleksandar and Vučetić, Filip and Milivojević, Aleksandar",
year = "2023",
abstract = "Bucket-wheel excavators are continuously working machines for removal of waste and useful materials in open-pit mines, mainly used for mining of lignite. The purpose of a tooth gear ring is to rotate the excavator using two reducers. Due to this, the structural integrity of such elements is of great importance for the safe and reliable operation of the bucket-wheel excavator as a whole. In order to ensure its proper function, non-destructive testing (NDT) methods (namely magnetic particles testing) was performed after casting of gears. NDT revealed the presence of cracks with varying lengths (10-110 mm), which were located in the gear teeth, its main body and the openings used for connections between segments. For this reason, it was necessary to adopt a repair welding technology which would eliminate the cracks. Since the tooth gear ring was made of GS-40MnCrSi3V low-alloyed cast steel, electrode 42 4 B 42 H5 (designation according to EN 499E) was selected as filler material, due to its exceptional mechanical properties, suitability for welding of low-carbon low-alloyed steels and low hydrogen content. Manual arc welding was the procedure used in this case. Since these repairs were all performed on the surface of the tooth gear ring segments, final NDT included only magnetic particle and penetrant testing, both of which had shown that the repair technology was successfully applied, i.e. not new defects were detected in the repaired gear ring elements.",
publisher = "Elsevier B.V.",
journal = "Second International Symposium on Risk Analysis and Safety of Complex Structures and Components (IRAS 2023)",
title = "Repairing of cracks on tooth gear ring of a bucket-wheel excavator",
pages = "32-27",
volume = "48",
doi = "10.1016/j.prostr.2023.07.106"
}

Miladinov, M., Sedmak, S., Đorđević, B., Sedmak, A., Vučetić, F.,& Milivojević, A.. (2023). Repairing of cracks on tooth gear ring of a bucket-wheel excavator. in Second International Symposium on Risk Analysis and Safety of Complex Structures and Components (IRAS 2023)
Elsevier B.V.., 48, 27-32.
https://doi.org/10.1016/j.prostr.2023.07.106

Miladinov M, Sedmak S, Đorđević B, Sedmak A, Vučetić F, Milivojević A. Repairing of cracks on tooth gear ring of a bucket-wheel excavator. in Second International Symposium on Risk Analysis and Safety of Complex Structures and Components (IRAS 2023). 2023;48:27-32.
doi:10.1016/j.prostr.2023.07.106 .

Miladinov, Milan, Sedmak, Simon, Đorđević, Branislav, Sedmak, Aleksandar, Vučetić, Filip, Milivojević, Aleksandar, "Repairing of cracks on tooth gear ring of a bucket-wheel excavator" in Second International Symposium on Risk Analysis and Safety of Complex Structures and Components (IRAS 2023), 48 (2023):27-32,
https://doi.org/10.1016/j.prostr.2023.07.106 . .

TY  - JOUR
AU  - Aranđelović, Mihajlo
AU  - Sedmak, Simon
AU  - Sedmak, Aleksandar
AU  - Đorđević, Branislav
AU  - Jovičić, Radomir
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7084
AB  - This paper presents the development of numerical models which were used to simulate
the behaviour of welded joints containing different combinations of multiple defects under tensile
loads. Four representative combinations of defects were selected (including undercuts, incomplete
root penetration, misalignments…), based on practical experience. In order to create accurate and
functional models, this research involve a number of stages. This paper will focus on the various
improvements made to the models, which started in relatively simple form. For this purpose, initial
experimental and numerical analyses were carried out on specimens made of low-alloyed lowcarbon steel S235, and after their accuracy was verified, the same methodology was applied to
specimens made of higher quality material, steel S275. Improvements made to the models involved
geometry, different combinations of boundary conditions and loads, and some were based on stressstrain states obtained by a combination of tensile testing and digital image correlation. The final
result was a set of detailed numerical models which accurately simulated the behaviour of welded
joints with multiple defects in them.
PB  - Trans Tech Publications
T2  - Materials Science Forum
T1  - Development and Improvement of Numerical Models of Welded Joints with Multiple Defects
EP  - 161
SP  - 153
VL  - 1095
DO  - 10.4028/p-mQTw2J
ER  - 

