TY  - JOUR
AU  - Sedmak, Aleksandar
AU  - Arsić, Miodrag
AU  - Šarkočević, Živče
AU  - Međo, Bojan
AU  - Rakin, Marko
AU  - Arsić, D.
AU  - Lazić, V.
PY  - 2020
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4560
AB  - Experimental investigation of the integrity of casing pipes, used in the oil drilling rigs, withdrawn after about 70,000 h of service, has been conducted, together with numerical simulation. Pipes were manufactured by the high frequency contact welding (HF) of API J55 steel. The influence of corrosion damage is investigated by means of pressure test of a pipe with different damage levels made by machining the circular holes. The finite element analysis of the damaged pipe subjected to internal pressure is conducted to simulate the stress state in the pipe and to establish the criteria for the maximum pressure that a damaged pipe can withstand. Several analytical expressions were used to estimate the maximum pressure in a damaged pipeline, and the solutions were compared to predictions of finite element models and experimental results.
T2  - International Journal of Pressure Vessels and Piping
T1  - Remaining strength of API J55 steel casing pipes damaged by corrosion
VL  - 188
DO  - 10.1016/j.ijpvp.2020.104230
ER  - 

@article{
author = "Sedmak, Aleksandar and Arsić, Miodrag and Šarkočević, Živče and Međo, Bojan and Rakin, Marko and Arsić, D. and Lazić, V.",
year = "2020",
abstract = "Experimental investigation of the integrity of casing pipes, used in the oil drilling rigs, withdrawn after about 70,000 h of service, has been conducted, together with numerical simulation. Pipes were manufactured by the high frequency contact welding (HF) of API J55 steel. The influence of corrosion damage is investigated by means of pressure test of a pipe with different damage levels made by machining the circular holes. The finite element analysis of the damaged pipe subjected to internal pressure is conducted to simulate the stress state in the pipe and to establish the criteria for the maximum pressure that a damaged pipe can withstand. Several analytical expressions were used to estimate the maximum pressure in a damaged pipeline, and the solutions were compared to predictions of finite element models and experimental results.",
journal = "International Journal of Pressure Vessels and Piping",
title = "Remaining strength of API J55 steel casing pipes damaged by corrosion",
volume = "188",
doi = "10.1016/j.ijpvp.2020.104230"
}

Sedmak, A., Arsić, M., Šarkočević, Ž., Međo, B., Rakin, M., Arsić, D.,& Lazić, V.. (2020). Remaining strength of API J55 steel casing pipes damaged by corrosion. in International Journal of Pressure Vessels and Piping, 188.
https://doi.org/10.1016/j.ijpvp.2020.104230

Sedmak A, Arsić M, Šarkočević Ž, Međo B, Rakin M, Arsić D, Lazić V. Remaining strength of API J55 steel casing pipes damaged by corrosion. in International Journal of Pressure Vessels and Piping. 2020;188.
doi:10.1016/j.ijpvp.2020.104230 .

Sedmak, Aleksandar, Arsić, Miodrag, Šarkočević, Živče, Međo, Bojan, Rakin, Marko, Arsić, D., Lazić, V., "Remaining strength of API J55 steel casing pipes damaged by corrosion" in International Journal of Pressure Vessels and Piping, 188 (2020),
https://doi.org/10.1016/j.ijpvp.2020.104230 . .

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://TechnoRep.tmf.bg.ac.rs/handle/123456789/4567
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  - Society for Structural Integrity and Life, Institute for Material Testing
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 = "Society for Structural Integrity and Life, Institute for Material Testing",
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
Society for Structural Integrity and Life, Institute for Material Testing., 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  - Mrdak, Mihailo
AU  - Međo, Bojan
AU  - Veljić, Darko
AU  - Arsić, Miodrag
AU  - Rakin, Marko
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4237
AB  - In this paper, structural and mechanical properties of APS - atmospheric plasma spray coating Al-12Si are presented. The aim of the research was the optimisation of the flow of powder to produce layers with optimal mechanical and structural properties that will be applied to the worn out parts of airplanes. Three groups of samples were produced, by utilising three powder feed rates: 30 g/min, 45 g/min and 60 g/min. Evaluation of layers' microhardness was done using HV0.3 method and the bond strength was determined by testing of tensile strength. Surface morphology of the deposited powder particles was examined on SEM (Scanning Electron Microscope). The microstructure of the coating with the best measured mechanical properties was subsequently examined in etched condition on optical microscope and SEM (in accordance with the standard PN 585005, Pratt & Whitney). Also, fracture morphology of this coating in deposited state was examined using SEM. It was found that powder feed control with atmospheric plasma spraying can produce dense layers of Al-12Si coating with good bond strength.
PB  - Walter de Gruyter Gmbh, Berlin
T2  - Reviews on Advanced Materials Science
T1  - The influence of powder feed rate on mechanical properties of atmospheric plasma spray (APS) Al-12Si coating
EP  - 81
IS  - 1
SP  - 75
VL  - 58
DO  - 10.1515/rams-2019-0007
ER  - 

@article{
author = "Mrdak, Mihailo and Međo, Bojan and Veljić, Darko and Arsić, Miodrag and Rakin, Marko",
year = "2019",
abstract = "In this paper, structural and mechanical properties of APS - atmospheric plasma spray coating Al-12Si are presented. The aim of the research was the optimisation of the flow of powder to produce layers with optimal mechanical and structural properties that will be applied to the worn out parts of airplanes. Three groups of samples were produced, by utilising three powder feed rates: 30 g/min, 45 g/min and 60 g/min. Evaluation of layers' microhardness was done using HV0.3 method and the bond strength was determined by testing of tensile strength. Surface morphology of the deposited powder particles was examined on SEM (Scanning Electron Microscope). The microstructure of the coating with the best measured mechanical properties was subsequently examined in etched condition on optical microscope and SEM (in accordance with the standard PN 585005, Pratt & Whitney). Also, fracture morphology of this coating in deposited state was examined using SEM. It was found that powder feed control with atmospheric plasma spraying can produce dense layers of Al-12Si coating with good bond strength.",
publisher = "Walter de Gruyter Gmbh, Berlin",
journal = "Reviews on Advanced Materials Science",
title = "The influence of powder feed rate on mechanical properties of atmospheric plasma spray (APS) Al-12Si coating",
pages = "81-75",
number = "1",
volume = "58",
doi = "10.1515/rams-2019-0007"
}

Mrdak, M., Međo, B., Veljić, D., Arsić, M.,& Rakin, M.. (2019). The influence of powder feed rate on mechanical properties of atmospheric plasma spray (APS) Al-12Si coating. in Reviews on Advanced Materials Science
Walter de Gruyter Gmbh, Berlin., 58(1), 75-81.
https://doi.org/10.1515/rams-2019-0007

Mrdak M, Međo B, Veljić D, Arsić M, Rakin M. The influence of powder feed rate on mechanical properties of atmospheric plasma spray (APS) Al-12Si coating. in Reviews on Advanced Materials Science. 2019;58(1):75-81.
doi:10.1515/rams-2019-0007 .

Mrdak, Mihailo, Međo, Bojan, Veljić, Darko, Arsić, Miodrag, Rakin, Marko, "The influence of powder feed rate on mechanical properties of atmospheric plasma spray (APS) Al-12Si coating" in Reviews on Advanced Materials Science, 58, no. 1 (2019):75-81,
https://doi.org/10.1515/rams-2019-0007 . .

TY  - CONF
AU  - Međo, Bojan
AU  - Musrati, Walid
AU  - Arsić, Miodrag
AU  - Gubeljak, Nenad
AU  - Štefane, Primož
AU  - Rakin, Marko
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6295
PB  - Savez mašinskih i elektrotehničkih inženjera i tehničara Srbije
C3  - Međunarodni kongres o procesnoj industriji - Procesing
T1  - Određivanje otpornosti prema lomu materijala cevovoda primenom epruveta oblika prstena
EP  - 40
SP  - 35
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6295
ER  - 

@conference{
author = "Međo, Bojan and Musrati, Walid and Arsić, Miodrag and Gubeljak, Nenad and Štefane, Primož and Rakin, Marko",
year = "2018",
publisher = "Savez mašinskih i elektrotehničkih inženjera i tehničara Srbije",
journal = "Međunarodni kongres o procesnoj industriji - Procesing",
title = "Određivanje otpornosti prema lomu materijala cevovoda primenom epruveta oblika prstena",
pages = "40-35",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6295"
}

Međo, B., Musrati, W., Arsić, M., Gubeljak, N., Štefane, P.,& Rakin, M.. (2018). Određivanje otpornosti prema lomu materijala cevovoda primenom epruveta oblika prstena. in Međunarodni kongres o procesnoj industriji - Procesing
Savez mašinskih i elektrotehničkih inženjera i tehničara Srbije., 35-40.
https://hdl.handle.net/21.15107/rcub_technorep_6295

Međo B, Musrati W, Arsić M, Gubeljak N, Štefane P, Rakin M. Određivanje otpornosti prema lomu materijala cevovoda primenom epruveta oblika prstena. in Međunarodni kongres o procesnoj industriji - Procesing. 2018;:35-40.
https://hdl.handle.net/21.15107/rcub_technorep_6295 .

Međo, Bojan, Musrati, Walid, Arsić, Miodrag, Gubeljak, Nenad, Štefane, Primož, Rakin, Marko, "Određivanje otpornosti prema lomu materijala cevovoda primenom epruveta oblika prstena" in Međunarodni kongres o procesnoj industriji - Procesing (2018):35-40,
https://hdl.handle.net/21.15107/rcub_technorep_6295 .

TY  - JOUR
AU  - Međo, Bojan
AU  - Arsić, Miodrag
AU  - Rakin, Marko
AU  - Sedmak, Simon
AU  - Savić, Zoran
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3791
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 x 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  - Society for Structural Integrity and Life, Institute for Material Testing
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, Marko 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 x 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 = "Society for Structural Integrity and Life, Institute for Material Testing",
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
Society for Structural Integrity and Life, Institute for Material Testing., 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, Marko, 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  - JOUR
AU  - Dojčinović, Marina
AU  - Arsić, Miodrag
AU  - Bošnjak, Srđan
AU  - Murariu, Alin
AU  - Malesević, Zoranka
PY  - 2017
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3504
AB  - Hydropower plants need to develop means of protection of turbine and hydromechanical equipment from undesirable occurrences, such as degradation of parent material and/or weld metal of parts and structures caused by stresses and unpredictable influence of vibrations, fatigue, corrosion, erosion and cavitation. Results of tests that refer to the cavitation resistance of turbine runner blades made of cast steel 08X15H4 pi M pi, in accordance with GOST standard are presented in this paper. For the testing of cavitation resistance, the ultrasonic vibration test method is used (with the stationary sample), for which it is necessary to measure the mass loss during specified time intervals, while the cavitation resistance of the material is being defined, taking into account the incubation period and cavitation rate. Scanning electron microscope analysis is carried out to study the morphology of sample damage due to cavitation. The obtained results show that the tested steel has a good cavitation resistance and that fatigue is the main failure mechanism.
PB  - Society for Structural Integrity and Life, Institute for Material Testing
T2  - Structural Integrity and Life
T1  - Cavitation resistance of turbine runner blades at the hydropower plant 'Djerdap'
EP  - 60
IS  - 1
SP  - 55
VL  - 17
UR  - https://hdl.handle.net/21.15107/rcub_technorep_3504
ER  - 

