Flajs, Željko

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  • Flajs, Željko (6)

Author's Bibliography

Finite element calculation of redesigned welded joint at support for frame stage‐like structure

Arsić, Aleksandra; Flajs, Željko; Gašić, Vlada; Zrnić, Nenad

(University of Banja Luka Faculty of Mechanical Engineering, 2023)

TY  - CONF
AU  - Arsić, Aleksandra
AU  - Flajs, Željko
AU  - Gašić, Vlada
AU  - Zrnić, Nenad
PY  - 2023
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/7288
AB  - A numerical analysis of welded connection between two steel structures is performed with the usage of the finite element approach. A frame stage‐like structure is placed between the main horizontal girders of the structure of the hall. A visual inspection of the frame revealed numerous irregularities of welds which brought demand for redesign and overall check. The emphasis in this paper is comparative calculation of initial and redesigned welded end‐joints, without imposing the optimal technical solution. It is used modern and particular finite element software for calculation of welded joints. The values of stresses in the welded joint as well in plates and members are lower than the permitted values for both models. However, the influence on the main structure is reduced with redesigned technical solution. The level of stresses is lower along with reduction of rotational stiffness of the joint. This can be considered as a relief to the main girders of the hall structure and should be a cost and a goal for supporting any additional structure.
PB  - University of Banja Luka Faculty of Mechanical Engineering
C3  - 16th International Conference on Accomplishments in Mechanical and Industrial Engineering - DEMI 2023
T1  - Finite element calculation of redesigned welded joint at support for frame stage‐like structure
EP  - 516
SP  - 511
UR  - https://hdl.handle.net/21.15107/rcub_machinery_7288
ER  - 
@conference{
author = "Arsić, Aleksandra and Flajs, Željko and Gašić, Vlada and Zrnić, Nenad",
year = "2023",
abstract = "A numerical analysis of welded connection between two steel structures is performed with the usage of the finite element approach. A frame stage‐like structure is placed between the main horizontal girders of the structure of the hall. A visual inspection of the frame revealed numerous irregularities of welds which brought demand for redesign and overall check. The emphasis in this paper is comparative calculation of initial and redesigned welded end‐joints, without imposing the optimal technical solution. It is used modern and particular finite element software for calculation of welded joints. The values of stresses in the welded joint as well in plates and members are lower than the permitted values for both models. However, the influence on the main structure is reduced with redesigned technical solution. The level of stresses is lower along with reduction of rotational stiffness of the joint. This can be considered as a relief to the main girders of the hall structure and should be a cost and a goal for supporting any additional structure.",
publisher = "University of Banja Luka Faculty of Mechanical Engineering",
journal = "16th International Conference on Accomplishments in Mechanical and Industrial Engineering - DEMI 2023",
title = "Finite element calculation of redesigned welded joint at support for frame stage‐like structure",
pages = "516-511",
url = "https://hdl.handle.net/21.15107/rcub_machinery_7288"
}
Arsić, A., Flajs, Ž., Gašić, V.,& Zrnić, N.. (2023). Finite element calculation of redesigned welded joint at support for frame stage‐like structure. in 16th International Conference on Accomplishments in Mechanical and Industrial Engineering - DEMI 2023
University of Banja Luka Faculty of Mechanical Engineering., 511-516.
https://hdl.handle.net/21.15107/rcub_machinery_7288
Arsić A, Flajs Ž, Gašić V, Zrnić N. Finite element calculation of redesigned welded joint at support for frame stage‐like structure. in 16th International Conference on Accomplishments in Mechanical and Industrial Engineering - DEMI 2023. 2023;:511-516.
https://hdl.handle.net/21.15107/rcub_machinery_7288 .
Arsić, Aleksandra, Flajs, Željko, Gašić, Vlada, Zrnić, Nenad, "Finite element calculation of redesigned welded joint at support for frame stage‐like structure" in 16th International Conference on Accomplishments in Mechanical and Industrial Engineering - DEMI 2023 (2023):511-516,
https://hdl.handle.net/21.15107/rcub_machinery_7288 .

