TY  - JOUR
AU  - Arsić, Miodrag
AU  - Flajs, Željko
AU  - Sedmak, Aleksandar
AU  - Veg, Emil
AU  - Sedmak, Simon
PY  - 2022
UR  - http://rims.institutims.rs/handle/123456789/665
AB  - Causes of damage occurrence in vital components of welded structures of the bucket-wheel
excavator boom (DU1) at the coal landfill of the thermal power plant 'Nikola Tesla A' in Obrenovac
(Serbia) are investigated. Bucket-wheel excavator was produced by French company 'Ameco' and it
moves along the circular track. Taking into account lack of technical documentation, all tests and
were carried out under the assumption that welded structures were made of structural steels S355 and
S235. Investigation of causes of damage occurrence are based on results of non-destructive tests
(NDT) and tensometric measurements.
PB  - Trans Tech Publications Ltd, Switzerland
T2  - Engineering Innovations
T1  - Damage occurrence in welded structures of the bucket-wheel boom
EP  - 48
SP  - 41
VL  - 2
DO  - 10.4028/p-15iqnw
ER  - 

@article{
author = "Arsić, Miodrag and Flajs, Željko and Sedmak, Aleksandar and Veg, Emil and Sedmak, Simon",
year = "2022",
abstract = "Causes of damage occurrence in vital components of welded structures of the bucket-wheel
excavator boom (DU1) at the coal landfill of the thermal power plant 'Nikola Tesla A' in Obrenovac
(Serbia) are investigated. Bucket-wheel excavator was produced by French company 'Ameco' and it
moves along the circular track. Taking into account lack of technical documentation, all tests and
were carried out under the assumption that welded structures were made of structural steels S355 and
S235. Investigation of causes of damage occurrence are based on results of non-destructive tests
(NDT) and tensometric measurements.",
publisher = "Trans Tech Publications Ltd, Switzerland",
journal = "Engineering Innovations",
title = "Damage occurrence in welded structures of the bucket-wheel boom",
pages = "48-41",
volume = "2",
doi = "10.4028/p-15iqnw"
}

Arsić, M., Flajs, Ž., Sedmak, A., Veg, E.,& Sedmak, S.. (2022). Damage occurrence in welded structures of the bucket-wheel boom. in Engineering Innovations
Trans Tech Publications Ltd, Switzerland., 2, 41-48.
https://doi.org/10.4028/p-15iqnw

Arsić M, Flajs Ž, Sedmak A, Veg E, Sedmak S. Damage occurrence in welded structures of the bucket-wheel boom. in Engineering Innovations. 2022;2:41-48.
doi:10.4028/p-15iqnw .

Arsić, Miodrag, Flajs, Željko, Sedmak, Aleksandar, Veg, Emil, Sedmak, Simon, "Damage occurrence in welded structures of the bucket-wheel boom" in Engineering Innovations, 2 (2022):41-48,
https://doi.org/10.4028/p-15iqnw . .

TY  - JOUR
AU  - Arsić, Miodrag
AU  - Arsić, Dušan
AU  - Flajs, Željko
AU  - Grbović, Aleksandar
AU  - Todić, Aleksandar
PY  - 2021
UR  - http://rims.institutims.rs/handle/123456789/413
AB  - Loads at vital steel structures occur during their production and assembly (residual stresses), during the execution of functional tasks in exploitation (stationary and dynamic loads) and during the disturbed process of exploitation (non-stationary dynamic loads). Considering the fact that stress concentrators, corrosion and unpredictable effects that occur during exploitation must be taken into account as well, it is clear that loading of vital structures during the design phase can not be represented with a model in which the parameters change uniformly. Therefore only experimental non-destructive tests performed at large steel structures during exploitation enable the assessment of their current condition, need for particular repairs and assessment of integrity. In that way the data necessary for determination of causes of degradation of material and welded joints at structures, for the evaluation of mutual influence of equipment parts, as well as for determination of functionality and reliability of operation of drive systems. This primarily refers to vital steel structures of bucket-wheel excavators, dredgers and cranes, as well as to vital steel structures at hydroelectric equipment, thermal power plant equipment, bridges etc. This paper presents the analysis of causes for the occurrence of damages at the support structure of the boom of the bucket-wheel excavator, which is operating at the open pit coal mine near Kostolac (Serbia), that was executed on the basis of non-destructive tests. The paper also contains the procedure for the repair of damaged structure through the application of adequate welding, performed at existing and newly produced components, and the assessment of structural integrity after the repair based on non-compliances detected during the design process, as well as during the making of the support structure of the bucket-wheel excavator boom due to inadequate radiuses defined during the processes of design and production and due to the existence of flaws on the surface and within welded joints.
PB  - Pleiades Publishing Inc, New York
T2  - Russian Journal of Nondestructive Testing
T1  - Application of Non-Destructive Testing for Condition Analysis, Repair of Damages and Integrity Assessment of Vital Steel Structures
EP  - 931
IS  - 10
SP  - 918
VL  - 57
DO  - 10.1134/S1061830921100053
ER  - 

@article{
author = "Arsić, Miodrag and Arsić, Dušan and Flajs, Željko and Grbović, Aleksandar and Todić, Aleksandar",
year = "2021",
abstract = "Loads at vital steel structures occur during their production and assembly (residual stresses), during the execution of functional tasks in exploitation (stationary and dynamic loads) and during the disturbed process of exploitation (non-stationary dynamic loads). Considering the fact that stress concentrators, corrosion and unpredictable effects that occur during exploitation must be taken into account as well, it is clear that loading of vital structures during the design phase can not be represented with a model in which the parameters change uniformly. Therefore only experimental non-destructive tests performed at large steel structures during exploitation enable the assessment of their current condition, need for particular repairs and assessment of integrity. In that way the data necessary for determination of causes of degradation of material and welded joints at structures, for the evaluation of mutual influence of equipment parts, as well as for determination of functionality and reliability of operation of drive systems. This primarily refers to vital steel structures of bucket-wheel excavators, dredgers and cranes, as well as to vital steel structures at hydroelectric equipment, thermal power plant equipment, bridges etc. This paper presents the analysis of causes for the occurrence of damages at the support structure of the boom of the bucket-wheel excavator, which is operating at the open pit coal mine near Kostolac (Serbia), that was executed on the basis of non-destructive tests. The paper also contains the procedure for the repair of damaged structure through the application of adequate welding, performed at existing and newly produced components, and the assessment of structural integrity after the repair based on non-compliances detected during the design process, as well as during the making of the support structure of the bucket-wheel excavator boom due to inadequate radiuses defined during the processes of design and production and due to the existence of flaws on the surface and within welded joints.",
publisher = "Pleiades Publishing Inc, New York",
journal = "Russian Journal of Nondestructive Testing",
title = "Application of Non-Destructive Testing for Condition Analysis, Repair of Damages and Integrity Assessment of Vital Steel Structures",
pages = "931-918",
number = "10",
volume = "57",
doi = "10.1134/S1061830921100053"
}

Arsić, M., Arsić, D., Flajs, Ž., Grbović, A.,& Todić, A.. (2021). Application of Non-Destructive Testing for Condition Analysis, Repair of Damages and Integrity Assessment of Vital Steel Structures. in Russian Journal of Nondestructive Testing
Pleiades Publishing Inc, New York., 57(10), 918-931.
https://doi.org/10.1134/S1061830921100053

Arsić M, Arsić D, Flajs Ž, Grbović A, Todić A. Application of Non-Destructive Testing for Condition Analysis, Repair of Damages and Integrity Assessment of Vital Steel Structures. in Russian Journal of Nondestructive Testing. 2021;57(10):918-931.
doi:10.1134/S1061830921100053 .

Arsić, Miodrag, Arsić, Dušan, Flajs, Željko, Grbović, Aleksandar, Todić, Aleksandar, "Application of Non-Destructive Testing for Condition Analysis, Repair of Damages and Integrity Assessment of Vital Steel Structures" in Russian Journal of Nondestructive Testing, 57, no. 10 (2021):918-931,
https://doi.org/10.1134/S1061830921100053 . .

TY  - JOUR
AU  - Arsić, Miodrag
AU  - Flajs, Željko
AU  - Sedmak, Aleksandar
AU  - Veg, Emil
AU  - Sedmak, Simon
PY  - 2021
UR  - http://rims.institutims.rs/handle/123456789/411
AB  - Research is conducted on the causes of damage and the structural integrity assessment of the bucket-wheel boom welded lattice structures, before and after the repair of vital structures. Additionally, the paper describes the investigation conducted based on the results of non-destructive tests (visual-, magnetic particle-, dye penetrant-, and ultrasonic tests), results of tensometric measurements that refer to the stress-strain state, and results based on numerical calculation of stresses by finite element method, performed through the use of a 3D model in the software Radimpex Tower 6.0 (R). The results of tests and research performed after the repair of damaged structural welded sections show that the operational procedures are being obeyed.
PB  - Institut za ispitivanje materijala, Beograd
T2  - Structural Integrity and Life
T1  - Structural integrity assessment of welded bucket-wheel boom
EP  - 206
IS  - 2
SP  - 201
VL  - 21
UR  - https://hdl.handle.net/21.15107/rcub_rims_411
ER  - 

@article{
author = "Arsić, Miodrag and Flajs, Željko and Sedmak, Aleksandar and Veg, Emil and Sedmak, Simon",
year = "2021",
abstract = "Research is conducted on the causes of damage and the structural integrity assessment of the bucket-wheel boom welded lattice structures, before and after the repair of vital structures. Additionally, the paper describes the investigation conducted based on the results of non-destructive tests (visual-, magnetic particle-, dye penetrant-, and ultrasonic tests), results of tensometric measurements that refer to the stress-strain state, and results based on numerical calculation of stresses by finite element method, performed through the use of a 3D model in the software Radimpex Tower 6.0 (R). The results of tests and research performed after the repair of damaged structural welded sections show that the operational procedures are being obeyed.",
publisher = "Institut za ispitivanje materijala, Beograd",
journal = "Structural Integrity and Life",
title = "Structural integrity assessment of welded bucket-wheel boom",
pages = "206-201",
number = "2",
volume = "21",
url = "https://hdl.handle.net/21.15107/rcub_rims_411"
}

Arsić, M., Flajs, Ž., Sedmak, A., Veg, E.,& Sedmak, S.. (2021). Structural integrity assessment of welded bucket-wheel boom. in Structural Integrity and Life
Institut za ispitivanje materijala, Beograd., 21(2), 201-206.
https://hdl.handle.net/21.15107/rcub_rims_411

Arsić M, Flajs Ž, Sedmak A, Veg E, Sedmak S. Structural integrity assessment of welded bucket-wheel boom. in Structural Integrity and Life. 2021;21(2):201-206.
https://hdl.handle.net/21.15107/rcub_rims_411 .

Arsić, Miodrag, Flajs, Željko, Sedmak, Aleksandar, Veg, Emil, Sedmak, Simon, "Structural integrity assessment of welded bucket-wheel boom" in Structural Integrity and Life, 21, no. 2 (2021):201-206,
https://hdl.handle.net/21.15107/rcub_rims_411 .

TY  - JOUR
AU  - Međo, Bojan
AU  - Arsić, Miodrag
AU  - Mladenović, Mladen
AU  - Savić, Zoran
AU  - Grabulov, Vencislav
AU  - Radosavljević, Zoran
AU  - Rakin, Marko
PY  - 2020
UR  - http://rims.institutims.rs/handle/123456789/381
AB  - Topic of this work is the integrity assessment of the pipeline section from hydropower plant Pirot. Crack-like defect size, maximum depth, is determined based on non-destructive evaluation - the largest crack depth is taken as the initial value for load carrying capacity estimation. Also, the crack dimensions (both length and depth) are varied. Limit pressure values are determined from 3D and 2D models of pipes with axial cracks on external surface. The influence of tensile loading on the load carrying capacity of the pipes with circumferential cracks is also examined. Integrity of pipes with both types of defects (axial and circumferential) is assessed through application of FAD diagrams.
PB  - Institut za ispitivanje materijala, Beograd
T2  - Structural Integrity and Life
T1  - Influence of defects on limit loads and integrity of the pipeline at hydropower plant 'Pirot'
EP  - 86
IS  - 1
SP  - 82
VL  - 20
UR  - https://hdl.handle.net/21.15107/rcub_technorep_4567
ER  - 

@article{
author = "Međo, Bojan and Arsić, Miodrag and Mladenović, Mladen and Savić, Zoran and Grabulov, Vencislav and Radosavljević, Zoran and Rakin, Marko",
year = "2020",
abstract = "Topic of this work is the integrity assessment of the pipeline section from hydropower plant Pirot. Crack-like defect size, maximum depth, is determined based on non-destructive evaluation - the largest crack depth is taken as the initial value for load carrying capacity estimation. Also, the crack dimensions (both length and depth) are varied. Limit pressure values are determined from 3D and 2D models of pipes with axial cracks on external surface. The influence of tensile loading on the load carrying capacity of the pipes with circumferential cracks is also examined. Integrity of pipes with both types of defects (axial and circumferential) is assessed through application of FAD diagrams.",
publisher = "Institut za ispitivanje materijala, Beograd",
journal = "Structural Integrity and Life",
title = "Influence of defects on limit loads and integrity of the pipeline at hydropower plant 'Pirot'",
pages = "86-82",
number = "1",
volume = "20",
url = "https://hdl.handle.net/21.15107/rcub_technorep_4567"
}

Međo, B., Arsić, M., Mladenović, M., Savić, Z., Grabulov, V., Radosavljević, Z.,& Rakin, M.. (2020). Influence of defects on limit loads and integrity of the pipeline at hydropower plant 'Pirot'. in Structural Integrity and Life
Institut za ispitivanje materijala, Beograd., 20(1), 82-86.
https://hdl.handle.net/21.15107/rcub_technorep_4567

Međo B, Arsić M, Mladenović M, Savić Z, Grabulov V, Radosavljević Z, Rakin M. Influence of defects on limit loads and integrity of the pipeline at hydropower plant 'Pirot'. in Structural Integrity and Life. 2020;20(1):82-86.
https://hdl.handle.net/21.15107/rcub_technorep_4567 .

Međo, Bojan, Arsić, Miodrag, Mladenović, Mladen, Savić, Zoran, Grabulov, Vencislav, Radosavljević, Zoran, Rakin, Marko, "Influence of defects on limit loads and integrity of the pipeline at hydropower plant 'Pirot'" in Structural Integrity and Life, 20, no. 1 (2020):82-86,
https://hdl.handle.net/21.15107/rcub_technorep_4567 .

