TY  - JOUR
AU  - Bošnjak, Srđan
AU  - Zrnić, Nenad
AU  - Momčilović, Dejan
AU  - Gnjatović, Nebojša
AU  - Milenović, Ivan Lj.
PY  - 2020
UR  - http://rims.institutims.rs/handle/123456789/391
AB  - Tie-rods of the bucket wheel and counterweight booms are vital parts of the bucket wheel excavator slewing superstructure. This paper is dedicated to the problem of identifying the stress state of the critical cross-section ('net section') of the eye plates on these tie-rods. It presents the results of the experimental and numerical investigations carried out on the eyebar model. The results show the appearance of a plastic deformation in the zone near the contour of the hole even when the eye is subjected to the loads within the range of the permissible loads prescribed by the standard DIN 22261-2. Plastification in the eye net section occurs across the full thickness of the plate, but it does not jeopardize the integrity of the structure. The stress value in the eye net section, calculated in accordance with the standard DIN 22261-2, is significantly lower than the actual stress values around the hole and serves only as a comparative value for the static strength proof for the eye.
PB  - Elsevier Sci Ltd, Oxford
T2  - Engineering Structures
T1  - Tie-rods of the bucket wheel excavator slewing superstructure: A study of the eye plate stress state
VL  - 207
DO  - 10.1016/j.engstruct.2020.110233
ER  - 

@article{
author = "Bošnjak, Srđan and Zrnić, Nenad and Momčilović, Dejan and Gnjatović, Nebojša and Milenović, Ivan Lj.",
year = "2020",
abstract = "Tie-rods of the bucket wheel and counterweight booms are vital parts of the bucket wheel excavator slewing superstructure. This paper is dedicated to the problem of identifying the stress state of the critical cross-section ('net section') of the eye plates on these tie-rods. It presents the results of the experimental and numerical investigations carried out on the eyebar model. The results show the appearance of a plastic deformation in the zone near the contour of the hole even when the eye is subjected to the loads within the range of the permissible loads prescribed by the standard DIN 22261-2. Plastification in the eye net section occurs across the full thickness of the plate, but it does not jeopardize the integrity of the structure. The stress value in the eye net section, calculated in accordance with the standard DIN 22261-2, is significantly lower than the actual stress values around the hole and serves only as a comparative value for the static strength proof for the eye.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Engineering Structures",
title = "Tie-rods of the bucket wheel excavator slewing superstructure: A study of the eye plate stress state",
volume = "207",
doi = "10.1016/j.engstruct.2020.110233"
}

Bošnjak, S., Zrnić, N., Momčilović, D., Gnjatović, N.,& Milenović, I. Lj.. (2020). Tie-rods of the bucket wheel excavator slewing superstructure: A study of the eye plate stress state. in Engineering Structures
Elsevier Sci Ltd, Oxford., 207.
https://doi.org/10.1016/j.engstruct.2020.110233

Bošnjak S, Zrnić N, Momčilović D, Gnjatović N, Milenović IL. Tie-rods of the bucket wheel excavator slewing superstructure: A study of the eye plate stress state. in Engineering Structures. 2020;207.
doi:10.1016/j.engstruct.2020.110233 .

Bošnjak, Srđan, Zrnić, Nenad, Momčilović, Dejan, Gnjatović, Nebojša, Milenović, Ivan Lj., "Tie-rods of the bucket wheel excavator slewing superstructure: A study of the eye plate stress state" in Engineering Structures, 207 (2020),
https://doi.org/10.1016/j.engstruct.2020.110233 . .

TY  - JOUR
AU  - Bošnjak, Srđan
AU  - Zrnić, Nenad
AU  - Momčilović, Dejan
AU  - Gnjatović, Nebojša
AU  - Milenović, Ivan
PY  - 2020
UR  - http://rims.institutims.rs/handle/123456789/451
AB  - An original method for validation of the number of buckets on the working device of a bucket wheel excavator based on the dynamic response of its slewing superstructure (SS) is presented. A set of 16 seemingly acceptable solutions which satisfied the rigid design restrictions, based on the preservation of the existing (a) bucket wheel drivetrain, (b) theoretical capacity, (c) characteristics of the excavated soil and (d) position of the superstructure centre of gravity (CoG), was analysed. Already on the basis of the limiting vertical and lateral accelerations of the bucket wheel centre, which represents a well-grounded indicator of its dynamic behaviour prescribed by the code
DIN 22261-2, 14 out of 16 analysed design variants have been discarded, reducing the set of possible solutions to only two – the originally-designed variant (with 17 buckets), and the variant with 20 buckets. Conclusions on the validity of these two design variants were derived on the basis of the dynamic response analysis of the referent points of the SS. The analysis of the impact of soiling on the dynamic response of the SS has shown that negative dynamic effects, observed in the preceding analysis of the originally-designed solution, increase with the amount
of the adhered material. Although the redesigned variant with 20 buckets has proven as the only suitable solution from the standpoint of dynamic behaviour of the SS, the results have to be assessed carefully due to the fact that the reduction of the mass of the bucket wheel steel structure by more than 14% leads to the appearance of unfavourable dynamic effects, even though the SS CoG position is preserved.
T2  - Engineering Structures
T1  - Bucket wheel excavators_Dynamic response as a criterion for validation of the total number of buckets
VL  - 207
DO  - 10.1016/j.engstruct.2020.110233
ER  - 

