Change search
Link to record
Permanent link

Direct link
BETA
Publications (10 of 14) Show all publications
Jonsén, P., Hammarberg, S., Pålsson, B. & Lindkvist, G. (2019). Preliminary validation of a new way to model physical interactions between pulp, charge and mill structure in tumbling mills. Minerals Engineering, 130, 76-84
Open this publication in new window or tab >>Preliminary validation of a new way to model physical interactions between pulp, charge and mill structure in tumbling mills
2019 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 130, p. 76-84Article in journal (Refereed) Published
Abstract [en]

Modelling of wet grinding in tumbling mills is an interesting challenge. A key factor is that the pulp fluid and its simultaneous interactions with both the charge and the mill structure have to be handled in a computationally efficient way. In this work, the pulp fluid is modelled with a Lagrange based method based on the particle finite element method (PFEM) that gives the opportunity to model free surface flow. This method gives robustness and stability to the fluid model and is efficient as it gives possibility to use larger time steps. The PFEM solver can be coupled to other solvers as in this case both the finite element method (FEM) solver for the mill structure and the DEM solver for the ball charge. The combined PFEM-DEM-FEM model presented here can predict charge motion and responses from the mill structure, as well as the pulp liquid flow and pressure. All cases presented here are numerically modelled and validated against experimentally measured driving torque signatures from an instrumented small-scale batch ball mill equipped with a torque meter and charge movements captured from high-speed video. Numerical results are in good agreement with experimental torque measurements and the PFEM solver also improves on efficiency and robustness for solving charge movements in wet tumbling mill systems.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Grinding, Modelling, Simulation, Validation
National Category
Applied Mechanics Metallurgy and Metallic Materials
Research subject
Solid Mechanics; Mineral Processing
Identifiers
urn:nbn:se:ltu:diva-71226 (URN)10.1016/j.mineng.2018.10.013 (DOI)000452937000010 ()2-s2.0-85054850385 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-10-16 (svasva)

Available from: 2018-10-16 Created: 2018-10-16 Last updated: 2019-02-01Bibliographically approved
Lindkvist, G., Ahlin, H. & Oldenburg, M. (2015). Hot Stamping of Tailored Component: Experiments and Numerical Analysis (ed.). In: (Ed.), Kurt Steinhoff; Mats Oldenburg; Braham Prakash (Ed.), Hot Sheet Metal Forming of High-Performance Steel 5th International Conference: May 31-June 3, Toronto, Canada : Proceedings. Paper presented at International Conference on Hot Sheet Metal Forming of High-Performance Steel : 31/05/2015 - 03/06/2015 (pp. 755-763). Auerbach: Verlag Wissenschaftliche Scripten
Open this publication in new window or tab >>Hot Stamping of Tailored Component: Experiments and Numerical Analysis
2015 (English)In: Hot Sheet Metal Forming of High-Performance Steel 5th International Conference: May 31-June 3, Toronto, Canada : Proceedings / [ed] Kurt Steinhoff; Mats Oldenburg; Braham Prakash, Auerbach: Verlag Wissenschaftliche Scripten , 2015, p. 755-763Conference paper, Published paper (Refereed)
Abstract [en]

This study is concerned with plasticity and ductile fracture modelling aspects of press hardened steels, where multiple phases of different yield strength, work hardening and ductility are present. Macroscopic constitutive properties are determined using a semi-analytical approach termed Mean Field Homogenization (MFH), based on the properties of individual phases and micro-topology. This is combined with a phenomenological ductile fracture initiation criterion formulated in stress space at the microscopic scale. Localization enhanced kinematics are introduced at the macro-scale when instability is signaled by a local bifurcation analysis of the homogenized material. Discontinuities in the strain field are introduced into a quadrilateral shell based on the weak discontinuity approach. Fracture properties and flow curves up to large strains are determined from single phase tensile experiments using digital image correlation. The predictions of the integrated MFH and fracture model is compared with experimental results on steel sheets with different thermal histories, in terms of fracture prediction and and overall mechanical properties

