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Azizoğlu, Yağız
Publications (4 of 4) Show all publications
Azizoğlu, Y., Gärdsback, M., Sjöberg, B. & Lindgren, L.-E. (2017). Finite Element Analysis of cold pilgering using elastic roll dies. Paper presented at International Conference on the Technology of Plasticity, ICTP 2017, Cambridge, United Kingdom, 17-22 September 2017. Procedia Engineering, 207, 2370-2375
Open this publication in new window or tab >>Finite Element Analysis of cold pilgering using elastic roll dies
2017 (English)In: Procedia Engineering, ISSN 1877-7058, E-ISSN 1877-7058, Vol. 207, p. 2370-2375Article in journal (Refereed) Published
Abstract [en]

A finite element model of cold pilgering with elastic roll dies have been developed and used to investigate the influence of roll die deformation on the material flow, contact region, roll separating force and tube dimensions. Full scale experiments were performed to validate the contact surface and tube dimensions. The results show that the influence of roll die flattening is not significant on the contact length. However, elastic deformation of roll die has strong influence on both the wall thickness reduction and roll separating force. Thus it is recommended to consider elasticity of roll dies when forces and tube dimensions are estimated.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
cold pilgering, cold forming, tube forming, roll flattening, contact length, roll separating force, finite element method, tool elasticity, tube dimension
National Category
Applied Mechanics Other Materials Engineering
Research subject
Material Mechanics
Identifiers
urn:nbn:se:ltu:diva-62938 (URN)10.1016/j.proeng.2017.10.1010 (DOI)2-s2.0-85036627374 (Scopus ID)
Conference
International Conference on the Technology of Plasticity, ICTP 2017, Cambridge, United Kingdom, 17-22 September 2017
Note

Konferensartikel i tidskrift

Available from: 2017-04-07 Created: 2017-04-07 Last updated: 2019-09-12Bibliographically approved
Azizoğlu, Y. (2017). Modeling of Cold Pilgering of Tubes. (Licentiate dissertation). Luleå: Luleå university of technology
Open this publication in new window or tab >>Modeling of Cold Pilgering of Tubes
2017 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Cold pilgering is a challenging tube forming process in terms of modeling due to the complexity in kinematic of tools, friction condition and material behavior. The process development has mostly been based on simple formulas and costly full-scale tryouts. The aim in this study is to develop validated Finite element models of cold pilgering to increase the understanding of influence of the process parameters on the produced tubes.

In the course of this thesis, three-dimensional mechanical and thermo-mechanical Finite element models of cold pilgering were developed. The commercial code MSC.Marc was used in the simulations. General 3D models are needed to be able to capture asymmetric deformation in cold pilgering. It was found that tool deflections together with elastic deformation of roll dies have considerable influence on the rolling force. Furthermore, the strain rate and temperature effects on the response of the material and thereby on the rolling force were evaluated.

Place, publisher, year, edition, pages
Luleå: Luleå university of technology, 2017
Series
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757
Keywords
Cold pilgering, finite element method, tube forming, tool elasticity, roll flattening
National Category
Mechanical Engineering Other Materials Engineering
Research subject
Material Mechanics
Identifiers
urn:nbn:se:ltu:diva-62941 (URN)978-91-7583-872-4 (ISBN)978-91-7583-873-1 (ISBN)
Presentation
2017-05-31, E130, Luleå tekniska universitet, Luleå, 10:00 (English)
Opponent
Supervisors
Available from: 2017-04-12 Created: 2017-04-07 Last updated: 2019-06-04Bibliographically approved
Azizoğlu, Y., Gärdsback, M., Sjöberg, B. & Lindgren, L.-E. (2016). Finite element modeling of tube deformation during cold pilgering. In: Saanouni, K; Chenot, JL; Duval, JL (Ed.), NUMIFORM 2016: The 12th International Conference on Numerical Methods in Industrial Forming Processes. Paper presented at 12th International Conference on Numerical Methods in Industrial Forming Processes (NUMIFORM),Troyes,France, 04-07 July 2016 (pp. 1-8). , 80, Article ID 15004.
Open this publication in new window or tab >>Finite element modeling of tube deformation during cold pilgering
2016 (English)In: NUMIFORM 2016: The 12th International Conference on Numerical Methods in Industrial Forming Processes / [ed] Saanouni, K; Chenot, JL; Duval, JL, 2016, Vol. 80, p. 1-8, article id 15004Conference paper, Published paper (Refereed)
Abstract [en]