Damage occurrence in welded structures of the bucket-wheel boom

Arsić, Miodrag; Flajs, Željko; Sedmak, Aleksandar; Veg, Emil; Sedmak, Simon

(Trans Tech Publications Ltd, Switzerland, 2022)

TY  - JOUR
AU  - Arsić, Miodrag
AU  - Flajs, Željko
AU  - Sedmak, Aleksandar
AU  - Veg, Emil
AU  - Sedmak, Simon
PY  - 2022
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/6030
AB  - Causes of damage occurrence in vital components of welded structures of the bucket-wheel excavator boom (DU1) at the coal landfill of the thermal power plant 'Nikola Tesla A' in Obrenovac (Serbia) are investigated. Bucket-wheel excavator was produced by French company 'Ameco' and it moves along the circular track. Taking into account lack of technical documentation, all tests and were carried out under the assumption that welded structures were made of structural steels S355 and S235. Investigation of causes of damage occurrence are based on results of non-destructive tests (NDT) and tensometric measurements.
PB  - Trans Tech Publications Ltd, Switzerland
T2  - Engineering Innovations
T1  - Damage occurrence in welded structures of the bucket-wheel boom
EP  - 48
SP  - 41
VL  - 2
DO  - 10.4028/p-15iqnw
ER  - 
@article{
author = "Arsić, Miodrag and Flajs, Željko and Sedmak, Aleksandar and Veg, Emil and Sedmak, Simon",
year = "2022",
abstract = "Causes of damage occurrence in vital components of welded structures of the bucket-wheel excavator boom (DU1) at the coal landfill of the thermal power plant 'Nikola Tesla A' in Obrenovac (Serbia) are investigated. Bucket-wheel excavator was produced by French company 'Ameco' and it moves along the circular track. Taking into account lack of technical documentation, all tests and were carried out under the assumption that welded structures were made of structural steels S355 and S235. Investigation of causes of damage occurrence are based on results of non-destructive tests (NDT) and tensometric measurements.",
publisher = "Trans Tech Publications Ltd, Switzerland",
journal = "Engineering Innovations",
title = "Damage occurrence in welded structures of the bucket-wheel boom",
pages = "48-41",
volume = "2",
doi = "10.4028/p-15iqnw"
}
Arsić, M., Flajs, Ž., Sedmak, A., Veg, E.,& Sedmak, S.. (2022). Damage occurrence in welded structures of the bucket-wheel boom. in Engineering Innovations
Trans Tech Publications Ltd, Switzerland., 2, 41-48.
https://doi.org/10.4028/p-15iqnw
Arsić M, Flajs Ž, Sedmak A, Veg E, Sedmak S. Damage occurrence in welded structures of the bucket-wheel boom. in Engineering Innovations. 2022;2:41-48.
doi:10.4028/p-15iqnw .
Arsić, Miodrag, Flajs, Željko, Sedmak, Aleksandar, Veg, Emil, Sedmak, Simon, "Damage occurrence in welded structures of the bucket-wheel boom" in Engineering Innovations, 2 (2022):41-48,
https://doi.org/10.4028/p-15iqnw . .

Structural integrity assessment of welded bucket-wheel boom

Arsić, Miodrag; Flajs, Željko; Sedmak, Aleksandar; Veg, Emil; Sedmak, Simon

(Institut za ispitivanje materijala, Beograd, 2021)

