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  - JOUR
AU  - Zrilić, Milorad
AU  - Grabulov, Vencislav
AU  - Burzić, Zijah
AU  - Arsić, Miodrag
AU  - Sedmak, S.
PY  - 2007
UR  - http://rims.institutims.rs/handle/123456789/58
AB  - in order to gain the benefits of weldable high-strength steels in pressurized equipment applications, satisfactory toughness and crack properties of the welded joint, both in the weld metal and the heat-affected-zone (HAZ), are required. Experimental investigations of toughness and crack resistance parameters through static and impact tests of a high-strength, low-alloy steel (HSLA) with a nominal yield strength of 700MPa and its welded joint, were performed on Charpy-sized specimens, V-notched and pre-cracked, of the parent metal, weld metal and HAZ. The selected electrode produced slight undermatching and enabled the welded joints to be manufactured without cold cracks. The impact energy and its parts responsible for crack initiation and propagation were determined by toughness evaluation. Crack sensitivity, defined as the ratio of the impact energy for V-notched and for pre-cracked specimens, enabled a comparison of the homogeneous microstructure of the parent metal and the weld metal, and of the heterogeneous microstructure of the heat-affected-zone (HAZ), which indicated a better crack toughness behaviour of the HAZ. The results obtained showed that the toughness and crack resistance of the weld metal were significantly lower than those of the parent metal and the HAZ. The fracture mechanics parameters, J(Ic), integral, and plane strain fracture toughness, K-Ic, as well as J resistance curves expressed the degradation less.
PB  - Elsevier Sci Ltd, Oxford
T2  - International Journal of Pressure Vessels and Piping
T1  - Static and impact crack properties of a high-strength steel welded joint
EP  - 150
IS  - 3
SP  - 139
VL  - 84
DO  - 10.1016/j.ijpvp.2006.09.021
ER  - 

@article{
author = "Zrilić, Milorad and Grabulov, Vencislav and Burzić, Zijah and Arsić, Miodrag and Sedmak, S.",
year = "2007",
abstract = "in order to gain the benefits of weldable high-strength steels in pressurized equipment applications, satisfactory toughness and crack properties of the welded joint, both in the weld metal and the heat-affected-zone (HAZ), are required. Experimental investigations of toughness and crack resistance parameters through static and impact tests of a high-strength, low-alloy steel (HSLA) with a nominal yield strength of 700MPa and its welded joint, were performed on Charpy-sized specimens, V-notched and pre-cracked, of the parent metal, weld metal and HAZ. The selected electrode produced slight undermatching and enabled the welded joints to be manufactured without cold cracks. The impact energy and its parts responsible for crack initiation and propagation were determined by toughness evaluation. Crack sensitivity, defined as the ratio of the impact energy for V-notched and for pre-cracked specimens, enabled a comparison of the homogeneous microstructure of the parent metal and the weld metal, and of the heterogeneous microstructure of the heat-affected-zone (HAZ), which indicated a better crack toughness behaviour of the HAZ. The results obtained showed that the toughness and crack resistance of the weld metal were significantly lower than those of the parent metal and the HAZ. The fracture mechanics parameters, J(Ic), integral, and plane strain fracture toughness, K-Ic, as well as J resistance curves expressed the degradation less.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "International Journal of Pressure Vessels and Piping",
title = "Static and impact crack properties of a high-strength steel welded joint",
pages = "150-139",
number = "3",
volume = "84",
doi = "10.1016/j.ijpvp.2006.09.021"
}

Zrilić, M., Grabulov, V., Burzić, Z., Arsić, M.,& Sedmak, S.. (2007). Static and impact crack properties of a high-strength steel welded joint. in International Journal of Pressure Vessels and Piping
Elsevier Sci Ltd, Oxford., 84(3), 139-150.
https://doi.org/10.1016/j.ijpvp.2006.09.021

Zrilić M, Grabulov V, Burzić Z, Arsić M, Sedmak S. Static and impact crack properties of a high-strength steel welded joint. in International Journal of Pressure Vessels and Piping. 2007;84(3):139-150.
doi:10.1016/j.ijpvp.2006.09.021 .

Zrilić, Milorad, Grabulov, Vencislav, Burzić, Zijah, Arsić, Miodrag, Sedmak, S., "Static and impact crack properties of a high-strength steel welded joint" in International Journal of Pressure Vessels and Piping, 84, no. 3 (2007):139-150,
https://doi.org/10.1016/j.ijpvp.2006.09.021 . .