TY  - JOUR
AU  - Musrati, Walid
AU  - Međo, Bojan
AU  - Cvijović-Alagić, Ivana
AU  - Gubeljak, Nenad
AU  - Štefane, Primož
AU  - Radosavljević, Zoran
AU  - Rakin, Marko
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6607
AB  - Steel pipelines in industrial plants consist of different elements, including seamless and/or welded (seam) pipes. Properties of welded pipes, including their fracture behaviour, depend on the characteristics of both, the base metal, and the weld metal. In this work, two seam pipes are considered having different diameters and manufactured of P235TR1 steel. Hardness and microstructure were examined on the samples which contained the seam zone, to capture the influence of heterogeneity. Fracture resistance of the pipeline material, i.e. of both base metals and both seams, was determined by experimental examination of the recently proposed Pipe ring notch bending specimens with sharp stress concentrators. Differences between the two tested pipes, including the influence of the heterogeneity caused by the welded joint, were determined by comparison of the crack growth resistance curves. Effects of the initial stress concentrator shape, sharp machined notch or fatigue precrack are discussed.
AB  - Čelični cevovodi u industrijskim postrojenjima se sastoje od različitih elemenata, uključujući bešavne i/ili
zavarene (šavne) cevi. Osobine šavnih cevi, uključujući ponašanje materijala cevi pri lomu, zavise i od
osnovnog metala i od metala šava. U ovom radu razmatrane su dve šavne cevi različitih prečnika,
izrađene od čelika P235TR1. Tvrdoća i mikrostruktura su analizirane na uzorcima isečenim iz cevi u zoni
šava, da bi se odredio uticaj heterogenosti. Otpornost prema lomu materijala cevovoda, tj. oba osnovna
metala i oba šava, je određena na osnovu ispitivanja epruveta oblika prstena sa oštrim koncentratorima
napona, predloženih u prethodnim studijama. Poređenjem krivih otpornosti prema rastu prsline
određene su razlike između dve ispitivane cevi, kao i uticaj heterogenosti izazvan postojanjem zavarenog
spoja. Razmotren je uticaj oblika početnog koncentratora napona, oštrog žleba odnosno zamorne
početne prsline.
PB  - Association of the Chemical Engineers of Serbia
T2  - Hemijska industrija
T1  - Microstructure, hardness and fracture resistance of P235TR1 seam steel pipes of different diameters
T1  - Otpornost prema lomu, tvrdoća i mikrostruktura šavnih cevi različitog prečnika izrađenih od čelika P235TR1
EP  - 165
IS  - 2
SP  - 155
VL  - 77
DO  - 10.2298/HEMIND230222016M
ER  - 

@article{
author = "Musrati, Walid and Međo, Bojan and Cvijović-Alagić, Ivana and Gubeljak, Nenad and Štefane, Primož and Radosavljević, Zoran and Rakin, Marko",
year = "2023",
abstract = "Steel pipelines in industrial plants consist of different elements, including seamless and/or welded (seam) pipes. Properties of welded pipes, including their fracture behaviour, depend on the characteristics of both, the base metal, and the weld metal. In this work, two seam pipes are considered having different diameters and manufactured of P235TR1 steel. Hardness and microstructure were examined on the samples which contained the seam zone, to capture the influence of heterogeneity. Fracture resistance of the pipeline material, i.e. of both base metals and both seams, was determined by experimental examination of the recently proposed Pipe ring notch bending specimens with sharp stress concentrators. Differences between the two tested pipes, including the influence of the heterogeneity caused by the welded joint, were determined by comparison of the crack growth resistance curves. Effects of the initial stress concentrator shape, sharp machined notch or fatigue precrack are discussed., Čelični cevovodi u industrijskim postrojenjima se sastoje od različitih elemenata, uključujući bešavne i/ili
zavarene (šavne) cevi. Osobine šavnih cevi, uključujući ponašanje materijala cevi pri lomu, zavise i od
osnovnog metala i od metala šava. U ovom radu razmatrane su dve šavne cevi različitih prečnika,
izrađene od čelika P235TR1. Tvrdoća i mikrostruktura su analizirane na uzorcima isečenim iz cevi u zoni
šava, da bi se odredio uticaj heterogenosti. Otpornost prema lomu materijala cevovoda, tj. oba osnovna
metala i oba šava, je određena na osnovu ispitivanja epruveta oblika prstena sa oštrim koncentratorima
napona, predloženih u prethodnim studijama. Poređenjem krivih otpornosti prema rastu prsline
određene su razlike između dve ispitivane cevi, kao i uticaj heterogenosti izazvan postojanjem zavarenog
spoja. Razmotren je uticaj oblika početnog koncentratora napona, oštrog žleba odnosno zamorne
početne prsline.",
publisher = "Association of the Chemical Engineers of Serbia",
journal = "Hemijska industrija",
title = "Microstructure, hardness and fracture resistance of P235TR1 seam steel pipes of different diameters, Otpornost prema lomu, tvrdoća i mikrostruktura šavnih cevi različitog prečnika izrađenih od čelika P235TR1",
pages = "165-155",
number = "2",
volume = "77",
doi = "10.2298/HEMIND230222016M"
}