@article{
author = "Aranđelović, Mihajlo and Sedmak, Simon and Sedmak, Aleksandar and Đorđević, Branislav and Jovičić, Radomir",
year = "2023",
abstract = "This paper presents the development of numerical models which were used to simulate
the behaviour of welded joints containing different combinations of multiple defects under tensile
loads. Four representative combinations of defects were selected (including undercuts, incomplete
root penetration, misalignments…), based on practical experience. In order to create accurate and
functional models, this research involve a number of stages. This paper will focus on the various
improvements made to the models, which started in relatively simple form. For this purpose, initial
experimental and numerical analyses were carried out on specimens made of low-alloyed lowcarbon steel S235, and after their accuracy was verified, the same methodology was applied to
specimens made of higher quality material, steel S275. Improvements made to the models involved
geometry, different combinations of boundary conditions and loads, and some were based on stressstrain states obtained by a combination of tensile testing and digital image correlation. The final
result was a set of detailed numerical models which accurately simulated the behaviour of welded
joints with multiple defects in them.",
publisher = "Trans Tech Publications",
journal = "Materials Science Forum",
title = "Development and Improvement of Numerical Models of Welded Joints with Multiple Defects",
pages = "161-153",
volume = "1095",
doi = "10.4028/p-mQTw2J"
}

Aranđelović, M., Sedmak, S., Sedmak, A., Đorđević, B.,& Jovičić, R.. (2023). Development and Improvement of Numerical Models of Welded Joints with Multiple Defects. in Materials Science Forum
Trans Tech Publications., 1095, 153-161.
https://doi.org/10.4028/p-mQTw2J

Aranđelović M, Sedmak S, Sedmak A, Đorđević B, Jovičić R. Development and Improvement of Numerical Models of Welded Joints with Multiple Defects. in Materials Science Forum. 2023;1095:153-161.
doi:10.4028/p-mQTw2J .

Aranđelović, Mihajlo, Sedmak, Simon, Sedmak, Aleksandar, Đorđević, Branislav, Jovičić, Radomir, "Development and Improvement of Numerical Models of Welded Joints with Multiple Defects" in Materials Science Forum, 1095 (2023):153-161,
https://doi.org/10.4028/p-mQTw2J . .

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  - 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  - CONF
AU  - Đorđević, Branislav
AU  - Mastilović, Sreten
AU  - Sedmak, Aleksandar
AU  - Dimić, Aleksandar
AU  - Sedmak, Simon
AU  - Aranđelović, Mihajlo
PY  - 2023
UR  - https://www.sciencedirect.com/journal/procedia-structural-integrity/vol/47/suppl/C
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7100
AB  - The large scatter of the experimental fracture toughness data, characteristic of all ferritic steels in the ductile-to-brittle transition temperature region, imposed the need to include statistical methods for data processing. Due to the inherent stochasticity, the application of fracture mechanics concepts in the characterization of the DTB transition phenomenon has remained a challenging task over the past 50 years. Various models were developed based on statistical approach to data processing in order to capture the salient features of the phenomenon, but all of them have certain limitations because of the intrinsic complexity of the problem. However, all these models provided a solid basis for the continued development of new approaches in the characterization of DTB. Such two novel models are compared herein. They include size effects and utilize scaling of geometrically similar C(T) specimens, with the aim of obtaining predictions of the fracture toughness. Both proposed models have the weakest link statistics in common. In the present study, the EURO fracture toughness data set for 22NiMoCr37 reactor steel is used and the experimental data obtained at temperature of -60 °C is selected to demonstrate the accuracy of the estimates. 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, taking into account the inherent scatter of the experimental data. The estimate of KJc cumulative distribution function obtained by extrapolation using the novel two-step-scaling method is sensitive to the statistical size of the input data sets.
PB  - Elsevier B.V.
C3  - 27th International Conference on Fracture and Structural Integrity (IGF27)
T1  - Comparison of two recent approaches to DTB characterization of ferritic steels
EP  - 596
SP  - 589
VL  - 47
DO  - 10.1016/j.prostr.2023.07.065
ER  - 

