TY  - CONF
AU  - Aranđelović, Mihajlo
AU  - Sedmak, Simon
AU  - Jovičić, Radomir
AU  - Petrović, Ana
AU  - Dikić, Stefan
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6422
AB  - This paper presents the continued efforts in investigating behaviour of low-alloyed low-carbon steel welded joints in the presence of different combinations of multiple welding defects, (undercuts, incomplete root penetration, misalignments). Since these defect combinations can greatly affect the integrity of welded joints, due to significant changes in geometry which are induced by their presence. For this reason, a total of 8 numerical models were made, including four different defect combinations (2 models for each group). This number of models was equal to the number of actual test specimens that were used for tensile test experiments, which also provided the necessary input data (mechanical properties) for each model. The goal was to determine if the two models from each group were sufficiently similar to each other, so that in the future research, they could be replaced by a single, unified model for each defect combination. Comparison was made in terms of stress and strain distribution, and it was determined that three out of four models have nearly identical values, whereas the first group specimens had shown slightly bigger differences, which were still acceptable. Thus, it was concluded that a single representative model could be made for each defect combination group.
C3  - ECF23, European Conference on Fracture 2022, Procedia Structural Integrity
T1  - Optimisation of numerical models of welded joints with multiple defect combinations
UR  - https://hdl.handle.net/21.15107/rcub_machinery_6017
ER  - 

@conference{
author = "Aranđelović, Mihajlo and Sedmak, Simon and Jovičić, Radomir and Petrović, Ana and Dikić, Stefan",
year = "2022",
abstract = "This paper presents the continued efforts in investigating behaviour of low-alloyed low-carbon steel welded joints in the presence of different combinations of multiple welding defects, (undercuts, incomplete root penetration, misalignments). Since these defect combinations can greatly affect the integrity of welded joints, due to significant changes in geometry which are induced by their presence. For this reason, a total of 8 numerical models were made, including four different defect combinations (2 models for each group). This number of models was equal to the number of actual test specimens that were used for tensile test experiments, which also provided the necessary input data (mechanical properties) for each model. The goal was to determine if the two models from each group were sufficiently similar to each other, so that in the future research, they could be replaced by a single, unified model for each defect combination. Comparison was made in terms of stress and strain distribution, and it was determined that three out of four models have nearly identical values, whereas the first group specimens had shown slightly bigger differences, which were still acceptable. Thus, it was concluded that a single representative model could be made for each defect combination group.",
journal = "ECF23, European Conference on Fracture 2022, Procedia Structural Integrity",
title = "Optimisation of numerical models of welded joints with multiple defect combinations",
url = "https://hdl.handle.net/21.15107/rcub_machinery_6017"
}

Aranđelović, M., Sedmak, S., Jovičić, R., Petrović, A.,& Dikić, S.. (2022). Optimisation of numerical models of welded joints with multiple defect combinations. in ECF23, European Conference on Fracture 2022, Procedia Structural Integrity.
https://hdl.handle.net/21.15107/rcub_machinery_6017

Aranđelović M, Sedmak S, Jovičić R, Petrović A, Dikić S. Optimisation of numerical models of welded joints with multiple defect combinations. in ECF23, European Conference on Fracture 2022, Procedia Structural Integrity. 2022;.
https://hdl.handle.net/21.15107/rcub_machinery_6017 .

Aranđelović, Mihajlo, Sedmak, Simon, Jovičić, Radomir, Petrović, Ana, Dikić, Stefan, "Optimisation of numerical models of welded joints with multiple defect combinations" in ECF23, European Conference on Fracture 2022, Procedia Structural Integrity (2022),
https://hdl.handle.net/21.15107/rcub_machinery_6017 .