Musrati, W., Međo, B., Cvijović-Alagić, I., Gubeljak, N., Štefane, P., Radosavljević, Z.,& Rakin, M.. (2023). Microstructure, hardness and fracture resistance of P235TR1 seam steel pipes of different diameters. in Hemijska industrija
Association of the Chemical Engineers of Serbia., 77(2), 155-165.
https://doi.org/10.2298/HEMIND230222016M

Musrati W, Međo B, Cvijović-Alagić I, Gubeljak N, Štefane P, Radosavljević Z, Rakin M. Microstructure, hardness and fracture resistance of P235TR1 seam steel pipes of different diameters. in Hemijska industrija. 2023;77(2):155-165.
doi:10.2298/HEMIND230222016M .

Musrati, Walid, Međo, Bojan, Cvijović-Alagić, Ivana, Gubeljak, Nenad, Štefane, Primož, Radosavljević, Zoran, Rakin, Marko, "Microstructure, hardness and fracture resistance of P235TR1 seam steel pipes of different diameters" in Hemijska industrija, 77, no. 2 (2023):155-165,
https://doi.org/10.2298/HEMIND230222016M . .

TY  - CONF
AU  - Rakin, Marko
AU  - Međo, Bojan
AU  - Musrati, Walid
AU  - Gubeljak, Nenad
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6179
AB  - In recent years, several attempts have been made by research groups worldwide to propose and verify new laboratory specimens
for measurement of pipeline materials fracture resistance. The main reason for these efforts is the requirement of standard
fracture mechanics procedures for relatively large specimen thickness, i.e. plane strain conditions. It is almost impossible,
and also too conservative, to apply such an approach to the thin-walled pipes, which form the majority of industrial pipelines.
Failure resistance of pipeline steel is examined by testing the recently proposed Pipe Ring Notched Bend (PRNB) specimens
with different dimensions. The seam, i.e. longitudinal weld, is analysed as a source of material heterogeneity;
however, seamless pipes are also examined. The results are repeatable, and the dependence on the specimen geometry is
not significant (it is even lower than it could be expected from standard thick fracture mechanics specimens). The seam
materials (weld metals) have shown different fracture behaviour for different batches/sizes of the pipes; they have either
lower or similar fracture resistance in comparison with the base material. Briefly, it can be said that fracture testing of a
relatively small amount of specimens revealed a lot of important data about the resistance of the pipes to ductile failure.
Fracture is modelled by application of the micromechanical approach in software package Abaqus, in particular the
Complete Gurson model. Additionally, the model is used for prediction of fracture resistance in plane strain conditions.
This can be useful for comparison of the examined pipe materials and others with known plane strain fracture properties.
Currently, the authors are working on a new geometry: pipe rings with a sharp notch exposed to tensile loading. This
will form a comprehensive approach to pipeline testing, where two geometries and two loading regimes (bending and
tension) will be available in the framework of a unified testing procedure.
C3  - 3rd Global Webinar on Materials Science and Engineering
T1  - Failure assessment of steel pipes using non-standard ring specimens.
SP  - 11
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6179
ER  - 