Place, publisher, year, edition, pages
Auerbach: Verlag Wissenschaftliche Scripten, 2015
Series
CHS2-Series ; 5
National Category
Applied Mechanics Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Solid Mechanics; Machine Elements
Identifiers
urn:nbn:se:ltu:diva-27482 (URN)0f433d10-620c-4da7-bff7-72e03ee5e644 (Local ID)9783957350237 (ISBN)0f433d10-620c-4da7-bff7-72e03ee5e644 (Archive number)0f433d10-620c-4da7-bff7-72e03ee5e644 (OAI)
Conference
International Conference on Hot Sheet Metal Forming of High-Performance Steel : 31/05/2015 - 03/06/2015
Note
Validerad; 2016; Nivå 1; 20160429 (andbra)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-04-12Bibliographically approved
Aidanpää, J.-O. & Lindkvist, G. (2011). Dynamics of a rubbing Jeffcott rotor with three blades (ed.). In: (Ed.), Christos H. Skiadas; Ioannis Dimotikalis; Charilaos Skiadas (Ed.), Chaos Theory: Modeling, Simulation and Applications: Selected Papers from the 3rd Chaotic Modeling and Simulation International Conference (CHAOS2010). Paper presented at Chaotic Modeling and Simulation International Conference : CHAOS 2010 01/06/2010 - 04/06/2010 (pp. 97-104). Singapore: World Scientific Publishing Co Pte Ltd, Part II. Invited and Contributed Papers
Open this publication in new window or tab >>Dynamics of a rubbing Jeffcott rotor with three blades
2011 (English)In: Chaos Theory: Modeling, Simulation and Applications: Selected Papers from the 3rd Chaotic Modeling and Simulation International Conference (CHAOS2010) / [ed] Christos H. Skiadas; Ioannis Dimotikalis; Charilaos Skiadas, Singapore: World Scientific Publishing Co Pte Ltd , 2011, Vol. Part II. Invited and Contributed Papers, p. 97-104Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Singapore: World Scientific Publishing Co Pte Ltd, 2011
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-35409 (URN)9f0e05f2-8bdc-4fcf-9056-8fa93c695659 (Local ID)978-981-4350-33-4 (ISBN)9f0e05f2-8bdc-4fcf-9056-8fa93c695659 (Archive number)9f0e05f2-8bdc-4fcf-9056-8fa93c695659 (OAI)
Conference
Chaotic Modeling and Simulation International Conference : CHAOS 2010 01/06/2010 - 04/06/2010
Note
Godkänd; 2011; 20111230 (gorlind)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-04-12Bibliographically approved
Lindkvist, G., Häggblad, H.-Å. & Oldenburg, M. (2011). Numerical prediction of failure in high temperature formblowing and hardening (ed.). In: (Ed.), Mats Oldenburg; Kurt Steinhoff; Braham Prakash (Ed.), Hot sheet metal forming of high-performance steel, CHS2: 3rd international conference, Proceedings. Kassel, Germany, June 13-17, 2011. Paper presented at International Conference on Hot Sheet Metal Forming of High-Perfomance Steel : 13/06/2011 - 17/06/2011 (pp. 57-64). Auerbach: Verlag Wissenschaftliche Scripten
Open this publication in new window or tab >>Numerical prediction of failure in high temperature formblowing and hardening
2011 (English)In: Hot sheet metal forming of high-performance steel, CHS2: 3rd international conference, Proceedings. Kassel, Germany, June 13-17, 2011 / [ed] Mats Oldenburg; Kurt Steinhoff; Braham Prakash, Auerbach: Verlag Wissenschaftliche Scripten , 2011, p. 57-64Conference paper, Published paper (Refereed)
Abstract [en]

The process studied in this work is high temperature formblowing and hardening (HTFH). Bursting failure is an irrecoverable failure mode present in the HTFH process. The main objective was to determine if a ductile fracture criterion would be possible to use as pre-bursting failure indicator in finite element (FE) simulations of the forming process. The failure criterion was implemented in the utilised FE code. Calibration was performed by the use of analytical forming limit curves (FLC:s). The FLC:s were derived from experimentally obtained stress-strain curves for different temperatures using theory for localised necking. Experiments with the HTFH process in the form of burst tests were performed. Experimental data and output from thermomechanical FE simula-tions of the process were compared. Results indicated that the implemented numerical criterion predicted failure prior to irrecoverable experimental failure. It is concluded that the implemented fracture criterion can be used as a failure indicator in FE simulations of the HTFH process.