TY  - JOUR
AU  - Arsić, Miodrag
AU  - Flajs, Željko
AU  - Sedmak, Aleksandar
AU  - Veg, Emil
AU  - Sedmak, Simon
PY  - 2021
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/3561
AB  - Research is conducted on the causes of damage and the structural integrity assessment of the bucket-wheel boom welded lattice structures, before and after the repair of vital structures. Additionally, the paper describes the investigation conducted based on the results of non-destructive tests (visual-, magnetic particle-, dye penetrant-, and ultrasonic tests), results of tensometric measurements that refer to the stress-strain state, and results based on numerical calculation of stresses by finite element method, performed through the use of a 3D model in the software Radimpex Tower 6.0 (R). The results of tests and research performed after the repair of damaged structural welded sections show that the operational procedures are being obeyed.
PB  - Institut za ispitivanje materijala, Beograd
T2  - Structural Integrity and Life-Integritet I Vek Konstrukcija
T1  - Structural integrity assessment of welded bucket-wheel boom
EP  - 206
IS  - 2
SP  - 201
VL  - 21
UR  - https://hdl.handle.net/21.15107/rcub_machinery_3561
ER  - 
@article{
author = "Arsić, Miodrag and Flajs, Željko and Sedmak, Aleksandar and Veg, Emil and Sedmak, Simon",
year = "2021",
abstract = "Research is conducted on the causes of damage and the structural integrity assessment of the bucket-wheel boom welded lattice structures, before and after the repair of vital structures. Additionally, the paper describes the investigation conducted based on the results of non-destructive tests (visual-, magnetic particle-, dye penetrant-, and ultrasonic tests), results of tensometric measurements that refer to the stress-strain state, and results based on numerical calculation of stresses by finite element method, performed through the use of a 3D model in the software Radimpex Tower 6.0 (R). The results of tests and research performed after the repair of damaged structural welded sections show that the operational procedures are being obeyed.",
publisher = "Institut za ispitivanje materijala, Beograd",
journal = "Structural Integrity and Life-Integritet I Vek Konstrukcija",
title = "Structural integrity assessment of welded bucket-wheel boom",
pages = "206-201",
number = "2",
volume = "21",
url = "https://hdl.handle.net/21.15107/rcub_machinery_3561"
}
Arsić, M., Flajs, Ž., Sedmak, A., Veg, E.,& Sedmak, S.. (2021). Structural integrity assessment of welded bucket-wheel boom. in Structural Integrity and Life-Integritet I Vek Konstrukcija
Institut za ispitivanje materijala, Beograd., 21(2), 201-206.
https://hdl.handle.net/21.15107/rcub_machinery_3561
Arsić M, Flajs Ž, Sedmak A, Veg E, Sedmak S. Structural integrity assessment of welded bucket-wheel boom. in Structural Integrity and Life-Integritet I Vek Konstrukcija. 2021;21(2):201-206.
https://hdl.handle.net/21.15107/rcub_machinery_3561 .
Arsić, Miodrag, Flajs, Željko, Sedmak, Aleksandar, Veg, Emil, Sedmak, Simon, "Structural integrity assessment of welded bucket-wheel boom" in Structural Integrity and Life-Integritet I Vek Konstrukcija, 21, no. 2 (2021):201-206,
https://hdl.handle.net/21.15107/rcub_machinery_3561 .

Application of Non-Destructive Testing for Condition Analysis, Repair of Damages and Integrity Assessment of Vital Steel Structures

Arsić, Miodrag; Arsić, Dušan; Flajs, Željko; Grbović, Aleksandar; Todić, Aleksandar

(Pleiades Publishing Inc, New York, 2021)