TY  - JOUR
AU  - Arsić, Miodrag
AU  - Savković, Mile
AU  - Mladenović, Mladen
AU  - Bošković, Goran
AU  - Savić, Zoran
PY  - 2019
UR  - http://rims.institutims.rs/handle/123456789/365
AB  - Na deponiji uglja termoelektrane "Nikola Tesla A" u Obrenovcu (Srbija), rade dva rotorna bagera interne oznake DU1 i DU2, koji su proizved francuske fabrike "Ameco" i kreću se po kružnoj stazi (tzv. polarna staza), uz napomenu da u Istočnoj Evropi rade samo tri bagera tog tipa. Treći rotorni bager istog proizvođača radi na deponiji uglja termoelektrane "Nikola Tesla B" u Obrenovcu. U radu je prikazana analiza stanja vitalne čelične konstrukcije kabine rukovaoca rotornog bagera DU 2, izrađene od cevi različitih prečnika i debljina lima, nakon havarije izazvane udarom kamena u poprečni nosač konstrukcije. Kamen se nalazio u otkopanom uglju jedne od kašika rotora bagera. Prilikom udara kamena poprečni nosač konstrukcije kabine rukovaoca se savio i popucali su zavareni spojevi između prirubnica na sredini poprečnog nosača i zavareni spojevi na mestima veze poprečnog nosača sa vertikalnim nosačima konstrukcije. S obzirom da korisnik bagera ne poseduje projektnu i tehničku dokumentaciju sanacija oštećenja sprovedena je pod predpostavkom da je rešetkasta konstrukcija kabine rukovaoca bagera izrađena od konstrukcijskih čelika, koji se uglavnom primenjuju za izradu rotornih bagera. Na osnovu analiza stanja nakon privremene sanacije oštećenja došlo se do zaključka da je za trajno obezbeđenje integriteta noseće čelične konstrukcije kabine rukovaoca rotornog bagera du2 kao celine potrebno izvršiti zamenu oštećenog poprečnog noseća čelične konstrukcije.
AB  - There are 2 bucket -wheel reclaimers, internally labelled as DU1 and DU2, made by French manufacturer 'Ameco', that operate at the open pit surface mine which belongs to the thermal power plant 'Nikola Tesla A' in Obrenovac. They are moving along the polar path and it should be noted that there are only 3 reclaimers of that kind in Eastern Europe. The third bucketwheel reclaimer, made by the same manufacturer, operates at the open pit surface mine that belongs to the thermal power plant 'Nikola Tesla B' in Obrenovac. In this paper the state analysis of the vital steel structure of the bucket-wheel reclaimer DU2 operators' cabin, made of pipes of various diameters and thicknesses, after the breakdown caused by a rock that hit the horizontal support of the structure is presented. The rock was located in the excavated coal within a bucket of the bucket-wheel reclaimer. The horizontal support of the operators' cabin structure has Bent and welded joints between flanges at the middle of the horizontal support, as well as welded joints at bonds of the horizontal support with vertical supports of the structure, have cracked due to the impact of the rock. Taking into account the fact that the user of the bucket-wheel reclaimer does not own the design and technical documentation, damage repair was carried out under the assumption that the lattice structure of the operators' cabin was made of structural steels, which are mostly being used for the manufacture of bucket-wheel reclaimers. On the basis of state analysis after the temporary repair of damages the conclusion arose that for the permanent provision of integrity of the support steel structure of the bucket-wheel reclaimer DU-2 operators' cabin as a whole it is necessary to replace the damaged horizontal support.
PB  - Institut IMK "14. oktobar", Kruševac
T2  - IMK-14 - Istraživanje i razvoj
T1  - Analiza stanja vitalne čelične konstrukcije kabine rukovaoca rotornog bagera nakon havarije i sanacije
T1  - State analysis of the vital steel structure of the bucket-wheel reclaimer operators cabin after the breakdown and the rehabilitation
EP  - 46
IS  - 2
SP  - 43
VL  - 25
DO  - 10.5937/IMK1902043A
ER  - 

@article{
author = "Arsić, Miodrag and Savković, Mile and Mladenović, Mladen and Bošković, Goran and Savić, Zoran",
year = "2019",
abstract = "Na deponiji uglja termoelektrane "Nikola Tesla A" u Obrenovcu (Srbija), rade dva rotorna bagera interne oznake DU1 i DU2, koji su proizved francuske fabrike "Ameco" i kreću se po kružnoj stazi (tzv. polarna staza), uz napomenu da u Istočnoj Evropi rade samo tri bagera tog tipa. Treći rotorni bager istog proizvođača radi na deponiji uglja termoelektrane "Nikola Tesla B" u Obrenovcu. U radu je prikazana analiza stanja vitalne čelične konstrukcije kabine rukovaoca rotornog bagera DU 2, izrađene od cevi različitih prečnika i debljina lima, nakon havarije izazvane udarom kamena u poprečni nosač konstrukcije. Kamen se nalazio u otkopanom uglju jedne od kašika rotora bagera. Prilikom udara kamena poprečni nosač konstrukcije kabine rukovaoca se savio i popucali su zavareni spojevi između prirubnica na sredini poprečnog nosača i zavareni spojevi na mestima veze poprečnog nosača sa vertikalnim nosačima konstrukcije. S obzirom da korisnik bagera ne poseduje projektnu i tehničku dokumentaciju sanacija oštećenja sprovedena je pod predpostavkom da je rešetkasta konstrukcija kabine rukovaoca bagera izrađena od konstrukcijskih čelika, koji se uglavnom primenjuju za izradu rotornih bagera. Na osnovu analiza stanja nakon privremene sanacije oštećenja došlo se do zaključka da je za trajno obezbeđenje integriteta noseće čelične konstrukcije kabine rukovaoca rotornog bagera du2 kao celine potrebno izvršiti zamenu oštećenog poprečnog noseća čelične konstrukcije., There are 2 bucket -wheel reclaimers, internally labelled as DU1 and DU2, made by French manufacturer 'Ameco', that operate at the open pit surface mine which belongs to the thermal power plant 'Nikola Tesla A' in Obrenovac. They are moving along the polar path and it should be noted that there are only 3 reclaimers of that kind in Eastern Europe. The third bucketwheel reclaimer, made by the same manufacturer, operates at the open pit surface mine that belongs to the thermal power plant 'Nikola Tesla B' in Obrenovac. In this paper the state analysis of the vital steel structure of the bucket-wheel reclaimer DU2 operators' cabin, made of pipes of various diameters and thicknesses, after the breakdown caused by a rock that hit the horizontal support of the structure is presented. The rock was located in the excavated coal within a bucket of the bucket-wheel reclaimer. The horizontal support of the operators' cabin structure has Bent and welded joints between flanges at the middle of the horizontal support, as well as welded joints at bonds of the horizontal support with vertical supports of the structure, have cracked due to the impact of the rock. Taking into account the fact that the user of the bucket-wheel reclaimer does not own the design and technical documentation, damage repair was carried out under the assumption that the lattice structure of the operators' cabin was made of structural steels, which are mostly being used for the manufacture of bucket-wheel reclaimers. On the basis of state analysis after the temporary repair of damages the conclusion arose that for the permanent provision of integrity of the support steel structure of the bucket-wheel reclaimer DU-2 operators' cabin as a whole it is necessary to replace the damaged horizontal support.",
publisher = "Institut IMK "14. oktobar", Kruševac",
journal = "IMK-14 - Istraživanje i razvoj",
title = "Analiza stanja vitalne čelične konstrukcije kabine rukovaoca rotornog bagera nakon havarije i sanacije, State analysis of the vital steel structure of the bucket-wheel reclaimer operators cabin after the breakdown and the rehabilitation",
pages = "46-43",
number = "2",
volume = "25",
doi = "10.5937/IMK1902043A"
}

Arsić, M., Savković, M., Mladenović, M., Bošković, G.,& Savić, Z.. (2019). Analiza stanja vitalne čelične konstrukcije kabine rukovaoca rotornog bagera nakon havarije i sanacije. in IMK-14 - Istraživanje i razvoj
Institut IMK "14. oktobar", Kruševac., 25(2), 43-46.
https://doi.org/10.5937/IMK1902043A

Arsić M, Savković M, Mladenović M, Bošković G, Savić Z. Analiza stanja vitalne čelične konstrukcije kabine rukovaoca rotornog bagera nakon havarije i sanacije. in IMK-14 - Istraživanje i razvoj. 2019;25(2):43-46.
doi:10.5937/IMK1902043A .

Arsić, Miodrag, Savković, Mile, Mladenović, Mladen, Bošković, Goran, Savić, Zoran, "Analiza stanja vitalne čelične konstrukcije kabine rukovaoca rotornog bagera nakon havarije i sanacije" in IMK-14 - Istraživanje i razvoj, 25, no. 2 (2019):43-46,
https://doi.org/10.5937/IMK1902043A . .

TY  - JOUR
AU  - Arsić, Miodrag
AU  - Bošnjak, Srđan
AU  - Sedmak, Simon
AU  - Vistać, Brane
AU  - Savić, Zoran
PY  - 2019
UR  - http://rims.institutims.rs/handle/123456789/361
AB  - During the revitalization of the hydroelectric generating station A4 at the hydro power plant 'Djerdap 1', all of its parts are subjected to non-destructive testing. Cracks are detected in cast part of generator rotor hub, in the flange area toward the turbine shaft. Cracks were 10-500 mm long (determined by magnetic particle tests) and 60-100 mm deep (ultrasonic tests). The generator rotor hub is made of cast steel 25L, in accordance with the standard 977-75. The welding/surface welding repair technology in the detected crack zones of the cast part of generator rotor hub includes a large number of details, due to the structural solution and generator rotor function in service. It was also necessary to provide the carefully undertaken activities in order to enable safe operation and continuous use of the rotor hub. Failing to notice, underestimation or incorrect perception of important details could cause significant problems in hydroelectric generating station operation. The paper, due to specifics of reparation technology, contains arranged preparatory activities for the procedure apart from the welding/surface welding technology. It is of importance to mention a huge amount of money savings, The manufacture of a new generator rotor would cost over 4 million EUR (generator mass is over 300 tonnes), not taking into account the time needed for its making (6-12 months), which is directly related to the amount of energy a hydroelectric generating station can produce during that period. This technology of repair welding is also applicable for other components and structures of the turbine and the hydromechanical equipment subjected to various causes of damage during exploitation.
PB  - Institut za ispitivanje materijala, Beograd
T2  - Structural Integrity and Life
T1  - Repair of cracks detected in cast components of vertical Kaplan turbine rotor hub
EP  - 250
IS  - 3
SP  - 243
VL  - 19
UR  - https://hdl.handle.net/21.15107/rcub_rims_361
ER  - 

@article{
author = "Arsić, Miodrag and Bošnjak, Srđan and Sedmak, Simon and Vistać, Brane and Savić, Zoran",
year = "2019",
abstract = "During the revitalization of the hydroelectric generating station A4 at the hydro power plant 'Djerdap 1', all of its parts are subjected to non-destructive testing. Cracks are detected in cast part of generator rotor hub, in the flange area toward the turbine shaft. Cracks were 10-500 mm long (determined by magnetic particle tests) and 60-100 mm deep (ultrasonic tests). The generator rotor hub is made of cast steel 25L, in accordance with the standard 977-75. The welding/surface welding repair technology in the detected crack zones of the cast part of generator rotor hub includes a large number of details, due to the structural solution and generator rotor function in service. It was also necessary to provide the carefully undertaken activities in order to enable safe operation and continuous use of the rotor hub. Failing to notice, underestimation or incorrect perception of important details could cause significant problems in hydroelectric generating station operation. The paper, due to specifics of reparation technology, contains arranged preparatory activities for the procedure apart from the welding/surface welding technology. It is of importance to mention a huge amount of money savings, The manufacture of a new generator rotor would cost over 4 million EUR (generator mass is over 300 tonnes), not taking into account the time needed for its making (6-12 months), which is directly related to the amount of energy a hydroelectric generating station can produce during that period. This technology of repair welding is also applicable for other components and structures of the turbine and the hydromechanical equipment subjected to various causes of damage during exploitation.",
publisher = "Institut za ispitivanje materijala, Beograd",
journal = "Structural Integrity and Life",
title = "Repair of cracks detected in cast components of vertical Kaplan turbine rotor hub",
pages = "250-243",
number = "3",
volume = "19",
url = "https://hdl.handle.net/21.15107/rcub_rims_361"
}

Arsić, M., Bošnjak, S., Sedmak, S., Vistać, B.,& Savić, Z.. (2019). Repair of cracks detected in cast components of vertical Kaplan turbine rotor hub. in Structural Integrity and Life
Institut za ispitivanje materijala, Beograd., 19(3), 243-250.
https://hdl.handle.net/21.15107/rcub_rims_361

Arsić M, Bošnjak S, Sedmak S, Vistać B, Savić Z. Repair of cracks detected in cast components of vertical Kaplan turbine rotor hub. in Structural Integrity and Life. 2019;19(3):243-250.
https://hdl.handle.net/21.15107/rcub_rims_361 .

Arsić, Miodrag, Bošnjak, Srđan, Sedmak, Simon, Vistać, Brane, Savić, Zoran, "Repair of cracks detected in cast components of vertical Kaplan turbine rotor hub" in Structural Integrity and Life, 19, no. 3 (2019):243-250,
https://hdl.handle.net/21.15107/rcub_rims_361 .

TY  - JOUR
AU  - Arsić, Miodrag
AU  - Grabulov, Vencislav
AU  - Mladenović, Mladen
AU  - Savić, Zoran
PY  - 2018
UR  - http://rims.institutims.rs/handle/123456789/339
AB  - Hidroelektrana Pirot, koja je izgrađena 1990 godine, je akumulaciona elektrana derivacionog tipa, koja se sastoji od dva nadzemna vertikalna agregata sa Francis turbinama nominalne snage 41,5 MW, proizvedene u Češkoj Republici, tunela i ukopanog cevovoda ukupne dužine 2030 m i prečnika od O 3000 mm do O 3500 mm. Cevovod debljine lima 22 mm je izrađen od čelika kvaliteta S275J2G3 (stara oznaka Č.0462). Maksimalni pritisak u njemu ispred turbinskog zatvarača je 2,5 MP. Na cevovodu se u kontinuitetu od završetka izgradnje i puštanja u rad sprovode geodetska merenja kada je cevovod prazan i neopterećen hidrostatičkim pritiskom i kada je cevovod pun. Pregledom i analizom dobijenih podataka o pomeranjima duž trase cevovoda utvrđeno je da od 2003-2004 godine postoje znatno veće razlike u pomeranjima za pun i prazan cevovod, nego u prethodnom periodu. U radu je izvršena analiza trenutnog stanja i ocena čvrstoče cevovoda kao celine na osnovu rezultata ispitivanja sučeonih zavarenih spojeva i ukrsnih masta metodama bez razaranja u zoni preloma na stacionaži - dužini cevovoda 1+263m (vizuelno ispitivanje, ispitivanje magnetnim česticama, ispitivanje penetrantima, ispitivanje ultrazvukom, radiografsko ispitivanje, metalografsko ispitivanje metodom replika).
AB  - Hydro power plant Pirot, which was built in 1990, is an accumulation-derivative power plant, which consists of 2 above-ground vertical hydroelectric generating sets that contain Francis turbines with nominal power of 41,5 MW, manufactured in Czech Republic, a tunnel and a sunken pipeline with overall length of 2.030 m and diameter that ranges from 3.000 to 3.500 m. Pipes have been made of S275J2G3 steel. Pipe wall is 22 mm thick. Maximum pressure of 2.5 MPa occurs in front of the turbine cover. Geodetic measurements have been conducted permanently from the day the assembly was finished and pipeline was put into service, both when pipeline is empty and unloaded by hydrostatic pressure and when it is full. Analysis of obtained data regarding the movements along the pipeline route showed that from year 2003 there are significantly higher differences in movements comparing the situations when the pipeline is full and when it is empty in comparison with the previous period. This paper contains the analysis of current state and strength evaluation of the pipeline as a whole on the basis of results of non-destructive tests performed on the vital butt - welded joint in the curvature area at chainage 1+263 m (visual testing, magnetic particle testing, penetrant testing, ultrasonic testing, radiographic testing, metallographic replication testing).
PB  - DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd
T2  - Zavarivanje i zavarene konstrukcije
T1  - Analiza trenutnog stanja i ocena čvrstoće cevovoda na hidroelektrani Pirot
T1  - Analysis of current state and strength evaluation of the pipeline at hydro power plant 'Pirot'
EP  - 22
IS  - 1
SP  - 17
VL  - 63
DO  - 10.5937/zzk1801017A
ER  - 