@conference{
author = "Đorđević, Branislav and Mastilović, Sreten and Sedmak, Aleksandar and Dimić, Aleksandar and Sedmak, Simon and Aranđelović, Mihajlo",
year = "2023",
abstract = "The large scatter of the experimental fracture toughness data, characteristic of all ferritic steels in the ductile-to-brittle transition temperature region, imposed the need to include statistical methods for data processing. Due to the inherent stochasticity, the application of fracture mechanics concepts in the characterization of the DTB transition phenomenon has remained a challenging task over the past 50 years. Various models were developed based on statistical approach to data processing in order to capture the salient features of the phenomenon, but all of them have certain limitations because of the intrinsic complexity of the problem. However, all these models provided a solid basis for the continued development of new approaches in the characterization of DTB. Such two novel models are compared herein. They include size effects and utilize scaling of geometrically similar C(T) specimens, with the aim of obtaining predictions of the fracture toughness. Both proposed models have the weakest link statistics in common. In the present study, the EURO fracture toughness data set for 22NiMoCr37 reactor steel is used and the experimental data obtained at temperature of -60 °C is selected to demonstrate the accuracy of the estimates. 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, taking into account the inherent scatter of the experimental data. The estimate of KJc cumulative distribution function obtained by extrapolation using the novel two-step-scaling method is sensitive to the statistical size of the input data sets.",
publisher = "Elsevier B.V.",
journal = "27th International Conference on Fracture and Structural Integrity (IGF27)",
title = "Comparison of two recent approaches to DTB characterization of ferritic steels",
pages = "596-589",
volume = "47",
doi = "10.1016/j.prostr.2023.07.065"
}

Đorđević, B., Mastilović, S., Sedmak, A., Dimić, A., Sedmak, S.,& Aranđelović, M.. (2023). Comparison of two recent approaches to DTB characterization of ferritic steels. in 27th International Conference on Fracture and Structural Integrity (IGF27)
Elsevier B.V.., 47, 589-596.
https://doi.org/10.1016/j.prostr.2023.07.065

Đorđević B, Mastilović S, Sedmak A, Dimić A, Sedmak S, Aranđelović M. Comparison of two recent approaches to DTB characterization of ferritic steels. in 27th International Conference on Fracture and Structural Integrity (IGF27). 2023;47:589-596.
doi:10.1016/j.prostr.2023.07.065 .

Đorđević, Branislav, Mastilović, Sreten, Sedmak, Aleksandar, Dimić, Aleksandar, Sedmak, Simon, Aranđelović, Mihajlo, "Comparison of two recent approaches to DTB characterization of ferritic steels" in 27th International Conference on Fracture and Structural Integrity (IGF27), 47 (2023):589-596,
https://doi.org/10.1016/j.prostr.2023.07.065 . .

TY  - JOUR
AU  - Jevtić, Ivana
AU  - Golubović, Zorana
AU  - Mladenović, Goran
AU  - Berto, Filippo
AU  - Sedmak, Aleksandar
AU  - Milovanović, Aleksa
AU  - Milošević, Miloš
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7011
AB  - Selective laser sintering (SLS) is one of the additive manufacturing technologies dedicated to the production of high-quality parts with complex geometries. Here, polyamide 12 (PA12) is a commonly used material, for manufacturing parts with sufficient mechanical and thermal properties. In SLS, many manufacturing parameters have an effect on the mechanical properties of final parts. Even the decision regarding the orientation of a part in a powder bed may have a significant effect on the mechanical properties. In this research, the influence of horizontal (H) and vertical (V) printing orientations on the ultimate tensile strength (UTS) of fabricated PA12 specimens are examined. Our research findings show that H specimens exhibit larger deformations and smaller UTS value scatter in comparison with V specimens. Also, worth pointing out is the fact that V-oriented specimens have a higher elastic modulus. One can assume that the sintering process is more effective in V specimens, due to a more uniform laser beam trajectory than in the H specimens' case.
PB  - Springer
T2  - Journal of Mechanical and Technology
T1  - Printing orientation influence on tensile strength of PA12 specimens obtained by SLS
EP  - 6
IS  - 11
SP  - 1
VL  - 37
DO  - 10.1007/s12206-023-2306-4
ER  - 