@article{
author = "Dojčinović, Marina and Arsić, Miodrag and Bošnjak, Srđan and Murariu, Alin and Malesević, Zoranka",
year = "2017",
abstract = "Hydropower plants need to develop means of protection of turbine and hydromechanical equipment from undesirable occurrences, such as degradation of parent material and/or weld metal of parts and structures caused by stresses and unpredictable influence of vibrations, fatigue, corrosion, erosion and cavitation. Results of tests that refer to the cavitation resistance of turbine runner blades made of cast steel 08X15H4 pi M pi, in accordance with GOST standard are presented in this paper. For the testing of cavitation resistance, the ultrasonic vibration test method is used (with the stationary sample), for which it is necessary to measure the mass loss during specified time intervals, while the cavitation resistance of the material is being defined, taking into account the incubation period and cavitation rate. Scanning electron microscope analysis is carried out to study the morphology of sample damage due to cavitation. The obtained results show that the tested steel has a good cavitation resistance and that fatigue is the main failure mechanism.",
publisher = "Society for Structural Integrity and Life, Institute for Material Testing",
journal = "Structural Integrity and Life",
title = "Cavitation resistance of turbine runner blades at the hydropower plant 'Djerdap'",
pages = "60-55",
number = "1",
volume = "17",
url = "https://hdl.handle.net/21.15107/rcub_technorep_3504"
}

Dojčinović, M., Arsić, M., Bošnjak, S., Murariu, A.,& Malesević, Z.. (2017). Cavitation resistance of turbine runner blades at the hydropower plant 'Djerdap'. in Structural Integrity and Life
Society for Structural Integrity and Life, Institute for Material Testing., 17(1), 55-60.
https://hdl.handle.net/21.15107/rcub_technorep_3504

Dojčinović M, Arsić M, Bošnjak S, Murariu A, Malesević Z. Cavitation resistance of turbine runner blades at the hydropower plant 'Djerdap'. in Structural Integrity and Life. 2017;17(1):55-60.
https://hdl.handle.net/21.15107/rcub_technorep_3504 .

Dojčinović, Marina, Arsić, Miodrag, Bošnjak, Srđan, Murariu, Alin, Malesević, Zoranka, "Cavitation resistance of turbine runner blades at the hydropower plant 'Djerdap'" in Structural Integrity and Life, 17, no. 1 (2017):55-60,
https://hdl.handle.net/21.15107/rcub_technorep_3504 .

TY  - JOUR
AU  - Međo, Bojan
AU  - Arsić, Miodrag
AU  - Rakin, Marko
AU  - Sedmak, Simon
AU  - Malesević, Zoranka
AU  - Savić, Zoran
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3159
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  - Society for Structural Integrity and Life, Institute for Material Testing
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 Malesević, 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 = "Society for Structural Integrity and Life, Institute for Material Testing",
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., Malesević, 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
Society for Structural Integrity and Life, Institute for Material Testing., 16(2), 71-78.
https://hdl.handle.net/21.15107/rcub_technorep_3159

Međo B, Arsić M, Rakin M, Sedmak S, Malesević 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, Malesević, 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  - Međo, Bojan
AU  - Rakin, Marko
AU  - Gubeljak, Nenad
AU  - Matvienko, Y.
AU  - Arsić, Miodrag
AU  - Šarkočević, Živče
AU  - Sedmak, Aleksandar
PY  - 2015
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3057
AB  - Working conditions of casing pipes in drilling rigs can significantly influence the initiation and development of damage in the material, and therefore also the safe service of the entire system. In this work, an integrity assessment of a pipe with initial defect (machined surface crack) is presented. The position of this defect is on the external surface; unlike transport pipes, where internal surface is often endangered due to the contact with the fluid, casing pipes are also often exposed to damages at the external surface. A pipe segment exposed to internal pressure is examined experimentally and numerically, using the finite element method. Experimental setup included tracking of crack mouth opening displacement (CMOD) values, as well as J integral. Criteria for pipe failure are determined on the finite element (FE) models of the pipe; fracture initiation and plastic collapse are considered as failure mechanisms. Several 3D models with different crack sizes are evaluated. 2D plane strain models are also examined, to determine the applicability limits of this simplified approach. Integrity assessment criteria for the analysed geometries are discussed. Assessment of fracture resistance of the pipeline material is also considered in this work. Besides the standard SENB specimens, Ring specimens cut from the pipe are tested, and the results are compared. Both specimen geometries are modelled using local approach to fracture, by application of the micromechanical Complete Gurson model (CGM), developed by Z.L. Zhang. It is shown that the Ring specimens have similar fracture conditions under bending load as SENB specimens. Since they are much simpler to fabricate from the pipe than standard specimens, it is concluded that they can be used for assessment of fracture of the pipes with axial cracks.
PB  - Pergamon-Elsevier Science Ltd, Oxford
T2  - Engineering Failure Analysis
T1  - Failure resistance of drilling rig casing pipes with an axial crack
EP  - 440
SP  - 429
VL  - 58
DO  - 10.1016/j.engfailanal.2015.05.015
ER  - 

@article{
author = "Međo, Bojan and Rakin, Marko and Gubeljak, Nenad and Matvienko, Y. and Arsić, Miodrag and Šarkočević, Živče and Sedmak, Aleksandar",
year = "2015",
abstract = "Working conditions of casing pipes in drilling rigs can significantly influence the initiation and development of damage in the material, and therefore also the safe service of the entire system. In this work, an integrity assessment of a pipe with initial defect (machined surface crack) is presented. The position of this defect is on the external surface; unlike transport pipes, where internal surface is often endangered due to the contact with the fluid, casing pipes are also often exposed to damages at the external surface. A pipe segment exposed to internal pressure is examined experimentally and numerically, using the finite element method. Experimental setup included tracking of crack mouth opening displacement (CMOD) values, as well as J integral. Criteria for pipe failure are determined on the finite element (FE) models of the pipe; fracture initiation and plastic collapse are considered as failure mechanisms. Several 3D models with different crack sizes are evaluated. 2D plane strain models are also examined, to determine the applicability limits of this simplified approach. Integrity assessment criteria for the analysed geometries are discussed. Assessment of fracture resistance of the pipeline material is also considered in this work. Besides the standard SENB specimens, Ring specimens cut from the pipe are tested, and the results are compared. Both specimen geometries are modelled using local approach to fracture, by application of the micromechanical Complete Gurson model (CGM), developed by Z.L. Zhang. It is shown that the Ring specimens have similar fracture conditions under bending load as SENB specimens. Since they are much simpler to fabricate from the pipe than standard specimens, it is concluded that they can be used for assessment of fracture of the pipes with axial cracks.",
publisher = "Pergamon-Elsevier Science Ltd, Oxford",
journal = "Engineering Failure Analysis",
title = "Failure resistance of drilling rig casing pipes with an axial crack",
pages = "440-429",
volume = "58",
doi = "10.1016/j.engfailanal.2015.05.015"
}

Međo, B., Rakin, M., Gubeljak, N., Matvienko, Y., Arsić, M., Šarkočević, Ž.,& Sedmak, A.. (2015). Failure resistance of drilling rig casing pipes with an axial crack. in Engineering Failure Analysis
Pergamon-Elsevier Science Ltd, Oxford., 58, 429-440.
https://doi.org/10.1016/j.engfailanal.2015.05.015

Međo B, Rakin M, Gubeljak N, Matvienko Y, Arsić M, Šarkočević Ž, Sedmak A. Failure resistance of drilling rig casing pipes with an axial crack. in Engineering Failure Analysis. 2015;58:429-440.
doi:10.1016/j.engfailanal.2015.05.015 .

Međo, Bojan, Rakin, Marko, Gubeljak, Nenad, Matvienko, Y., Arsić, Miodrag, Šarkočević, Živče, Sedmak, Aleksandar, "Failure resistance of drilling rig casing pipes with an axial crack" in Engineering Failure Analysis, 58 (2015):429-440,
https://doi.org/10.1016/j.engfailanal.2015.05.015 . .

TY  - JOUR
AU  - Dimić, Ivana
AU  - Međo, Bojan
AU  - Rakin, Marko
AU  - Arsić, Miodrag
AU  - Šarkočević, Živče
AU  - Sedmak, Aleksandar
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2803
AB  - Working conditions of casing pipes in drilling rigs can significantly influence the initiation and development of damage in the material, and therefore also the safe service of the entire system. In this work, an integrity assessment of a steel pipe with initial defect (machined surface crack) is presented. The position of this defect is on the external surface; unlike transport pipes, where internal surface is often endangered due to the contact with the fluid, casing pipes are often exposed to damages at the external surface. Analyzed crack is in axial direction, bearing in mind that this type of defect most significantly decreases the load carrying capacity of the cylindrical pressurized components. A pipe segment exposed to internal pressure is analyzed experimentally and numerically, using the finite element method. The experimental setup included the tracking of crack mouth opening displacement (CMOD) values, as well as J integral, which is determined by application of direct measurement. Criteria for pipe failure are determined on finite element models of the pipe; fracture initiation and plastic collapse are considered as failure mechanisms. The size of the crack is varied in the finite element models; several 3D models with different crack sizes (length and depth) are evaluated. Dependence of maximum internal pressure on the defect size is obtained. 2D plane strain models are also examined, with an aim to determine the applicability limits of this simplified approach. Based on the obtained results, integrity assessment criteria for the analyzed geometries are discussed.
PB  - Elsevier Science Bv, Amsterdam
T2  - 20th European Conference on Fracture
T1  - Failure prediction of gas and oil drilling rig pipelines with axial defects
EP  - 960
SP  - 955
VL  - 3
DO  - 10.1016/j.mspro.2014.06.155
ER  - 

@article{
author = "Dimić, Ivana and Međo, Bojan and Rakin, Marko and Arsić, Miodrag and Šarkočević, Živče and Sedmak, Aleksandar",
year = "2014",
abstract = "Working conditions of casing pipes in drilling rigs can significantly influence the initiation and development of damage in the material, and therefore also the safe service of the entire system. In this work, an integrity assessment of a steel pipe with initial defect (machined surface crack) is presented. The position of this defect is on the external surface; unlike transport pipes, where internal surface is often endangered due to the contact with the fluid, casing pipes are often exposed to damages at the external surface. Analyzed crack is in axial direction, bearing in mind that this type of defect most significantly decreases the load carrying capacity of the cylindrical pressurized components. A pipe segment exposed to internal pressure is analyzed experimentally and numerically, using the finite element method. The experimental setup included the tracking of crack mouth opening displacement (CMOD) values, as well as J integral, which is determined by application of direct measurement. Criteria for pipe failure are determined on finite element models of the pipe; fracture initiation and plastic collapse are considered as failure mechanisms. The size of the crack is varied in the finite element models; several 3D models with different crack sizes (length and depth) are evaluated. Dependence of maximum internal pressure on the defect size is obtained. 2D plane strain models are also examined, with an aim to determine the applicability limits of this simplified approach. Based on the obtained results, integrity assessment criteria for the analyzed geometries are discussed.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "20th European Conference on Fracture",
title = "Failure prediction of gas and oil drilling rig pipelines with axial defects",
pages = "960-955",
volume = "3",
doi = "10.1016/j.mspro.2014.06.155"
}

Dimić, I., Međo, B., Rakin, M., Arsić, M., Šarkočević, Ž.,& Sedmak, A.. (2014). Failure prediction of gas and oil drilling rig pipelines with axial defects. in 20th European Conference on Fracture
Elsevier Science Bv, Amsterdam., 3, 955-960.
https://doi.org/10.1016/j.mspro.2014.06.155

Dimić I, Međo B, Rakin M, Arsić M, Šarkočević Ž, Sedmak A. Failure prediction of gas and oil drilling rig pipelines with axial defects. in 20th European Conference on Fracture. 2014;3:955-960.
doi:10.1016/j.mspro.2014.06.155 .