@conference{
author = "Rakin, Marko and Međo, Bojan and Musrati, Walid and Gubeljak, Nenad",
year = "2022",
abstract = "In recent years, several attempts have been made by research groups worldwide to propose and verify new laboratory specimens
for measurement of pipeline materials fracture resistance. The main reason for these efforts is the requirement of standard
fracture mechanics procedures for relatively large specimen thickness, i.e. plane strain conditions. It is almost impossible,
and also too conservative, to apply such an approach to the thin-walled pipes, which form the majority of industrial pipelines.
Failure resistance of pipeline steel is examined by testing the recently proposed Pipe Ring Notched Bend (PRNB) specimens
with different dimensions. The seam, i.e. longitudinal weld, is analysed as a source of material heterogeneity;
however, seamless pipes are also examined. The results are repeatable, and the dependence on the specimen geometry is
not significant (it is even lower than it could be expected from standard thick fracture mechanics specimens). The seam
materials (weld metals) have shown different fracture behaviour for different batches/sizes of the pipes; they have either
lower or similar fracture resistance in comparison with the base material. Briefly, it can be said that fracture testing of a
relatively small amount of specimens revealed a lot of important data about the resistance of the pipes to ductile failure.
Fracture is modelled by application of the micromechanical approach in software package Abaqus, in particular the
Complete Gurson model. Additionally, the model is used for prediction of fracture resistance in plane strain conditions.
This can be useful for comparison of the examined pipe materials and others with known plane strain fracture properties.
Currently, the authors are working on a new geometry: pipe rings with a sharp notch exposed to tensile loading. This
will form a comprehensive approach to pipeline testing, where two geometries and two loading regimes (bending and
tension) will be available in the framework of a unified testing procedure.",
journal = "3rd Global Webinar on Materials Science and Engineering",
title = "Failure assessment of steel pipes using non-standard ring specimens.",
pages = "11",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6179"
}

Rakin, M., Međo, B., Musrati, W.,& Gubeljak, N.. (2022). Failure assessment of steel pipes using non-standard ring specimens.. in 3rd Global Webinar on Materials Science and Engineering, 11.
https://hdl.handle.net/21.15107/rcub_technorep_6179

Rakin M, Međo B, Musrati W, Gubeljak N. Failure assessment of steel pipes using non-standard ring specimens.. in 3rd Global Webinar on Materials Science and Engineering. 2022;:11.
https://hdl.handle.net/21.15107/rcub_technorep_6179 .

Rakin, Marko, Međo, Bojan, Musrati, Walid, Gubeljak, Nenad, "Failure assessment of steel pipes using non-standard ring specimens." in 3rd Global Webinar on Materials Science and Engineering (2022):11,
https://hdl.handle.net/21.15107/rcub_technorep_6179 .

TY  - JOUR
AU  - Musrati, Walid
AU  - Međo, Bojan
AU  - Gubeljak, Nenad
AU  - Stefane, Primoz
AU  - Veljić, Darko
AU  - Sedmak, Aleksandar
AU  - Rakin, Marko
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4055
AB  - The topic of this work is analysis of fracture behaviour and resistance of the thin-walled seamless and seam steel pipes, through application of the recently proposed ring-shaped specimen (PRNB - Pipe Ring Notched Bend). The main loading of these pipes in exploitation is internal pressure, which is why axial defects present a significant threat to their integrity and work safety. The ring-shaped specimen geometry is fairly simple to fabricate from a new or exploited pipeline and the specimens have the same thermo-mechanical treatment, assembly conditions, etc. as the actual structure. Experimental-numerical procedure is applied for prediction of the fracture behaviour; this included material characterisation, testing of ring specimens by bending, as well as micromechanical analysis of ductile fracture. In experimental testing, the deformation of the specimens is monitored by using the stereometric measurement system. Numerical analysis is performed in software package Simulia Abaqus, including the application of the micromechanical Complete Gurson model (CGM). The results obtained in this study, along with some previously published results, lead to conclusion that PRNB specimen is a good option for testing of fracture resistance of cylindrical elements such as pipes.
PB  - Elsevier, Amsterdam
T2  - Theoretical and Applied Fracture Mechanics
T1  - Fracture assessment of seam and seamless steel pipes by application of the ring-shaped bending specimens
VL  - 103
DO  - 10.1016/j.tafmec.2019.102302
ER  - 

