TY  - CONF
AU  - Sedmak, Aleksandar
AU  - Younise, Bashir
AU  - Rakin, Marko
AU  - Međo, Bojan
AU  - Gubeljak, Nenad
AU  - Burzić, M.
AU  - Kozak, Drazan
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1974
AB  - Ductile damage development in welded joints of high strength low alloyed (HSLA) steel NIOMOL 490K was examined experimentally and analyzed using the micromechanical approach. Single-edge notched bend (SENB) specimens, cut from the welded plates and subsequently pre-cracked in HAZ and WM, were tested. True stress - true strain curves of the heat-affected zone (HAZ) and weld metal (WM) were determined on the smooth tensile plate specimen, by application of a combined experimental-numerical procedure which included stereometric strain measurement and finite element analysis. The complete Gurson model (CGM) was applied to estimate the fracture behavior of the analyzed zones of the joint. An important property of this model is that critical damage parameter value (used as failure criterion) is not a material constant-it is calculated in every load step, based on the stress and strain state in the structure. This feature is especially important in the examined joints, since the material heterogeneity causes pronounced stress and strain gradients. Finite element software Abaqus was used for numerical analysis. The crack growth initiation was predicted at the moment when damage parameter reaches its critical value in the element nearest to the crack tip. The advance of damage (i.e. the crack growth) was modeled by tracking the loss of load carrying capacity in the ligament (local stiffness reduction in the elements). It is concluded that the micromechanical approach can be used to assess the effects of constraint and heterogeneity on the fracture of the examined HSLA steel welded joints. HAZ fracture properties concerning both crack growth initiation and stable growth are slightly better in comparison with WM, as obtained by testing the SENB specimens with pre-cracks in these two weld zones. The influence of the finite element (FE) size on the results was also analyzed. It is found that the finite element size near the crack tip strongly influences the prediction of crack initiation and growth, and that there is a very significant difference in appropriate FE size between the WM and HAZ. For the analyzed materials, this size corresponds to the mean free path between the non-metallic inclusions in the examined welded joint zones.
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  - Ductile fracture resistance of the weld metal and heat affected zone in a HSLA steel welded joint
UR  - https://hdl.handle.net/21.15107/rcub_technorep_1974
ER  - 

@conference{
author = "Sedmak, Aleksandar and Younise, Bashir and Rakin, Marko and Međo, Bojan and Gubeljak, Nenad and Burzić, M. and Kozak, Drazan",
year = "2012",
abstract = "Ductile damage development in welded joints of high strength low alloyed (HSLA) steel NIOMOL 490K was examined experimentally and analyzed using the micromechanical approach. Single-edge notched bend (SENB) specimens, cut from the welded plates and subsequently pre-cracked in HAZ and WM, were tested. True stress - true strain curves of the heat-affected zone (HAZ) and weld metal (WM) were determined on the smooth tensile plate specimen, by application of a combined experimental-numerical procedure which included stereometric strain measurement and finite element analysis. The complete Gurson model (CGM) was applied to estimate the fracture behavior of the analyzed zones of the joint. An important property of this model is that critical damage parameter value (used as failure criterion) is not a material constant-it is calculated in every load step, based on the stress and strain state in the structure. This feature is especially important in the examined joints, since the material heterogeneity causes pronounced stress and strain gradients. Finite element software Abaqus was used for numerical analysis. The crack growth initiation was predicted at the moment when damage parameter reaches its critical value in the element nearest to the crack tip. The advance of damage (i.e. the crack growth) was modeled by tracking the loss of load carrying capacity in the ligament (local stiffness reduction in the elements). It is concluded that the micromechanical approach can be used to assess the effects of constraint and heterogeneity on the fracture of the examined HSLA steel welded joints. HAZ fracture properties concerning both crack growth initiation and stable growth are slightly better in comparison with WM, as obtained by testing the SENB specimens with pre-cracks in these two weld zones. The influence of the finite element (FE) size on the results was also analyzed. It is found that the finite element size near the crack tip strongly influences the prediction of crack initiation and growth, and that there is a very significant difference in appropriate FE size between the WM and HAZ. For the analyzed materials, this size corresponds to the mean free path between the non-metallic inclusions in the examined welded joint zones.",
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 = "Ductile fracture resistance of the weld metal and heat affected zone in a HSLA steel welded joint",
url = "https://hdl.handle.net/21.15107/rcub_technorep_1974"
}