TY  - JOUR
AU  - Petronić, Sanja
AU  - Milovanović, Dubravka
AU  - Milosavljević, Anđelka
AU  - Radovanović, Željko
AU  - Cekić-Erić, Olivera
AU  - Jovičić, Radomir
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4279
AB  - In this paper, the influence of parameters of laser processing (drilling, cutting, welding and laser shock peening) on microstructure of superalloy Nimonic 263 are investigated. Drilling and welding process are carried out on the Nd: YAG laser model LS-HTS Mobile P160. When drilling the holes, the parameters of pulse frequency (5 Hz, 7 Hz and 9 Hz) and the pulses duration (1.8 ms to 3.6 ms) are varied. The microstructure is investigated and geometrical and metallurgical characteristics of the holes are determined.Cutting is carried out on the laser BISTRONIC, (2000), BISTAR 3015. The parameters that were varied are as follows: the average laser power, laser velocity, the pressure of the assisting gas and the focus position. Based on the geometrical characteristics of the cuts and surface morphology the optimal parameters are discussed and defined. The laser welded joints of Nimonic 263, in addition to microscopic examination and surface profilometry, were subjected to the destructive testing. During the laser shock peening, the samples were exposed to laser light at a wavelength of 1064 nm and 532 nm, with the number of accumulated pulses 50, 100 and 200. The operating laser was Nd: YAG EKSPLO, SL212P model. Structural analysis of Nimonic 263 was carried out using light microscopy, scanning electron microscopy and EDS analysis. Microhardness measurements were carried out using the Vickers method under load of 9,81N. Profilometry was performed on a contactless profilometer Zygo Newview 7100.
AB  - U ovom radu, proučavan je uticaj parametara određenih procesa laserske tehnike obrade materijala superlegure Nimonic 263 - bušenje, rezanje, zavarivanje i mehanička obrada laserom. Bušenje i zavarivanje su vršeni na laseru Nd:YAG laserom model HTS Mobile LS-P160. Prilikom bušenja rupa varirani su parametri frekvencije impulsa (5 Hz, 7Hz i 9 Hz) i dužine trajanja impulsa (1,8 ms do 3,6 ms). Ispitivana je mikrostruktura i određene su geometrijske i metalurške karakteristike rupa dobijenih ovim parametrima, na osnovu čega je izvršena optimizacija parametara obrade. Rezanje je izvedeno na laseru tipa Bistronic laser, (2000), BISTAR 3015. Varirani su parametri srednje snage lasera, brzina lasera, pritisak gasa i položaj fokusa. Na osnovu dobijenih geometrijskih karakteristika rezova i površinske morfologije diskutovani su i određeni optimalni parametri. Laserom zavareni spojevi limova legure Nimonik 263 su, osim mikroskopskih i profilometrijskih ispitivanja površina, ispitivani i metodom sa razaranjem. Prilikom laserskog deformacionog ojačavanja uzorci su bili izloženi laserskom svetlu na talasnoj dužini od 1064 nm i 532 nm, sa brojem akumuliranih impulsa: 50, 100 i 200. U svim delovima eksperimenta strukturna analiza superlegure Nimonic 263 izvedena je pomoću svetlosne mikroskopije (SM), skenirajuće elektronske mikroskopije (SEM) i EDS-analize. Merenja mikrotvrdoće vršena su pomoću metode Vikersa pod opterećenjem od 9,81N. Profilometrija je izvedena na beskontaktnom profilometru Zygo NewView 7100.
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - Laser treatments of Nimonic 263 nickel-based superalloy
T1  - Laserske obrade superlegure Nimonik 263
EP  - 43
IS  - 1
SP  - 26
VL  - 60
DO  - 10.5937/zasmat1901026P
ER  - 