@article{
author = "Jevtić, Ivana and Golubović, Zorana and Mladenović, Goran and Berto, Filippo and Sedmak, Aleksandar and Milovanović, Aleksa and Milošević, Miloš",
year = "2023",
abstract = "Selective laser sintering (SLS) is one of the additive manufacturing technologies dedicated to the production of high-quality parts with complex geometries. Here, polyamide 12 (PA12) is a commonly used material, for manufacturing parts with sufficient mechanical and thermal properties. In SLS, many manufacturing parameters have an effect on the mechanical properties of final parts. Even the decision regarding the orientation of a part in a powder bed may have a significant effect on the mechanical properties. In this research, the influence of horizontal (H) and vertical (V) printing orientations on the ultimate tensile strength (UTS) of fabricated PA12 specimens are examined. Our research findings show that H specimens exhibit larger deformations and smaller UTS value scatter in comparison with V specimens. Also, worth pointing out is the fact that V-oriented specimens have a higher elastic modulus. One can assume that the sintering process is more effective in V specimens, due to a more uniform laser beam trajectory than in the H specimens' case.",
publisher = "Springer",
journal = "Journal of Mechanical and Technology",
title = "Printing orientation influence on tensile strength of PA12 specimens obtained by SLS",
pages = "6-1",
number = "11",
volume = "37",
doi = "10.1007/s12206-023-2306-4"
}

Jevtić, I., Golubović, Z., Mladenović, G., Berto, F., Sedmak, A., Milovanović, A.,& Milošević, M.. (2023). Printing orientation influence on tensile strength of PA12 specimens obtained by SLS. in Journal of Mechanical and Technology
Springer., 37(11), 1-6.
https://doi.org/10.1007/s12206-023-2306-4

Jevtić I, Golubović Z, Mladenović G, Berto F, Sedmak A, Milovanović A, Milošević M. Printing orientation influence on tensile strength of PA12 specimens obtained by SLS. in Journal of Mechanical and Technology. 2023;37(11):1-6.
doi:10.1007/s12206-023-2306-4 .

Jevtić, Ivana, Golubović, Zorana, Mladenović, Goran, Berto, Filippo, Sedmak, Aleksandar, Milovanović, Aleksa, Milošević, Miloš, "Printing orientation influence on tensile strength of PA12 specimens obtained by SLS" in Journal of Mechanical and Technology, 37, no. 11 (2023):1-6,
https://doi.org/10.1007/s12206-023-2306-4 . .

TY  - JOUR
AU  - Prokić Cvetković, Radica
AU  - Popović, Olivera
AU  - Radović, Ljubica
AU  - Sedmak, Aleksandar
AU  - Cvetković, Ivana
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/5570
AB  - This paper deals with a three-component aluminum alloy AlMg4.5Mn that was welded using a GTAW process in the shielded atmosphere of Ar+70%He+0.015%N2. The weld-metal toughness was evaluated at three different temperatures using instrumental Charpy pendulum impact testing to measure not only the total energy, but also the crack initiation energy and the crack growth energy. Fractographic analysis of the fracture surfaces and EDS analysis of large second-phase particles on fractured surfaces at each temperature were also carried out. Fractographic analysis at different temperatures indicated a clearly distinguishable fracture mechanism. It was inferred that the absorbed energy was closely correlated with the fracturing of surfaces. Moreover, it was concluded that with decrease in the amount of microscopic voids and dimples, the total energy absorbed also decreased.
PB  - MDPI
T2  - Sustainability
T1  - Fracture Behavior of AlMg4.5Mn Weld Metal at Different Temperatures under Impact Loading
IS  - 2
SP  - 1550
VL  - 15
DO  - 10.3390/su15021550
ER  - 