@article{
author = "Arsić, Miodrag and Grabulov, Vencislav and Mladenović, Mladen and Savić, Zoran",
year = "2018",
abstract = "Hidroelektrana Pirot, koja je izgrađena 1990 godine, je akumulaciona elektrana derivacionog tipa, koja se sastoji od dva nadzemna vertikalna agregata sa Francis turbinama nominalne snage 41,5 MW, proizvedene u Češkoj Republici, tunela i ukopanog cevovoda ukupne dužine 2030 m i prečnika od O 3000 mm do O 3500 mm. Cevovod debljine lima 22 mm je izrađen od čelika kvaliteta S275J2G3 (stara oznaka Č.0462). Maksimalni pritisak u njemu ispred turbinskog zatvarača je 2,5 MP. Na cevovodu se u kontinuitetu od završetka izgradnje i puštanja u rad sprovode geodetska merenja kada je cevovod prazan i neopterećen hidrostatičkim pritiskom i kada je cevovod pun. Pregledom i analizom dobijenih podataka o pomeranjima duž trase cevovoda utvrđeno je da od 2003-2004 godine postoje znatno veće razlike u pomeranjima za pun i prazan cevovod, nego u prethodnom periodu. U radu je izvršena analiza trenutnog stanja i ocena čvrstoče cevovoda kao celine na osnovu rezultata ispitivanja sučeonih zavarenih spojeva i ukrsnih masta metodama bez razaranja u zoni preloma na stacionaži - dužini cevovoda 1+263m (vizuelno ispitivanje, ispitivanje magnetnim česticama, ispitivanje penetrantima, ispitivanje ultrazvukom, radiografsko ispitivanje, metalografsko ispitivanje metodom replika)., Hydro power plant Pirot, which was built in 1990, is an accumulation-derivative power plant, which consists of 2 above-ground vertical hydroelectric generating sets that contain Francis turbines with nominal power of 41,5 MW, manufactured in Czech Republic, a tunnel and a sunken pipeline with overall length of 2.030 m and diameter that ranges from 3.000 to 3.500 m. Pipes have been made of S275J2G3 steel. Pipe wall is 22 mm thick. Maximum pressure of 2.5 MPa occurs in front of the turbine cover. Geodetic measurements have been conducted permanently from the day the assembly was finished and pipeline was put into service, both when pipeline is empty and unloaded by hydrostatic pressure and when it is full. Analysis of obtained data regarding the movements along the pipeline route showed that from year 2003 there are significantly higher differences in movements comparing the situations when the pipeline is full and when it is empty in comparison with the previous period. This paper contains the analysis of current state and strength evaluation of the pipeline as a whole on the basis of results of non-destructive tests performed on the vital butt - welded joint in the curvature area at chainage 1+263 m (visual testing, magnetic particle testing, penetrant testing, ultrasonic testing, radiographic testing, metallographic replication testing).",
publisher = "DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd",
journal = "Zavarivanje i zavarene konstrukcije",
title = "Analiza trenutnog stanja i ocena čvrstoće cevovoda na hidroelektrani Pirot, Analysis of current state and strength evaluation of the pipeline at hydro power plant 'Pirot'",
pages = "22-17",
number = "1",
volume = "63",
doi = "10.5937/zzk1801017A"
}

Arsić, M., Grabulov, V., Mladenović, M.,& Savić, Z.. (2018). Analiza trenutnog stanja i ocena čvrstoće cevovoda na hidroelektrani Pirot. in Zavarivanje i zavarene konstrukcije
DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd., 63(1), 17-22.
https://doi.org/10.5937/zzk1801017A

Arsić M, Grabulov V, Mladenović M, Savić Z. Analiza trenutnog stanja i ocena čvrstoće cevovoda na hidroelektrani Pirot. in Zavarivanje i zavarene konstrukcije. 2018;63(1):17-22.
doi:10.5937/zzk1801017A .

Arsić, Miodrag, Grabulov, Vencislav, Mladenović, Mladen, Savić, Zoran, "Analiza trenutnog stanja i ocena čvrstoće cevovoda na hidroelektrani Pirot" in Zavarivanje i zavarene konstrukcije, 63, no. 1 (2018):17-22,
https://doi.org/10.5937/zzk1801017A . .

TY  - JOUR
AU  - Međo, Bojan
AU  - Arsić, Miodrag
AU  - Rakin, M.
AU  - Sedmak, Simon
AU  - Savić, Zoran
PY  - 2018
UR  - http://rims.institutims.rs/handle/123456789/343
AB  - Vital components of the beam that enable conjoint operation of two bridge cranes are braces and threaded spindle. The beam connects two bridge cranes with overall lifting capacity of 500 t (2 × 250 t) and enables their simultaneous conjoint operation during the rehabilitation or major overhaul of hydroelectric generating set equipment at the hydro power plant ‘'Djerdap 2’. Two braces are being installed instead of two hooks when this situation occurs. The threaded spindle is loaded with 500 t (5 MN), while braces are loaded with 250 t (2.5 MN) each. Integrity of structures is a relatively new scientific and engineering discipline which in a broader sense comprises condition analysis, behaviour diagnostics, service life evaluation and rehabilitation of structures, which means that beside the usual situation in which it is necessary to evaluate the integrity of a structure when a flaw is detected by means of non-destructive tests, this discipline also comprises stress condition analysis for the crackless structure, most often through the use of finite element method. This is the way to obtain precise and detailed distribution of displacements, deformations and stresses, which enables determination of weak spots on the structure, even before crack initiation. Non-destructive tests are performed in order to analyse the current condition of braces and the threaded spindle. On the basis of performed analytical calculations it is determined that the integrity is not threatened, although some internal non-homogeneities are detected by ultrasonic testing.
PB  - Institut za ispitivanje materijala, Beograd
T2  - Structural Integrity and Life
T1  - Integrity assessment of vital beam components that enable conjoint operation of two bridge cranes
EP  - 59
IS  - 1
SP  - 53
VL  - 18
UR  - https://hdl.handle.net/21.15107/rcub_technorep_3791
ER  - 

@article{
author = "Međo, Bojan and Arsić, Miodrag and Rakin, M. and Sedmak, Simon and Savić, Zoran",
year = "2018",
abstract = "Vital components of the beam that enable conjoint operation of two bridge cranes are braces and threaded spindle. The beam connects two bridge cranes with overall lifting capacity of 500 t (2 × 250 t) and enables their simultaneous conjoint operation during the rehabilitation or major overhaul of hydroelectric generating set equipment at the hydro power plant ‘'Djerdap 2’. Two braces are being installed instead of two hooks when this situation occurs. The threaded spindle is loaded with 500 t (5 MN), while braces are loaded with 250 t (2.5 MN) each. Integrity of structures is a relatively new scientific and engineering discipline which in a broader sense comprises condition analysis, behaviour diagnostics, service life evaluation and rehabilitation of structures, which means that beside the usual situation in which it is necessary to evaluate the integrity of a structure when a flaw is detected by means of non-destructive tests, this discipline also comprises stress condition analysis for the crackless structure, most often through the use of finite element method. This is the way to obtain precise and detailed distribution of displacements, deformations and stresses, which enables determination of weak spots on the structure, even before crack initiation. Non-destructive tests are performed in order to analyse the current condition of braces and the threaded spindle. On the basis of performed analytical calculations it is determined that the integrity is not threatened, although some internal non-homogeneities are detected by ultrasonic testing.",
publisher = "Institut za ispitivanje materijala, Beograd",
journal = "Structural Integrity and Life",
title = "Integrity assessment of vital beam components that enable conjoint operation of two bridge cranes",
pages = "59-53",
number = "1",
volume = "18",
url = "https://hdl.handle.net/21.15107/rcub_technorep_3791"
}

Međo, B., Arsić, M., Rakin, M., Sedmak, S.,& Savić, Z.. (2018). Integrity assessment of vital beam components that enable conjoint operation of two bridge cranes. in Structural Integrity and Life
Institut za ispitivanje materijala, Beograd., 18(1), 53-59.
https://hdl.handle.net/21.15107/rcub_technorep_3791

Međo B, Arsić M, Rakin M, Sedmak S, Savić Z. Integrity assessment of vital beam components that enable conjoint operation of two bridge cranes. in Structural Integrity and Life. 2018;18(1):53-59.
https://hdl.handle.net/21.15107/rcub_technorep_3791 .

Međo, Bojan, Arsić, Miodrag, Rakin, M., Sedmak, Simon, Savić, Zoran, "Integrity assessment of vital beam components that enable conjoint operation of two bridge cranes" in Structural Integrity and Life, 18, no. 1 (2018):53-59,
https://hdl.handle.net/21.15107/rcub_technorep_3791 .

TY  - CONF
AU  - Arsić, Miodrag
AU  - Bošnjak, Srđan
AU  - Gnjatović, Nebojša
AU  - Sedmak, Simon
AU  - Arsić, D.
AU  - Savić, Zoran
PY  - 2018
UR  - http://rims.institutims.rs/handle/123456789/334
AB  - This paper presents a methodological approach for the assessment of service life of vital welded structures of a bucket-wheel excavator Sch Rs 650/5x24 ('Thyssen Krupp', Germany) boom, subjected to cyclic loading with a variable amplitude through the use of experimental tests carried out in order to determine operational strength and growth of a fatigue crack. Realized researches and results presented in this paper offer great possibilities for the analyses of behaviour of vital welded structures of the bucket-wheel boom. By the application of the measurement device with 8 channels for registration and processing of electric signals HBM Spider 8 and measurement tapes HBM 6/350xXY31 deformations were measured at vital welded structures of the boom in the area of the bucket-wheel, made of steels St 37.2 and St 52.3 in accordance with standard DIN 17100, or steels S235J2G3 and S355J2G3 in accordance with standard EN 10025-2. The objective of the test is to determine if there is a possibility of occurrence of plastic deformations or initial cracks due to fatigue at vital welded structures. Tests that refer to the growth of the fatigue crack located at the welded joint have been carried out by bending at three points with asymmetric load R = 0.5 (R = sigma(min) / sigma(max)) at the specimen with a single edge notch. Tests were performed through the use of controlled force, ranging between F-max and F-min at the high frequency pulsator 'Cracktronic', while obtainment of data regarding the crack growth was carried out through the use of measurement gauge ARM A-10.
PB  - Elsevier Science Bv, Amsterdam
C3  - ECF22 - Loading and Environmental Effects on Structural Integrity
T1  - Determination of Residual Fatigue Life of Welded Structures at Bucket-Wheel Excavators through the Use of Fracture Mechanics
EP  - 84
SP  - 79
VL  - 13
DO  - 10.1016/j.prostr.2018.12.014
ER  - 

@conference{
author = "Arsić, Miodrag and Bošnjak, Srđan and Gnjatović, Nebojša and Sedmak, Simon and Arsić, D. and Savić, Zoran",
year = "2018",
abstract = "This paper presents a methodological approach for the assessment of service life of vital welded structures of a bucket-wheel excavator Sch Rs 650/5x24 ('Thyssen Krupp', Germany) boom, subjected to cyclic loading with a variable amplitude through the use of experimental tests carried out in order to determine operational strength and growth of a fatigue crack. Realized researches and results presented in this paper offer great possibilities for the analyses of behaviour of vital welded structures of the bucket-wheel boom. By the application of the measurement device with 8 channels for registration and processing of electric signals HBM Spider 8 and measurement tapes HBM 6/350xXY31 deformations were measured at vital welded structures of the boom in the area of the bucket-wheel, made of steels St 37.2 and St 52.3 in accordance with standard DIN 17100, or steels S235J2G3 and S355J2G3 in accordance with standard EN 10025-2. The objective of the test is to determine if there is a possibility of occurrence of plastic deformations or initial cracks due to fatigue at vital welded structures. Tests that refer to the growth of the fatigue crack located at the welded joint have been carried out by bending at three points with asymmetric load R = 0.5 (R = sigma(min) / sigma(max)) at the specimen with a single edge notch. Tests were performed through the use of controlled force, ranging between F-max and F-min at the high frequency pulsator 'Cracktronic', while obtainment of data regarding the crack growth was carried out through the use of measurement gauge ARM A-10.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "ECF22 - Loading and Environmental Effects on Structural Integrity",
title = "Determination of Residual Fatigue Life of Welded Structures at Bucket-Wheel Excavators through the Use of Fracture Mechanics",
pages = "84-79",
volume = "13",
doi = "10.1016/j.prostr.2018.12.014"
}

Arsić, M., Bošnjak, S., Gnjatović, N., Sedmak, S., Arsić, D.,& Savić, Z.. (2018). Determination of Residual Fatigue Life of Welded Structures at Bucket-Wheel Excavators through the Use of Fracture Mechanics. in ECF22 - Loading and Environmental Effects on Structural Integrity
Elsevier Science Bv, Amsterdam., 13, 79-84.
https://doi.org/10.1016/j.prostr.2018.12.014

Arsić M, Bošnjak S, Gnjatović N, Sedmak S, Arsić D, Savić Z. Determination of Residual Fatigue Life of Welded Structures at Bucket-Wheel Excavators through the Use of Fracture Mechanics. in ECF22 - Loading and Environmental Effects on Structural Integrity. 2018;13:79-84.
doi:10.1016/j.prostr.2018.12.014 .

Arsić, Miodrag, Bošnjak, Srđan, Gnjatović, Nebojša, Sedmak, Simon, Arsić, D., Savić, Zoran, "Determination of Residual Fatigue Life of Welded Structures at Bucket-Wheel Excavators through the Use of Fracture Mechanics" in ECF22 - Loading and Environmental Effects on Structural Integrity, 13 (2018):79-84,
https://doi.org/10.1016/j.prostr.2018.12.014 . .