@article{
author = "Petronić, Sanja and Milovanović, Dubravka and Milosavljević, Anđelka and Radovanović, Željko and Cekić-Erić, Olivera and Jovičić, Radomir",
year = "2019",
abstract = "In this paper, the influence of parameters of laser processing (drilling, cutting, welding and laser shock peening) on microstructure of superalloy Nimonic 263 are investigated. Drilling and welding process are carried out on the Nd: YAG laser model LS-HTS Mobile P160. When drilling the holes, the parameters of pulse frequency (5 Hz, 7 Hz and 9 Hz) and the pulses duration (1.8 ms to 3.6 ms) are varied. The microstructure is investigated and geometrical and metallurgical characteristics of the holes are determined.Cutting is carried out on the laser BISTRONIC, (2000), BISTAR 3015. The parameters that were varied are as follows: the average laser power, laser velocity, the pressure of the assisting gas and the focus position. Based on the geometrical characteristics of the cuts and surface morphology the optimal parameters are discussed and defined. The laser welded joints of Nimonic 263, in addition to microscopic examination and surface profilometry, were subjected to the destructive testing. During the laser shock peening, the samples were exposed to laser light at a wavelength of 1064 nm and 532 nm, with the number of accumulated pulses 50, 100 and 200. The operating laser was Nd: YAG EKSPLO, SL212P model. Structural analysis of Nimonic 263 was carried out using light microscopy, scanning electron microscopy and EDS analysis. Microhardness measurements were carried out using the Vickers method under load of 9,81N. Profilometry was performed on a contactless profilometer Zygo Newview 7100., U ovom radu, proučavan je uticaj parametara određenih procesa laserske tehnike obrade materijala superlegure Nimonic 263 - bušenje, rezanje, zavarivanje i mehanička obrada laserom. Bušenje i zavarivanje su vršeni na laseru Nd:YAG laserom model HTS Mobile LS-P160. Prilikom bušenja rupa varirani su parametri frekvencije impulsa (5 Hz, 7Hz i 9 Hz) i dužine trajanja impulsa (1,8 ms do 3,6 ms). Ispitivana je mikrostruktura i određene su geometrijske i metalurške karakteristike rupa dobijenih ovim parametrima, na osnovu čega je izvršena optimizacija parametara obrade. Rezanje je izvedeno na laseru tipa Bistronic laser, (2000), BISTAR 3015. Varirani su parametri srednje snage lasera, brzina lasera, pritisak gasa i položaj fokusa. Na osnovu dobijenih geometrijskih karakteristika rezova i površinske morfologije diskutovani su i određeni optimalni parametri. Laserom zavareni spojevi limova legure Nimonik 263 su, osim mikroskopskih i profilometrijskih ispitivanja površina, ispitivani i metodom sa razaranjem. Prilikom laserskog deformacionog ojačavanja uzorci su bili izloženi laserskom svetlu na talasnoj dužini od 1064 nm i 532 nm, sa brojem akumuliranih impulsa: 50, 100 i 200. U svim delovima eksperimenta strukturna analiza superlegure Nimonic 263 izvedena je pomoću svetlosne mikroskopije (SM), skenirajuće elektronske mikroskopije (SEM) i EDS-analize. Merenja mikrotvrdoće vršena su pomoću metode Vikersa pod opterećenjem od 9,81N. Profilometrija je izvedena na beskontaktnom profilometru Zygo NewView 7100.",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "Laser treatments of Nimonic 263 nickel-based superalloy, Laserske obrade superlegure Nimonik 263",
pages = "43-26",
number = "1",
volume = "60",
doi = "10.5937/zasmat1901026P"
}

Petronić, S., Milovanović, D., Milosavljević, A., Radovanović, Ž., Cekić-Erić, O.,& Jovičić, R.. (2019). Laser treatments of Nimonic 263 nickel-based superalloy. in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 60(1), 26-43.
https://doi.org/10.5937/zasmat1901026P

Petronić S, Milovanović D, Milosavljević A, Radovanović Ž, Cekić-Erić O, Jovičić R. Laser treatments of Nimonic 263 nickel-based superalloy. in Zaštita materijala. 2019;60(1):26-43.
doi:10.5937/zasmat1901026P .