@article{
author = "Prokić Cvetković, Radica and Popović, Olivera and Radović, Ljubica and Sedmak, Aleksandar and Cvetković, Ivana",
year = "2023",
abstract = "This paper deals with a three-component aluminum alloy AlMg4.5Mn that was welded using a GTAW process in the shielded atmosphere of Ar+70%He+0.015%N2. The weld-metal toughness was evaluated at three different temperatures using instrumental Charpy pendulum impact testing to measure not only the total energy, but also the crack initiation energy and the crack growth energy. Fractographic analysis of the fracture surfaces and EDS analysis of large second-phase particles on fractured surfaces at each temperature were also carried out. Fractographic analysis at different temperatures indicated a clearly distinguishable fracture mechanism. It was inferred that the absorbed energy was closely correlated with the fracturing of surfaces. Moreover, it was concluded that with decrease in the amount of microscopic voids and dimples, the total energy absorbed also decreased.",
publisher = "MDPI",
journal = "Sustainability",
title = "Fracture Behavior of AlMg4.5Mn Weld Metal at Different Temperatures under Impact Loading",
number = "2",
pages = "1550",
volume = "15",
doi = "10.3390/su15021550"
}

Prokić Cvetković, R., Popović, O., Radović, L., Sedmak, A.,& Cvetković, I.. (2023). Fracture Behavior of AlMg4.5Mn Weld Metal at Different Temperatures under Impact Loading. in Sustainability
MDPI., 15(2), 1550.
https://doi.org/10.3390/su15021550

Prokić Cvetković R, Popović O, Radović L, Sedmak A, Cvetković I. Fracture Behavior of AlMg4.5Mn Weld Metal at Different Temperatures under Impact Loading. in Sustainability. 2023;15(2):1550.
doi:10.3390/su15021550 .

Prokić Cvetković, Radica, Popović, Olivera, Radović, Ljubica, Sedmak, Aleksandar, Cvetković, Ivana, "Fracture Behavior of AlMg4.5Mn Weld Metal at Different Temperatures under Impact Loading" in Sustainability, 15, no. 2 (2023):1550,
https://doi.org/10.3390/su15021550 . .

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  - CONF
AU  - Mastilović, Sreten
AU  - Đorđević, Branislav
AU  - Sedmak, Aleksandar
PY  - 2023
UR  - http://www.ssm.kg.ac.rs/congress_2023/papers/
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7099
AB  - The fracture toughness of ferritic steels in the DTB (ductile-to-brittle) transition temperature
region is a stochastic extrinsic property known for pronounced experimental data scatter that
necessitates statistical approach in the DTB characterization. The novel two-step-scaling (2SS)
method, proposed recently for the size effect-modeling across the DTB transition region, is
developed based on the weakest-link statistics and the two-parametric Weibull distribution.
Specifically, the size sensitivity of the Weibull parameters of scale and shape are built into the
appropriate framework. This approach is upgraded in this article to render the comparison with
the existing models more transparent. Specifically, the original 2SS method is enhanced by
adding a lower limit on fracture toughness, resulting in the translated (three-parameter) Weibull
cumulative distribution function. This third Weibull parameter, often dubbed the location
parameter, defines a threshold value that limits the accessible fracture toughness domain. The
upgraded 2SS approach is compared to two established methods of the DTB fracture toughness
assessment, which favorably reflected upon its generality and application flexibility.
C3  - 9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia
T1  - UPGRADED TWO-STEP-SCALING APPROACH TO THE DTB CHARACTERIZATION OF FERRITIC STEELS
UR  - https://hdl.handle.net/21.15107/rcub_machinery_7099
ER  - 