Dimić, Ivana, Međo, Bojan, Rakin, Marko, Arsić, Miodrag, Šarkočević, Živče, Sedmak, Aleksandar, "Failure prediction of gas and oil drilling rig pipelines with axial defects" in 20th European Conference on Fracture, 3 (2014):955-960,
https://doi.org/10.1016/j.mspro.2014.06.155 . .

TY  - CONF
AU  - Rakin, Marko
AU  - Međo, Bojan
AU  - Arsić, Miodrag
AU  - Šarkočević, Živče
AU  - Sedmak, Aleksandar
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2740
AB  - The subject of this work is examination of API J55 steel casing pipes manufactured by high frequency (HF) contact welding. Since the pipes were withdrawn after about 70 000 hours of service in an oil drilling rig, the influence of the exploitation conditions on the material properties is determined. Experimental analysis includes tensile, impact toughness and fatigue testing of the specimens cut from the exploited pipe and the new pipe manufactured from the same-grade material. Additionally, pipe with flaws (stress concentrators) is tested by subjecting to internal pressure. The analysed stress concentrators represent defects which are often found in the exploitation: localized corrosion damages (corrosion pits). They were simulated by machining on the external surface of the pipe wall. The behavior of the pipes with these defects is determined by strain measurement and finite element analysis in software package Abaqus. The dimensions of the defects are varied, in order to determine the dependence of load carrying capacity on their depth and length. Several expressions from the literature are applied for estimation of the maximum pressure in damaged pipelines, and the solutions are compared with the predictions of finite element models. Additionally, triaxiality values at the bottom of the defects are compared with those obtained on tensile specimens, having in mind the key role of this parameter in ductile fracture initiation.
PB  - Trans Tech Publications Ltd, Durnten-Zurich
C3  - Proceedings of the 14th Symposium on Experimental Stress Analysis and Materials Testing
T1  - Effect of Exploitation Conditions and Flaw Geometry on the Load Carrying Capacity of Casing Pipes for Oil Drilling Rigs
EP  - +
SP  - 65
VL  - 601
DO  - 10.4028/www.scientific.net/KEM.601.65
ER  - 

@conference{
author = "Rakin, Marko and Međo, Bojan and Arsić, Miodrag and Šarkočević, Živče and Sedmak, Aleksandar",
year = "2014",
abstract = "The subject of this work is examination of API J55 steel casing pipes manufactured by high frequency (HF) contact welding. Since the pipes were withdrawn after about 70 000 hours of service in an oil drilling rig, the influence of the exploitation conditions on the material properties is determined. Experimental analysis includes tensile, impact toughness and fatigue testing of the specimens cut from the exploited pipe and the new pipe manufactured from the same-grade material. Additionally, pipe with flaws (stress concentrators) is tested by subjecting to internal pressure. The analysed stress concentrators represent defects which are often found in the exploitation: localized corrosion damages (corrosion pits). They were simulated by machining on the external surface of the pipe wall. The behavior of the pipes with these defects is determined by strain measurement and finite element analysis in software package Abaqus. The dimensions of the defects are varied, in order to determine the dependence of load carrying capacity on their depth and length. Several expressions from the literature are applied for estimation of the maximum pressure in damaged pipelines, and the solutions are compared with the predictions of finite element models. Additionally, triaxiality values at the bottom of the defects are compared with those obtained on tensile specimens, having in mind the key role of this parameter in ductile fracture initiation.",
publisher = "Trans Tech Publications Ltd, Durnten-Zurich",
journal = "Proceedings of the 14th Symposium on Experimental Stress Analysis and Materials Testing",
title = "Effect of Exploitation Conditions and Flaw Geometry on the Load Carrying Capacity of Casing Pipes for Oil Drilling Rigs",
pages = "+-65",
volume = "601",
doi = "10.4028/www.scientific.net/KEM.601.65"
}

Rakin, M., Međo, B., Arsić, M., Šarkočević, Ž.,& Sedmak, A.. (2014). Effect of Exploitation Conditions and Flaw Geometry on the Load Carrying Capacity of Casing Pipes for Oil Drilling Rigs. in Proceedings of the 14th Symposium on Experimental Stress Analysis and Materials Testing
Trans Tech Publications Ltd, Durnten-Zurich., 601, 65-+.
https://doi.org/10.4028/www.scientific.net/KEM.601.65

Rakin M, Međo B, Arsić M, Šarkočević Ž, Sedmak A. Effect of Exploitation Conditions and Flaw Geometry on the Load Carrying Capacity of Casing Pipes for Oil Drilling Rigs. in Proceedings of the 14th Symposium on Experimental Stress Analysis and Materials Testing. 2014;601:65-+.
doi:10.4028/www.scientific.net/KEM.601.65 .

Rakin, Marko, Međo, Bojan, Arsić, Miodrag, Šarkočević, Živče, Sedmak, Aleksandar, "Effect of Exploitation Conditions and Flaw Geometry on the Load Carrying Capacity of Casing Pipes for Oil Drilling Rigs" in Proceedings of the 14th Symposium on Experimental Stress Analysis and Materials Testing, 601 (2014):65-+,
https://doi.org/10.4028/www.scientific.net/KEM.601.65 . .

TY  - JOUR
AU  - Šarkočević, Živče
AU  - Arsić, Miodrag
AU  - Sedmak, Aleksandar
AU  - Međo, Bojan
AU  - Mišić, Milan
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2599
AB  - The subject of the paper is analysis of the integrity of welded pipes made of API J55 steel by high frequency contact welding (HF). Experimental research on the mechanical properties of the base material was conducted on pipes withdrawn from exploatation after 70 000 hours at service. Defect influence of the surface crack on the integrity of pipes was tested using hydrostatic pressure of pipes with axial surface crack in the base material. Fracture behaviour was tested using modified compact specimen (CT), with the initial crack in the base material, welded joint and heat affected zone (HAZ). Critical value of the tensile strength factors KIc was determined based on the critical value J of the integral JIc. Apart from the experimental research, based on the derived values of Kr and Sr and by applying fracture analysis diagram (FAD) an assessment of the integrity of welded pipes with axial surface crack on the outer surface area was conducted.
AB  - Predmet rada je analiza integriteta zavarenih cevi izrađenih od čelika API J55 visokofrekventnim kontaktnim zavarivanjem (VF). Eksperimentalna ispitivanja mehaničkih osobina osnovnog materijala su izvršena na cevima povučenim iz ekspolatacije posle 70 000 sati rada. Uticaj oštećenja tipa površinske prsline na integritet cevi ispitan je hidrostatičkim pritiskom cevi sa aksijalnom površinskom prslinom u osnovnom materijalu. Ponašanje pri lomu je ispitivano korištenjem modifikovanih kompaktnih epruveta za zatezanje (CT), s početnom prslinom u osnovnom materijalu, zavarenom spoju i zoni uticaja toplote (ZUT). Kritična vrednost faktora intenziteta napona KIc određena je na osnovu kritične vrednosti J integrala JIc. Osim eksperimentalnog istraživanja, na osnovu dobijenih vrednosti za Kr i Sr primenom dijagrama analize loma (FAD) izvršena je procena integriteta zavarenih cevi sa aksijalnom površinskom prslinom na spoljašnjoj površini.
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - Assessment of the integrity of welded pipes
T1  - Procena integriteta zavarenih cevi
EP  - 292
IS  - 3
SP  - 287
VL  - 55
DO  - 10.5937/ZasMat1403287S
ER  - 

@article{
author = "Šarkočević, Živče and Arsić, Miodrag and Sedmak, Aleksandar and Međo, Bojan and Mišić, Milan",
year = "2014",
abstract = "The subject of the paper is analysis of the integrity of welded pipes made of API J55 steel by high frequency contact welding (HF). Experimental research on the mechanical properties of the base material was conducted on pipes withdrawn from exploatation after 70 000 hours at service. Defect influence of the surface crack on the integrity of pipes was tested using hydrostatic pressure of pipes with axial surface crack in the base material. Fracture behaviour was tested using modified compact specimen (CT), with the initial crack in the base material, welded joint and heat affected zone (HAZ). Critical value of the tensile strength factors KIc was determined based on the critical value J of the integral JIc. Apart from the experimental research, based on the derived values of Kr and Sr and by applying fracture analysis diagram (FAD) an assessment of the integrity of welded pipes with axial surface crack on the outer surface area was conducted., Predmet rada je analiza integriteta zavarenih cevi izrađenih od čelika API J55 visokofrekventnim kontaktnim zavarivanjem (VF). Eksperimentalna ispitivanja mehaničkih osobina osnovnog materijala su izvršena na cevima povučenim iz ekspolatacije posle 70 000 sati rada. Uticaj oštećenja tipa površinske prsline na integritet cevi ispitan je hidrostatičkim pritiskom cevi sa aksijalnom površinskom prslinom u osnovnom materijalu. Ponašanje pri lomu je ispitivano korištenjem modifikovanih kompaktnih epruveta za zatezanje (CT), s početnom prslinom u osnovnom materijalu, zavarenom spoju i zoni uticaja toplote (ZUT). Kritična vrednost faktora intenziteta napona KIc određena je na osnovu kritične vrednosti J integrala JIc. Osim eksperimentalnog istraživanja, na osnovu dobijenih vrednosti za Kr i Sr primenom dijagrama analize loma (FAD) izvršena je procena integriteta zavarenih cevi sa aksijalnom površinskom prslinom na spoljašnjoj površini.",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "Assessment of the integrity of welded pipes, Procena integriteta zavarenih cevi",
pages = "292-287",
number = "3",
volume = "55",
doi = "10.5937/ZasMat1403287S"
}

Šarkočević, Ž., Arsić, M., Sedmak, A., Međo, B.,& Mišić, M.. (2014). Assessment of the integrity of welded pipes. in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 55(3), 287-292.
https://doi.org/10.5937/ZasMat1403287S

Šarkočević Ž, Arsić M, Sedmak A, Međo B, Mišić M. Assessment of the integrity of welded pipes. in Zaštita materijala. 2014;55(3):287-292.
doi:10.5937/ZasMat1403287S .

Šarkočević, Živče, Arsić, Miodrag, Sedmak, Aleksandar, Međo, Bojan, Mišić, Milan, "Assessment of the integrity of welded pipes" in Zaštita materijala, 55, no. 3 (2014):287-292,
https://doi.org/10.5937/ZasMat1403287S . .