A three-dimensional finite element model of cold pilgering of stainless steel tubes is developed in this paper. The objective is to use the model to increase the understanding of forces and deformations in the process. The focus is on the influence of vertical displacements of the roll stand and axial displacements of the mandrel and tube. Therefore, the rigid tools and the tube are supported with elastic springs. Additionally, the influences of friction coefficients in the tube/mandrel and tube/roll interfaces are examined. A sensitivity study is performed to investigate the influences of these parameters on the strain path and the roll separation force. The results show the importance of accounting for the displacements of the tube and rigid tools on the roll separation force and the accumulative plastic strain.

Series
MATEC Web of conferences, ISSN 2261-236X ; 80
National Category
Other Materials Engineering
Research subject
Material Mechanics
Identifiers
urn:nbn:se:ltu:diva-62640 (URN)10.1051/matecconf/20168015004 (DOI)000392331100086 ()2-s2.0-85016095165 (Scopus ID)
Conference
12th International Conference on Numerical Methods in Industrial Forming Processes (NUMIFORM),Troyes,France, 04-07 July 2016
Available from: 2017-03-23 Created: 2017-03-23 Last updated: 2018-07-10Bibliographically approved
Azizoğlu, Y., Gärdsback, M., Sjöberg, B. & Lindgren, L.-E. (2015). Finite Element Modelling of Cold Pilgering of Tubes (ed.). In: (Ed.), E. Oñate; D.R.J. Owen; D. Peric; M. Chiumenti (Ed.), Computational Plasticity XIII: Fundamentals and Applications - Proceedings of the 13th International Conference on Computational Plasticity - Fundamentals and Applications,held in Barcelona, Spain, 1-3 September 2015. Paper presented at International Conference on Computational Plasticity. Fundamentals and Applications : 01/09/2015 - 03/09/2015 (pp. 716-726). Barcelona: International Center for Numerical Methods in Engineering (CIMNE)
Open this publication in new window or tab >>Finite Element Modelling of Cold Pilgering of Tubes
2015 (English)In: Computational Plasticity XIII: Fundamentals and Applications - Proceedings of the 13th International Conference on Computational Plasticity - Fundamentals and Applications,held in Barcelona, Spain, 1-3 September 2015 / [ed] E. Oñate; D.R.J. Owen; D. Peric; M. Chiumenti, Barcelona: International Center for Numerical Methods in Engineering (CIMNE), 2015, p. 716-726Conference paper, Published paper (Refereed)
Abstract [en]

Cold pilgering is a cold forming process used during manufacturing of seamless tubes. The tube with a mandrel inside is fed forward and rotated in stepwise increments, while the roll stand moves back and forth. The total plastic deformation of the tube is such that the cross-sectional area of the tube decreases and the length of the tube increases during the process. However, this is performed in many small incremental steps, where the direction of deformation in a material point changes at each stroke. Most published models of cold pilgering use simplified material models. In reality, the flow stress is dependent on temperature, strain rate, strain history and microstructure. In this work, temperature and strain rate distributions are computed, using a 3D thermo-mechanical FE model, and the influence of temperature and strain rate on the rolling force is investigated. The Johnson-Cook model is employed to describe the flow stress using isotropic hardening. The results show that strain rate and temperature have a significant influence on the roll separation force

Place, publisher, year, edition, pages
Barcelona: International Center for Numerical Methods in Engineering (CIMNE), 2015
National Category
Other Materials Engineering
Research subject
Material Mechanics
Identifiers
urn:nbn:se:ltu:diva-40526 (URN)000380573600069 ()2-s2.0-84992261190 (Scopus ID)fb3a73cd-20e7-4301-bd32-362df80d0902 (Local ID)978-84-944244-6-5 (ISBN)fb3a73cd-20e7-4301-bd32-362df80d0902 (Archive number)fb3a73cd-20e7-4301-bd32-362df80d0902 (OAI)
Conference
International Conference on Computational Plasticity. Fundamentals and Applications : 01/09/2015 - 03/09/2015
Note

Validerad; 2016; Nivå 1; 2016-10-06 (andbra)

Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2017-11-25Bibliographically approved
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