Sedmak, A., Younise, B., Rakin, M., Međo, B., Gubeljak, N., Burzić, M.,& Kozak, D.. (2012). Ductile fracture resistance of the weld metal and heat affected zone in a HSLA steel welded joint. 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_1974

Sedmak A, Younise B, Rakin M, Međo B, Gubeljak N, Burzić M, Kozak D. Ductile fracture resistance of the weld metal and heat affected zone in a HSLA steel welded joint. in 19th European Conference on Fracture: Fracture Mechanics for Durability, Reliability and Safety, ECF. 2012;.
https://hdl.handle.net/21.15107/rcub_technorep_1974 .

Sedmak, Aleksandar, Younise, Bashir, Rakin, Marko, Međo, Bojan, Gubeljak, Nenad, Burzić, M., Kozak, Drazan, "Ductile fracture resistance of the weld metal and heat affected zone in a HSLA steel welded joint" in 19th European Conference on Fracture: Fracture Mechanics for Durability, Reliability and Safety, ECF (2012),
https://hdl.handle.net/21.15107/rcub_technorep_1974 .

TY  - JOUR
AU  - Younise, Bashir
AU  - Rakin, Marko
AU  - Međo, Bojan
AU  - Gubeljak, Nenad
AU  - Kozak, Drazan
AU  - Sedmak, Aleksandar
PY  - 2011
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1744
AB  - In this paper, constraint effect on ductile fracture initiation and propagation has been studied. Three-dimensional finite element analyses of mismatched welded joints made of high strength steel, have been performed for centre-cracked tensile (CCT) specimens. Different weld widths and material mismatching ratios have been considered. Ductile fracture parameter crack tip opening displacement at crack growth initiation (CTODi), has been obtained for centre-cracked tensile (CCT) specimens using local approach to fracture and compared with experimental results of single edge bend specimens. Micromechanical complete Gurson model has been applied to investigate fracture behaviour of cracked welded joints. Crack tip constraint has been analysed through stress triaxiality in order to study transferability of fracture parameters from one geometry to another
PB  - Faculty of Mechanical Engineering in Slavonski Brod, Faculty of Electrical Engineering in Osijek, Faculty of Civil Engineering in Osijek
T2  - Tehnicki vjesnik
T1  - Numerical analysis of constraint effect on ductile tearing in strength mismatched welded cct specimens using micromechanical approach
EP  - 340
IS  - 3
SP  - 333
VL  - 18
UR  - https://hdl.handle.net/21.15107/rcub_technorep_1744
ER  - 

@article{
author = "Younise, Bashir and Rakin, Marko and Međo, Bojan and Gubeljak, Nenad and Kozak, Drazan and Sedmak, Aleksandar",
year = "2011",
abstract = "In this paper, constraint effect on ductile fracture initiation and propagation has been studied. Three-dimensional finite element analyses of mismatched welded joints made of high strength steel, have been performed for centre-cracked tensile (CCT) specimens. Different weld widths and material mismatching ratios have been considered. Ductile fracture parameter crack tip opening displacement at crack growth initiation (CTODi), has been obtained for centre-cracked tensile (CCT) specimens using local approach to fracture and compared with experimental results of single edge bend specimens. Micromechanical complete Gurson model has been applied to investigate fracture behaviour of cracked welded joints. Crack tip constraint has been analysed through stress triaxiality in order to study transferability of fracture parameters from one geometry to another",
publisher = "Faculty of Mechanical Engineering in Slavonski Brod, Faculty of Electrical Engineering in Osijek, Faculty of Civil Engineering in Osijek",
journal = "Tehnicki vjesnik",
title = "Numerical analysis of constraint effect on ductile tearing in strength mismatched welded cct specimens using micromechanical approach",
pages = "340-333",
number = "3",
volume = "18",
url = "https://hdl.handle.net/21.15107/rcub_technorep_1744"
}