@article{
author = "Musrati, Walid and Međo, Bojan and Gubeljak, Nenad and Stefane, Primoz and Veljić, Darko and Sedmak, Aleksandar and Rakin, Marko",
year = "2019",
abstract = "The topic of this work is analysis of fracture behaviour and resistance of the thin-walled seamless and seam steel pipes, through application of the recently proposed ring-shaped specimen (PRNB - Pipe Ring Notched Bend). The main loading of these pipes in exploitation is internal pressure, which is why axial defects present a significant threat to their integrity and work safety. The ring-shaped specimen geometry is fairly simple to fabricate from a new or exploited pipeline and the specimens have the same thermo-mechanical treatment, assembly conditions, etc. as the actual structure. Experimental-numerical procedure is applied for prediction of the fracture behaviour; this included material characterisation, testing of ring specimens by bending, as well as micromechanical analysis of ductile fracture. In experimental testing, the deformation of the specimens is monitored by using the stereometric measurement system. Numerical analysis is performed in software package Simulia Abaqus, including the application of the micromechanical Complete Gurson model (CGM). The results obtained in this study, along with some previously published results, lead to conclusion that PRNB specimen is a good option for testing of fracture resistance of cylindrical elements such as pipes.",
publisher = "Elsevier, Amsterdam",
journal = "Theoretical and Applied Fracture Mechanics",
title = "Fracture assessment of seam and seamless steel pipes by application of the ring-shaped bending specimens",
volume = "103",
doi = "10.1016/j.tafmec.2019.102302"
}

Musrati, W., Međo, B., Gubeljak, N., Stefane, P., Veljić, D., Sedmak, A.,& Rakin, M.. (2019). Fracture assessment of seam and seamless steel pipes by application of the ring-shaped bending specimens. in Theoretical and Applied Fracture Mechanics
Elsevier, Amsterdam., 103.
https://doi.org/10.1016/j.tafmec.2019.102302

Musrati W, Međo B, Gubeljak N, Stefane P, Veljić D, Sedmak A, Rakin M. Fracture assessment of seam and seamless steel pipes by application of the ring-shaped bending specimens. in Theoretical and Applied Fracture Mechanics. 2019;103.
doi:10.1016/j.tafmec.2019.102302 .

Musrati, Walid, Međo, Bojan, Gubeljak, Nenad, Stefane, Primoz, Veljić, Darko, Sedmak, Aleksandar, Rakin, Marko, "Fracture assessment of seam and seamless steel pipes by application of the ring-shaped bending specimens" in Theoretical and Applied Fracture Mechanics, 103 (2019),
https://doi.org/10.1016/j.tafmec.2019.102302 . .