TY  - JOUR
AU  - Rakin, Marko
AU  - Bajić, Nikola
AU  - Mrdak, Mihailo
AU  - Veljić, Darko
AU  - Arsić, Miodrag
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2385
AB  - The aim of this study was to master new quality cored wires made of steel strips and the cores filled with metal powders and low molecular hydrophobic compounds. For experimental research, the specimens were made of micro alloyed steel type NIOMOL 490K intended for making welded structures subjected to dynamic loads and effects of low temperature. Welding of test specimens was done using the MAG method in CO2 shielding with two new quality cored wires. The testing included the determination of mechanical properties of the base metal (BM) and the weld metal (WM), which apart from having sufficient strength must also have good toughness. The microstructures of BM, WM and heat affected zone (HAZ) were analysed, due to possible formation of a heterogeneous microstructure, which can reduce toughness. Results of testing of welded joints should define a new quality of cored wires in view of welding-technological characteristics. The results indicate that the new quality cored wires can produce good mechanical-structural properties of welded joints.
PB  - University of Osijek, Tech Fac, Slavonski Brod
T2  - Tehnicki vjesnik-Technical Gazette
T1  - Analysis of mechanical and structural properties of micro alloyed steel welded joints depending on quality of cored wire
EP  - 640
IS  - 4
SP  - 635
VL  - 20
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2385
ER  - 

@article{
author = "Rakin, Marko and Bajić, Nikola and Mrdak, Mihailo and Veljić, Darko and Arsić, Miodrag",
year = "2013",
abstract = "The aim of this study was to master new quality cored wires made of steel strips and the cores filled with metal powders and low molecular hydrophobic compounds. For experimental research, the specimens were made of micro alloyed steel type NIOMOL 490K intended for making welded structures subjected to dynamic loads and effects of low temperature. Welding of test specimens was done using the MAG method in CO2 shielding with two new quality cored wires. The testing included the determination of mechanical properties of the base metal (BM) and the weld metal (WM), which apart from having sufficient strength must also have good toughness. The microstructures of BM, WM and heat affected zone (HAZ) were analysed, due to possible formation of a heterogeneous microstructure, which can reduce toughness. Results of testing of welded joints should define a new quality of cored wires in view of welding-technological characteristics. The results indicate that the new quality cored wires can produce good mechanical-structural properties of welded joints.",
publisher = "University of Osijek, Tech Fac, Slavonski Brod",
journal = "Tehnicki vjesnik-Technical Gazette",
title = "Analysis of mechanical and structural properties of micro alloyed steel welded joints depending on quality of cored wire",
pages = "640-635",
number = "4",
volume = "20",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2385"
}

Rakin, M., Bajić, N., Mrdak, M., Veljić, D.,& Arsić, M.. (2013). Analysis of mechanical and structural properties of micro alloyed steel welded joints depending on quality of cored wire. in Tehnicki vjesnik-Technical Gazette
University of Osijek, Tech Fac, Slavonski Brod., 20(4), 635-640.
https://hdl.handle.net/21.15107/rcub_technorep_2385

Rakin M, Bajić N, Mrdak M, Veljić D, Arsić M. Analysis of mechanical and structural properties of micro alloyed steel welded joints depending on quality of cored wire. in Tehnicki vjesnik-Technical Gazette. 2013;20(4):635-640.
https://hdl.handle.net/21.15107/rcub_technorep_2385 .

Rakin, Marko, Bajić, Nikola, Mrdak, Mihailo, Veljić, Darko, Arsić, Miodrag, "Analysis of mechanical and structural properties of micro alloyed steel welded joints depending on quality of cored wire" in Tehnicki vjesnik-Technical Gazette, 20, no. 4 (2013):635-640,
https://hdl.handle.net/21.15107/rcub_technorep_2385 .

TY  - JOUR
AU  - Šarkočević, Živče
AU  - Arsić, Miodrag
AU  - Rakin, Marko
AU  - Međo, Bojan
AU  - Mišić, Milan
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2302
AB  - Steel pipes in oil and gas wells are continuously exposed to the process of corrosion-assisted elevated temperatures and pressures prevailing in the interior of the tube. Corrosion can lead to significant reduction of mechanical properties of steels and welded joints which may under unfavorable conditions, lead to breaking of pipes even faster if the stresses are higher. Failures of welded pipes in oil and gas wells, caused by errors in the preparation of tubes and / or their damage in service, in addition to the impact on the reliability and safety in the work and have environmental impacts on the environment and the quality of land, water and air. Protection of welded pipes in oil wells belong to the highly responsible structures that are susceptible to corrosion. It is therefore important to know the remaining strength of pipe in the event of corrosion damage. This paper presents the results of testing of damage API J55 steel, used for the production of protective high-frequency pipe welding contact (VF). Investigated tube was withdrawn from service after about 70 000 operating hours (8 years) in the oil rig. Experiments were performed on the protective welded pipes from service by the closed tori spherical head, the mechanical treatment simulated by the corrosive damage to the outer surface of the tube. For determining the resistance of welded pipes to damage were measured and calculated deformations are the main normal stresses. The application of the ASME B31G, modified ASME B31G, calculate the maximum pressures of damaged pipes.
AB  - Čelične cevi u naftnim i gasnim bušotinama su kontinuirano izložene procesu korozije potpomognutom povišenim temperaturama i pritiscima, koji vladaju u unutrašnjosti cevi. Korozija može da dovede do značajnog smanjenja mehaničkih osobina čelika i zavarenog spoja što može pod nepovoljnim uslovima predstavljati uvod u lom cevi i to brže ukoliko su naprezanja veća. Otkazi zavarenih cevi u naftnim i gasnim bušotinama, nastali usled grešaka u izradi cevi i/ili njihovog oštećenja u eksploataciji, pored uticaja na pouzdanost i bezbednost u radu imaju i ekološki uticaj na okolinu, odnosno na kvalitet zemlje, vode i vazduha. Zaštitne zavarene cevi u naftnim bušotinama spadaju u visoko odgovorne konstrukcije koje su osetljive na koroziju. Zato je bitno poznavati preostalu čvrstoću cevi u slučaju pojave korozionog oštećenja. U radu su prikazani rezultati ispitivanja nivoa oštećenja čelika APIJ55, korišćenog za izradu zaštitnih cevi visokofrekventnim kontaktnim postupkom zavarivanja (VF). Ispitivana cev je povučena iz eksploatacije nakon približno 70 000 radnih sati (8 godina) u naftnoj bušotini. Eksperimentalna ispitivanja su izvršena na zaštitnim zavarenim cevima iz eksploatacije koje su zatvorene torisferičnim dancima, sa mehaničkom obradom simuluranim korozionim oštećenjima na spoljašnjoj površini cevi. Za određivanja otpornosti zaštitnih zavarenih cevi prema oštećenju izvršeno je merenje deformacija i izračunati su glavni normalni naponi. Primenom postupka ASME B31G, modifikovanog ASME B31G, izračunati su maksimalni pritisci oštećenih cevi.
PB  - Engineering Society for Corrosion, Belgrade, Serbia
T2  - Zaštita materijala
T1  - Corrosion resistance of welded pipe in oil wells
T1  - Otpornost na koroziju zavarenih cevi u naftnim bušotinama
EP  - 63
IS  - 1
SP  - 57
VL  - 54
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2302
ER  - 

@article{
author = "Šarkočević, Živče and Arsić, Miodrag and Rakin, Marko and Međo, Bojan and Mišić, Milan",
year = "2013",
abstract = "Steel pipes in oil and gas wells are continuously exposed to the process of corrosion-assisted elevated temperatures and pressures prevailing in the interior of the tube. Corrosion can lead to significant reduction of mechanical properties of steels and welded joints which may under unfavorable conditions, lead to breaking of pipes even faster if the stresses are higher. Failures of welded pipes in oil and gas wells, caused by errors in the preparation of tubes and / or their damage in service, in addition to the impact on the reliability and safety in the work and have environmental impacts on the environment and the quality of land, water and air. Protection of welded pipes in oil wells belong to the highly responsible structures that are susceptible to corrosion. It is therefore important to know the remaining strength of pipe in the event of corrosion damage. This paper presents the results of testing of damage API J55 steel, used for the production of protective high-frequency pipe welding contact (VF). Investigated tube was withdrawn from service after about 70 000 operating hours (8 years) in the oil rig. Experiments were performed on the protective welded pipes from service by the closed tori spherical head, the mechanical treatment simulated by the corrosive damage to the outer surface of the tube. For determining the resistance of welded pipes to damage were measured and calculated deformations are the main normal stresses. The application of the ASME B31G, modified ASME B31G, calculate the maximum pressures of damaged pipes., Čelične cevi u naftnim i gasnim bušotinama su kontinuirano izložene procesu korozije potpomognutom povišenim temperaturama i pritiscima, koji vladaju u unutrašnjosti cevi. Korozija može da dovede do značajnog smanjenja mehaničkih osobina čelika i zavarenog spoja što može pod nepovoljnim uslovima predstavljati uvod u lom cevi i to brže ukoliko su naprezanja veća. Otkazi zavarenih cevi u naftnim i gasnim bušotinama, nastali usled grešaka u izradi cevi i/ili njihovog oštećenja u eksploataciji, pored uticaja na pouzdanost i bezbednost u radu imaju i ekološki uticaj na okolinu, odnosno na kvalitet zemlje, vode i vazduha. Zaštitne zavarene cevi u naftnim bušotinama spadaju u visoko odgovorne konstrukcije koje su osetljive na koroziju. Zato je bitno poznavati preostalu čvrstoću cevi u slučaju pojave korozionog oštećenja. U radu su prikazani rezultati ispitivanja nivoa oštećenja čelika APIJ55, korišćenog za izradu zaštitnih cevi visokofrekventnim kontaktnim postupkom zavarivanja (VF). Ispitivana cev je povučena iz eksploatacije nakon približno 70 000 radnih sati (8 godina) u naftnoj bušotini. Eksperimentalna ispitivanja su izvršena na zaštitnim zavarenim cevima iz eksploatacije koje su zatvorene torisferičnim dancima, sa mehaničkom obradom simuluranim korozionim oštećenjima na spoljašnjoj površini cevi. Za određivanja otpornosti zaštitnih zavarenih cevi prema oštećenju izvršeno je merenje deformacija i izračunati su glavni normalni naponi. Primenom postupka ASME B31G, modifikovanog ASME B31G, izračunati su maksimalni pritisci oštećenih cevi.",
publisher = "Engineering Society for Corrosion, Belgrade, Serbia",
journal = "Zaštita materijala",
title = "Corrosion resistance of welded pipe in oil wells, Otpornost na koroziju zavarenih cevi u naftnim bušotinama",
pages = "63-57",
number = "1",
volume = "54",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2302"
}

Šarkočević, Ž., Arsić, M., Rakin, M., Međo, B.,& Mišić, M.. (2013). Corrosion resistance of welded pipe in oil wells. in Zaštita materijala
Engineering Society for Corrosion, Belgrade, Serbia., 54(1), 57-63.
https://hdl.handle.net/21.15107/rcub_technorep_2302

Šarkočević Ž, Arsić M, Rakin M, Međo B, Mišić M. Corrosion resistance of welded pipe in oil wells. in Zaštita materijala. 2013;54(1):57-63.
https://hdl.handle.net/21.15107/rcub_technorep_2302 .

Šarkočević, Živče, Arsić, Miodrag, Rakin, Marko, Međo, Bojan, Mišić, Milan, "Corrosion resistance of welded pipe in oil wells" in Zaštita materijala, 54, no. 1 (2013):57-63,
https://hdl.handle.net/21.15107/rcub_technorep_2302 .