TY  - JOUR
AU  - Arsić, Miodrag
AU  - Malešević, Zoranka
AU  - Mladenović, Mladen
AU  - Savić, Zoran
AU  - Bošković, Goran
PY  - 2017
UR  - http://rims.institutims.rs/handle/123456789/313
AB  - Hidroelektrana Pirot, koja je izgrađena 1990 godine, je akumulaciona elektrana derivacionog tipa, koja se sastoji od dva nadzemna vertikalna agregata sa Francis turbinama nominalne snage 41,5 MW, proizvedene u Češkoj Republici, tunela i ukopanog cevovoda ukupne dužine 2030 m i prečnika od Ø 3000 mm do Ø 3500 mm. Cevovod debljine lima 22 mm je izrađen od čelika kvaliteta S275J2G3 (stara oznaka Č.0462). Maksimalni pritisak u njemu ispred turbinskog zatvarača je 2,5 MP. Cevovod je projektovan i izgrađen bez ankernih blokova na prelomima, što pretstavlja retkost u svetu. Na cevovodu se u kontinuitetu od završetka izgradnje i puštanja u rad sprovode geodetska merenja kada je cevovod prazan i neopterećen hidrostatickim pritiskom i kada je cevovod pun. Pregledom i analizom dobijenih podataka o pomeranjima duz trase cevovoda utvrđeno je da od 2003-2004 godine postoje znatno veće razlike u pomeranjima za pun i prazan cevovod, nego u prethodnom periodu. Te razlike se prvenstveno odnose na tangencijalna pomeranja za temena oznake 6, 7 i 8, koja se u odnosu na period do 2002 godine kreću od 3 mm za teme 8 do 5 mm za teme 6. Pored geodetskih merenja u kontinuitetu se, sa unutrašnje strane cevovoda, sprovode i merenja promena horizontalnih i vertikalnih prečnika. Iz tih podataka se moze videti da u periodu 2003-2004 godine postoji i značajan trend povečanja horizontalnih, kao i manje izraženo smanjenje vertikalnih prečnika. U radu je izvršena analiza trenutnog stanja i ocena integriteta cevovoda kao celine na osnovu rezultata ispitivanja vitalnog sučeonog zavarenog spoja metodama bez razaranja u zoni preloma na stacionaži - dužini cevovoda 1+263 m (vizuelno ispitivanje, ispitivanje magnetnim česticama, ispitivanje penetrantima, ispitivanje ultrazvukom, radiografsko ispitivanje, metalografsko ispitivanje metodom replika).
AB  - Hydro power plant Pirot, which was built in 1990, is an accumulation-derivative power plant, which consists of 2 above-ground vertical hydroelectric generating sets that contain Francis turbines with nominal power of 41,5 MW, manufactured in Czech Republic, a tunnel and a sunken pipeline with overall length of 2.030 m and diameter that ranges from 3.000 to 3.500 m. Pipes have been made of S275J2G3 steel. Pipe wall is 22 mm thick. Maximum pressure of 2.5 MPa occurs in front of the turbine cover. Pipeline has been designed and built without anchor blocks at curvatures, which is a rarity elsewhere. Geodetic measurements have been conducted permanently from the day the assembly was finished and pipeline was put into service, both when pipeline is empty and unloaded by hydrostatic pressure and when it is full. Analysis of obtained data regarding the movements along the pipeline route showed that from year 2003 there are significantly higher differences in movements comparing the situations when the pipeline is full and when it is empty in comparison with the previous period. Those differences primarily refer to tangential movements of vertices marked with numbers 6, 7 and 8, which, compared to the period until year 2002, are in the range from 3 mm for vertex 8 to 5 mm for vertex 6. Apart from geodetic measurements, the measurement of pipe diameter in 2 directions is also being carried out permanently. Those data show that from year 2003 the diameter in horizontal direction started to increase significantly, while at the same time the diameter in vertical direction started to decrease less significantly. This paper contains the analysis of current state and integrity evaluation of the pipeline as a whole on the basis of results of non-destructive tests performed on the vital butt-welded joint in the curvature area at chainage 1+263 m (visual testing, magnetic particle testing, penetrant testing, ultrasonic testing, radiographic testing, metallographic replication testing.
PB  - Institut IMK "14. oktobar", Kruševac
T2  - IMK-14 - Istraživanje i razvoj
T1  - Analiza trenutnog stanja i ocena integriteta cevovoda na hidroelektrani Pirot
T1  - Analysis of current state and integrity evaluation of the pipeline at hydro power plant 'Pirot'
EP  - 14
IS  - 1
SP  - 9
VL  - 23
DO  - 10.5937/IMK1701009A
ER  - 

@article{
author = "Arsić, Miodrag and Malešević, Zoranka and Mladenović, Mladen and Savić, Zoran and Bošković, Goran",
year = "2017",
abstract = "Hidroelektrana Pirot, koja je izgrađena 1990 godine, je akumulaciona elektrana derivacionog tipa, koja se sastoji od dva nadzemna vertikalna agregata sa Francis turbinama nominalne snage 41,5 MW, proizvedene u Češkoj Republici, tunela i ukopanog cevovoda ukupne dužine 2030 m i prečnika od Ø 3000 mm do Ø 3500 mm. Cevovod debljine lima 22 mm je izrađen od čelika kvaliteta S275J2G3 (stara oznaka Č.0462). Maksimalni pritisak u njemu ispred turbinskog zatvarača je 2,5 MP. Cevovod je projektovan i izgrađen bez ankernih blokova na prelomima, što pretstavlja retkost u svetu. Na cevovodu se u kontinuitetu od završetka izgradnje i puštanja u rad sprovode geodetska merenja kada je cevovod prazan i neopterećen hidrostatickim pritiskom i kada je cevovod pun. Pregledom i analizom dobijenih podataka o pomeranjima duz trase cevovoda utvrđeno je da od 2003-2004 godine postoje znatno veće razlike u pomeranjima za pun i prazan cevovod, nego u prethodnom periodu. Te razlike se prvenstveno odnose na tangencijalna pomeranja za temena oznake 6, 7 i 8, koja se u odnosu na period do 2002 godine kreću od 3 mm za teme 8 do 5 mm za teme 6. Pored geodetskih merenja u kontinuitetu se, sa unutrašnje strane cevovoda, sprovode i merenja promena horizontalnih i vertikalnih prečnika. Iz tih podataka se moze videti da u periodu 2003-2004 godine postoji i značajan trend povečanja horizontalnih, kao i manje izraženo smanjenje vertikalnih prečnika. U radu je izvršena analiza trenutnog stanja i ocena integriteta cevovoda kao celine na osnovu rezultata ispitivanja vitalnog sučeonog zavarenog spoja metodama bez razaranja u zoni preloma na stacionaži - dužini cevovoda 1+263 m (vizuelno ispitivanje, ispitivanje magnetnim česticama, ispitivanje penetrantima, ispitivanje ultrazvukom, radiografsko ispitivanje, metalografsko ispitivanje metodom replika)., Hydro power plant Pirot, which was built in 1990, is an accumulation-derivative power plant, which consists of 2 above-ground vertical hydroelectric generating sets that contain Francis turbines with nominal power of 41,5 MW, manufactured in Czech Republic, a tunnel and a sunken pipeline with overall length of 2.030 m and diameter that ranges from 3.000 to 3.500 m. Pipes have been made of S275J2G3 steel. Pipe wall is 22 mm thick. Maximum pressure of 2.5 MPa occurs in front of the turbine cover. Pipeline has been designed and built without anchor blocks at curvatures, which is a rarity elsewhere. Geodetic measurements have been conducted permanently from the day the assembly was finished and pipeline was put into service, both when pipeline is empty and unloaded by hydrostatic pressure and when it is full. Analysis of obtained data regarding the movements along the pipeline route showed that from year 2003 there are significantly higher differences in movements comparing the situations when the pipeline is full and when it is empty in comparison with the previous period. Those differences primarily refer to tangential movements of vertices marked with numbers 6, 7 and 8, which, compared to the period until year 2002, are in the range from 3 mm for vertex 8 to 5 mm for vertex 6. Apart from geodetic measurements, the measurement of pipe diameter in 2 directions is also being carried out permanently. Those data show that from year 2003 the diameter in horizontal direction started to increase significantly, while at the same time the diameter in vertical direction started to decrease less significantly. This paper contains the analysis of current state and integrity evaluation of the pipeline as a whole on the basis of results of non-destructive tests performed on the vital butt-welded joint in the curvature area at chainage 1+263 m (visual testing, magnetic particle testing, penetrant testing, ultrasonic testing, radiographic testing, metallographic replication testing.",
publisher = "Institut IMK "14. oktobar", Kruševac",
journal = "IMK-14 - Istraživanje i razvoj",
title = "Analiza trenutnog stanja i ocena integriteta cevovoda na hidroelektrani Pirot, Analysis of current state and integrity evaluation of the pipeline at hydro power plant 'Pirot'",
pages = "14-9",
number = "1",
volume = "23",
doi = "10.5937/IMK1701009A"
}

Arsić, M., Malešević, Z., Mladenović, M., Savić, Z.,& Bošković, G.. (2017). Analiza trenutnog stanja i ocena integriteta cevovoda na hidroelektrani Pirot. in IMK-14 - Istraživanje i razvoj
Institut IMK "14. oktobar", Kruševac., 23(1), 9-14.
https://doi.org/10.5937/IMK1701009A

Arsić M, Malešević Z, Mladenović M, Savić Z, Bošković G. Analiza trenutnog stanja i ocena integriteta cevovoda na hidroelektrani Pirot. in IMK-14 - Istraživanje i razvoj. 2017;23(1):9-14.
doi:10.5937/IMK1701009A .

Arsić, Miodrag, Malešević, Zoranka, Mladenović, Mladen, Savić, Zoran, Bošković, Goran, "Analiza trenutnog stanja i ocena integriteta cevovoda na hidroelektrani Pirot" in IMK-14 - Istraživanje i razvoj, 23, no. 1 (2017):9-14,
https://doi.org/10.5937/IMK1701009A . .

TY  - JOUR
AU  - Sedmak, Aleksandar
AU  - Bošnjak, Srđan
AU  - Arsić, Miodrag
AU  - Sedmak, S.A.
AU  - Savić, Zoran
PY  - 2016
UR  - http://rims.institutims.rs/handle/123456789/304
AB  - This paper presents integrity and life estimation of turbine runner cover in a vertical pipe turbines, Kaplan 200 MW nominal output power, produced in Russia, and built in six hydro-generation units of hydroelectric power plant „Đerdap 1” in Serbia. Fatigue and corrosion-fatigue interaction have been taken into account using experimentally obtained material properties, as well as analytical and numerical calculations of stress state, to estimate appropriate safety factors. Fatigue crack growth rate, da/dN, was also calculated, indicated that internal defects of circular or elliptical shape, found out by ultrasonic testing, do not affect reliable operation of runner cover.
PB  - Gruppo Italiano Frattura
T2  - Frattura ed Integrita Strutturale
T1  - Integrity and life estimation of turbine runner cover in a hydro power plant
EP  - 68
IS  - 36
SP  - 63
VL  - 10
DO  - 10.3221/IGF-ESIS.36.07
ER  - 

@article{
author = "Sedmak, Aleksandar and Bošnjak, Srđan and Arsić, Miodrag and Sedmak, S.A. and Savić, Zoran",
year = "2016",
abstract = "This paper presents integrity and life estimation of turbine runner cover in a vertical pipe turbines, Kaplan 200 MW nominal output power, produced in Russia, and built in six hydro-generation units of hydroelectric power plant „Đerdap 1” in Serbia. Fatigue and corrosion-fatigue interaction have been taken into account using experimentally obtained material properties, as well as analytical and numerical calculations of stress state, to estimate appropriate safety factors. Fatigue crack growth rate, da/dN, was also calculated, indicated that internal defects of circular or elliptical shape, found out by ultrasonic testing, do not affect reliable operation of runner cover.",
publisher = "Gruppo Italiano Frattura",
journal = "Frattura ed Integrita Strutturale",
title = "Integrity and life estimation of turbine runner cover in a hydro power plant",
pages = "68-63",
number = "36",
volume = "10",
doi = "10.3221/IGF-ESIS.36.07"
}

Sedmak, A., Bošnjak, S., Arsić, M., Sedmak, S.A.,& Savić, Z.. (2016). Integrity and life estimation of turbine runner cover in a hydro power plant. in Frattura ed Integrita Strutturale
Gruppo Italiano Frattura., 10(36), 63-68.
https://doi.org/10.3221/IGF-ESIS.36.07

Sedmak A, Bošnjak S, Arsić M, Sedmak S, Savić Z. Integrity and life estimation of turbine runner cover in a hydro power plant. in Frattura ed Integrita Strutturale. 2016;10(36):63-68.
doi:10.3221/IGF-ESIS.36.07 .

Sedmak, Aleksandar, Bošnjak, Srđan, Arsić, Miodrag, Sedmak, S.A., Savić, Zoran, "Integrity and life estimation of turbine runner cover in a hydro power plant" in Frattura ed Integrita Strutturale, 10, no. 36 (2016):63-68,
https://doi.org/10.3221/IGF-ESIS.36.07 . .

TY  - JOUR
AU  - Međo, Bojan
AU  - Arsić, Miodrag
AU  - Rakin, Marko
AU  - Sedmak, Simon
AU  - Malešević, Zoranka
AU  - Savić, Zoran
PY  - 2016
UR  - http://rims.institutims.rs/handle/123456789/303
AB  - Vertical Kaplan turbines with nominal power of 176 MW manufactured in Russia are installed in 6 hydroelectric generating sets at hydro power plant 'Djerdap 1' (Kladovo, Serbia). Most of the components are made of materials in accordance to GOST and ASTM standards. During rehabilitation of hydroelectric generating set, the analysis of the current state and integrity assessment of turbine regulation system pipeline required non-destructive tests on parent material and welded joints between pipes and pipes-elbows. The purpose of the regulation system, comprising of the pipeline for the turbine regulator oil supply, is to open and close vanes of the guide vane apparatus and to regulate the position of runner blades and their number of revolutions. Internal pressure in the regulation system is p = 4 MPa. Structural integrity is a recent scientific and engineering discipline which in broader sense comprises state analysis and behaviour diagnostics, service life assessment and rehabilitation of structures, meaning that beside the usual situation where structural integrity assessment is required when flaws are detected by non-destructive testing, this discipline is also includes stress state analysis. This approach is especially important for welded structures, since cracktype flaws can originate from welding and from unfavourable service conditions. In this paper, the results of non-destructive tests referring to the lack of penetration in roots of butt-welded joints between pipes and pipes-elbows, as well as tensile test results of technical specimens with reinforcements and in specimens with parallel machined sides and standard dimensions, are presented in order to carry out the integrity assessment of the turbine regulation system pipeline of hydroelectric generating set A6 at hydro power plant Djerdap 1. Results of analytical strength calculation of butt-welded joints between 2 pipes, and pipe-elbow with a lack of penetration in the root are also presented.
PB  - Institut za ispitivanje materijala, Beograd
T2  - Structural Integrity and Life
T1  - Integrity assessment of regulation system pipeline elements in hydroelectric generating set a6 of hydro power plant 'djerdap 1'
EP  - 78
IS  - 2
SP  - 71
VL  - 16
UR  - https://hdl.handle.net/21.15107/rcub_technorep_3159
ER  - 

@article{
author = "Međo, Bojan and Arsić, Miodrag and Rakin, Marko and Sedmak, Simon and Malešević, Zoranka and Savić, Zoran",
year = "2016",
abstract = "Vertical Kaplan turbines with nominal power of 176 MW manufactured in Russia are installed in 6 hydroelectric generating sets at hydro power plant 'Djerdap 1' (Kladovo, Serbia). Most of the components are made of materials in accordance to GOST and ASTM standards. During rehabilitation of hydroelectric generating set, the analysis of the current state and integrity assessment of turbine regulation system pipeline required non-destructive tests on parent material and welded joints between pipes and pipes-elbows. The purpose of the regulation system, comprising of the pipeline for the turbine regulator oil supply, is to open and close vanes of the guide vane apparatus and to regulate the position of runner blades and their number of revolutions. Internal pressure in the regulation system is p = 4 MPa. Structural integrity is a recent scientific and engineering discipline which in broader sense comprises state analysis and behaviour diagnostics, service life assessment and rehabilitation of structures, meaning that beside the usual situation where structural integrity assessment is required when flaws are detected by non-destructive testing, this discipline is also includes stress state analysis. This approach is especially important for welded structures, since cracktype flaws can originate from welding and from unfavourable service conditions. In this paper, the results of non-destructive tests referring to the lack of penetration in roots of butt-welded joints between pipes and pipes-elbows, as well as tensile test results of technical specimens with reinforcements and in specimens with parallel machined sides and standard dimensions, are presented in order to carry out the integrity assessment of the turbine regulation system pipeline of hydroelectric generating set A6 at hydro power plant Djerdap 1. Results of analytical strength calculation of butt-welded joints between 2 pipes, and pipe-elbow with a lack of penetration in the root are also presented.",
publisher = "Institut za ispitivanje materijala, Beograd",
journal = "Structural Integrity and Life",
title = "Integrity assessment of regulation system pipeline elements in hydroelectric generating set a6 of hydro power plant 'djerdap 1'",
pages = "78-71",
number = "2",
volume = "16",
url = "https://hdl.handle.net/21.15107/rcub_technorep_3159"
}

Međo, B., Arsić, M., Rakin, M., Sedmak, S., Malešević, Z.,& Savić, Z.. (2016). Integrity assessment of regulation system pipeline elements in hydroelectric generating set a6 of hydro power plant 'djerdap 1'. in Structural Integrity and Life
Institut za ispitivanje materijala, Beograd., 16(2), 71-78.
https://hdl.handle.net/21.15107/rcub_technorep_3159

Međo B, Arsić M, Rakin M, Sedmak S, Malešević Z, Savić Z. Integrity assessment of regulation system pipeline elements in hydroelectric generating set a6 of hydro power plant 'djerdap 1'. in Structural Integrity and Life. 2016;16(2):71-78.
https://hdl.handle.net/21.15107/rcub_technorep_3159 .