Petronić, Sanja, Milovanović, Dubravka, Milosavljević, Anđelka, Radovanović, Željko, Cekić-Erić, Olivera, Jovičić, Radomir, "Laser treatments of Nimonic 263 nickel-based superalloy" in Zaštita materijala, 60, no. 1 (2019):26-43,
https://doi.org/10.5937/zasmat1901026P . .

TY  - JOUR
AU  - Bakić, Ramo
AU  - Milović, Ljubica
AU  - Jovičić, Radomir
AU  - Sedmak, Stojan
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2295
AB  - According to the Pressure Equipment Directive (PED 97/23/EC) a new produced storage tank can be accepted on the market only if the required quality is proved. In this way the structural integrity might be at the requested level. However, it is not possible to apply all rules and standards for the quality during service and after performed repairs that are necessary to sustain the structural integrity of the storage tank. Storage tanks of steel are produced in general as cylindrical or spherical, and individual segments are joined by welding. Welded joints are prone to crack occurrence, and for that they are critical locations for safety and structural integrity. According to standard EN ISO 5817 cracks are not acceptable defects in welded structures, and detected cracks have to be removed. The applicability of quality assurance approach to repaired pressure equipment is analyzed and discussed in this paper. In the first case welded joints in spherical storage tanks produced of normalized high strength steel (460 MPa yield stress) microalloyed with vanadium are analyzed, considering repair and structural integrity assessment. In the second case, dissimilar welded joints of structural and stainless steel are examined.
AB  - Prema Direktivi za opremu pod pritiskom (PED 97/23/ EC) novo proizvedeni rezervoari se mogu prihvatiti za tržište samo ako je zahtevani kvalitet i dokazan. Na taj način integritet konstrukcije može biti na zahtevanom nivou. Ipak nije moguće sprovesti sva pravila i standarde za kvalitet tokom eksploatacije i posle izvedenih popravki, potrebnih da se održi integritet konstrukcije rezervoara. Rezervoari od čelika se uglavnom proizvode kao cilindrični ili sferni, na kojima su pojedinačni segmenti spojeni zavarivanjem. Zavareni spojevi su skloni pojavi prslina, i zbog toga su oni kritična mesta za sigurnost i integritet konstrukcije. Prema standardu EN ISO 5817 prsline nisu dopuštene greške na zavarenim konstrukcijama, i otkrivene prsline treba da se eliminišu. Primenljivost pristupa osiguranja kvaliteta na popravljenu opremu pod pritiskom je u ovom radu analizirana i diskutovana. U prvom primeru su analizirani sferni rezervoari izrađeni od normalizovanog čelika visoke čvrstoće (napon tečenja 460 MPa) mikrolegiranog vanadijumom, razmatranjem popravke i ocene integriteta konstrukcije. U drugom primeru su ispitivani raznorodni zavareni spojevi konstrukcijskog i nerđajućeg čelika.
PB  - Society for Structural Integrity and Life, Institute for Material Testing
T2  - Integritet i vek konstrukcija
T1  - Quality assurance of storage tanks after in-service crack repairs
T1  - Osiguranje kvaliteta rezervoara u eksploataciji posle popravke prslina
EP  - 74
IS  - 1
SP  - 63
VL  - 13
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2295
ER  - 