TY  - JOUR
AU  - Rakin, Marko
AU  - Arsić, Miodrag
AU  - Bošnjak, Srđan
AU  - Gnjatović, Nebojša
AU  - Međo, Bojan
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2449
AB  - In order to reduce the testing costs for structural welded joints and production losses due to excavator standstill, a new method for integrity and reliability assessment of welded joints during exploitation of bucket wheel excavators has been developed. In this paper, a part of non-destructive testing results for the butt welded joints on bucket wheel boom, counterweight boom and discharging boom is presented, prior to the repair of the collapsed bucket wheel excavator SchRs 1760x32/5. It has been in operational mode for 17 years prior to the collapse, in other words it has been subjected to aproximatelly 2 125.000 cycles of variable loading. Hypergeometric distribution has been used for calculation of probability that x welded joints, which comprise n welded joints with defects, would be selected for testing out of overall number of joints Q. The integrity assessment for welded structures of bucket wheel excavators has been performed on the basis of defect analysis and probabilistic assessment of the fatigue crack growth in welded joints. By using this method, the testing costs have been reduced by 70 % through optimized scope of the inspections and time periods between them.
PB  - University of Osijek, Tech Fac, Slavonski Brod
T2  - Tehnicki vjesnik-Technical Gazette
T1  - Integrity assessment of bucket wheel excavator welded structures by using the single selection method
EP  - 816
IS  - 5
SP  - 811
VL  - 20
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2449
ER  - 

@article{
author = "Rakin, Marko and Arsić, Miodrag and Bošnjak, Srđan and Gnjatović, Nebojša and Međo, Bojan",
year = "2013",
abstract = "In order to reduce the testing costs for structural welded joints and production losses due to excavator standstill, a new method for integrity and reliability assessment of welded joints during exploitation of bucket wheel excavators has been developed. In this paper, a part of non-destructive testing results for the butt welded joints on bucket wheel boom, counterweight boom and discharging boom is presented, prior to the repair of the collapsed bucket wheel excavator SchRs 1760x32/5. It has been in operational mode for 17 years prior to the collapse, in other words it has been subjected to aproximatelly 2 125.000 cycles of variable loading. Hypergeometric distribution has been used for calculation of probability that x welded joints, which comprise n welded joints with defects, would be selected for testing out of overall number of joints Q. The integrity assessment for welded structures of bucket wheel excavators has been performed on the basis of defect analysis and probabilistic assessment of the fatigue crack growth in welded joints. By using this method, the testing costs have been reduced by 70 % through optimized scope of the inspections and time periods between them.",
publisher = "University of Osijek, Tech Fac, Slavonski Brod",
journal = "Tehnicki vjesnik-Technical Gazette",
title = "Integrity assessment of bucket wheel excavator welded structures by using the single selection method",
pages = "816-811",
number = "5",
volume = "20",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2449"
}

Rakin, M., Arsić, M., Bošnjak, S., Gnjatović, N.,& Međo, B.. (2013). Integrity assessment of bucket wheel excavator welded structures by using the single selection method. in Tehnicki vjesnik-Technical Gazette
University of Osijek, Tech Fac, Slavonski Brod., 20(5), 811-816.
https://hdl.handle.net/21.15107/rcub_technorep_2449

Rakin M, Arsić M, Bošnjak S, Gnjatović N, Međo B. Integrity assessment of bucket wheel excavator welded structures by using the single selection method. in Tehnicki vjesnik-Technical Gazette. 2013;20(5):811-816.
https://hdl.handle.net/21.15107/rcub_technorep_2449 .

Rakin, Marko, Arsić, Miodrag, Bošnjak, Srđan, Gnjatović, Nebojša, Međo, Bojan, "Integrity assessment of bucket wheel excavator welded structures by using the single selection method" in Tehnicki vjesnik-Technical Gazette, 20, no. 5 (2013):811-816,
https://hdl.handle.net/21.15107/rcub_technorep_2449 .

TY  - JOUR
AU  - Lazić-Vulicević, Ljubica
AU  - Arsić, Miodrag
AU  - Šarkočević, Živče
AU  - Sedmak, Aleksandar
AU  - Rakin, Marko
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2465
AB  - Structural life of welded pipes made of API J55 steel by high-frequency (HF) welding has been evaluated. Experimental tests of base metal mechanical properties, including fatigue properties, were conducted on pipes after 70.000 hours of service in an oil drilling rig. The fatigue crack growth rate and fatigue threshold is obtained using the pre-cracked Charpy specimens. The number of cycles to the final fracture is then calculated using initial and critical crack depths. Based on the number of cycles to the final fracture and the remaining fatigue lifetime of pipes with axial outer surface crack are determined. It was shown that the remaining fatigue lifetime is more sensitive to the changes in the stress range than to the initial crack depth.
PB  - University of Osijek, Tech Fac, Slavonski Brod
T2  - Tehnicki vjesnik-Technical Gazette
T1  - Structural life assessment of oil rig pipes made of api j55 steel by high frequency welding
EP  - 1094
IS  - 6
SP  - 1091
VL  - 20
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2465
ER  - 

@article{
author = "Lazić-Vulicević, Ljubica and Arsić, Miodrag and Šarkočević, Živče and Sedmak, Aleksandar and Rakin, Marko",
year = "2013",
abstract = "Structural life of welded pipes made of API J55 steel by high-frequency (HF) welding has been evaluated. Experimental tests of base metal mechanical properties, including fatigue properties, were conducted on pipes after 70.000 hours of service in an oil drilling rig. The fatigue crack growth rate and fatigue threshold is obtained using the pre-cracked Charpy specimens. The number of cycles to the final fracture is then calculated using initial and critical crack depths. Based on the number of cycles to the final fracture and the remaining fatigue lifetime of pipes with axial outer surface crack are determined. It was shown that the remaining fatigue lifetime is more sensitive to the changes in the stress range than to the initial crack depth.",
publisher = "University of Osijek, Tech Fac, Slavonski Brod",
journal = "Tehnicki vjesnik-Technical Gazette",
title = "Structural life assessment of oil rig pipes made of api j55 steel by high frequency welding",
pages = "1094-1091",
number = "6",
volume = "20",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2465"
}

Lazić-Vulicević, L., Arsić, M., Šarkočević, Ž., Sedmak, A.,& Rakin, M.. (2013). Structural life assessment of oil rig pipes made of api j55 steel by high frequency welding. in Tehnicki vjesnik-Technical Gazette
University of Osijek, Tech Fac, Slavonski Brod., 20(6), 1091-1094.
https://hdl.handle.net/21.15107/rcub_technorep_2465

Lazić-Vulicević L, Arsić M, Šarkočević Ž, Sedmak A, Rakin M. Structural life assessment of oil rig pipes made of api j55 steel by high frequency welding. in Tehnicki vjesnik-Technical Gazette. 2013;20(6):1091-1094.
https://hdl.handle.net/21.15107/rcub_technorep_2465 .

Lazić-Vulicević, Ljubica, Arsić, Miodrag, Šarkočević, Živče, Sedmak, Aleksandar, Rakin, Marko, "Structural life assessment of oil rig pipes made of api j55 steel by high frequency welding" in Tehnicki vjesnik-Technical Gazette, 20, no. 6 (2013):1091-1094,
https://hdl.handle.net/21.15107/rcub_technorep_2465 .

TY  - JOUR
AU  - Dimić, Ivana
AU  - Arsić, Miodrag
AU  - Međo, Bojan
AU  - Stefanović, Ana
AU  - Grabulov, Vencislav
AU  - Rakin, Marko
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2515
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  - University of Osijek, Tech Fac, Slavonski Brod
T2  - Tehnicki vjesnik-Technical Gazette
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 = "University of Osijek, Tech Fac, Slavonski Brod",
journal = "Tehnicki vjesnik-Technical Gazette",
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 Tehnicki vjesnik-Technical Gazette
University of Osijek, Tech Fac, Slavonski Brod., 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 Tehnicki vjesnik-Technical Gazette. 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 Tehnicki vjesnik-Technical Gazette, 20, no. 2 (2013):285-290,
https://hdl.handle.net/21.15107/rcub_technorep_2515 .

TY  - JOUR
AU  - Međo, Bojan
AU  - Rakin, Marko
AU  - Arsić, Miodrag
AU  - Šarkočević, Živče
AU  - Zrilić, Milorad
AU  - Putić, Slaviša
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2191
AB  - The subject of this study was the application of local approach to ductile fracture in order to estimate the integrity of damaged seam casing pipes for oil and gas drilling rigs. The experimental testing included tensile testing of specimens and a pressure test of a pipe with different levels of damage simulated by machined notches. In exploitation, such structures (i.e., pipes with local thin areas) can fail by the ductile fracture mechanism or by plastic collapse in the ligament. However, the majority of the procedures for determining their integrity are based on limit loads, i.e., plastic collapse criteria. In this work, a pipe subjected to internal pressure was modelled using the finite element method and local approach to fracture (the Complete Gurson Model - CGM), with the aim of determining damage development in the material (i.e., at the bottom of a machined defect) and of establishing the criteria for the maximum pressure that a damaged pipe can withstand. The results obtained using the micromechanical model are discussed and compared with several often used limit load expressions from the literature and a stress-based finite element criterion. It is shown that local approach can give appropriate results and represent failure criterion for pipes with local thin areas. [doi:10.2320/matertrans.M2011210]
PB  - Japan Inst Metals, Sendai
T2  - Materials Transactions
T1  - Determination of the Load Carrying Capacity of Damaged Pipes Using Local Approach to Fracture
EP  - 190
IS  - 1
SP  - 185
VL  - 53
DO  - 10.2320/matertrans.M2011210
ER  - 

@article{
author = "Međo, Bojan and Rakin, Marko and Arsić, Miodrag and Šarkočević, Živče and Zrilić, Milorad and Putić, Slaviša",
year = "2012",
abstract = "The subject of this study was the application of local approach to ductile fracture in order to estimate the integrity of damaged seam casing pipes for oil and gas drilling rigs. The experimental testing included tensile testing of specimens and a pressure test of a pipe with different levels of damage simulated by machined notches. In exploitation, such structures (i.e., pipes with local thin areas) can fail by the ductile fracture mechanism or by plastic collapse in the ligament. However, the majority of the procedures for determining their integrity are based on limit loads, i.e., plastic collapse criteria. In this work, a pipe subjected to internal pressure was modelled using the finite element method and local approach to fracture (the Complete Gurson Model - CGM), with the aim of determining damage development in the material (i.e., at the bottom of a machined defect) and of establishing the criteria for the maximum pressure that a damaged pipe can withstand. The results obtained using the micromechanical model are discussed and compared with several often used limit load expressions from the literature and a stress-based finite element criterion. It is shown that local approach can give appropriate results and represent failure criterion for pipes with local thin areas. [doi:10.2320/matertrans.M2011210]",
publisher = "Japan Inst Metals, Sendai",
journal = "Materials Transactions",
title = "Determination of the Load Carrying Capacity of Damaged Pipes Using Local Approach to Fracture",
pages = "190-185",
number = "1",
volume = "53",
doi = "10.2320/matertrans.M2011210"
}

Međo, B., Rakin, M., Arsić, M., Šarkočević, Ž., Zrilić, M.,& Putić, S.. (2012). Determination of the Load Carrying Capacity of Damaged Pipes Using Local Approach to Fracture. in Materials Transactions
Japan Inst Metals, Sendai., 53(1), 185-190.
https://doi.org/10.2320/matertrans.M2011210

Međo B, Rakin M, Arsić M, Šarkočević Ž, Zrilić M, Putić S. Determination of the Load Carrying Capacity of Damaged Pipes Using Local Approach to Fracture. in Materials Transactions. 2012;53(1):185-190.
doi:10.2320/matertrans.M2011210 .

Međo, Bojan, Rakin, Marko, Arsić, Miodrag, Šarkočević, Živče, Zrilić, Milorad, Putić, Slaviša, "Determination of the Load Carrying Capacity of Damaged Pipes Using Local Approach to Fracture" in Materials Transactions, 53, no. 1 (2012):185-190,
https://doi.org/10.2320/matertrans.M2011210 . .