Međo, Bojan, Arsić, Miodrag, Rakin, Marko, Sedmak, Simon, Malešević, Zoranka, Savić, Zoran, "Integrity assessment of regulation system pipeline elements in hydroelectric generating set a6 of hydro power plant 'djerdap 1'" in Structural Integrity and Life, 16, no. 2 (2016):71-78,
https://hdl.handle.net/21.15107/rcub_technorep_3159 .

TY  - JOUR
AU  - Arsić, Miodrag
AU  - Bošnjak, Srđan
AU  - Sedmak, Simon
AU  - Šarkočević, Živče
AU  - Savić, Zoran
AU  - Radu, D.
PY  - 2016
UR  - http://rims.institutims.rs/handle/123456789/298
AB  - Results of non-destructive testing of the Kaplan turbine runner manhole welded structure are presented, on the basis of which the repair methodology is defined. During repair, the welding technology for elements of the manhole is modified along with the proposal given for the modification of its structural design, because the finite element method calculation proved that the rectangular welded structure of the manhole was significantly better than round welded structure when it comes to integrity and service life.
PB  - Institut za ispitivanje materijala, Beograd
T2  - Structural Integrity and Life
T1  - Determination of damage and repair methodology for the runner manhole of Kaplan turbine at the hydro power plant 'Djerdap 1'
EP  - 153
IS  - 3
SP  - 149
VL  - 16
UR  - https://hdl.handle.net/21.15107/rcub_rims_298
ER  - 

@article{
author = "Arsić, Miodrag and Bošnjak, Srđan and Sedmak, Simon and Šarkočević, Živče and Savić, Zoran and Radu, D.",
year = "2016",
abstract = "Results of non-destructive testing of the Kaplan turbine runner manhole welded structure are presented, on the basis of which the repair methodology is defined. During repair, the welding technology for elements of the manhole is modified along with the proposal given for the modification of its structural design, because the finite element method calculation proved that the rectangular welded structure of the manhole was significantly better than round welded structure when it comes to integrity and service life.",
publisher = "Institut za ispitivanje materijala, Beograd",
journal = "Structural Integrity and Life",
title = "Determination of damage and repair methodology for the runner manhole of Kaplan turbine at the hydro power plant 'Djerdap 1'",
pages = "153-149",
number = "3",
volume = "16",
url = "https://hdl.handle.net/21.15107/rcub_rims_298"
}

Arsić, M., Bošnjak, S., Sedmak, S., Šarkočević, Ž., Savić, Z.,& Radu, D.. (2016). Determination of damage and repair methodology for the runner manhole of Kaplan turbine at the hydro power plant 'Djerdap 1'. in Structural Integrity and Life
Institut za ispitivanje materijala, Beograd., 16(3), 149-153.
https://hdl.handle.net/21.15107/rcub_rims_298

Arsić M, Bošnjak S, Sedmak S, Šarkočević Ž, Savić Z, Radu D. Determination of damage and repair methodology for the runner manhole of Kaplan turbine at the hydro power plant 'Djerdap 1'. in Structural Integrity and Life. 2016;16(3):149-153.
https://hdl.handle.net/21.15107/rcub_rims_298 .

Arsić, Miodrag, Bošnjak, Srđan, Sedmak, Simon, Šarkočević, Živče, Savić, Zoran, Radu, D., "Determination of damage and repair methodology for the runner manhole of Kaplan turbine at the hydro power plant 'Djerdap 1'" in Structural Integrity and Life, 16, no. 3 (2016):149-153,
https://hdl.handle.net/21.15107/rcub_rims_298 .

TY  - JOUR
AU  - Arsić, Miodrag
AU  - Savić, Zoran
AU  - Sedmak, Aleksandar
AU  - Bošnjak, Srđan
AU  - Sedmak, Simon
PY  - 2016
UR  - http://rims.institutims.rs/handle/123456789/296
AB  - This paper presents results of experimental examinations of stress concentration influence to fatigue life of butt welded joints with K-groove, produced from the most frequently used structural steel S355J2+N. One group of experiments comprised examinations carried out on the K-groove specimens with stress concentrators of edged notch type. Specimens with short cracks (limited length of initial crack), defined on the basis of the experience from fracture mechanics by the three points bending examinations, have been examined according to standard for the determination of S-N curve, and aimed to determine fatigue strengths for different lengths of initial crack and Relationship between fatigue strength and crack length. Other group of experiments comprised examinations of specimens with edge notch, prepared in accordance with ASTM E 399 for three points bending, in order to establish regularity between crack growth and range of exerted stress intensity factor aimed to determine resistance of welded joint to initial crack growth, namely fatigue threshold (ΔKth).
PB  - Gruppo Italiano Frattura
T2  - Frattura ed Integrita Strutturale
T1  - Experimental examination of fatigue life of welded joint with stress concentration
EP  - 35
IS  - 36
SP  - 27
VL  - 10
DO  - 10.3221/IGF-ESIS.36.03
ER  - 

@article{
author = "Arsić, Miodrag and Savić, Zoran and Sedmak, Aleksandar and Bošnjak, Srđan and Sedmak, Simon",
year = "2016",
abstract = "This paper presents results of experimental examinations of stress concentration influence to fatigue life of butt welded joints with K-groove, produced from the most frequently used structural steel S355J2+N. One group of experiments comprised examinations carried out on the K-groove specimens with stress concentrators of edged notch type. Specimens with short cracks (limited length of initial crack), defined on the basis of the experience from fracture mechanics by the three points bending examinations, have been examined according to standard for the determination of S-N curve, and aimed to determine fatigue strengths for different lengths of initial crack and Relationship between fatigue strength and crack length. Other group of experiments comprised examinations of specimens with edge notch, prepared in accordance with ASTM E 399 for three points bending, in order to establish regularity between crack growth and range of exerted stress intensity factor aimed to determine resistance of welded joint to initial crack growth, namely fatigue threshold (ΔKth).",
publisher = "Gruppo Italiano Frattura",
journal = "Frattura ed Integrita Strutturale",
title = "Experimental examination of fatigue life of welded joint with stress concentration",
pages = "35-27",
number = "36",
volume = "10",
doi = "10.3221/IGF-ESIS.36.03"
}

Arsić, M., Savić, Z., Sedmak, A., Bošnjak, S.,& Sedmak, S.. (2016). Experimental examination of fatigue life of welded joint with stress concentration. in Frattura ed Integrita Strutturale
Gruppo Italiano Frattura., 10(36), 27-35.
https://doi.org/10.3221/IGF-ESIS.36.03

Arsić M, Savić Z, Sedmak A, Bošnjak S, Sedmak S. Experimental examination of fatigue life of welded joint with stress concentration. in Frattura ed Integrita Strutturale. 2016;10(36):27-35.
doi:10.3221/IGF-ESIS.36.03 .

Arsić, Miodrag, Savić, Zoran, Sedmak, Aleksandar, Bošnjak, Srđan, Sedmak, Simon, "Experimental examination of fatigue life of welded joint with stress concentration" in Frattura ed Integrita Strutturale, 10, no. 36 (2016):27-35,
https://doi.org/10.3221/IGF-ESIS.36.03 . .

TY  - JOUR
AU  - Sedmak, Simon
AU  - Arsić, Miodrag
AU  - Bošnjak, Srđan
AU  - Malešević, Zoranka
AU  - Savić, Zoran
AU  - Radu, D.
PY  - 2016
UR  - http://rims.institutims.rs/handle/123456789/288
AB  - This paper presents the integrity and reliability evaluation of the heating system as a whole, based on results of metallographic tests performed on parent material and the ultrasonic measurement of wall thickness of elbows made of steel St 35.8.
PB  - Institut za ispitivanje materijala, Beograd
T2  - Structural Integrity and Life
T1  - Effect of locally damaged elbow segments on the integrity and reliability of the heating system
EP  - 170
IS  - 3
SP  - 167
VL  - 16
UR  - https://hdl.handle.net/21.15107/rcub_rims_288
ER  - 

@article{
author = "Sedmak, Simon and Arsić, Miodrag and Bošnjak, Srđan and Malešević, Zoranka and Savić, Zoran and Radu, D.",
year = "2016",
abstract = "This paper presents the integrity and reliability evaluation of the heating system as a whole, based on results of metallographic tests performed on parent material and the ultrasonic measurement of wall thickness of elbows made of steel St 35.8.",
publisher = "Institut za ispitivanje materijala, Beograd",
journal = "Structural Integrity and Life",
title = "Effect of locally damaged elbow segments on the integrity and reliability of the heating system",
pages = "170-167",
number = "3",
volume = "16",
url = "https://hdl.handle.net/21.15107/rcub_rims_288"
}

Sedmak, S., Arsić, M., Bošnjak, S., Malešević, Z., Savić, Z.,& Radu, D.. (2016). Effect of locally damaged elbow segments on the integrity and reliability of the heating system. in Structural Integrity and Life
Institut za ispitivanje materijala, Beograd., 16(3), 167-170.
https://hdl.handle.net/21.15107/rcub_rims_288

Sedmak S, Arsić M, Bošnjak S, Malešević Z, Savić Z, Radu D. Effect of locally damaged elbow segments on the integrity and reliability of the heating system. in Structural Integrity and Life. 2016;16(3):167-170.
https://hdl.handle.net/21.15107/rcub_rims_288 .

Sedmak, Simon, Arsić, Miodrag, Bošnjak, Srđan, Malešević, Zoranka, Savić, Zoran, Radu, D., "Effect of locally damaged elbow segments on the integrity and reliability of the heating system" in Structural Integrity and Life, 16, no. 3 (2016):167-170,
https://hdl.handle.net/21.15107/rcub_rims_288 .

TY  - JOUR
AU  - Sedmak, Simon
AU  - Arsić, Miodrag
AU  - Bajić, Darko R.
AU  - Mladenović, Mladen
AU  - Savić, Zoran
PY  - 2015
UR  - http://rims.institutims.rs/handle/123456789/262
AB  - Presented are results of non-destructive tests performed on the parent material and welded joints of structural parts of a breeches pipe (collar and anchor), and results of destructive tests performed on the parent material of the anchor. Non-destructive testing included visual (VT), mag-netic particle (MT), and ultrasonic testing (UT), while destructive tests included determination of chemical com-position, tensile properties, impact energy and hardness. Based on test results it is established that the major cause for the occurrence of damage in the carrying structure of the breeches pipe no.1 of pipeline III, or in other words, the degradation of anchor parent material and welded joints between the collar and anchor, and between the pipeline and anchor, is in the fact that the breeches pipe started to lean, not on the collar, as specified by design, but on the anchor that could not endure all loads occurring in service.
PB  - Institut za ispitivanje materijala, Beograd
T2  - Structural Integrity and Life
T1  - Analysis of causes of degradation of parent material and weld metal of breeches pipe at hydro power plant 'Perućica'
EP  - 151
IS  - 3
SP  - 147
VL  - 15
UR  - https://hdl.handle.net/21.15107/rcub_rims_262
ER  - 

@article{
author = "Sedmak, Simon and Arsić, Miodrag and Bajić, Darko R. and Mladenović, Mladen and Savić, Zoran",
year = "2015",
abstract = "Presented are results of non-destructive tests performed on the parent material and welded joints of structural parts of a breeches pipe (collar and anchor), and results of destructive tests performed on the parent material of the anchor. Non-destructive testing included visual (VT), mag-netic particle (MT), and ultrasonic testing (UT), while destructive tests included determination of chemical com-position, tensile properties, impact energy and hardness. Based on test results it is established that the major cause for the occurrence of damage in the carrying structure of the breeches pipe no.1 of pipeline III, or in other words, the degradation of anchor parent material and welded joints between the collar and anchor, and between the pipeline and anchor, is in the fact that the breeches pipe started to lean, not on the collar, as specified by design, but on the anchor that could not endure all loads occurring in service.",
publisher = "Institut za ispitivanje materijala, Beograd",
journal = "Structural Integrity and Life",
title = "Analysis of causes of degradation of parent material and weld metal of breeches pipe at hydro power plant 'Perućica'",
pages = "151-147",
number = "3",
volume = "15",
url = "https://hdl.handle.net/21.15107/rcub_rims_262"
}

Sedmak, S., Arsić, M., Bajić, D. R., Mladenović, M.,& Savić, Z.. (2015). Analysis of causes of degradation of parent material and weld metal of breeches pipe at hydro power plant 'Perućica'. in Structural Integrity and Life
Institut za ispitivanje materijala, Beograd., 15(3), 147-151.
https://hdl.handle.net/21.15107/rcub_rims_262

Sedmak S, Arsić M, Bajić DR, Mladenović M, Savić Z. Analysis of causes of degradation of parent material and weld metal of breeches pipe at hydro power plant 'Perućica'. in Structural Integrity and Life. 2015;15(3):147-151.
https://hdl.handle.net/21.15107/rcub_rims_262 .

Sedmak, Simon, Arsić, Miodrag, Bajić, Darko R., Mladenović, Mladen, Savić, Zoran, "Analysis of causes of degradation of parent material and weld metal of breeches pipe at hydro power plant 'Perućica'" in Structural Integrity and Life, 15, no. 3 (2015):147-151,
https://hdl.handle.net/21.15107/rcub_rims_262 .