@conference{
author = "Mastilović, Sreten and Đorđević, Branislav and Sedmak, Aleksandar",
year = "2023",
abstract = "The fracture toughness of ferritic steels in the DTB (ductile-to-brittle) transition temperature
region is a stochastic extrinsic property known for pronounced experimental data scatter that
necessitates statistical approach in the DTB characterization. The novel two-step-scaling (2SS)
method, proposed recently for the size effect-modeling across the DTB transition region, is
developed based on the weakest-link statistics and the two-parametric Weibull distribution.
Specifically, the size sensitivity of the Weibull parameters of scale and shape are built into the
appropriate framework. This approach is upgraded in this article to render the comparison with
the existing models more transparent. Specifically, the original 2SS method is enhanced by
adding a lower limit on fracture toughness, resulting in the translated (three-parameter) Weibull
cumulative distribution function. This third Weibull parameter, often dubbed the location
parameter, defines a threshold value that limits the accessible fracture toughness domain. The
upgraded 2SS approach is compared to two established methods of the DTB fracture toughness
assessment, which favorably reflected upon its generality and application flexibility.",
journal = "9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia",
title = "UPGRADED TWO-STEP-SCALING APPROACH TO THE DTB CHARACTERIZATION OF FERRITIC STEELS",
url = "https://hdl.handle.net/21.15107/rcub_machinery_7099"
}

Mastilović, S., Đorđević, B.,& Sedmak, A.. (2023). UPGRADED TWO-STEP-SCALING APPROACH TO THE DTB CHARACTERIZATION OF FERRITIC STEELS. in 9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia.
https://hdl.handle.net/21.15107/rcub_machinery_7099

Mastilović S, Đorđević B, Sedmak A. UPGRADED TWO-STEP-SCALING APPROACH TO THE DTB CHARACTERIZATION OF FERRITIC STEELS. in 9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia. 2023;.
https://hdl.handle.net/21.15107/rcub_machinery_7099 .

Mastilović, Sreten, Đorđević, Branislav, Sedmak, Aleksandar, "UPGRADED TWO-STEP-SCALING APPROACH TO THE DTB CHARACTERIZATION OF FERRITIC STEELS" in 9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia (2023),
https://hdl.handle.net/21.15107/rcub_machinery_7099 .

TY  - CONF
AU  - Đorđević, Branislav
AU  - Mastilović, Sreten
AU  - Petrovski, Blagoj
AU  - Sedmak, Aleksandar
AU  - Dimić, Aleksandar
PY  - 2023
UR  - http://cnntechno.com/docs/7_CNN_book_of_abstracts.pdf
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7095
AB  - In this paper is presented the 1-point method for material behaviour prediction, in terms of fracture toughness, of the ferritic steel EN 1.6310 in the transition temperature regime (-60°C and -90°C). Experiments were carried out at two different temperatures, representing two studies joined in one. Experimental testing was performed according to ASTM 1820 standard. This 1-point method is based on statistical processing (of 2-parameters Weibull statistics) of obtained experimental results, i.e. scattered J-integral values, of C(T) specimens with different geometries. Fixing value of one Weibull parameter and taking into account size-dependence of second one, fracture probabilities in the function of J-integral for large C(T)100 and C(T)200 were determined based on testing of C(T)50 specimen size. This research pointed out the sensitivty of proposed method on statistical sample size. One of the aims of proposed method was reducing the cost and price of laboratory tests in overall by predicting material behaviour and testing smaller C(T) specimen size. This research represents an upgrade of the Landes and Heerens works, and it is dedicated to their efforts in understanding and characterisation of transition temperature regime of ferritic steels.
PB  - University of Belgrade - Faculty of Mechanical Engineering
C3  - International Conference of Experimental and Numerical Investigations and New Technologies (CNN TECH 2023), 04-07 July 2023, Programme and The Book of Abstracts
T1  - A METHOD FOR FRACTURE PROBABILITY ASSESSMENT IN FUNCTION OF J-INTEGRAL IN TRANSITION TEMPERATURE REGIME OF FERRITIC STEEL
SP  - 21
UR  - https://hdl.handle.net/21.15107/rcub_machinery_7095
ER  - 