TY  - CONF
AU  - Rakin, Marko
AU  - Međo, Bojan
AU  - Arsić, Miodrag
AU  - Šarkočević, Živče
AU  - Ivanović, I.
AU  - Sedmak, Aleksandar
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2216
AB  - Seam casing pipe used in an oil drilling rig, manufactured by high frequency (HF) contact welding of API J55 steel, is tested. The influence of an initial defect (machined surface crack) is analysed, by performing pressure test of a pipe segment closed at both ends. Besides the damages at the internal surface, casing pipes are exposed to damage at the external surface, which is why such configuration is analysed here. Measurement of strains and crack mouth opening displacement (CMOD) enabled the application of direct method for J integral evaluation. This procedure is based on the path independence of the J integral and can be applied both in laboratory conditions (on specimens) and on structures. However, it requires a demanding experimental - computational procedure, which is accomplished here using the developed routine. Additionally, the behaviour of the pipe under internal pressure, including fracture mechanics parameters determination, is modelled numerically (by finite element method) in software package Abaqus. The pressure is applied as distributed load acting on the inner surface of the three-dimensional model, and axial tension is applied at the end of the pipe to simulate the closed end. J integral values determined numerically and using direct method are used for estimation of the critical pressure corresponding to the crack growth initiation. Additionally, plastic limit load, i.e. pressure which causes yielding of the ligament, is determined. Based on the results, criteria for pipe integrity assessment are discussed.
PB  - Trans Tech Publications Ltd, Durnten-Zurich
C3  - Advances in Fracture and Damage Mechanics X
T1  - API J55 Steel Casing Pipe with an Initial Surface Crack under Internal Pressure - Determination of Fracture Parameters
EP  - +
SP  - 577
VL  - 488-489
DO  - 10.4028/www.scientific.net/KEM.488-489.577
ER  - 

@conference{
author = "Rakin, Marko and Međo, Bojan and Arsić, Miodrag and Šarkočević, Živče and Ivanović, I. and Sedmak, Aleksandar",
year = "2012",
abstract = "Seam casing pipe used in an oil drilling rig, manufactured by high frequency (HF) contact welding of API J55 steel, is tested. The influence of an initial defect (machined surface crack) is analysed, by performing pressure test of a pipe segment closed at both ends. Besides the damages at the internal surface, casing pipes are exposed to damage at the external surface, which is why such configuration is analysed here. Measurement of strains and crack mouth opening displacement (CMOD) enabled the application of direct method for J integral evaluation. This procedure is based on the path independence of the J integral and can be applied both in laboratory conditions (on specimens) and on structures. However, it requires a demanding experimental - computational procedure, which is accomplished here using the developed routine. Additionally, the behaviour of the pipe under internal pressure, including fracture mechanics parameters determination, is modelled numerically (by finite element method) in software package Abaqus. The pressure is applied as distributed load acting on the inner surface of the three-dimensional model, and axial tension is applied at the end of the pipe to simulate the closed end. J integral values determined numerically and using direct method are used for estimation of the critical pressure corresponding to the crack growth initiation. Additionally, plastic limit load, i.e. pressure which causes yielding of the ligament, is determined. Based on the results, criteria for pipe integrity assessment are discussed.",
publisher = "Trans Tech Publications Ltd, Durnten-Zurich",
journal = "Advances in Fracture and Damage Mechanics X",
title = "API J55 Steel Casing Pipe with an Initial Surface Crack under Internal Pressure - Determination of Fracture Parameters",
pages = "+-577",
volume = "488-489",
doi = "10.4028/www.scientific.net/KEM.488-489.577"
}

Rakin, M., Međo, B., Arsić, M., Šarkočević, Ž., Ivanović, I.,& Sedmak, A.. (2012). API J55 Steel Casing Pipe with an Initial Surface Crack under Internal Pressure - Determination of Fracture Parameters. in Advances in Fracture and Damage Mechanics X
Trans Tech Publications Ltd, Durnten-Zurich., 488-489, 577-+.
https://doi.org/10.4028/www.scientific.net/KEM.488-489.577

Rakin M, Međo B, Arsić M, Šarkočević Ž, Ivanović I, Sedmak A. API J55 Steel Casing Pipe with an Initial Surface Crack under Internal Pressure - Determination of Fracture Parameters. in Advances in Fracture and Damage Mechanics X. 2012;488-489:577-+.
doi:10.4028/www.scientific.net/KEM.488-489.577 .

Rakin, Marko, Međo, Bojan, Arsić, Miodrag, Šarkočević, Živče, Ivanović, I., Sedmak, Aleksandar, "API J55 Steel Casing Pipe with an Initial Surface Crack under Internal Pressure - Determination of Fracture Parameters" in Advances in Fracture and Damage Mechanics X, 488-489 (2012):577-+,
https://doi.org/10.4028/www.scientific.net/KEM.488-489.577 . .

TY  - CONF
AU  - Rakin, Marko
AU  - Arsić, Miodrag
AU  - Šarkočević, Živče
AU  - Međo, Bojan
AU  - Tomović, N.
AU  - Sedmak, Aleksandar
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1975
AB  - The paper deals with the integrity assessment of API J55 steel casing pipes for drilling rigs, manufactured by high frequency contact welding procedure. The influence of corrosion defects on the pipeline load carrying capacity is determined through pressure test of a pipe with corrosion damages simulated by machining the circular holes. Finite element analysis of the damaged pipe subjected to internal pressure is used for determining the stress/strain conditions in the damaged area of the pipe. Also, numerical model was used for establishing the load carrying capacity of the pipe with different damage levels (i.e. defect depth and length). Several expressions from the literature are used for estimation of the maximum pressure in the damaged section of the pipe, and the solutions are compared with the predictions of finite element models and experimental results.
PB  - 19th European Conference on Fracture: Fracture Mechanics for Durability, Reliability and Safety, ECF 2012
C3  - 19th European Conference on Fracture: Fracture Mechanics for Durability, Reliability and Safety, ECF
T1  - Damaged welded pipes for oil and gas rigs exposed to internal pressure - Failure estimation
UR  - https://hdl.handle.net/21.15107/rcub_technorep_1975
ER  - 

@conference{
author = "Rakin, Marko and Arsić, Miodrag and Šarkočević, Živče and Međo, Bojan and Tomović, N. and Sedmak, Aleksandar",
year = "2012",
abstract = "The paper deals with the integrity assessment of API J55 steel casing pipes for drilling rigs, manufactured by high frequency contact welding procedure. The influence of corrosion defects on the pipeline load carrying capacity is determined through pressure test of a pipe with corrosion damages simulated by machining the circular holes. Finite element analysis of the damaged pipe subjected to internal pressure is used for determining the stress/strain conditions in the damaged area of the pipe. Also, numerical model was used for establishing the load carrying capacity of the pipe with different damage levels (i.e. defect depth and length). Several expressions from the literature are used for estimation of the maximum pressure in the damaged section of the pipe, and the solutions are compared with the predictions of finite element models and experimental results.",
publisher = "19th European Conference on Fracture: Fracture Mechanics for Durability, Reliability and Safety, ECF 2012",
journal = "19th European Conference on Fracture: Fracture Mechanics for Durability, Reliability and Safety, ECF",
title = "Damaged welded pipes for oil and gas rigs exposed to internal pressure - Failure estimation",
url = "https://hdl.handle.net/21.15107/rcub_technorep_1975"
}

Rakin, M., Arsić, M., Šarkočević, Ž., Međo, B., Tomović, N.,& Sedmak, A.. (2012). Damaged welded pipes for oil and gas rigs exposed to internal pressure - Failure estimation. in 19th European Conference on Fracture: Fracture Mechanics for Durability, Reliability and Safety, ECF
19th European Conference on Fracture: Fracture Mechanics for Durability, Reliability and Safety, ECF 2012..
https://hdl.handle.net/21.15107/rcub_technorep_1975

Rakin M, Arsić M, Šarkočević Ž, Međo B, Tomović N, Sedmak A. Damaged welded pipes for oil and gas rigs exposed to internal pressure - Failure estimation. in 19th European Conference on Fracture: Fracture Mechanics for Durability, Reliability and Safety, ECF. 2012;.
https://hdl.handle.net/21.15107/rcub_technorep_1975 .

Rakin, Marko, Arsić, Miodrag, Šarkočević, Živče, Međo, Bojan, Tomović, N., Sedmak, Aleksandar, "Damaged welded pipes for oil and gas rigs exposed to internal pressure - Failure estimation" in 19th European Conference on Fracture: Fracture Mechanics for Durability, Reliability and Safety, ECF (2012),
https://hdl.handle.net/21.15107/rcub_technorep_1975 .

TY  - JOUR
AU  - Burzić, Meri
AU  - Prokić-Cvetković, Radica
AU  - Manjgo, Mersida
AU  - Milović, Ljubica
AU  - Arsić, Miodrag
AU  - Popović, Olivera
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2052
AB  - The effect of vibration on the variation of residual stresses in butt-welded steel plates and on the impact energy in characteristic zones of a welded joint is analysed in this paper. An important segment occurring as a result of welding is the phenomenon of residual stresses in the welded joint zone. Residual stress measurements are conducted both on butt-welded plates that were not vibrated during welding and on plates simultaneously welded and vibrated. It is concluded that the vibration process noticeably decreases the level of stresses in the zone of the butt weld, i.e. the result is relaxation and plane stress state. Impact energy tests have shown that vibration favourably affects the total impact energy by increasing it both in specimens notched in the weld metal (WM) and in the heat-affected zone (HAZ). It is also concluded that the correlation between the distribution of crack initiation- and crack propagation energy, as vital components in the assessment of welded joint ductility, is improved.
AB  - Istraživanje uticaja vibracija na promenu zaostalih napona kod sučeono zavarenih čeličnih ploča i promena energije udara u karakterističnim zonama zavarenog spoja analizirana je u ovom radu. Bitan segment, koji se javlja kao posledica zavarivanja, je pojava zaostalih napona u zoni zavarenog spoja. Merenje zaostalih napona je rađeno na sučeono zavarenim pločama koje nisu vibrirane u toku zavarivanja i kod ploča koje su istovremeno zavarivane i vibrirane. Uočeno je da proces vibracija znatno smanjuje nivo zaostalih napona u zoni sučeono zavarenog spoja, odnosno, dolazi do relaksacije i uravnoteženja stanja napona. Ispitivanja energije udara su pokazala da vibracije pozitivno utiču na povećanje ukupne energije udara i kod epruveta sa zarezom u metalu šava i u zoni uticaja toplote. Uočen je i bolji odnos raspodele energije stvaranja i energije širenja prsline, kao važnih komponenti u oceni plastičnosti zavarenog spoja.
PB  - Society for Structural Integrity and Life, Institute for Material Testing
T2  - Integritet i vek konstrukcija
T1  - Effect of vibration on the variation of residual stresses and impact energy in butt-welded joints
T1  - Uticaj vibracija na promenu zaostalih napona i energije udara kod sučeono zavarenih spojeva
EP  - 220
IS  - 3
SP  - 215
VL  - 12
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2052
ER  - 

@article{
author = "Burzić, Meri and Prokić-Cvetković, Radica and Manjgo, Mersida and Milović, Ljubica and Arsić, Miodrag and Popović, Olivera",
year = "2012",
abstract = "The effect of vibration on the variation of residual stresses in butt-welded steel plates and on the impact energy in characteristic zones of a welded joint is analysed in this paper. An important segment occurring as a result of welding is the phenomenon of residual stresses in the welded joint zone. Residual stress measurements are conducted both on butt-welded plates that were not vibrated during welding and on plates simultaneously welded and vibrated. It is concluded that the vibration process noticeably decreases the level of stresses in the zone of the butt weld, i.e. the result is relaxation and plane stress state. Impact energy tests have shown that vibration favourably affects the total impact energy by increasing it both in specimens notched in the weld metal (WM) and in the heat-affected zone (HAZ). It is also concluded that the correlation between the distribution of crack initiation- and crack propagation energy, as vital components in the assessment of welded joint ductility, is improved., Istraživanje uticaja vibracija na promenu zaostalih napona kod sučeono zavarenih čeličnih ploča i promena energije udara u karakterističnim zonama zavarenog spoja analizirana je u ovom radu. Bitan segment, koji se javlja kao posledica zavarivanja, je pojava zaostalih napona u zoni zavarenog spoja. Merenje zaostalih napona je rađeno na sučeono zavarenim pločama koje nisu vibrirane u toku zavarivanja i kod ploča koje su istovremeno zavarivane i vibrirane. Uočeno je da proces vibracija znatno smanjuje nivo zaostalih napona u zoni sučeono zavarenog spoja, odnosno, dolazi do relaksacije i uravnoteženja stanja napona. Ispitivanja energije udara su pokazala da vibracije pozitivno utiču na povećanje ukupne energije udara i kod epruveta sa zarezom u metalu šava i u zoni uticaja toplote. Uočen je i bolji odnos raspodele energije stvaranja i energije širenja prsline, kao važnih komponenti u oceni plastičnosti zavarenog spoja.",
publisher = "Society for Structural Integrity and Life, Institute for Material Testing",
journal = "Integritet i vek konstrukcija",
title = "Effect of vibration on the variation of residual stresses and impact energy in butt-welded joints, Uticaj vibracija na promenu zaostalih napona i energije udara kod sučeono zavarenih spojeva",
pages = "220-215",
number = "3",
volume = "12",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2052"
}

Burzić, M., Prokić-Cvetković, R., Manjgo, M., Milović, L., Arsić, M.,& Popović, O.. (2012). Effect of vibration on the variation of residual stresses and impact energy in butt-welded joints. in Integritet i vek konstrukcija
Society for Structural Integrity and Life, Institute for Material Testing., 12(3), 215-220.
https://hdl.handle.net/21.15107/rcub_technorep_2052

Burzić M, Prokić-Cvetković R, Manjgo M, Milović L, Arsić M, Popović O. Effect of vibration on the variation of residual stresses and impact energy in butt-welded joints. in Integritet i vek konstrukcija. 2012;12(3):215-220.
https://hdl.handle.net/21.15107/rcub_technorep_2052 .