TY  - CONF
AU  - Arsić, Miodrag
AU  - Vistać, Brane
AU  - Bošnjak, Srđan
AU  - Grabulov, Vencislav
AU  - Savić, Zoran
PY  - 2014
UR  - http://rims.institutims.rs/handle/123456789/248
AB  - Vertical Kaplan turbines, manufactured in Russia and with nominal power of 200 MW, have been installed in 6 hydroelectric generating units at ’Djerdap 1’. During the refurbishment of hydropower plant experimental non-destructive tests were performed in order to determine the state of turbine components. During the course of testing damage was detected at sleeves and welded shields of guide vanes, which occurred as a consequence of turbine shaft vibrations. 1782 mm long guide vane sleeves were made of cast steel 25L (GOST standard), 260 mm long sleeve was made of forged steel St 25 (GOST standard), while welded shields of guide vanes were made of austenitic steel 08X18H10T (GOST standard). Results of experimental tests and methodology for reparation of damaged surfaces of sleeves and welded shields of guide vanes are presented in this paper. It was necessary, due to the structural solution used for the design of guide vanes and their function during service, to define a large number of details, carefully reconsider them and carry out all activities with extreme care in order to enable the safe operation and continuous use of vanes through the use of reparation methodology for welding/surface welding of sleeves and welded shields. Overlooking, underestimation or incorrect perception of important details could cause significant problems during turbine operation.
PB  - Trans Tech Publications Ltd
C3  - Advanced Materials Research
T1  - Methodology for reparation of damaged sleeves and welded shield sections of guide vanes at hydropower plant DJERDAP 1
EP  - 13
SP  - 8
VL  - 1029
DO  - 10.4028/www.scientific.net/AMR.1029.8
ER  - 

@conference{
author = "Arsić, Miodrag and Vistać, Brane and Bošnjak, Srđan and Grabulov, Vencislav and Savić, Zoran",
year = "2014",
abstract = "Vertical Kaplan turbines, manufactured in Russia and with nominal power of 200 MW, have been installed in 6 hydroelectric generating units at ’Djerdap 1’. During the refurbishment of hydropower plant experimental non-destructive tests were performed in order to determine the state of turbine components. During the course of testing damage was detected at sleeves and welded shields of guide vanes, which occurred as a consequence of turbine shaft vibrations. 1782 mm long guide vane sleeves were made of cast steel 25L (GOST standard), 260 mm long sleeve was made of forged steel St 25 (GOST standard), while welded shields of guide vanes were made of austenitic steel 08X18H10T (GOST standard). Results of experimental tests and methodology for reparation of damaged surfaces of sleeves and welded shields of guide vanes are presented in this paper. It was necessary, due to the structural solution used for the design of guide vanes and their function during service, to define a large number of details, carefully reconsider them and carry out all activities with extreme care in order to enable the safe operation and continuous use of vanes through the use of reparation methodology for welding/surface welding of sleeves and welded shields. Overlooking, underestimation or incorrect perception of important details could cause significant problems during turbine operation.",
publisher = "Trans Tech Publications Ltd",
journal = "Advanced Materials Research",
title = "Methodology for reparation of damaged sleeves and welded shield sections of guide vanes at hydropower plant DJERDAP 1",
pages = "13-8",
volume = "1029",
doi = "10.4028/www.scientific.net/AMR.1029.8"
}

Arsić, M., Vistać, B., Bošnjak, S., Grabulov, V.,& Savić, Z.. (2014). Methodology for reparation of damaged sleeves and welded shield sections of guide vanes at hydropower plant DJERDAP 1. in Advanced Materials Research
Trans Tech Publications Ltd., 1029, 8-13.
https://doi.org/10.4028/www.scientific.net/AMR.1029.8

Arsić M, Vistać B, Bošnjak S, Grabulov V, Savić Z. Methodology for reparation of damaged sleeves and welded shield sections of guide vanes at hydropower plant DJERDAP 1. in Advanced Materials Research. 2014;1029:8-13.
doi:10.4028/www.scientific.net/AMR.1029.8 .

Arsić, Miodrag, Vistać, Brane, Bošnjak, Srđan, Grabulov, Vencislav, Savić, Zoran, "Methodology for reparation of damaged sleeves and welded shield sections of guide vanes at hydropower plant DJERDAP 1" in Advanced Materials Research, 1029 (2014):8-13,
https://doi.org/10.4028/www.scientific.net/AMR.1029.8 . .

TY  - CONF
AU  - Arsić, Miodrag
AU  - Bošnjak, Srđan
AU  - Grabulov, Vencislav
AU  - Veljović, Aleksandar
AU  - Savić, Zoran
PY  - 2014
UR  - http://rims.institutims.rs/handle/123456789/238
AB  - Stable supply tank, with volume V = 250 m3 and operating pressure p = 1,5 MPa, of generation unit 6 at thermal power plant 'Nikola Tesla A' in Obrenovac, is designed for water-steam working fluid. It was made of steel Č 1204 as a single-part welded structure with a single wall. Cylindrical tank shell consists of 8 segments, while torispherical deep bottoms consist of 3 segments. The tank is in the horizontal position and it lays on 4 supports. There are five manometers installed at the tank for pressure control, as well as 5 spring-loaded safety valves. In this paper results of non-destructive tests performed on the tank are presented. Mechanical damages on parent material, up to 1.5 mm deep, were detected at the outer surface of the cylindrical section of the right bottom (as seen from the boiler) and on the inner surface of the shell, as well as sporadic pitting corrosion, up to 0.5 mm deep, and 2 mm misalignment of sheet metals in areas where shell segments are joined. Crack type linear indications were detected on the surface of welded joints through the use of magnetic particle testing. Through ultrasonic and radiographic testing it was determined that the homogeneity of welded joints is satisfactory. Hardness testing was performed on all segments of the tank, and obtained values were in the range between 118 and 130 HB. Metallographic examination, performed on specimens of all segments of the tank, showed that microstructure of material is either fine-grained or striped ferrite-pearlite. On the basis of test results the repair technology for shell and bottom segments was made, while on the basis of the analytical calculation of tank strength the integrity evaluation was carried out for the upcoming period of service, depending on the category of the vessel.
PB  - Trans Tech Publications Ltd
C3  - Advanced Materials Research
T1  - Analysis of current state and integrity evaluation for the supply tank of generation unit 6 of thermal power plant Nikola Tesla ”A”, Obrenovac
EP  - 19
SP  - 14
VL  - 1029
DO  - 10.4028/www.scientific.net/AMR.1029.14
ER  - 

@conference{
author = "Arsić, Miodrag and Bošnjak, Srđan and Grabulov, Vencislav and Veljović, Aleksandar and Savić, Zoran",
year = "2014",
abstract = "Stable supply tank, with volume V = 250 m3 and operating pressure p = 1,5 MPa, of generation unit 6 at thermal power plant 'Nikola Tesla A' in Obrenovac, is designed for water-steam working fluid. It was made of steel Č 1204 as a single-part welded structure with a single wall. Cylindrical tank shell consists of 8 segments, while torispherical deep bottoms consist of 3 segments. The tank is in the horizontal position and it lays on 4 supports. There are five manometers installed at the tank for pressure control, as well as 5 spring-loaded safety valves. In this paper results of non-destructive tests performed on the tank are presented. Mechanical damages on parent material, up to 1.5 mm deep, were detected at the outer surface of the cylindrical section of the right bottom (as seen from the boiler) and on the inner surface of the shell, as well as sporadic pitting corrosion, up to 0.5 mm deep, and 2 mm misalignment of sheet metals in areas where shell segments are joined. Crack type linear indications were detected on the surface of welded joints through the use of magnetic particle testing. Through ultrasonic and radiographic testing it was determined that the homogeneity of welded joints is satisfactory. Hardness testing was performed on all segments of the tank, and obtained values were in the range between 118 and 130 HB. Metallographic examination, performed on specimens of all segments of the tank, showed that microstructure of material is either fine-grained or striped ferrite-pearlite. On the basis of test results the repair technology for shell and bottom segments was made, while on the basis of the analytical calculation of tank strength the integrity evaluation was carried out for the upcoming period of service, depending on the category of the vessel.",
publisher = "Trans Tech Publications Ltd",
journal = "Advanced Materials Research",
title = "Analysis of current state and integrity evaluation for the supply tank of generation unit 6 of thermal power plant Nikola Tesla ”A”, Obrenovac",
pages = "19-14",
volume = "1029",
doi = "10.4028/www.scientific.net/AMR.1029.14"
}

Arsić, M., Bošnjak, S., Grabulov, V., Veljović, A.,& Savić, Z.. (2014). Analysis of current state and integrity evaluation for the supply tank of generation unit 6 of thermal power plant Nikola Tesla ”A”, Obrenovac. in Advanced Materials Research
Trans Tech Publications Ltd., 1029, 14-19.
https://doi.org/10.4028/www.scientific.net/AMR.1029.14

Arsić M, Bošnjak S, Grabulov V, Veljović A, Savić Z. Analysis of current state and integrity evaluation for the supply tank of generation unit 6 of thermal power plant Nikola Tesla ”A”, Obrenovac. in Advanced Materials Research. 2014;1029:14-19.
doi:10.4028/www.scientific.net/AMR.1029.14 .

Arsić, Miodrag, Bošnjak, Srđan, Grabulov, Vencislav, Veljović, Aleksandar, Savić, Zoran, "Analysis of current state and integrity evaluation for the supply tank of generation unit 6 of thermal power plant Nikola Tesla ”A”, Obrenovac" in Advanced Materials Research, 1029 (2014):14-19,
https://doi.org/10.4028/www.scientific.net/AMR.1029.14 . .

TY  - JOUR
AU  - Arsić, Miodrag
AU  - Vistać, Brane
AU  - Bošnjak, Srđan
AU  - Bošković, Goran
AU  - Savić, Zoran
PY  - 2014
UR  - http://rims.institutims.rs/handle/123456789/245
AB  - Turbine and hydromechanical equipment at hydro power plant 'Đerdap 1' is subjected to service conditions which lead to degradation of materials and structures. Taking into account the frequency of failure occurrence and experience accumulated through long term testing and determination of state, it can be concluded that basic causes of equipment degradation are: oscillations, fatigue, corrosion, erosion and cavitation. It is the responsibility of manufacturers of turbine and hydromechanical equipment to make sure that all vital parts and supporting structures are made in compliance with technical requirements, suitable standards and european directives that refer to structural integrity. Applicability of Pressure Equipment Directive 97/23/EC and Machinery Directive 98/37/EEC is especially relevant, due to the fact that certain parts and structures of turbine regulation system, lubrication system, turbine runner and measurement system are subject to one of the above mentioned directives. This paper contains the overview and basic parameters of new and general approach to standardization and technical harmonization of hydro power plant equipment that refers to structural integrity.
PB  - Institut IMK "14. oktobar", Kruševac
T2  - IMK-14 - Istraživanje i razvoj
T1  - Guidelines for technical regulations and standardization of turbine and hydromechanical equipment during production and exploitation
EP  - 7
IS  - 1
SP  - 1
VL  - 20
DO  - 10.5937/IMK1401001A
ER  - 

@article{
author = "Arsić, Miodrag and Vistać, Brane and Bošnjak, Srđan and Bošković, Goran and Savić, Zoran",
year = "2014",
abstract = "Turbine and hydromechanical equipment at hydro power plant 'Đerdap 1' is subjected to service conditions which lead to degradation of materials and structures. Taking into account the frequency of failure occurrence and experience accumulated through long term testing and determination of state, it can be concluded that basic causes of equipment degradation are: oscillations, fatigue, corrosion, erosion and cavitation. It is the responsibility of manufacturers of turbine and hydromechanical equipment to make sure that all vital parts and supporting structures are made in compliance with technical requirements, suitable standards and european directives that refer to structural integrity. Applicability of Pressure Equipment Directive 97/23/EC and Machinery Directive 98/37/EEC is especially relevant, due to the fact that certain parts and structures of turbine regulation system, lubrication system, turbine runner and measurement system are subject to one of the above mentioned directives. This paper contains the overview and basic parameters of new and general approach to standardization and technical harmonization of hydro power plant equipment that refers to structural integrity.",
publisher = "Institut IMK "14. oktobar", Kruševac",
journal = "IMK-14 - Istraživanje i razvoj",
title = "Guidelines for technical regulations and standardization of turbine and hydromechanical equipment during production and exploitation",
pages = "7-1",
number = "1",
volume = "20",
doi = "10.5937/IMK1401001A"
}

Arsić, M., Vistać, B., Bošnjak, S., Bošković, G.,& Savić, Z.. (2014). Guidelines for technical regulations and standardization of turbine and hydromechanical equipment during production and exploitation. in IMK-14 - Istraživanje i razvoj
Institut IMK "14. oktobar", Kruševac., 20(1), 1-7.
https://doi.org/10.5937/IMK1401001A

Arsić M, Vistać B, Bošnjak S, Bošković G, Savić Z. Guidelines for technical regulations and standardization of turbine and hydromechanical equipment during production and exploitation. in IMK-14 - Istraživanje i razvoj. 2014;20(1):1-7.
doi:10.5937/IMK1401001A .

Arsić, Miodrag, Vistać, Brane, Bošnjak, Srđan, Bošković, Goran, Savić, Zoran, "Guidelines for technical regulations and standardization of turbine and hydromechanical equipment during production and exploitation" in IMK-14 - Istraživanje i razvoj, 20, no. 1 (2014):1-7,
https://doi.org/10.5937/IMK1401001A . .

TY  - CONF
AU  - Odanović, Zoran
AU  - Arsić, Miodrag
AU  - Grabulov, Vencislav
AU  - Đurđević, Mile
PY  - 2013
UR  - http://rims.institutims.rs/handle/123456789/215
AB  - Metal materials are subjected to innumerable time-dependent degradation mechanisms when operate in power, petrochemical and refinery plant. These materials are subjected to multiaxial stresses, creep, fatigue, corrosion and abrasion. As a result of service especially at high temperatures and high pressures, can lead to forming cracks, damages or failures. In situation of breakdown in such systems there is a need for weld repair on plant components and repair work can be expensive and time-consuming. Most weld repairs of low alloy steels require high-temperature post weld heat treatment (PWHT); but in certain repairs, however, this is not always possible. Expenses of the repair work could be reduced if the weld repairing is performed on site. Also, application of the nickel based filler metal can be alternative to performing PWHT. These repair welding procedures with Ni based filler metal could be categorized as cold repair welding. Purpose of presented investigation was to compare a repair welding technology with filler austenite material based on Ni and without application of the PWHT, with a classical repair welding procedure with preheating and PWHT and using a filler metal with chemical composition similar to parent metal. Properties comparison of the welded joints obtained by these two repair welding technologies was performed for the Cr-Mo steel (13CrMo4-5) by the metal arc welding procedure with covered electrode (MMA - 111). Weldability analysis by the analytical equations and technological tests for determination of the sensitivity to crack forming for cold and hot cracks by the CTS and Y tests, were performed for both repair welding technologies. Tensile tests, absorbed energies tests, banding tests and hardness measurements were performed on trial joins. Light optical microscopy (LOM) was applied for microstructure analysis. The fracture toughness of welded joints obtained by both investigated technologies, were estimated by the calculated stress intensity factor KIc and dynamic stress intensity factor KId for weld metal and heat affected zone. All of the obtained results were analyzed and discussed. It was concluded that repair welding technology with Ni base filler material without PWHT, enables welded joints without the appearance of cracks, with a good mechanical properties, slightly higher hardness in the HAZ, but with lower expenses compared to standard repair welding technology. In applying this technology in emergency welding repairing on-site, on the equipment and industrial facilities with high security requirements, inspection using non destructive technique has to be frequently applied compared to standard procedures.
PB  - Trans Tech Publications Ltd, Durnten-Zurich
C3  - Structural Integrity of Welded Structures
T1  - Investigation of the Repair Welding Technology Using Ni Base Electrode
EP  - 32
SP  - 25
VL  - 814
DO  - 10.4028/www.scientific.net/AMR.814.25
ER  - 

@conference{
author = "Odanović, Zoran and Arsić, Miodrag and Grabulov, Vencislav and Đurđević, Mile",
year = "2013",
abstract = "Metal materials are subjected to innumerable time-dependent degradation mechanisms when operate in power, petrochemical and refinery plant. These materials are subjected to multiaxial stresses, creep, fatigue, corrosion and abrasion. As a result of service especially at high temperatures and high pressures, can lead to forming cracks, damages or failures. In situation of breakdown in such systems there is a need for weld repair on plant components and repair work can be expensive and time-consuming. Most weld repairs of low alloy steels require high-temperature post weld heat treatment (PWHT); but in certain repairs, however, this is not always possible. Expenses of the repair work could be reduced if the weld repairing is performed on site. Also, application of the nickel based filler metal can be alternative to performing PWHT. These repair welding procedures with Ni based filler metal could be categorized as cold repair welding. Purpose of presented investigation was to compare a repair welding technology with filler austenite material based on Ni and without application of the PWHT, with a classical repair welding procedure with preheating and PWHT and using a filler metal with chemical composition similar to parent metal. Properties comparison of the welded joints obtained by these two repair welding technologies was performed for the Cr-Mo steel (13CrMo4-5) by the metal arc welding procedure with covered electrode (MMA - 111). Weldability analysis by the analytical equations and technological tests for determination of the sensitivity to crack forming for cold and hot cracks by the CTS and Y tests, were performed for both repair welding technologies. Tensile tests, absorbed energies tests, banding tests and hardness measurements were performed on trial joins. Light optical microscopy (LOM) was applied for microstructure analysis. The fracture toughness of welded joints obtained by both investigated technologies, were estimated by the calculated stress intensity factor KIc and dynamic stress intensity factor KId for weld metal and heat affected zone. All of the obtained results were analyzed and discussed. It was concluded that repair welding technology with Ni base filler material without PWHT, enables welded joints without the appearance of cracks, with a good mechanical properties, slightly higher hardness in the HAZ, but with lower expenses compared to standard repair welding technology. In applying this technology in emergency welding repairing on-site, on the equipment and industrial facilities with high security requirements, inspection using non destructive technique has to be frequently applied compared to standard procedures.",
publisher = "Trans Tech Publications Ltd, Durnten-Zurich",
journal = "Structural Integrity of Welded Structures",
title = "Investigation of the Repair Welding Technology Using Ni Base Electrode",
pages = "32-25",
volume = "814",
doi = "10.4028/www.scientific.net/AMR.814.25"
}

Odanović, Z., Arsić, M., Grabulov, V.,& Đurđević, M.. (2013). Investigation of the Repair Welding Technology Using Ni Base Electrode. in Structural Integrity of Welded Structures
Trans Tech Publications Ltd, Durnten-Zurich., 814, 25-32.
https://doi.org/10.4028/www.scientific.net/AMR.814.25

Odanović Z, Arsić M, Grabulov V, Đurđević M. Investigation of the Repair Welding Technology Using Ni Base Electrode. in Structural Integrity of Welded Structures. 2013;814:25-32.
doi:10.4028/www.scientific.net/AMR.814.25 .