@conference{
author = "Đorđević, Branislav and Mastilović, Sreten and Petrovski, Blagoj and Sedmak, Aleksandar and Dimić, Aleksandar",
year = "2023",
abstract = "In this paper is presented the 1-point method for material behaviour prediction, in terms of fracture toughness, of the ferritic steel EN 1.6310 in the transition temperature regime (-60°C and -90°C). Experiments were carried out at two different temperatures, representing two studies joined in one. Experimental testing was performed according to ASTM 1820 standard. This 1-point method is based on statistical processing (of 2-parameters Weibull statistics) of obtained experimental results, i.e. scattered J-integral values, of C(T) specimens with different geometries. Fixing value of one Weibull parameter and taking into account size-dependence of second one, fracture probabilities in the function of J-integral for large C(T)100 and C(T)200 were determined based on testing of C(T)50 specimen size. This research pointed out the sensitivty of proposed method on statistical sample size. One of the aims of proposed method was reducing the cost and price of laboratory tests in overall by predicting material behaviour and testing smaller C(T) specimen size. This research represents an upgrade of the Landes and Heerens works, and it is dedicated to their efforts in understanding and characterisation of transition temperature regime of ferritic steels.",
publisher = "University of Belgrade - Faculty of Mechanical Engineering",
journal = "International Conference of Experimental and Numerical Investigations and New Technologies (CNN TECH 2023), 04-07 July 2023, Programme and The Book of Abstracts",
title = "A METHOD FOR FRACTURE PROBABILITY ASSESSMENT IN FUNCTION OF J-INTEGRAL IN TRANSITION TEMPERATURE REGIME OF FERRITIC STEEL",
pages = "21",
url = "https://hdl.handle.net/21.15107/rcub_machinery_7095"
}

Đorđević, B., Mastilović, S., Petrovski, B., Sedmak, A.,& Dimić, A.. (2023). A METHOD FOR FRACTURE PROBABILITY ASSESSMENT IN FUNCTION OF J-INTEGRAL IN TRANSITION TEMPERATURE REGIME OF FERRITIC STEEL. in International Conference of Experimental and Numerical Investigations and New Technologies (CNN TECH 2023), 04-07 July 2023, Programme and The Book of Abstracts
University of Belgrade - Faculty of Mechanical Engineering., 21.
https://hdl.handle.net/21.15107/rcub_machinery_7095

Đorđević B, Mastilović S, Petrovski B, Sedmak A, Dimić A. A METHOD FOR FRACTURE PROBABILITY ASSESSMENT IN FUNCTION OF J-INTEGRAL IN TRANSITION TEMPERATURE REGIME OF FERRITIC STEEL. in International Conference of Experimental and Numerical Investigations and New Technologies (CNN TECH 2023), 04-07 July 2023, Programme and The Book of Abstracts. 2023;:21.
https://hdl.handle.net/21.15107/rcub_machinery_7095 .

Đorđević, Branislav, Mastilović, Sreten, Petrovski, Blagoj, Sedmak, Aleksandar, Dimić, Aleksandar, "A METHOD FOR FRACTURE PROBABILITY ASSESSMENT IN FUNCTION OF J-INTEGRAL IN TRANSITION TEMPERATURE REGIME OF FERRITIC STEEL" in International Conference of Experimental and Numerical Investigations and New Technologies (CNN TECH 2023), 04-07 July 2023, Programme and The Book of Abstracts (2023):21,
https://hdl.handle.net/21.15107/rcub_machinery_7095 .