Place, publisher, year, edition, pages
Auerbach: Verlag Wissenschaftliche Scripten, 2011
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-37932 (URN)c206228b-0782-492d-bbde-af3086105bbb (Local ID)978-3-942267-17-5 (ISBN)c206228b-0782-492d-bbde-af3086105bbb (Archive number)c206228b-0782-492d-bbde-af3086105bbb (OAI)
Conference
International Conference on Hot Sheet Metal Forming of High-Perfomance Steel : 13/06/2011 - 17/06/2011
Note
Godkänd; 2011; 20111230 (gorlind)Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2018-04-12Bibliographically approved
Oldenburg, M. & Lindkvist, G. (2011). Tool thermal conditions for tailored material properties (ed.). Paper presented at . HTM: Journal of Heat Treatment and Materials: Zeitschrift für Werkstoffe, Wärmebehandlung, Fertigung, 66(6), 329-334
Open this publication in new window or tab >>Tool thermal conditions for tailored material properties
2011 (English)In: HTM: Journal of Heat Treatment and Materials: Zeitschrift für Werkstoffe, Wärmebehandlung, Fertigung, ISSN 0341-101X, Vol. 66, no 6, p. 329-334Article in journal (Refereed) Published
Abstract [en]

With the press hardening technology it is possible to produce components with tailor- made material properties. The present work is based on a comprehensive thermo-mechanical material model for simulation of press hardening and similar processes. The model accounts for and predicts time dependent and timeindependent phase transformations, mechanical and thermal properties as well as transformation plasticity during the complete cooling and deformation process from 900 °C to room temperature. The model predicts the microstructure evolution during the complete process as well as the final fractions. The thermal contact properties and the thermal properties in the tools have influence on the final material state. Solutions for tool heating and cooling for manufacturing of components with soft zones are studied. Based on the results from the press hardening simulations, thermal properties of special tool materials are taken into account in order to optimise the manufacturing thermal cycle.

National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-8662 (URN)73169046-65a9-4783-becd-caaae6440e45 (Local ID)73169046-65a9-4783-becd-caaae6440e45 (Archive number)73169046-65a9-4783-becd-caaae6440e45 (OAI)
Note
Godkänd; 2011; 20111230 (gorlind)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-04-12Bibliographically approved
Oldenburg, M. & Lindkvist, G. (2011). Tool thermal cycle design for manufacturing of components with tailored material properties (ed.). In: (Ed.), Mats Oldenburg; Kurt Steinhoff; Braham Prakash (Ed.), Hot sheet metal forming of high-performance steel, CHS2: 3rd international conference, June 13-17 2011, Kassel, Tyskland. Proceedings. Paper presented at International Conference on Hot Sheet Metal Forming of High-Perfomance Steel : 13/06/2011 - 17/06/2011 (pp. 203-2010). Auerbach: Verlag Wissenschaftliche Scripten
Open this publication in new window or tab >>Tool thermal cycle design for manufacturing of components with tailored material properties
2011 (English)In: Hot sheet metal forming of high-performance steel, CHS2: 3rd international conference, June 13-17 2011, Kassel, Tyskland. Proceedings / [ed] Mats Oldenburg; Kurt Steinhoff; Braham Prakash, Auerbach: Verlag Wissenschaftliche Scripten , 2011, p. 203-2010Conference paper, Published paper (Refereed)
Abstract [en]