Odanović, Zoran, Arsić, Miodrag, Grabulov, Vencislav, Đurđević, Mile, "Investigation of the Repair Welding Technology Using Ni Base Electrode" in Structural Integrity of Welded Structures, 814 (2013):25-32,
https://doi.org/10.4028/www.scientific.net/AMR.814.25 . .

TY  - JOUR
AU  - Dimić, Ivana
AU  - Arsić, Miodrag
AU  - Međo, Bojan
AU  - Stefanović, Ana
AU  - Grabulov, Vencislav
AU  - Rakin, Marko
PY  - 2013
UR  - http://rims.institutims.rs/handle/123456789/202
AB  - Since local defects reduce the load-carrying capacity and deformation ability of a piping system, an analysis is undertaken to quantify the influence of weld defects on integrity of the pipe elbows subjected to internal pressure. Incompletely filled groove is examined, because this type of defect was previously detected by ultrasonic measurement on the inner surface of the pipeline from a hydro-power plant. Three-dimensional finite element analysis is conducted using Abaqus software package. The influence of weld defect geometry (its depth, length and location) on the elbow integrity is determined. Additionally, decrease of load carrying capacity is determined for the case when a crack has initiated at the bottom of the defect. The influence of finite element type (hexahedral or tetrahedral) is examined.
PB  - Faculty of Mechanical Engineering in Slavonski Brod, Faculty of Electrical Engineering in Osijek, Faculty of Civil Engineering in Osijek
T2  - Tehnički vjesnik
T1  - Effect of welded joint imperfection on the integrity of pipe elbows subjected to internal pressure
EP  - 290
IS  - 2
SP  - 285
VL  - 20
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2515
ER  - 

@article{
author = "Dimić, Ivana and Arsić, Miodrag and Međo, Bojan and Stefanović, Ana and Grabulov, Vencislav and Rakin, Marko",
year = "2013",
abstract = "Since local defects reduce the load-carrying capacity and deformation ability of a piping system, an analysis is undertaken to quantify the influence of weld defects on integrity of the pipe elbows subjected to internal pressure. Incompletely filled groove is examined, because this type of defect was previously detected by ultrasonic measurement on the inner surface of the pipeline from a hydro-power plant. Three-dimensional finite element analysis is conducted using Abaqus software package. The influence of weld defect geometry (its depth, length and location) on the elbow integrity is determined. Additionally, decrease of load carrying capacity is determined for the case when a crack has initiated at the bottom of the defect. The influence of finite element type (hexahedral or tetrahedral) is examined.",
publisher = "Faculty of Mechanical Engineering in Slavonski Brod, Faculty of Electrical Engineering in Osijek, Faculty of Civil Engineering in Osijek",
journal = "Tehnički vjesnik",
title = "Effect of welded joint imperfection on the integrity of pipe elbows subjected to internal pressure",
pages = "290-285",
number = "2",
volume = "20",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2515"
}

Dimić, I., Arsić, M., Međo, B., Stefanović, A., Grabulov, V.,& Rakin, M.. (2013). Effect of welded joint imperfection on the integrity of pipe elbows subjected to internal pressure. in Tehnički vjesnik
Faculty of Mechanical Engineering in Slavonski Brod, Faculty of Electrical Engineering in Osijek, Faculty of Civil Engineering in Osijek., 20(2), 285-290.
https://hdl.handle.net/21.15107/rcub_technorep_2515

Dimić I, Arsić M, Međo B, Stefanović A, Grabulov V, Rakin M. Effect of welded joint imperfection on the integrity of pipe elbows subjected to internal pressure. in Tehnički vjesnik. 2013;20(2):285-290.
https://hdl.handle.net/21.15107/rcub_technorep_2515 .

Dimić, Ivana, Arsić, Miodrag, Međo, Bojan, Stefanović, Ana, Grabulov, Vencislav, Rakin, Marko, "Effect of welded joint imperfection on the integrity of pipe elbows subjected to internal pressure" in Tehnički vjesnik, 20, no. 2 (2013):285-290,
https://hdl.handle.net/21.15107/rcub_technorep_2515 .

TY  - CONF
AU  - Arsić, Miodrag
AU  - Odanović, Zoran
AU  - Bošnjak, Srđan
AU  - Mladenović, Mladen
AU  - Savić, Zoran
PY  - 2013
UR  - http://rims.institutims.rs/handle/123456789/209
AB  - During the refurbishment of the hydroelectric generating set A6 on HPP "Djerdap 1", for the state analysis and assessment of the level and causes of degradation of the structure of the vertical Kaplan turbine runner guide vane apparatus non-destructive tests and inspections, as well as destructive tests of base material and welded joints, have been carried out after 40 years of service. Results of non-destructive tests performed on welded joints are presented in this paper (magnetic particle and ultrasonic inspection), as well as results of destructive tests of the base material and welded joints (testing of tensile properties, impact testing, metallographic analyses of the structure). A large number of crack type line indications were detected by magnetic particle inspections, while the occurrence of partial penetration in roots of welded joints was detected by ultrasonic inspections, as well as lamellar tearing of the base material. Tensile properties of tested samples taken in longitudinal and transverse direction fulfilled the requirements of the standard with certain deviations, which does not stand for samples taken in z-direction with significantly lower values of contraction of the cross-section than minimum prescribed values, which proves that base material is not resistant to the occurrence of lamellar cracks. Metallographic tests performed on specimens taken from the base material in longitudinal and transverse direction showed that the microstructure is stripe-shaped and ferrite-pearlite with non-metallic inclusions of oxide, sulphide, silicate and aluminate type, while metallographic tests performed on specimens taken from welded joints showed that their microstructure is stripe-shaped and ferrite-pearlite with non-metallic inclusions of oxide type. A large number of micro- and macro-cracks were detected in the microstructure as well. Experimental tests enabled the determination of the causes of occurrence of lamellar tearing in base material and crack type defects in welded joints, while analytical calculation that refers to the stress state enabled integrity of welded structure of the upper ring of the turbine runner guide vane apparatus.
PB  - Trans Tech Publications Ltd, Durnten-Zurich
C3  - Structural Integrity of Welded Structures
T1  - State Analysis and Integrity of Welded Structures of the Upper Ring of the Turbine Runner Guide Vane Apparatus of Hydroelectric Generating Set A6 on Hydro Power Plant Djerdap 1
EP  - +
SP  - 7
VL  - 814
DO  - 10.4028/www.scientific.net/AMR.814.7
ER  - 

@conference{
author = "Arsić, Miodrag and Odanović, Zoran and Bošnjak, Srđan and Mladenović, Mladen and Savić, Zoran",
year = "2013",
abstract = "During the refurbishment of the hydroelectric generating set A6 on HPP "Djerdap 1", for the state analysis and assessment of the level and causes of degradation of the structure of the vertical Kaplan turbine runner guide vane apparatus non-destructive tests and inspections, as well as destructive tests of base material and welded joints, have been carried out after 40 years of service. Results of non-destructive tests performed on welded joints are presented in this paper (magnetic particle and ultrasonic inspection), as well as results of destructive tests of the base material and welded joints (testing of tensile properties, impact testing, metallographic analyses of the structure). A large number of crack type line indications were detected by magnetic particle inspections, while the occurrence of partial penetration in roots of welded joints was detected by ultrasonic inspections, as well as lamellar tearing of the base material. Tensile properties of tested samples taken in longitudinal and transverse direction fulfilled the requirements of the standard with certain deviations, which does not stand for samples taken in z-direction with significantly lower values of contraction of the cross-section than minimum prescribed values, which proves that base material is not resistant to the occurrence of lamellar cracks. Metallographic tests performed on specimens taken from the base material in longitudinal and transverse direction showed that the microstructure is stripe-shaped and ferrite-pearlite with non-metallic inclusions of oxide, sulphide, silicate and aluminate type, while metallographic tests performed on specimens taken from welded joints showed that their microstructure is stripe-shaped and ferrite-pearlite with non-metallic inclusions of oxide type. A large number of micro- and macro-cracks were detected in the microstructure as well. Experimental tests enabled the determination of the causes of occurrence of lamellar tearing in base material and crack type defects in welded joints, while analytical calculation that refers to the stress state enabled integrity of welded structure of the upper ring of the turbine runner guide vane apparatus.",
publisher = "Trans Tech Publications Ltd, Durnten-Zurich",
journal = "Structural Integrity of Welded Structures",
title = "State Analysis and Integrity of Welded Structures of the Upper Ring of the Turbine Runner Guide Vane Apparatus of Hydroelectric Generating Set A6 on Hydro Power Plant Djerdap 1",
pages = "+-7",
volume = "814",
doi = "10.4028/www.scientific.net/AMR.814.7"
}

Arsić, M., Odanović, Z., Bošnjak, S., Mladenović, M.,& Savić, Z.. (2013). State Analysis and Integrity of Welded Structures of the Upper Ring of the Turbine Runner Guide Vane Apparatus of Hydroelectric Generating Set A6 on Hydro Power Plant Djerdap 1. in Structural Integrity of Welded Structures
Trans Tech Publications Ltd, Durnten-Zurich., 814, 7-+.
https://doi.org/10.4028/www.scientific.net/AMR.814.7

Arsić M, Odanović Z, Bošnjak S, Mladenović M, Savić Z. State Analysis and Integrity of Welded Structures of the Upper Ring of the Turbine Runner Guide Vane Apparatus of Hydroelectric Generating Set A6 on Hydro Power Plant Djerdap 1. in Structural Integrity of Welded Structures. 2013;814:7-+.
doi:10.4028/www.scientific.net/AMR.814.7 .

Arsić, Miodrag, Odanović, Zoran, Bošnjak, Srđan, Mladenović, Mladen, Savić, Zoran, "State Analysis and Integrity of Welded Structures of the Upper Ring of the Turbine Runner Guide Vane Apparatus of Hydroelectric Generating Set A6 on Hydro Power Plant Djerdap 1" in Structural Integrity of Welded Structures, 814 (2013):7-+,
https://doi.org/10.4028/www.scientific.net/AMR.814.7 . .

TY  - JOUR
AU  - Arsić, Miodrag
AU  - Vistać, Brane
AU  - Odanović, Zoran
AU  - Đorđević, Aleksandar
AU  - Savić, Zoran
PY  - 2012
UR  - http://rims.institutims.rs/handle/123456789/192
AB  - Na deset hidro-generatorskih jedinica 'Đerdap 2' ugrađene su horizontalne Kaplan turbine, nominalne snage 28 MW, izrađene u Rusiji. Posle 163411h rada (približno 22 godine) došlo je do loma vratila turbine agregata A6 u zoni velike koncentracije napona, na mestu prelaznog radijusa R80 između prirubnice i glavčine radnog kola. To je bio povod da se izvrše ispitivanja, metodama bez razaranja (vizuelno ispitivanje, ispitivanje penetrantima, ispitivanje magnetnim česticama, ultrazvučno ispitivanje), zavarenih spojeva i osnovnog materijala vratila ostalih turbina. Tim ispitivanjima utvrđeno je da na svim vratilima u zoni prelaznih radijusa, po čitavom obimu vratila, postoji veliki broj površinskih prslina, koje su mogle odgovarajućim projektom tehnologije reparaturnog zavarivanja da se saniraju iako su pojedinačne prsline bile dužine do 430 mm i dubine do 20 mm. Šuplja vratila turbina izrađena su, zavarivanjem, iz tri dela i to cilindrični delovi od čelika 20GS, a prirubnički deo vratila i sama prirubnica od čeličnog liva 20GSL. U cilju produženja radnog veka i ušteda na demontaži i montaži vratila turbina, razvijena je metodologija reparaturnog zavarivanja bez demontaže agregata. Metodologijom sanacije prslina na vratilima turbina je, zbog njihovog konstrukcionog rešenja i funkcije u eksploataciji, trebalo veliki broj detalja precizirati, pažljivo razmotriti i koordinisano izvršiti u cilju sigurnosti za njihovo ponovno korišćenje. Ukoliko bi se samo neki od ovih detalja prevideo, podcenio ili nepravilno sagledao, moglo bi doći do značajnih problema u radu kompletne turbine. U radu je, zbog specifičnosti sprovedene metodologije u sanaciji prslina, pored tehnologije zavarivanja data i procedura pripreme vratila sa redosledom izvođenja radova.
PB  - Institut IMK "14. oktobar", Kruševac
T2  - IMK-14 - Istraživanje i razvoj
T1  - Metodologija reparaturnog zavarivanja vratila turbina na hidroelektrani Đerdap 2 bez demontaže agregata
EP  - 80
IS  - 3
SP  - 73
VL  - 18
UR  - https://hdl.handle.net/21.15107/rcub_rims_192
ER  - 

