TY  - CONF
AU  - Arsić, Miodrag
AU  - Bošnjak, Srđan
AU  - Gnjatović, Nebojša
AU  - Mladenović, Mladen
AU  - Savić, Zoran
PY  - 2017
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/4931
AB  - During the rehabilitation of the hydroelectric generating set A6 at hydro power plant ’Djerdap 1’, state analysis and integrity assessment were carried out for all vital components and structures. After the completion of non-destructive and destructive tests carried out on parent material and
welded joints of the structure of the upper ring of guide vane apparatus as part of vertical Kaplan turbine runner, it was decided that it should be replaced with a new one, because parent material and welded joints were degraded beyond repair. Existing upper ring of guide vane apparatus was made of steel St 3, in accordance with GOST standard. New upper ring of
guide vane apparatus was manufactured through the use of steel S 235, in accordance with DIN standard. During ultrasonic testing 6 mm high lack of root penetration was detected at the load carrying welded joint along the entire circumference of the guide vane apparatus. It should be noted that there is no possibility of restoring the welded joint, because the occurrence of deformations at the structure has to be avoided. In this paper the results of the check of load carrying capacity of welded joints are presented, taking into account all weakened cross-sections. Determination of load carrying capacity and fatigue strength were carried
out in the usual way, as well as the stress state analysis performed through the use of finite element method in order to determine the influence of undercuts. Assessment of integrity and service life of the guide vane apparatus based on the influence of cracks on stress distribution and fracture mechanics parameters was also carried out.
PB  - University of Belgrade, Faculty of Mechanical Engineering
C3  - Proceedings of the XXII International Conference MHCL’17
T1  - Assessment of integrity and service life of the upper ring of turbine runner guide vane apparatus at hydro power plant ‘Đerdap 1’
EP  - 234
SP  - 231
UR  - https://hdl.handle.net/21.15107/rcub_machinery_4931
ER  - 

@conference{
author = "Arsić, Miodrag and Bošnjak, Srđan and Gnjatović, Nebojša and Mladenović, Mladen and Savić, Zoran",
year = "2017",
abstract = "During the rehabilitation of the hydroelectric generating set A6 at hydro power plant ’Djerdap 1’, state analysis and integrity assessment were carried out for all vital components and structures. After the completion of non-destructive and destructive tests carried out on parent material and
welded joints of the structure of the upper ring of guide vane apparatus as part of vertical Kaplan turbine runner, it was decided that it should be replaced with a new one, because parent material and welded joints were degraded beyond repair. Existing upper ring of guide vane apparatus was made of steel St 3, in accordance with GOST standard. New upper ring of
guide vane apparatus was manufactured through the use of steel S 235, in accordance with DIN standard. During ultrasonic testing 6 mm high lack of root penetration was detected at the load carrying welded joint along the entire circumference of the guide vane apparatus. It should be noted that there is no possibility of restoring the welded joint, because the occurrence of deformations at the structure has to be avoided. In this paper the results of the check of load carrying capacity of welded joints are presented, taking into account all weakened cross-sections. Determination of load carrying capacity and fatigue strength were carried
out in the usual way, as well as the stress state analysis performed through the use of finite element method in order to determine the influence of undercuts. Assessment of integrity and service life of the guide vane apparatus based on the influence of cracks on stress distribution and fracture mechanics parameters was also carried out.",
publisher = "University of Belgrade, Faculty of Mechanical Engineering",
journal = "Proceedings of the XXII International Conference MHCL’17",
title = "Assessment of integrity and service life of the upper ring of turbine runner guide vane apparatus at hydro power plant ‘Đerdap 1’",
pages = "234-231",
url = "https://hdl.handle.net/21.15107/rcub_machinery_4931"
}

Arsić, M., Bošnjak, S., Gnjatović, N., Mladenović, M.,& Savić, Z.. (2017). Assessment of integrity and service life of the upper ring of turbine runner guide vane apparatus at hydro power plant ‘Đerdap 1’. in Proceedings of the XXII International Conference MHCL’17
University of Belgrade, Faculty of Mechanical Engineering., 231-234.
https://hdl.handle.net/21.15107/rcub_machinery_4931

Arsić M, Bošnjak S, Gnjatović N, Mladenović M, Savić Z. Assessment of integrity and service life of the upper ring of turbine runner guide vane apparatus at hydro power plant ‘Đerdap 1’. in Proceedings of the XXII International Conference MHCL’17. 2017;:231-234.
https://hdl.handle.net/21.15107/rcub_machinery_4931 .

Arsić, Miodrag, Bošnjak, Srđan, Gnjatović, Nebojša, Mladenović, Mladen, Savić, Zoran, "Assessment of integrity and service life of the upper ring of turbine runner guide vane apparatus at hydro power plant ‘Đerdap 1’" in Proceedings of the XXII International Conference MHCL’17 (2017):231-234,
https://hdl.handle.net/21.15107/rcub_machinery_4931 .

TY  - JOUR
AU  - Sedmak, Simon
AU  - Arsić, M.
AU  - Bajić, Darko
AU  - Mladenović, Mladen
AU  - Savić, Zoran
PY  - 2015
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/2120
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_machinery_2120
ER  - 

@article{
author = "Sedmak, Simon and Arsić, M. and Bajić, Darko 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_machinery_2120"
}

Sedmak, S., Arsić, M., Bajić, D., 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_machinery_2120

Sedmak S, Arsić M, Bajić D, 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_machinery_2120 .

Sedmak, Simon, Arsić, M., Bajić, Darko, 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_machinery_2120 .

TY  - CONF
AU  - Arsić, Miodrag
AU  - Odanović, Zoran
AU  - Bošnjak, Srđan
AU  - Mladenović, Mladen
AU  - Savić, Zoran
PY  - 2013
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/1650
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 . .