@article{
author = "Bošnjak, Srđan and Zrnić, Nenad and Momčilović, Dejan and Gnjatović, Nebojša and Milenović, Ivan",
year = "2020",
abstract = "An original method for validation of the number of buckets on the working device of a bucket wheel excavator based on the dynamic response of its slewing superstructure (SS) is presented. A set of 16 seemingly acceptable solutions which satisfied the rigid design restrictions, based on the preservation of the existing (a) bucket wheel drivetrain, (b) theoretical capacity, (c) characteristics of the excavated soil and (d) position of the superstructure centre of gravity (CoG), was analysed. Already on the basis of the limiting vertical and lateral accelerations of the bucket wheel centre, which represents a well-grounded indicator of its dynamic behaviour prescribed by the code
DIN 22261-2, 14 out of 16 analysed design variants have been discarded, reducing the set of possible solutions to only two – the originally-designed variant (with 17 buckets), and the variant with 20 buckets. Conclusions on the validity of these two design variants were derived on the basis of the dynamic response analysis of the referent points of the SS. The analysis of the impact of soiling on the dynamic response of the SS has shown that negative dynamic effects, observed in the preceding analysis of the originally-designed solution, increase with the amount
of the adhered material. Although the redesigned variant with 20 buckets has proven as the only suitable solution from the standpoint of dynamic behaviour of the SS, the results have to be assessed carefully due to the fact that the reduction of the mass of the bucket wheel steel structure by more than 14% leads to the appearance of unfavourable dynamic effects, even though the SS CoG position is preserved.",
journal = "Engineering Structures",
title = "Bucket wheel excavators_Dynamic response as a criterion for validation of the total number of buckets",
volume = "207",
doi = "10.1016/j.engstruct.2020.110233"
}

Bošnjak, S., Zrnić, N., Momčilović, D., Gnjatović, N.,& Milenović, I.. (2020). Bucket wheel excavators_Dynamic response as a criterion for validation of the total number of buckets. in Engineering Structures, 207.
https://doi.org/10.1016/j.engstruct.2020.110233

Bošnjak S, Zrnić N, Momčilović D, Gnjatović N, Milenović I. Bucket wheel excavators_Dynamic response as a criterion for validation of the total number of buckets. in Engineering Structures. 2020;207.
doi:10.1016/j.engstruct.2020.110233 .

Bošnjak, Srđan, Zrnić, Nenad, Momčilović, Dejan, Gnjatović, Nebojša, Milenović, Ivan, "Bucket wheel excavators_Dynamic response as a criterion for validation of the total number of buckets" in Engineering Structures, 207 (2020),
https://doi.org/10.1016/j.engstruct.2020.110233 . .

TY  - JOUR
AU  - Bošnjak, Srđan
AU  - Gnjatović, Nebojša
AU  - Momčilović, Dejan
AU  - Milenović, Ivan Lj.
AU  - Gašić, V.M.
PY  - 2015
UR  - http://rims.institutims.rs/handle/123456789/276
AB  - This paper presents an investigation of the accident which occurred during startup of the extending structure from the transport position. In order to clarify the causes of crack occurrence along almost the entire surface of the lever cross-section, the authors performed visual, experimental (chemical composition, tensile properties, microhardness) as well as metallographic examinations. Stress states in the critical zone are defined by applying the finite element method (FEM). Based on the investigation results it was concluded that the lever breakdown is predominantly caused by both the 'operating-in' defect (the malfunction of the limit switch) and the 'manufacturing-in' defect (poor weld quality). The investigation results presented in this paper are important because same or similar problems could arise in supporting structures of various types of transportation, construction and mining machines.
PB  - Elsevier Ltd
T2  - Case Studies in Engineering Failure Analysis
T1  - Failure analysis of the mobile elevating work platform
EP  - 87
SP  - 80
VL  - 3
DO  - 10.1016/j.csefa.2015.03.005
ER  - 

@article{
author = "Bošnjak, Srđan and Gnjatović, Nebojša and Momčilović, Dejan and Milenović, Ivan Lj. and Gašić, V.M.",
year = "2015",
abstract = "This paper presents an investigation of the accident which occurred during startup of the extending structure from the transport position. In order to clarify the causes of crack occurrence along almost the entire surface of the lever cross-section, the authors performed visual, experimental (chemical composition, tensile properties, microhardness) as well as metallographic examinations. Stress states in the critical zone are defined by applying the finite element method (FEM). Based on the investigation results it was concluded that the lever breakdown is predominantly caused by both the 'operating-in' defect (the malfunction of the limit switch) and the 'manufacturing-in' defect (poor weld quality). The investigation results presented in this paper are important because same or similar problems could arise in supporting structures of various types of transportation, construction and mining machines.",
publisher = "Elsevier Ltd",
journal = "Case Studies in Engineering Failure Analysis",
title = "Failure analysis of the mobile elevating work platform",
pages = "87-80",
volume = "3",
doi = "10.1016/j.csefa.2015.03.005"
}

Bošnjak, S., Gnjatović, N., Momčilović, D., Milenović, I. Lj.,& Gašić, V.M.. (2015). Failure analysis of the mobile elevating work platform. in Case Studies in Engineering Failure Analysis
Elsevier Ltd., 3, 80-87.
https://doi.org/10.1016/j.csefa.2015.03.005

Bošnjak S, Gnjatović N, Momčilović D, Milenović IL, Gašić V. Failure analysis of the mobile elevating work platform. in Case Studies in Engineering Failure Analysis. 2015;3:80-87.
doi:10.1016/j.csefa.2015.03.005 .

Bošnjak, Srđan, Gnjatović, Nebojša, Momčilović, Dejan, Milenović, Ivan Lj., Gašić, V.M., "Failure analysis of the mobile elevating work platform" in Case Studies in Engineering Failure Analysis, 3 (2015):80-87,
https://doi.org/10.1016/j.csefa.2015.03.005 . .