TY  - JOUR
AU  - Arsić, Miodrag
AU  - Arsić, Dušan
AU  - Flajs, Željko
AU  - Grbović, Aleksandar
AU  - Todić, Aleksandar
PY  - 2021
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/3536
AB  - Loads at vital steel structures occur during their production and assembly (residual stresses), during the execution of functional tasks in exploitation (stationary and dynamic loads) and during the disturbed process of exploitation (non-stationary dynamic loads). Considering the fact that stress concentrators, corrosion and unpredictable effects that occur during exploitation must be taken into account as well, it is clear that loading of vital structures during the design phase can not be represented with a model in which the parameters change uniformly. Therefore only experimental non-destructive tests performed at large steel structures during exploitation enable the assessment of their current condition, need for particular repairs and assessment of integrity. In that way the data necessary for determination of causes of degradation of material and welded joints at structures, for the evaluation of mutual influence of equipment parts, as well as for determination of functionality and reliability of operation of drive systems. This primarily refers to vital steel structures of bucket-wheel excavators, dredgers and cranes, as well as to vital steel structures at hydroelectric equipment, thermal power plant equipment, bridges etc. This paper presents the analysis of causes for the occurrence of damages at the support structure of the boom of the bucket-wheel excavator, which is operating at the open pit coal mine near Kostolac (Serbia), that was executed on the basis of non-destructive tests. The paper also contains the procedure for the repair of damaged structure through the application of adequate welding, performed at existing and newly produced components, and the assessment of structural integrity after the repair based on non-compliances detected during the design process, as well as during the making of the support structure of the bucket-wheel excavator boom due to inadequate radiuses defined during the processes of design and production and due to the existence of flaws on the surface and within welded joints.
PB  - Pleiades Publishing Inc, New York
T2  - Russian Journal of Nondestructive Testing
T1  - Application of Non-Destructive Testing for Condition Analysis, Repair of Damages and Integrity Assessment of Vital Steel Structures
EP  - 931
IS  - 10
SP  - 918
VL  - 57
DO  - 10.1134/S1061830921100053
ER  - 
@article{
author = "Arsić, Miodrag and Arsić, Dušan and Flajs, Željko and Grbović, Aleksandar and Todić, Aleksandar",
year = "2021",
abstract = "Loads at vital steel structures occur during their production and assembly (residual stresses), during the execution of functional tasks in exploitation (stationary and dynamic loads) and during the disturbed process of exploitation (non-stationary dynamic loads). Considering the fact that stress concentrators, corrosion and unpredictable effects that occur during exploitation must be taken into account as well, it is clear that loading of vital structures during the design phase can not be represented with a model in which the parameters change uniformly. Therefore only experimental non-destructive tests performed at large steel structures during exploitation enable the assessment of their current condition, need for particular repairs and assessment of integrity. In that way the data necessary for determination of causes of degradation of material and welded joints at structures, for the evaluation of mutual influence of equipment parts, as well as for determination of functionality and reliability of operation of drive systems. This primarily refers to vital steel structures of bucket-wheel excavators, dredgers and cranes, as well as to vital steel structures at hydroelectric equipment, thermal power plant equipment, bridges etc. This paper presents the analysis of causes for the occurrence of damages at the support structure of the boom of the bucket-wheel excavator, which is operating at the open pit coal mine near Kostolac (Serbia), that was executed on the basis of non-destructive tests. The paper also contains the procedure for the repair of damaged structure through the application of adequate welding, performed at existing and newly produced components, and the assessment of structural integrity after the repair based on non-compliances detected during the design process, as well as during the making of the support structure of the bucket-wheel excavator boom due to inadequate radiuses defined during the processes of design and production and due to the existence of flaws on the surface and within welded joints.",
publisher = "Pleiades Publishing Inc, New York",
journal = "Russian Journal of Nondestructive Testing",
title = "Application of Non-Destructive Testing for Condition Analysis, Repair of Damages and Integrity Assessment of Vital Steel Structures",
pages = "931-918",
number = "10",
volume = "57",
doi = "10.1134/S1061830921100053"
}
Arsić, M., Arsić, D., Flajs, Ž., Grbović, A.,& Todić, A.. (2021). Application of Non-Destructive Testing for Condition Analysis, Repair of Damages and Integrity Assessment of Vital Steel Structures. in Russian Journal of Nondestructive Testing
Pleiades Publishing Inc, New York., 57(10), 918-931.
https://doi.org/10.1134/S1061830921100053
Arsić M, Arsić D, Flajs Ž, Grbović A, Todić A. Application of Non-Destructive Testing for Condition Analysis, Repair of Damages and Integrity Assessment of Vital Steel Structures. in Russian Journal of Nondestructive Testing. 2021;57(10):918-931.
doi:10.1134/S1061830921100053 .
Arsić, Miodrag, Arsić, Dušan, Flajs, Željko, Grbović, Aleksandar, Todić, Aleksandar, "Application of Non-Destructive Testing for Condition Analysis, Repair of Damages and Integrity Assessment of Vital Steel Structures" in Russian Journal of Nondestructive Testing, 57, no. 10 (2021):918-931,
https://doi.org/10.1134/S1061830921100053 . .
4
4

Deflection Calculation for Beam-type Structures from Measured Strain Data

Flajs, Željko; Veg, Emil; Gubeljak, Nenad; Šiniković, Goran

(Univ Osijek, Tech Fac, Slavonski Brod, 2020)