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  - Musrati, Walid
AU  - Međo, Bojan
AU  - Gubeljak, Nenad
AU  - Stefane, Primoz
AU  - Veljić, Darko
AU  - Sedmak, Aleksandar
AU  - Rakin, Marko
PY  - 2018
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3796
AB  - Application of pipelines is common in process industry and energetic facilities, as parts of storage and transport systems. Structural integrity and fracture resistance of the pipeline elements is typically assessed by testing fracture mechanics specimens, like compact tensile CT or single-edge notched bending, SENB. However, fabrication of these geometries is often not possible for thin-walled pressurized elements, commonly used in structures of process and energetic facilities. Therefore, some proposals for non-standard specimens have been given in the literature, differing by the position of the initial defects, in circumferential or axial direction, and by the degree of complexity of procedures for fabrication and testing. Recently proposed ring-shaped specimen (PRNB - Pipe Ring Notched Bend) is used here to assess the fracture resistance of pressurized cylinders with defects in axial direction, critical for the internal pressure loading. The specimens are simple to fabricate and have the same material history as the actual structure, such as thermo-mechanical treatment, assembly or exploitation conditions. In this work, the ring specimens are cut from the thin-walled non-alloy steel pipes for pressure purposes. Experimental-numerical procedure is applied for prediction of fracture behavior. The methods include material characterization, fracture testing and micromechanical analysis of specimen failure. The results obtained so far lead to conclusion that PRNB specimen is a good option for testing of fracture resistance of pipelines and small-scale vessels.
PB  - Elsevier Science Bv, Amsterdam
T2  - ECF22 - Loading and Environmental Effects on Structural Integrity
T1  - Fracture analysis of axially flawed ring-shaped bending specimen
EP  - 1833
SP  - 1828
VL  - 13
DO  - 10.1016/j.prostr.2018.12.333
ER  - 

@article{
author = "Musrati, Walid and Međo, Bojan and Gubeljak, Nenad and Stefane, Primoz and Veljić, Darko and Sedmak, Aleksandar and Rakin, Marko",
year = "2018",
abstract = "Application of pipelines is common in process industry and energetic facilities, as parts of storage and transport systems. Structural integrity and fracture resistance of the pipeline elements is typically assessed by testing fracture mechanics specimens, like compact tensile CT or single-edge notched bending, SENB. However, fabrication of these geometries is often not possible for thin-walled pressurized elements, commonly used in structures of process and energetic facilities. Therefore, some proposals for non-standard specimens have been given in the literature, differing by the position of the initial defects, in circumferential or axial direction, and by the degree of complexity of procedures for fabrication and testing. Recently proposed ring-shaped specimen (PRNB - Pipe Ring Notched Bend) is used here to assess the fracture resistance of pressurized cylinders with defects in axial direction, critical for the internal pressure loading. The specimens are simple to fabricate and have the same material history as the actual structure, such as thermo-mechanical treatment, assembly or exploitation conditions. In this work, the ring specimens are cut from the thin-walled non-alloy steel pipes for pressure purposes. Experimental-numerical procedure is applied for prediction of fracture behavior. The methods include material characterization, fracture testing and micromechanical analysis of specimen failure. The results obtained so far lead to conclusion that PRNB specimen is a good option for testing of fracture resistance of pipelines and small-scale vessels.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "ECF22 - Loading and Environmental Effects on Structural Integrity",
title = "Fracture analysis of axially flawed ring-shaped bending specimen",
pages = "1833-1828",
volume = "13",
doi = "10.1016/j.prostr.2018.12.333"
}

Musrati, W., Međo, B., Gubeljak, N., Stefane, P., Veljić, D., Sedmak, A.,& Rakin, M.. (2018). Fracture analysis of axially flawed ring-shaped bending specimen. in ECF22 - Loading and Environmental Effects on Structural Integrity
Elsevier Science Bv, Amsterdam., 13, 1828-1833.
https://doi.org/10.1016/j.prostr.2018.12.333

Musrati W, Međo B, Gubeljak N, Stefane P, Veljić D, Sedmak A, Rakin M. Fracture analysis of axially flawed ring-shaped bending specimen. in ECF22 - Loading and Environmental Effects on Structural Integrity. 2018;13:1828-1833.
doi:10.1016/j.prostr.2018.12.333 .

Musrati, Walid, Međo, Bojan, Gubeljak, Nenad, Stefane, Primoz, Veljić, Darko, Sedmak, Aleksandar, Rakin, Marko, "Fracture analysis of axially flawed ring-shaped bending specimen" in ECF22 - Loading and Environmental Effects on Structural Integrity, 13 (2018):1828-1833,
https://doi.org/10.1016/j.prostr.2018.12.333 . .