Younise, B., Rakin, M., Međo, B., Gubeljak, N., Kozak, D.,& Sedmak, A.. (2011). Numerical analysis of constraint effect on ductile tearing in strength mismatched welded cct specimens using micromechanical approach. in Tehnicki vjesnik
Faculty of Mechanical Engineering in Slavonski Brod, Faculty of Electrical Engineering in Osijek, Faculty of Civil Engineering in Osijek., 18(3), 333-340.
https://hdl.handle.net/21.15107/rcub_technorep_1744

Younise B, Rakin M, Međo B, Gubeljak N, Kozak D, Sedmak A. Numerical analysis of constraint effect on ductile tearing in strength mismatched welded cct specimens using micromechanical approach. in Tehnicki vjesnik. 2011;18(3):333-340.
https://hdl.handle.net/21.15107/rcub_technorep_1744 .

Younise, Bashir, Rakin, Marko, Međo, Bojan, Gubeljak, Nenad, Kozak, Drazan, Sedmak, Aleksandar, "Numerical analysis of constraint effect on ductile tearing in strength mismatched welded cct specimens using micromechanical approach" in Tehnicki vjesnik, 18, no. 3 (2011):333-340,
https://hdl.handle.net/21.15107/rcub_technorep_1744 .

TY  - JOUR
AU  - Hreha, Pavol
AU  - Hloch, Sergej
AU  - Magurova, Dagmar
AU  - Valicek, Jan
AU  - Kozak, Drazan
AU  - Harnicarova, Marta
AU  - Rakin, Marko
PY  - 2010
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/1538
AB  - Abrasive water jet technology has been recently used mainly in industrial areas. This technology provides several advantages in comparison with conventional methods. At present, it is used in medicine. This paper discusses the possibility of using water jet technology in medicine. The paper describes the benefits and usage in orthopedic surgery, plastic surgery, neurosurgery, dermatology, urology, and in dental surgery.
PB  - Faculty of Mechanical Engineering in Slavonski Brod, Faculty of Electrical Engineering in Osijek, Faculty of Civil Engineering in Osijek
T2  - Tehnicki vjesnik
T1  - Water jet technology used in medicine
EP  - 240
IS  - 2
SP  - 237
VL  - 17
UR  - https://hdl.handle.net/21.15107/rcub_technorep_1538
ER  - 

@article{
author = "Hreha, Pavol and Hloch, Sergej and Magurova, Dagmar and Valicek, Jan and Kozak, Drazan and Harnicarova, Marta and Rakin, Marko",
year = "2010",
abstract = "Abrasive water jet technology has been recently used mainly in industrial areas. This technology provides several advantages in comparison with conventional methods. At present, it is used in medicine. This paper discusses the possibility of using water jet technology in medicine. The paper describes the benefits and usage in orthopedic surgery, plastic surgery, neurosurgery, dermatology, urology, and in dental surgery.",
publisher = "Faculty of Mechanical Engineering in Slavonski Brod, Faculty of Electrical Engineering in Osijek, Faculty of Civil Engineering in Osijek",
journal = "Tehnicki vjesnik",
title = "Water jet technology used in medicine",
pages = "240-237",
number = "2",
volume = "17",
url = "https://hdl.handle.net/21.15107/rcub_technorep_1538"
}

Hreha, P., Hloch, S., Magurova, D., Valicek, J., Kozak, D., Harnicarova, M.,& Rakin, M.. (2010). Water jet technology used in medicine. in Tehnicki vjesnik
Faculty of Mechanical Engineering in Slavonski Brod, Faculty of Electrical Engineering in Osijek, Faculty of Civil Engineering in Osijek., 17(2), 237-240.
https://hdl.handle.net/21.15107/rcub_technorep_1538

Hreha P, Hloch S, Magurova D, Valicek J, Kozak D, Harnicarova M, Rakin M. Water jet technology used in medicine. in Tehnicki vjesnik. 2010;17(2):237-240.
https://hdl.handle.net/21.15107/rcub_technorep_1538 .

Hreha, Pavol, Hloch, Sergej, Magurova, Dagmar, Valicek, Jan, Kozak, Drazan, Harnicarova, Marta, Rakin, Marko, "Water jet technology used in medicine" in Tehnicki vjesnik, 17, no. 2 (2010):237-240,
https://hdl.handle.net/21.15107/rcub_technorep_1538 .

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 .