TY  - CONF
AU  - Mastilović, Sreten
AU  - Đorđević, Branislav
AU  - Sedmak, Aleksandar
PY  - 2023
UR  - http://www.ssm.kg.ac.rs/congress_2023/papers/
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7098
AB  - The ferritic steels, widely used as pressure-vessel materials in nuclear industry, are prone to
embrittlement when exposed to neutron irradiation or temperature reduction within the DTB
(ductile-to-brittle) transition region. This embrittlement may be accompanied by the increased
size effect, which is a pronounced consequence of fracture mechanics not exhibited in the
traditional plasticity theory. Therefore, the fracture toughness in the DTB transition temperature
region is a stochastic extrinsic property well known for its aleatory variability. Consequently, the
extremely-pronounced experimental data scatter necessitates the use of the statistical approach to
material characterization. The recently proposed two-step-scaling approach to estimate the size
effect of fracture toughness CDF (cumulative density function) in the DTB transition region relies
heavily on regularity of arrangement of experimental data points for the two input sample sizes.
This regularity of measurement values becomes an inherently iffy proposition in the case of
statistically small data sets. Therefore, the ability of our novel approach to predict objectively the
fracture toughness probability outside the experimental domain may be impaired in absence of the
sufficient statistical size of the input data sets. Since the large-scale fracture toughness tests for
nuclear pressure-vessel steels at low temperatures are very expensive, the present study is
concerned with this issue of the statistically sufficient sample size. There are various statistical
techniques to determine the sample size needed for a study, including power analysis and sample
size calculation formulas. The appropriate method depends on the type of study, the research
question, and the statistical analysis planned. These issues are addressed in this article.
C3  - 9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia.
T1  - A NOTE ON THE EFFECT OF STATISTICAL SAMPLE SIZE ON FRACTURE TOUGHNESS CHARACTERIZATION IN THE DTB TRANSITION REGION
UR  - https://hdl.handle.net/21.15107/rcub_machinery_7098
ER  - 

@conference{
author = "Mastilović, Sreten and Đorđević, Branislav and Sedmak, Aleksandar",
year = "2023",
abstract = "The ferritic steels, widely used as pressure-vessel materials in nuclear industry, are prone to
embrittlement when exposed to neutron irradiation or temperature reduction within the DTB
(ductile-to-brittle) transition region. This embrittlement may be accompanied by the increased
size effect, which is a pronounced consequence of fracture mechanics not exhibited in the
traditional plasticity theory. Therefore, the fracture toughness in the DTB transition temperature
region is a stochastic extrinsic property well known for its aleatory variability. Consequently, the
extremely-pronounced experimental data scatter necessitates the use of the statistical approach to
material characterization. The recently proposed two-step-scaling approach to estimate the size
effect of fracture toughness CDF (cumulative density function) in the DTB transition region relies
heavily on regularity of arrangement of experimental data points for the two input sample sizes.
This regularity of measurement values becomes an inherently iffy proposition in the case of
statistically small data sets. Therefore, the ability of our novel approach to predict objectively the
fracture toughness probability outside the experimental domain may be impaired in absence of the
sufficient statistical size of the input data sets. Since the large-scale fracture toughness tests for
nuclear pressure-vessel steels at low temperatures are very expensive, the present study is
concerned with this issue of the statistically sufficient sample size. There are various statistical
techniques to determine the sample size needed for a study, including power analysis and sample
size calculation formulas. The appropriate method depends on the type of study, the research
question, and the statistical analysis planned. These issues are addressed in this article.",
journal = "9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia.",
title = "A NOTE ON THE EFFECT OF STATISTICAL SAMPLE SIZE ON FRACTURE TOUGHNESS CHARACTERIZATION IN THE DTB TRANSITION REGION",
url = "https://hdl.handle.net/21.15107/rcub_machinery_7098"
}

Mastilović, S., Đorđević, B.,& Sedmak, A.. (2023). A NOTE ON THE EFFECT OF STATISTICAL SAMPLE SIZE ON FRACTURE TOUGHNESS CHARACTERIZATION IN THE DTB TRANSITION REGION. in 9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia..
https://hdl.handle.net/21.15107/rcub_machinery_7098

Mastilović S, Đorđević B, Sedmak A. A NOTE ON THE EFFECT OF STATISTICAL SAMPLE SIZE ON FRACTURE TOUGHNESS CHARACTERIZATION IN THE DTB TRANSITION REGION. in 9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia.. 2023;.
https://hdl.handle.net/21.15107/rcub_machinery_7098 .

Mastilović, Sreten, Đorđević, Branislav, Sedmak, Aleksandar, "A NOTE ON THE EFFECT OF STATISTICAL SAMPLE SIZE ON FRACTURE TOUGHNESS CHARACTERIZATION IN THE DTB TRANSITION REGION" in 9th International Congress of the Serbian Society of Mechanics (ICSSM), July 5-7, 2023, Vrnjačka Banja, Serbia. (2023),
https://hdl.handle.net/21.15107/rcub_machinery_7098 .