Burzić, Meri, Prokić-Cvetković, Radica, Manjgo, Mersida, Milović, Ljubica, Arsić, Miodrag, Popović, Olivera, "Effect of vibration on the variation of residual stresses and impact energy in butt-welded joints" in Integritet i vek konstrukcija, 12, no. 3 (2012):215-220,
https://hdl.handle.net/21.15107/rcub_technorep_2052 .

TY  - CONF
AU  - Međo, Bojan
AU  - Rakin, Marko
AU  - Gubeljak, Nenad
AU  - Predan, J.
AU  - Arsić, Miodrag
AU  - Sedmak, Aleksandar
PY  - 2011
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1949
AB  - Among various micromechanical models for ductile fracture analysis using local approach, those based on the Gurson plastic flow criterion have been intensively developed in the past three decades. However, their application is still subject of many researches, with the aim to improve the assessment of ductile fracture in various, mainly metallic, materials. In this work, Gurson criterion is applied to welded joints produced with one or two different weld metals (one of these is overmatched, while the other is undermatched). Welded single-edge notched bend (SENB) specimens are examined, with an initial pre-crack located in the symmetry plane of each joint. Local approach is chosen for assessment of behaviour of the joints under the external loading, to capture the effect of material inhomogeneity and initial crack length on deformation and ductile fracture initiation in analysed specimens.
PB  - Trans Tech Publications Ltd, Durnten-Zurich
C3  - Materials Structure & Micromechanics of Fracture
T1  - Influence of crack length on ductile fracture initiation in welded joints with one and two weld metals
EP  - +
SP  - 578
VL  - 465
DO  - 10.4028/www.scientific.net/KEM.465.578
ER  - 

@conference{
author = "Međo, Bojan and Rakin, Marko and Gubeljak, Nenad and Predan, J. and Arsić, Miodrag and Sedmak, Aleksandar",
year = "2011",
abstract = "Among various micromechanical models for ductile fracture analysis using local approach, those based on the Gurson plastic flow criterion have been intensively developed in the past three decades. However, their application is still subject of many researches, with the aim to improve the assessment of ductile fracture in various, mainly metallic, materials. In this work, Gurson criterion is applied to welded joints produced with one or two different weld metals (one of these is overmatched, while the other is undermatched). Welded single-edge notched bend (SENB) specimens are examined, with an initial pre-crack located in the symmetry plane of each joint. Local approach is chosen for assessment of behaviour of the joints under the external loading, to capture the effect of material inhomogeneity and initial crack length on deformation and ductile fracture initiation in analysed specimens.",
publisher = "Trans Tech Publications Ltd, Durnten-Zurich",
journal = "Materials Structure & Micromechanics of Fracture",
title = "Influence of crack length on ductile fracture initiation in welded joints with one and two weld metals",
pages = "+-578",
volume = "465",
doi = "10.4028/www.scientific.net/KEM.465.578"
}

Međo, B., Rakin, M., Gubeljak, N., Predan, J., Arsić, M.,& Sedmak, A.. (2011). Influence of crack length on ductile fracture initiation in welded joints with one and two weld metals. in Materials Structure & Micromechanics of Fracture
Trans Tech Publications Ltd, Durnten-Zurich., 465, 578-+.
https://doi.org/10.4028/www.scientific.net/KEM.465.578

Međo B, Rakin M, Gubeljak N, Predan J, Arsić M, Sedmak A. Influence of crack length on ductile fracture initiation in welded joints with one and two weld metals. in Materials Structure & Micromechanics of Fracture. 2011;465:578-+.
doi:10.4028/www.scientific.net/KEM.465.578 .

Međo, Bojan, Rakin, Marko, Gubeljak, Nenad, Predan, J., Arsić, Miodrag, Sedmak, Aleksandar, "Influence of crack length on ductile fracture initiation in welded joints with one and two weld metals" in Materials Structure & Micromechanics of Fracture, 465 (2011):578-+,
https://doi.org/10.4028/www.scientific.net/KEM.465.578 . .

TY  - JOUR
AU  - Bošnjak, Srđan
AU  - Arsić, Miodrag
AU  - Zrnić, Nenad
AU  - Rakin, Marko
AU  - Pantelić, Milorad P.
PY  - 2011
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1928
AB  - The bucket wheel boom tie-rods are vital structural parts of the bucket wheel excavators (BWE) Their failures inevitably cause BWE collapse and are followed among other things by a substantial financial loss (millions of E) Non-destructive testing revealed a flaw in the butt welded Joint of the body and eye-plate of the bucket wheel tie-rod Its size exceeds the level allowed by current technical regulations An integrity assessment of the bucket wheel tie-rod has been carried out i e the remaining fatigue life has been determined based on the stress-state characteristics in the welded Joint and defined by experimental research in real working conditions The calculation results show that despite the excessive size of the internal flaw the welded Joint integrity is not compromised During periodical inspections of the welded joint in the past two years (BWE was put into operation in December 2007) changes that could compromise the structural integrity were not observed In this way by using a fail-safe philosophy design a considerable financial saving (ca 1 600 000 (sic)) was achieved while at the same time there was no threat to the worker s safety and life the safety of the machine and the production process in the open pit mine
PB  - Pergamon-Elsevier Science Ltd, Oxford
T2  - Engineering Failure Analysis
T1  - Bucket wheel excavator Integrity assessment of the bucket wheel boom tie-rod welded joint
EP  - 222
IS  - 1
SP  - 212
VL  - 18
DO  - 10.1016/j.engfailanal.2010.09.001
ER  - 

@article{
author = "Bošnjak, Srđan and Arsić, Miodrag and Zrnić, Nenad and Rakin, Marko and Pantelić, Milorad P.",
year = "2011",
abstract = "The bucket wheel boom tie-rods are vital structural parts of the bucket wheel excavators (BWE) Their failures inevitably cause BWE collapse and are followed among other things by a substantial financial loss (millions of E) Non-destructive testing revealed a flaw in the butt welded Joint of the body and eye-plate of the bucket wheel tie-rod Its size exceeds the level allowed by current technical regulations An integrity assessment of the bucket wheel tie-rod has been carried out i e the remaining fatigue life has been determined based on the stress-state characteristics in the welded Joint and defined by experimental research in real working conditions The calculation results show that despite the excessive size of the internal flaw the welded Joint integrity is not compromised During periodical inspections of the welded joint in the past two years (BWE was put into operation in December 2007) changes that could compromise the structural integrity were not observed In this way by using a fail-safe philosophy design a considerable financial saving (ca 1 600 000 (sic)) was achieved while at the same time there was no threat to the worker s safety and life the safety of the machine and the production process in the open pit mine",
publisher = "Pergamon-Elsevier Science Ltd, Oxford",
journal = "Engineering Failure Analysis",
title = "Bucket wheel excavator Integrity assessment of the bucket wheel boom tie-rod welded joint",
pages = "222-212",
number = "1",
volume = "18",
doi = "10.1016/j.engfailanal.2010.09.001"
}

Bošnjak, S., Arsić, M., Zrnić, N., Rakin, M.,& Pantelić, M. P.. (2011). Bucket wheel excavator Integrity assessment of the bucket wheel boom tie-rod welded joint. in Engineering Failure Analysis
Pergamon-Elsevier Science Ltd, Oxford., 18(1), 212-222.
https://doi.org/10.1016/j.engfailanal.2010.09.001

Bošnjak S, Arsić M, Zrnić N, Rakin M, Pantelić MP. Bucket wheel excavator Integrity assessment of the bucket wheel boom tie-rod welded joint. in Engineering Failure Analysis. 2011;18(1):212-222.
doi:10.1016/j.engfailanal.2010.09.001 .

Bošnjak, Srđan, Arsić, Miodrag, Zrnić, Nenad, Rakin, Marko, Pantelić, Milorad P., "Bucket wheel excavator Integrity assessment of the bucket wheel boom tie-rod welded joint" in Engineering Failure Analysis, 18, no. 1 (2011):212-222,
https://doi.org/10.1016/j.engfailanal.2010.09.001 . .

TY  - CONF
AU  - Međo, Bojan
AU  - Rakin, Marko
AU  - Gubeljak, Nenad
AU  - Arsić, Miodrag
AU  - Sedmak, Aleksandar
PY  - 2010
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1550
AB  - Local approach is applied to analysis of ductile fracture in steel welded joints. Welded single-edge notched bend (SENBspecimens with joints containing one or two weld metals are investigated. The Gurson plastic flow criterion is used, and the crack growth is modelled by observing damage in elements in front of the crack tip. The effect of various factors: microstructural parameters, joint width, initial crack length, as well as size and formulation of finite elements in the ligament, is examined. Special consideration is given to the connection between material microstructure and fracture behaviour, and it is found that initial porosity and finite element size that correspond to the microstructural quantities (volume fraction of non-metallic inclusions and mean free path between them, determined using quantitative microstructural analysisgive the most appropriate results. It is concluded that local approach enables estimation of ductile fracture initiation in analysed welded joints, also capturing the constraint effect caused by the different joint widths and effect of material inhomogeneity along the crack front of the joints with two different weld metals.
PB  - 18th European Conference on Fracture: Fracture of Materials and Structures from Micro to Macro Scale, ECF 2010
C3  - 18th European Conference on Fracture: Fracture of Materials and Structures from Micro to Macro Scale
T1  - Local approach to analysis of ductile fracture in welded joints-Influence factors
UR  - https://hdl.handle.net/21.15107/rcub_technorep_1550
ER  - 

@conference{
author = "Međo, Bojan and Rakin, Marko and Gubeljak, Nenad and Arsić, Miodrag and Sedmak, Aleksandar",
year = "2010",
abstract = "Local approach is applied to analysis of ductile fracture in steel welded joints. Welded single-edge notched bend (SENBspecimens with joints containing one or two weld metals are investigated. The Gurson plastic flow criterion is used, and the crack growth is modelled by observing damage in elements in front of the crack tip. The effect of various factors: microstructural parameters, joint width, initial crack length, as well as size and formulation of finite elements in the ligament, is examined. Special consideration is given to the connection between material microstructure and fracture behaviour, and it is found that initial porosity and finite element size that correspond to the microstructural quantities (volume fraction of non-metallic inclusions and mean free path between them, determined using quantitative microstructural analysisgive the most appropriate results. It is concluded that local approach enables estimation of ductile fracture initiation in analysed welded joints, also capturing the constraint effect caused by the different joint widths and effect of material inhomogeneity along the crack front of the joints with two different weld metals.",
publisher = "18th European Conference on Fracture: Fracture of Materials and Structures from Micro to Macro Scale, ECF 2010",
journal = "18th European Conference on Fracture: Fracture of Materials and Structures from Micro to Macro Scale",
title = "Local approach to analysis of ductile fracture in welded joints-Influence factors",
url = "https://hdl.handle.net/21.15107/rcub_technorep_1550"
}

Međo, B., Rakin, M., Gubeljak, N., Arsić, M.,& Sedmak, A.. (2010). Local approach to analysis of ductile fracture in welded joints-Influence factors. in 18th European Conference on Fracture: Fracture of Materials and Structures from Micro to Macro Scale
18th European Conference on Fracture: Fracture of Materials and Structures from Micro to Macro Scale, ECF 2010..
https://hdl.handle.net/21.15107/rcub_technorep_1550

Međo B, Rakin M, Gubeljak N, Arsić M, Sedmak A. Local approach to analysis of ductile fracture in welded joints-Influence factors. in 18th European Conference on Fracture: Fracture of Materials and Structures from Micro to Macro Scale. 2010;.
https://hdl.handle.net/21.15107/rcub_technorep_1550 .