@article{
author = "Bakić, Ramo and Milović, Ljubica and Jovičić, Radomir and Sedmak, Stojan",
year = "2013",
abstract = "According to the Pressure Equipment Directive (PED 97/23/EC) a new produced storage tank can be accepted on the market only if the required quality is proved. In this way the structural integrity might be at the requested level. However, it is not possible to apply all rules and standards for the quality during service and after performed repairs that are necessary to sustain the structural integrity of the storage tank. Storage tanks of steel are produced in general as cylindrical or spherical, and individual segments are joined by welding. Welded joints are prone to crack occurrence, and for that they are critical locations for safety and structural integrity. According to standard EN ISO 5817 cracks are not acceptable defects in welded structures, and detected cracks have to be removed. The applicability of quality assurance approach to repaired pressure equipment is analyzed and discussed in this paper. In the first case welded joints in spherical storage tanks produced of normalized high strength steel (460 MPa yield stress) microalloyed with vanadium are analyzed, considering repair and structural integrity assessment. In the second case, dissimilar welded joints of structural and stainless steel are examined., Prema Direktivi za opremu pod pritiskom (PED 97/23/ EC) novo proizvedeni rezervoari se mogu prihvatiti za tržište samo ako je zahtevani kvalitet i dokazan. Na taj način integritet konstrukcije može biti na zahtevanom nivou. Ipak nije moguće sprovesti sva pravila i standarde za kvalitet tokom eksploatacije i posle izvedenih popravki, potrebnih da se održi integritet konstrukcije rezervoara. Rezervoari od čelika se uglavnom proizvode kao cilindrični ili sferni, na kojima su pojedinačni segmenti spojeni zavarivanjem. Zavareni spojevi su skloni pojavi prslina, i zbog toga su oni kritična mesta za sigurnost i integritet konstrukcije. Prema standardu EN ISO 5817 prsline nisu dopuštene greške na zavarenim konstrukcijama, i otkrivene prsline treba da se eliminišu. Primenljivost pristupa osiguranja kvaliteta na popravljenu opremu pod pritiskom je u ovom radu analizirana i diskutovana. U prvom primeru su analizirani sferni rezervoari izrađeni od normalizovanog čelika visoke čvrstoće (napon tečenja 460 MPa) mikrolegiranog vanadijumom, razmatranjem popravke i ocene integriteta konstrukcije. U drugom primeru su ispitivani raznorodni zavareni spojevi konstrukcijskog i nerđajućeg čelika.",
publisher = "Society for Structural Integrity and Life, Institute for Material Testing",
journal = "Integritet i vek konstrukcija",
title = "Quality assurance of storage tanks after in-service crack repairs, Osiguranje kvaliteta rezervoara u eksploataciji posle popravke prslina",
pages = "74-63",
number = "1",
volume = "13",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2295"
}

Bakić, R., Milović, L., Jovičić, R.,& Sedmak, S.. (2013). Quality assurance of storage tanks after in-service crack repairs. in Integritet i vek konstrukcija
Society for Structural Integrity and Life, Institute for Material Testing., 13(1), 63-74.
https://hdl.handle.net/21.15107/rcub_technorep_2295

Bakić R, Milović L, Jovičić R, Sedmak S. Quality assurance of storage tanks after in-service crack repairs. in Integritet i vek konstrukcija. 2013;13(1):63-74.
https://hdl.handle.net/21.15107/rcub_technorep_2295 .

Bakić, Ramo, Milović, Ljubica, Jovičić, Radomir, Sedmak, Stojan, "Quality assurance of storage tanks after in-service crack repairs" in Integritet i vek konstrukcija, 13, no. 1 (2013):63-74,
https://hdl.handle.net/21.15107/rcub_technorep_2295 .

TY  - JOUR
AU  - Jovičić, Radomir
AU  - Sedmak, Aleksandar
AU  - Sedmak, Stojan
AU  - Milović, Ljubica
AU  - Jovičić, Katarina
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2049
AB  - After the occurrence of water droplets on the manhole outer wall of a storage tank for carbon dioxide, by detailed inspection, a net of cracks is detected in the manhole flange, close to the welded joint between the flange and manhole mantle. Since the droplets are found on the outer side, it is concluded that the through cracks are in question. The analysis of the number and the size of cracks, form and dimensions of manhole cracked segment, the properties of the applied material and stress state has lead to the conclusion that operational safety of the tank is endangered. In order to solve the problem, the damaged zone had to be eliminated and the shape of the manhole neck needed to be redesigned. After performed repairs, the storage tank could be put into operation again.
AB  - Posle pojave vodenih kapi na spoljašnjem zidu otvora za reviziju posude za skladištenje ugljen dioksida, detaljnom inspekcijom je otkrivena mreža prslina na prirubnici revizionog otvora, blizu zavarenog spoja između prirubnice i zida revizionog otvora. Pošto su kapljice uočene na spoljašnjoj strani, zaključuje se da su u pitanju prolazne prsline. Analizom broja i veličine prslina, oblika i dimenzija segmenta naprslog revizionog otvora, osobina primenjenog materijala i naponskog stanja, su doveli do zaključka da je radna sigurnost posude u opasnosti. Da bi se rešio ovaj problem, oštećena zona je morala da se ukloni, a oblik vrata revizionog otvora je morao da se rekonstruiše. Nakon obavljenih popravki, posuda za skladištenje je ponovo puštena u rad.
PB  - Society for Structural Integrity and Life, Institute for Material Testing
T2  - Integritet i vek konstrukcija
T1  - Leakage of an austenitic steel CO2 storage tank
T1  - Curenje posude za skladištenje CO2 od austenitnog čelika
EP  - 108
IS  - 2
SP  - 105
VL  - 12
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2049
ER  - 