With the press hardening technology, it is possible to produce automotive structural components with a tailor-made material property distribution. The properties can range from a soft ferrite dominated micro-structure to ultra-high strength martensitic structure. Tailor-made material prop-erty distribution is especially useful in components subjected to crash deformation. With this tech-nique it is possible to account for structural integrity and in the same time maximize the energy absorption in the structure. The present work is based on a comprehensive thermo-mechanical material model for simulation of press hardening and similar processes. The model accounts for and predicts time dependent and time-independent phase transformations, mechanical and thermal properties as well as transformation plasticity during the complete cooling and deformation proc-ess from 900 oC to room temperature. The model predicts the microstructure evolution during the complete process and the final fractions of martensite, bainite, perlite and ferrite. The thermal properties in the contact between the blank and the tools as well as the thermal properties in the tools have influence on the processes for tailor-made material properties. In this work, solutions for tool heating and cooling in the design of tools for manufacturing of components with soft zones are studied. Based on the results from the press hardening simulations, thermal properties of special tool materials are taken into account in order to optimise the manufacturing thermal cycle.

Place, publisher, year, edition, pages
Auerbach: Verlag Wissenschaftliche Scripten, 2011
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-39416 (URN)e2bf9256-a4e8-4812-95fc-fd54b44349fb (Local ID)978-3-942267-17-5 (ISBN)e2bf9256-a4e8-4812-95fc-fd54b44349fb (Archive number)e2bf9256-a4e8-4812-95fc-fd54b44349fb (OAI)
Conference
International Conference on Hot Sheet Metal Forming of High-Perfomance Steel : 13/06/2011 - 17/06/2011
Note
Godkänd; 2011; 20111209 (mo)Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2018-04-12Bibliographically approved
Lindkvist, G. (2010). Characterisation methods and simulation of deformation and failure in metal forming processes (ed.). (Doctoral dissertation). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Characterisation methods and simulation of deformation and failure in metal forming processes
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Tools for numerical analysis is a prerequisite in product development. Variations of the finite element method is widely used for simulation of metal manufacturing processes, for example sheet metal forming and hot stamping. However accurate the models are, there is still the issue of parameter estimation for the constitutive models used in the simulations.The increased use of high-strength steel in metal manufacturing processes necessitates forming at elevated temperatures. Formblowing and hardening (FH), where an austenitized profile blank is formed in a closed tool by injection of pressurised gas followed by rapid water cooling, is a recent development.The objectives are to increase knowledge regarding: characterisation methods for parameter estimation in constitutive models; numerical simulations of metal forming processes at elevated temperatures.Experimental material characterisation tests have been performed for deformation levels beyond plastic instability in standard tests. Methods for field measurements of deformation have been applied. Measurements were combined with inverse modelling for parameter estimation. Thermomechanical simulation models of the FH process have been developed. Complete process simulations were performed and compared with experiments. A pre-bursting failure criteria were implemented and compared with experimental burst tests.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2010. p. 34
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-18511 (URN)8f9d72f0-1641-11df-bae5-000ea68e967b (Local ID)978-91-7439-084-1 (ISBN)8f9d72f0-1641-11df-bae5-000ea68e967b (Archive number)8f9d72f0-1641-11df-bae5-000ea68e967b (OAI)
Note