@article{
author = "Arsić, Miodrag and Vistać, Brane and Odanović, Zoran and Đorđević, Aleksandar and Savić, Zoran",
year = "2012",
abstract = "Na deset hidro-generatorskih jedinica 'Đerdap 2' ugrađene su horizontalne Kaplan turbine, nominalne snage 28 MW, izrađene u Rusiji. Posle 163411h rada (približno 22 godine) došlo je do loma vratila turbine agregata A6 u zoni velike koncentracije napona, na mestu prelaznog radijusa R80 između prirubnice i glavčine radnog kola. To je bio povod da se izvrše ispitivanja, metodama bez razaranja (vizuelno ispitivanje, ispitivanje penetrantima, ispitivanje magnetnim česticama, ultrazvučno ispitivanje), zavarenih spojeva i osnovnog materijala vratila ostalih turbina. Tim ispitivanjima utvrđeno je da na svim vratilima u zoni prelaznih radijusa, po čitavom obimu vratila, postoji veliki broj površinskih prslina, koje su mogle odgovarajućim projektom tehnologije reparaturnog zavarivanja da se saniraju iako su pojedinačne prsline bile dužine do 430 mm i dubine do 20 mm. Šuplja vratila turbina izrađena su, zavarivanjem, iz tri dela i to cilindrični delovi od čelika 20GS, a prirubnički deo vratila i sama prirubnica od čeličnog liva 20GSL. U cilju produženja radnog veka i ušteda na demontaži i montaži vratila turbina, razvijena je metodologija reparaturnog zavarivanja bez demontaže agregata. Metodologijom sanacije prslina na vratilima turbina je, zbog njihovog konstrukcionog rešenja i funkcije u eksploataciji, trebalo veliki broj detalja precizirati, pažljivo razmotriti i koordinisano izvršiti u cilju sigurnosti za njihovo ponovno korišćenje. Ukoliko bi se samo neki od ovih detalja prevideo, podcenio ili nepravilno sagledao, moglo bi doći do značajnih problema u radu kompletne turbine. U radu je, zbog specifičnosti sprovedene metodologije u sanaciji prslina, pored tehnologije zavarivanja data i procedura pripreme vratila sa redosledom izvođenja radova.",
publisher = "Institut IMK "14. oktobar", Kruševac",
journal = "IMK-14 - Istraživanje i razvoj",
title = "Metodologija reparaturnog zavarivanja vratila turbina na hidroelektrani Đerdap 2 bez demontaže agregata",
pages = "80-73",
number = "3",
volume = "18",
url = "https://hdl.handle.net/21.15107/rcub_rims_192"
}

Arsić, M., Vistać, B., Odanović, Z., Đorđević, A.,& Savić, Z.. (2012). Metodologija reparaturnog zavarivanja vratila turbina na hidroelektrani Đerdap 2 bez demontaže agregata. in IMK-14 - Istraživanje i razvoj
Institut IMK "14. oktobar", Kruševac., 18(3), 73-80.
https://hdl.handle.net/21.15107/rcub_rims_192

Arsić M, Vistać B, Odanović Z, Đorđević A, Savić Z. Metodologija reparaturnog zavarivanja vratila turbina na hidroelektrani Đerdap 2 bez demontaže agregata. in IMK-14 - Istraživanje i razvoj. 2012;18(3):73-80.
https://hdl.handle.net/21.15107/rcub_rims_192 .

Arsić, Miodrag, Vistać, Brane, Odanović, Zoran, Đorđević, Aleksandar, Savić, Zoran, "Metodologija reparaturnog zavarivanja vratila turbina na hidroelektrani Đerdap 2 bez demontaže agregata" in IMK-14 - Istraživanje i razvoj, 18, no. 3 (2012):73-80,
https://hdl.handle.net/21.15107/rcub_rims_192 .

TY  - JOUR
AU  - Odanović, Zoran
AU  - Grabulov, Vencislav
AU  - Arsić, Miodrag
AU  - Đurđević, Mile
AU  - Katavić, Boris
PY  - 2011
UR  - http://rims.institutims.rs/handle/123456789/130
AB  - Najznačajniji delovi hidroelektrana, vratila turbina izložena su tokom rada visokim naprezanjima, puzamju, zamoru i koroziji. Zbog toga je korisno preduprediti oštećenja tokom rada, povećati pouzdanost i produžiti radni vek postrojenja. Eksploatacioni uslovi mogu da dovedu do prslina i loma u homogenom materijalu, tako da postoji potreba za reparaturom dela postrojenja. A ona može biti skupa ili dugotrajna. U okolnostima kada se reparatura izvodi na licu mesta, posebno pažljivo treba da se definiše tehnologija reparaturnog zavarivanja, parametri postupka, i izbor dodatnog materijala. U ovom istraživanju izbor dodatnog materijala je bio tema i dati su rezultati. Vratilo je izrađeno od čeličnog liva 20Mn5 i na njemu su metodama IBR, otkrivena oštećenja tipa prslina dužine do 400 mm i dubine do 20 mm. Kako je planirano da se reparatura izvede bez demontaže vratila, primena termičke obrade nije bila izvodljiva. Analiza zavarljivosti osnovnoog materijala urađena je korišćenjem analitičkih jednačina. Rezultati su pokazali da je zavarljivost ovog čelika ograničena. Za reparaturno zavarivanje izabran je postupak REL (111) i dve obložene austenitne elektrode sa ciljem određivanja pogodnosti za upotrebu kao potencijalnih dodatnih materijala za reparaturu. U ovom istraživanju ispitane su Fe-Ni-Cr-Mo elektroda i elektroda na bazi Ni i njihove osobine su upoređene. Ispitivanje zatezanjem, ispitivanje apsorbovane energije, ispitivanje savijanjem, merenje tvrdoće i ispiivanje osetljivosti kao što su 'CTS' i 'Y' probe, izvedeni su na ispitnim spojevima dobijenim zavarivanjem osnovnog materijala, 20Mn5, ispitivanje savijanjem, merenje tvrdoće i ispiivanje osetljivosti kao što su 'CTS' i 'Y' probe izvedeni su na ispitnim spojevima dobijenim zavarivanjem osnovnog materijala, čelika 20Mn5, sa ispitivanim dodatnim materijalima. Dobijeni rezultati su analizirani i na osnovu toga, odabrana je elektroda na bazi Ni kao pogodnija za reparaturno zavarivanje.
AB  - The most significant components of hydropower plants are turbine shafts and generator rotors which undergo time-dependent processes such as high stresses, creep, fatigue and corrosion. It is therefore desirable to prevent in-service damages, improve reliability and extend the operational life of the plant. Plant operation can lead to cracking and failures in homogeneous materials, therefore a need for repair welding on plant components, which can be expensive and time-consuming, exists. In the circumstances when repair welding has to be carried out on site, special care has to be taken in defining repair welding technology, process parameters and selection of filler materials. In this research a selection of filler materials for repair welding on site of hydropower turbine shaft was performed and results were presented. The shaft was made of the cast steel 20Mn5 and presence of damages in the form of cracks which were up to 400 mm long and up to 20 mm deep was detected through the use of NDT methods. As the repairing was planned to be carried out without disassembling of the shaft, application of heat treatment procedures was not feasible. Weldability analysis of the base material was performed through the use of analytical equations. Results have shown that weldability of this steel is limited. For the repair welding a MMA (111) welding process was selected and two covered austenitic electrodes were analyzed in order to establish the feasibility of their use as potential filler material for repairing. In this research a Fe-Ni-Cr-Mo electrode and Ni based electrode were tested and their properties were compared. Tensile testing, absorbed energies tests, bending tests, hardness measurements and sensitivity tests such as 'CTS' and 'Y' were performed on test joints obtained by welding of base material, 20Mn5 steel, with investigated filler materials. Obtained results were analyzed and a Ni based electrode was selected as most suitable for repair welding.
PB  - DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd
T2  - Zavarivanje i zavarene konstrukcije
T1  - Izbor optimalnog dodatnog materijala za reparaturno zavarivanje vratila turbine hidrocentrale na licu mesta
T1  - Selection of the optimal filler material for on-site repair welding of the turbine shaft at the hydropower plant
EP  - 166
IS  - 4
SP  - 149
VL  - 56
UR  - https://hdl.handle.net/21.15107/rcub_rims_130
ER  - 

@article{
author = "Odanović, Zoran and Grabulov, Vencislav and Arsić, Miodrag and Đurđević, Mile and Katavić, Boris",
year = "2011",
abstract = "Najznačajniji delovi hidroelektrana, vratila turbina izložena su tokom rada visokim naprezanjima, puzamju, zamoru i koroziji. Zbog toga je korisno preduprediti oštećenja tokom rada, povećati pouzdanost i produžiti radni vek postrojenja. Eksploatacioni uslovi mogu da dovedu do prslina i loma u homogenom materijalu, tako da postoji potreba za reparaturom dela postrojenja. A ona može biti skupa ili dugotrajna. U okolnostima kada se reparatura izvodi na licu mesta, posebno pažljivo treba da se definiše tehnologija reparaturnog zavarivanja, parametri postupka, i izbor dodatnog materijala. U ovom istraživanju izbor dodatnog materijala je bio tema i dati su rezultati. Vratilo je izrađeno od čeličnog liva 20Mn5 i na njemu su metodama IBR, otkrivena oštećenja tipa prslina dužine do 400 mm i dubine do 20 mm. Kako je planirano da se reparatura izvede bez demontaže vratila, primena termičke obrade nije bila izvodljiva. Analiza zavarljivosti osnovnoog materijala urađena je korišćenjem analitičkih jednačina. Rezultati su pokazali da je zavarljivost ovog čelika ograničena. Za reparaturno zavarivanje izabran je postupak REL (111) i dve obložene austenitne elektrode sa ciljem određivanja pogodnosti za upotrebu kao potencijalnih dodatnih materijala za reparaturu. U ovom istraživanju ispitane su Fe-Ni-Cr-Mo elektroda i elektroda na bazi Ni i njihove osobine su upoređene. Ispitivanje zatezanjem, ispitivanje apsorbovane energije, ispitivanje savijanjem, merenje tvrdoće i ispiivanje osetljivosti kao što su 'CTS' i 'Y' probe, izvedeni su na ispitnim spojevima dobijenim zavarivanjem osnovnog materijala, 20Mn5, ispitivanje savijanjem, merenje tvrdoće i ispiivanje osetljivosti kao što su 'CTS' i 'Y' probe izvedeni su na ispitnim spojevima dobijenim zavarivanjem osnovnog materijala, čelika 20Mn5, sa ispitivanim dodatnim materijalima. Dobijeni rezultati su analizirani i na osnovu toga, odabrana je elektroda na bazi Ni kao pogodnija za reparaturno zavarivanje., The most significant components of hydropower plants are turbine shafts and generator rotors which undergo time-dependent processes such as high stresses, creep, fatigue and corrosion. It is therefore desirable to prevent in-service damages, improve reliability and extend the operational life of the plant. Plant operation can lead to cracking and failures in homogeneous materials, therefore a need for repair welding on plant components, which can be expensive and time-consuming, exists. In the circumstances when repair welding has to be carried out on site, special care has to be taken in defining repair welding technology, process parameters and selection of filler materials. In this research a selection of filler materials for repair welding on site of hydropower turbine shaft was performed and results were presented. The shaft was made of the cast steel 20Mn5 and presence of damages in the form of cracks which were up to 400 mm long and up to 20 mm deep was detected through the use of NDT methods. As the repairing was planned to be carried out without disassembling of the shaft, application of heat treatment procedures was not feasible. Weldability analysis of the base material was performed through the use of analytical equations. Results have shown that weldability of this steel is limited. For the repair welding a MMA (111) welding process was selected and two covered austenitic electrodes were analyzed in order to establish the feasibility of their use as potential filler material for repairing. In this research a Fe-Ni-Cr-Mo electrode and Ni based electrode were tested and their properties were compared. Tensile testing, absorbed energies tests, bending tests, hardness measurements and sensitivity tests such as 'CTS' and 'Y' were performed on test joints obtained by welding of base material, 20Mn5 steel, with investigated filler materials. Obtained results were analyzed and a Ni based electrode was selected as most suitable for repair welding.",
publisher = "DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd",
journal = "Zavarivanje i zavarene konstrukcije",
title = "Izbor optimalnog dodatnog materijala za reparaturno zavarivanje vratila turbine hidrocentrale na licu mesta, Selection of the optimal filler material for on-site repair welding of the turbine shaft at the hydropower plant",
pages = "166-149",
number = "4",
volume = "56",
url = "https://hdl.handle.net/21.15107/rcub_rims_130"
}

Odanović, Z., Grabulov, V., Arsić, M., Đurđević, M.,& Katavić, B.. (2011). Izbor optimalnog dodatnog materijala za reparaturno zavarivanje vratila turbine hidrocentrale na licu mesta. in Zavarivanje i zavarene konstrukcije
DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd., 56(4), 149-166.
https://hdl.handle.net/21.15107/rcub_rims_130

Odanović Z, Grabulov V, Arsić M, Đurđević M, Katavić B. Izbor optimalnog dodatnog materijala za reparaturno zavarivanje vratila turbine hidrocentrale na licu mesta. in Zavarivanje i zavarene konstrukcije. 2011;56(4):149-166.
https://hdl.handle.net/21.15107/rcub_rims_130 .

Odanović, Zoran, Grabulov, Vencislav, Arsić, Miodrag, Đurđević, Mile, Katavić, Boris, "Izbor optimalnog dodatnog materijala za reparaturno zavarivanje vratila turbine hidrocentrale na licu mesta" in Zavarivanje i zavarene konstrukcije, 56, no. 4 (2011):149-166,
https://hdl.handle.net/21.15107/rcub_rims_130 .

TY  - CONF
AU  - Vistać, Brane
AU  - Arsić, Miodrag
AU  - Aleksić, Vujadin
AU  - Mladenović, Mladen
AU  - Jaković, Dragan
PY  - 2010
UR  - http://rims.institutims.rs/handle/123456789/798
PB  - Društvo za unapređivanje zavarivanja u Srbiji, Srbija
C3  - Dvadeset šesto savetovanje sa međunarodnim učešćem ZAVARIVANJE 2010
T1  - Tehnologija reparaturnog zavarivanja vratila turbine na hidroelektrani Đerdap bez demontaže agregata
EP  - 8
SP  - 1
UR  - https://hdl.handle.net/21.15107/rcub_rims_798
ER  - 

@conference{
author = "Vistać, Brane and Arsić, Miodrag and Aleksić, Vujadin and Mladenović, Mladen and Jaković, Dragan",
year = "2010",
publisher = "Društvo za unapređivanje zavarivanja u Srbiji, Srbija",
journal = "Dvadeset šesto savetovanje sa međunarodnim učešćem ZAVARIVANJE 2010",
title = "Tehnologija reparaturnog zavarivanja vratila turbine na hidroelektrani Đerdap bez demontaže agregata",
pages = "8-1",
url = "https://hdl.handle.net/21.15107/rcub_rims_798"
}

Vistać, B., Arsić, M., Aleksić, V., Mladenović, M.,& Jaković, D.. (2010). Tehnologija reparaturnog zavarivanja vratila turbine na hidroelektrani Đerdap bez demontaže agregata. in Dvadeset šesto savetovanje sa međunarodnim učešćem ZAVARIVANJE 2010
Društvo za unapređivanje zavarivanja u Srbiji, Srbija., 1-8.
https://hdl.handle.net/21.15107/rcub_rims_798

Vistać B, Arsić M, Aleksić V, Mladenović M, Jaković D. Tehnologija reparaturnog zavarivanja vratila turbine na hidroelektrani Đerdap bez demontaže agregata. in Dvadeset šesto savetovanje sa međunarodnim učešćem ZAVARIVANJE 2010. 2010;:1-8.
https://hdl.handle.net/21.15107/rcub_rims_798 .

Vistać, Brane, Arsić, Miodrag, Aleksić, Vujadin, Mladenović, Mladen, Jaković, Dragan, "Tehnologija reparaturnog zavarivanja vratila turbine na hidroelektrani Đerdap bez demontaže agregata" in Dvadeset šesto savetovanje sa međunarodnim učešćem ZAVARIVANJE 2010 (2010):1-8,
https://hdl.handle.net/21.15107/rcub_rims_798 .