@article{
author = "Jovičić, Radomir and Sedmak, Aleksandar and Sedmak, Stojan and Milović, Ljubica and Jovičić, Katarina",
year = "2012",
abstract = "After the occurrence of water droplets on the manhole outer wall of a storage tank for carbon dioxide, by detailed inspection, a net of cracks is detected in the manhole flange, close to the welded joint between the flange and manhole mantle. Since the droplets are found on the outer side, it is concluded that the through cracks are in question. The analysis of the number and the size of cracks, form and dimensions of manhole cracked segment, the properties of the applied material and stress state has lead to the conclusion that operational safety of the tank is endangered. In order to solve the problem, the damaged zone had to be eliminated and the shape of the manhole neck needed to be redesigned. After performed repairs, the storage tank could be put into operation again., Posle pojave vodenih kapi na spoljašnjem zidu otvora za reviziju posude za skladištenje ugljen dioksida, detaljnom inspekcijom je otkrivena mreža prslina na prirubnici revizionog otvora, blizu zavarenog spoja između prirubnice i zida revizionog otvora. Pošto su kapljice uočene na spoljašnjoj strani, zaključuje se da su u pitanju prolazne prsline. Analizom broja i veličine prslina, oblika i dimenzija segmenta naprslog revizionog otvora, osobina primenjenog materijala i naponskog stanja, su doveli do zaključka da je radna sigurnost posude u opasnosti. Da bi se rešio ovaj problem, oštećena zona je morala da se ukloni, a oblik vrata revizionog otvora je morao da se rekonstruiše. Nakon obavljenih popravki, posuda za skladištenje je ponovo puštena u rad.",
publisher = "Society for Structural Integrity and Life, Institute for Material Testing",
journal = "Integritet i vek konstrukcija",
title = "Leakage of an austenitic steel CO2 storage tank, Curenje posude za skladištenje CO2 od austenitnog čelika",
pages = "108-105",
number = "2",
volume = "12",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2049"
}

Jovičić, R., Sedmak, A., Sedmak, S., Milović, L.,& Jovičić, K.. (2012). Leakage of an austenitic steel CO2 storage tank. in Integritet i vek konstrukcija
Society for Structural Integrity and Life, Institute for Material Testing., 12(2), 105-108.
https://hdl.handle.net/21.15107/rcub_technorep_2049

Jovičić R, Sedmak A, Sedmak S, Milović L, Jovičić K. Leakage of an austenitic steel CO2 storage tank. in Integritet i vek konstrukcija. 2012;12(2):105-108.
https://hdl.handle.net/21.15107/rcub_technorep_2049 .

Jovičić, Radomir, Sedmak, Aleksandar, Sedmak, Stojan, Milović, Ljubica, Jovičić, Katarina, "Leakage of an austenitic steel CO2 storage tank" in Integritet i vek konstrukcija, 12, no. 2 (2012):105-108,
https://hdl.handle.net/21.15107/rcub_technorep_2049 .