Godkänd; 2010; 20100210 (gorlind); DISPUTATION Ämnesområde: Hållfasthetslära/Solid Mechanics Opponent: Professor Larsgunnar Nilsson, Linköpings universitet Ordförande: Professor Hans-Åke Häggblad, Luleå tekniska universitet Tid: Fredag den 12 mars 2010, kl 10.00 Plats: E 231, Luleå tekniska universitetAvailable from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-04-12Bibliographically approved
Oldenburg, M. & Lindkvist, G. (2010). Micro-structure evolution in the press hardening process with respect to tool and contact thermal properties (ed.). In: (Ed.), K. Mori; M. Pietrzyk; J. Kusiak; J. Majta; P. Hartley; J. Llin (Ed.), Proceedings of the 13th International Conference on Metal Forming: September 19 - 22, 2010, Hotel Nikko Toyohashi, Toyohashi, Japan. Paper presented at International Conference on Metal Forming : 19/09/2010 - 22/09/2010 (pp. 865-868). Weinheim: Wiley-VCH Verlagsgesellschaft
Open this publication in new window or tab >>Micro-structure evolution in the press hardening process with respect to tool and contact thermal properties
2010 (English)In: Proceedings of the 13th International Conference on Metal Forming: September 19 - 22, 2010, Hotel Nikko Toyohashi, Toyohashi, Japan / [ed] K. Mori; M. Pietrzyk; J. Kusiak; J. Majta; P. Hartley; J. Llin, Weinheim: Wiley-VCH Verlagsgesellschaft, 2010, p. 865-868Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Weinheim: Wiley-VCH Verlagsgesellschaft, 2010
Series
Steel Research International ; Special edition 2010
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-32384 (URN)6e09a850-cbb5-11df-a707-000ea68e967b (Local ID)978-3-514-00774-1 (ISBN)6e09a850-cbb5-11df-a707-000ea68e967b (Archive number)6e09a850-cbb5-11df-a707-000ea68e967b (OAI)
Conference
International Conference on Metal Forming : 19/09/2010 - 22/09/2010
Note
Godkänd; 2010; 20100929 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-04-12Bibliographically approved
Lindkvist, G., Häggblad, H.-Å. & Oldenburg, M. (2009). Thermo-mechanical simulation of high temperature formblowing and hardening (ed.). In: (Ed.), Mats Oldenburg; Kurt Steinhoff; Braham Parkash (Ed.), Hot sheet metal forming of high-performance steel, CHS2: 2nd international conference, June 15-17 2009, Luleå, Sweden. Proceedings. Paper presented at International Conference on Hot Sheet Metal Forming of High-Performance Steel : 15/06/2009 - 17/06/2009 (pp. 247-254). Bad Harzburg: GRIPS media
Open this publication in new window or tab >>Thermo-mechanical simulation of high temperature formblowing and hardening
2009 (English)In: Hot sheet metal forming of high-performance steel, CHS2: 2nd international conference, June 15-17 2009, Luleå, Sweden. Proceedings / [ed] Mats Oldenburg; Kurt Steinhoff; Braham Parkash, Bad Harzburg: GRIPS media , 2009, p. 247-254Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Bad Harzburg: GRIPS media, 2009
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-28760 (URN)2a8da2c0-5f19-11de-9f57-000ea68e967b (Local ID)978-3-937524-84-9 (ISBN)2a8da2c0-5f19-11de-9f57-000ea68e967b (Archive number)2a8da2c0-5f19-11de-9f57-000ea68e967b (OAI)
Conference
International Conference on Hot Sheet Metal Forming of High-Performance Steel : 15/06/2009 - 17/06/2009
Note
Godkänd; 2009; 20090622 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-04-12Bibliographically approved
Lindkvist, G. (2007). Simulering av formblåsning (ed.). In: (Ed.), Niklas Davidsson; Elianne Wassvik (Ed.), Svenska Mekanikdagar 2007: Program och abstracts. Paper presented at Svenska Mekanikdagar 2007 : 13/06/2007 - 15/06/2007 (pp. 71). Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Simulering av formblåsning
2007 (Swedish)In: Svenska Mekanikdagar 2007: Program och abstracts / [ed] Niklas Davidsson; Elianne Wassvik, Luleå: Luleå tekniska universitet, 2007, p. 71-Conference paper, Meeting abstract (Other academic)
Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2007
Series
Research report / Luleå University of Technology, ISSN 1402-1528 ; 2007:10
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-27500 (URN)0f9c40f0-5bbc-11dc-a955-000ea68e967b (Local ID)0f9c40f0-5bbc-11dc-a955-000ea68e967b (Archive number)0f9c40f0-5bbc-11dc-a955-000ea68e967b (OAI)
Conference
Svenska Mekanikdagar 2007 : 13/06/2007 - 15/06/2007
Note
Godkänd; 2007; 20070905 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-04-12Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-4634-4373

Search in DiVA

Show all publications