TY  - JOUR
AU  - Flajs, Željko
AU  - Veg, Emil
AU  - Gubeljak, Nenad
AU  - Šiniković, Goran
PY  - 2020
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/3396
AB  - Behavior of structures under various load types is determined by their deformation characteristics, global deformation characteristics - deflections and rotations, and local deformation characteristics - strains / stresses in structure base material. If we know global and local deformation characteristics of a structure, then it is possible to determine the structure behavior under acting loads, on the whole structure or at some part of that structure. The main objective of this research is to verify calculation algorithm for obtaining vertical displacements - the deflection of the structure, based on the known strain values in the structure base material, under acting load. The verification of the calculation algorithm is performed by comparing the numerical and experimental results.
PB  - Univ Osijek, Tech Fac, Slavonski Brod
T2  - Tehnički vjesnik
T1  - Deflection Calculation for Beam-type Structures from Measured Strain Data
EP  - 670
IS  - 2
SP  - 665
VL  - 27
DO  - 10.17559/TV-20200123124502
ER  - 
@article{
author = "Flajs, Željko and Veg, Emil and Gubeljak, Nenad and Šiniković, Goran",
year = "2020",
abstract = "Behavior of structures under various load types is determined by their deformation characteristics, global deformation characteristics - deflections and rotations, and local deformation characteristics - strains / stresses in structure base material. If we know global and local deformation characteristics of a structure, then it is possible to determine the structure behavior under acting loads, on the whole structure or at some part of that structure. The main objective of this research is to verify calculation algorithm for obtaining vertical displacements - the deflection of the structure, based on the known strain values in the structure base material, under acting load. The verification of the calculation algorithm is performed by comparing the numerical and experimental results.",
publisher = "Univ Osijek, Tech Fac, Slavonski Brod",
journal = "Tehnički vjesnik",
title = "Deflection Calculation for Beam-type Structures from Measured Strain Data",
pages = "670-665",
number = "2",
volume = "27",
doi = "10.17559/TV-20200123124502"
}
Flajs, Ž., Veg, E., Gubeljak, N.,& Šiniković, G.. (2020). Deflection Calculation for Beam-type Structures from Measured Strain Data. in Tehnički vjesnik
Univ Osijek, Tech Fac, Slavonski Brod., 27(2), 665-670.
https://doi.org/10.17559/TV-20200123124502
Flajs Ž, Veg E, Gubeljak N, Šiniković G. Deflection Calculation for Beam-type Structures from Measured Strain Data. in Tehnički vjesnik. 2020;27(2):665-670.
doi:10.17559/TV-20200123124502 .
Flajs, Željko, Veg, Emil, Gubeljak, Nenad, Šiniković, Goran, "Deflection Calculation for Beam-type Structures from Measured Strain Data" in Tehnički vjesnik, 27, no. 2 (2020):665-670,
https://doi.org/10.17559/TV-20200123124502 . .

Experimental study on the stresses at the i-beam end-plate moment connection

Gašić, Vlada; Arsić, Aleksandra; Flajs, Željko

(Institut za ispitivanje materijala, Beograd, 2019)

TY  - JOUR
AU  - Gašić, Vlada
AU  - Arsić, Aleksandra
AU  - Flajs, Željko
PY  - 2019
UR  - https://machinery.mas.bg.ac.rs/handle/123456789/3167
AB  - The paper deals with experimental study of the stresses at the bolted end-plate moment connection. The design parameters are adopted to include prying effects in joint. A stress level is obtained in the elements where the highest values occur in the tension zone of the end-plate. The accompanied finite element analysis is performed for comparing purposes with experimental results. It is shown that end-plate thickness should be the unavoidable joint parameter in structural analysis of frame-like structures.
PB  - Institut za ispitivanje materijala, Beograd
T2  - Structural Integrity and Life
T1  - Experimental study on the stresses at the i-beam end-plate moment connection
EP  - 57
IS  - 1
SP  - 53
VL  - 19
UR  - https://hdl.handle.net/21.15107/rcub_machinery_3167
ER  - 
@article{
author = "Gašić, Vlada and Arsić, Aleksandra and Flajs, Željko",
year = "2019",
abstract = "The paper deals with experimental study of the stresses at the bolted end-plate moment connection. The design parameters are adopted to include prying effects in joint. A stress level is obtained in the elements where the highest values occur in the tension zone of the end-plate. The accompanied finite element analysis is performed for comparing purposes with experimental results. It is shown that end-plate thickness should be the unavoidable joint parameter in structural analysis of frame-like structures.",
publisher = "Institut za ispitivanje materijala, Beograd",
journal = "Structural Integrity and Life",
title = "Experimental study on the stresses at the i-beam end-plate moment connection",
pages = "57-53",
number = "1",
volume = "19",
url = "https://hdl.handle.net/21.15107/rcub_machinery_3167"
}
Gašić, V., Arsić, A.,& Flajs, Ž.. (2019). Experimental study on the stresses at the i-beam end-plate moment connection. in Structural Integrity and Life
Institut za ispitivanje materijala, Beograd., 19(1), 53-57.
https://hdl.handle.net/21.15107/rcub_machinery_3167
Gašić V, Arsić A, Flajs Ž. Experimental study on the stresses at the i-beam end-plate moment connection. in Structural Integrity and Life. 2019;19(1):53-57.
https://hdl.handle.net/21.15107/rcub_machinery_3167 .
Gašić, Vlada, Arsić, Aleksandra, Flajs, Željko, "Experimental study on the stresses at the i-beam end-plate moment connection" in Structural Integrity and Life, 19, no. 1 (2019):53-57,
https://hdl.handle.net/21.15107/rcub_machinery_3167 .
4