Međo, Bojan, Rakin, Marko, Gubeljak, Nenad, Arsić, Miodrag, Sedmak, Aleksandar, "Local approach to analysis of ductile fracture in welded joints-Influence factors" in 18th European Conference on Fracture: Fracture of Materials and Structures from Micro to Macro Scale (2010),
https://hdl.handle.net/21.15107/rcub_technorep_1550 .

TY  - JOUR
AU  - Šarkočević, Živče
AU  - Arsić, Miodrag
AU  - Međo, Bojan
AU  - Kozak, Drazan
AU  - Rakin, Marko
AU  - Burzić, Zijah
AU  - Sedmak, Aleksandar
PY  - 2009
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1360
AB  - The subject of this paper is investigation of the damage level of API J55 steel, used for manufacturing casing pipes by high frequency (HF) contact welding. The analysed pipe was withdrawn after about 70 000 hours of service in an oil drilling rig. Experimental analysis included determining the mechanical properties of the base material and welded joint, in particular the tensile and impact toughness testing. Fracture behaviour is examined by testing the modified compact tension (CT) specimens machined with a pre-crack in the base metal, weld metal and heat affected zone (HAZ). The critical value of the stress intensity factor K(Ic) is determined using the critical value of the J integral J(Ic). Fatigue crack growth rate and fatigue threshold stress intensity factor range are determined by three point bending tests of the Charpy specimens with a V-notch. The investigation conducted on specimens cut from the exploited pipe and the new pipe of the same grade revealed that material properties were not seriously altered during the analysed period of service.
T2  - Strojarstvo
T1  - Damage Level Estimate of API J55 Steel for Welded Seam Casing Pipes
EP  - 311
IS  - 4
SP  - 303
VL  - 51
UR  - https://hdl.handle.net/21.15107/rcub_technorep_1360
ER  - 

@article{
author = "Šarkočević, Živče and Arsić, Miodrag and Međo, Bojan and Kozak, Drazan and Rakin, Marko and Burzić, Zijah and Sedmak, Aleksandar",
year = "2009",
abstract = "The subject of this paper is investigation of the damage level of API J55 steel, used for manufacturing casing pipes by high frequency (HF) contact welding. The analysed pipe was withdrawn after about 70 000 hours of service in an oil drilling rig. Experimental analysis included determining the mechanical properties of the base material and welded joint, in particular the tensile and impact toughness testing. Fracture behaviour is examined by testing the modified compact tension (CT) specimens machined with a pre-crack in the base metal, weld metal and heat affected zone (HAZ). The critical value of the stress intensity factor K(Ic) is determined using the critical value of the J integral J(Ic). Fatigue crack growth rate and fatigue threshold stress intensity factor range are determined by three point bending tests of the Charpy specimens with a V-notch. The investigation conducted on specimens cut from the exploited pipe and the new pipe of the same grade revealed that material properties were not seriously altered during the analysed period of service.",
journal = "Strojarstvo",
title = "Damage Level Estimate of API J55 Steel for Welded Seam Casing Pipes",
pages = "311-303",
number = "4",
volume = "51",
url = "https://hdl.handle.net/21.15107/rcub_technorep_1360"
}

Šarkočević, Ž., Arsić, M., Međo, B., Kozak, D., Rakin, M., Burzić, Z.,& Sedmak, A.. (2009). Damage Level Estimate of API J55 Steel for Welded Seam Casing Pipes. in Strojarstvo, 51(4), 303-311.
https://hdl.handle.net/21.15107/rcub_technorep_1360

Šarkočević Ž, Arsić M, Međo B, Kozak D, Rakin M, Burzić Z, Sedmak A. Damage Level Estimate of API J55 Steel for Welded Seam Casing Pipes. in Strojarstvo. 2009;51(4):303-311.
https://hdl.handle.net/21.15107/rcub_technorep_1360 .

Šarkočević, Živče, Arsić, Miodrag, Međo, Bojan, Kozak, Drazan, Rakin, Marko, Burzić, Zijah, Sedmak, Aleksandar, "Damage Level Estimate of API J55 Steel for Welded Seam Casing Pipes" in Strojarstvo, 51, no. 4 (2009):303-311,
https://hdl.handle.net/21.15107/rcub_technorep_1360 .

TY  - JOUR
AU  - Šarkočević, Živče
AU  - Arsić, Miodrag
AU  - Rakin, Marko
AU  - Međo, Bojan
AU  - Mladenović, Mladen
AU  - Jaković, Dragan
PY  - 2009
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1387
AB  - The selection of steel, the dimensions and methods of seam welded steel tubes fabrication are closely connected to the function of tube as a whole structure in specific working conditions, for a calculated service life. The quality of welded joints in the fabrication process of seam welded tubes is defined by properties the tubes must possess in order to satisfy defined requirements, and can be achieved by choosing appropriate procedures and welding parameters, by following control programmes in all fabricating operations, and through mechanical and technology stress and strain tests of base metal and seam welded joints. The paper presents the results of the mechanical properties of spiral welded pipes, the two production processes with different welding parameters. Tubes designed for oil and gas pipelines are made by welding the powder (EPP) steel increased strength of API X60.
AB  - Izbor čelika, dimenzija i načina proizvodnje zavarenih cevi je deo procesa konstruisanja, jer je u uskoj vezi sa funkcijom cevi kao konstrukcijske celine u određenim uslovima eksploatacije za predviđeni vek trajanja. Kvalitet zavarenih spojeva u procesu proizvodnje cevi definiše se karakteristikama koje one moraju posedovati da bi zadovoljile određene zahteve, što se postiže izborom odgovarajućih postupaka i parametara zavarivanja, sprovođenjem programa kontrole svih tehnoloških operacija u njihovoj izradi i mehaničkim i tehnološkim ispitivanjima otpornosti i deformacije osnovnog materijala i zavarenih spojeva cevi. U radu su prikazani rezultati ispitivanja mehaničkih osobina spiralno zavarenih cevi, za dva proizvodna procesa sa različitim parametrima zavarivanja. Cevi namenjene za naftovode i gasovode su izrađene zavarivanjem pod praškom (EPP) od čelika povećane čvrstoće API X60.
PB  - DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd
T2  - Zavarivanje i zavarene konstrukcije
T1  - Influence of SA procedure welding parameters on mechanical properties spiral welded steel tubes API X60
T1  - Uticaj parametara EPP postupka zavarivanja na mehaničke osobine spiralno zavarenih cevi od čelika API X60
EP  - 147
IS  - 4
SP  - 141
VL  - 54
UR  - https://hdl.handle.net/21.15107/rcub_technorep_1387
ER  - 

@article{
author = "Šarkočević, Živče and Arsić, Miodrag and Rakin, Marko and Međo, Bojan and Mladenović, Mladen and Jaković, Dragan",
year = "2009",
abstract = "The selection of steel, the dimensions and methods of seam welded steel tubes fabrication are closely connected to the function of tube as a whole structure in specific working conditions, for a calculated service life. The quality of welded joints in the fabrication process of seam welded tubes is defined by properties the tubes must possess in order to satisfy defined requirements, and can be achieved by choosing appropriate procedures and welding parameters, by following control programmes in all fabricating operations, and through mechanical and technology stress and strain tests of base metal and seam welded joints. The paper presents the results of the mechanical properties of spiral welded pipes, the two production processes with different welding parameters. Tubes designed for oil and gas pipelines are made by welding the powder (EPP) steel increased strength of API X60., Izbor čelika, dimenzija i načina proizvodnje zavarenih cevi je deo procesa konstruisanja, jer je u uskoj vezi sa funkcijom cevi kao konstrukcijske celine u određenim uslovima eksploatacije za predviđeni vek trajanja. Kvalitet zavarenih spojeva u procesu proizvodnje cevi definiše se karakteristikama koje one moraju posedovati da bi zadovoljile određene zahteve, što se postiže izborom odgovarajućih postupaka i parametara zavarivanja, sprovođenjem programa kontrole svih tehnoloških operacija u njihovoj izradi i mehaničkim i tehnološkim ispitivanjima otpornosti i deformacije osnovnog materijala i zavarenih spojeva cevi. U radu su prikazani rezultati ispitivanja mehaničkih osobina spiralno zavarenih cevi, za dva proizvodna procesa sa različitim parametrima zavarivanja. Cevi namenjene za naftovode i gasovode su izrađene zavarivanjem pod praškom (EPP) od čelika povećane čvrstoće API X60.",
publisher = "DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd",
journal = "Zavarivanje i zavarene konstrukcije",
title = "Influence of SA procedure welding parameters on mechanical properties spiral welded steel tubes API X60, Uticaj parametara EPP postupka zavarivanja na mehaničke osobine spiralno zavarenih cevi od čelika API X60",
pages = "147-141",
number = "4",
volume = "54",
url = "https://hdl.handle.net/21.15107/rcub_technorep_1387"
}

Šarkočević, Ž., Arsić, M., Rakin, M., Međo, B., Mladenović, M.,& Jaković, D.. (2009). Influence of SA procedure welding parameters on mechanical properties spiral welded steel tubes API X60. in Zavarivanje i zavarene konstrukcije
DUZS - Društvo za unapređivanje zavarivanja u Srbiji, Beograd., 54(4), 141-147.
https://hdl.handle.net/21.15107/rcub_technorep_1387

Šarkočević Ž, Arsić M, Rakin M, Međo B, Mladenović M, Jaković D. Influence of SA procedure welding parameters on mechanical properties spiral welded steel tubes API X60. in Zavarivanje i zavarene konstrukcije. 2009;54(4):141-147.
https://hdl.handle.net/21.15107/rcub_technorep_1387 .

Šarkočević, Živče, Arsić, Miodrag, Rakin, Marko, Međo, Bojan, Mladenović, Mladen, Jaković, Dragan, "Influence of SA procedure welding parameters on mechanical properties spiral welded steel tubes API X60" in Zavarivanje i zavarene konstrukcije, 54, no. 4 (2009):141-147,
https://hdl.handle.net/21.15107/rcub_technorep_1387 .