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Larsson, S., Rodriguez Prieto, J. M., Gustafsson, G., Häggblad, H.-Å. & Jonsén, P. (2021). The particle finite element method for transient granular material flow: modelling and validation. Computational Particle Mechanics, 8(1), 135-155
Open this publication in new window or tab >>The particle finite element method for transient granular material flow: modelling and validation
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2021 (English)In: Computational Particle Mechanics, ISSN 2196-4378, Vol. 8, no 1, p. 135-155Article in journal (Refereed) Published
Abstract [en]

The prediction of transient granular material flow is of fundamental industrial importance. The potential of using numerical methods in system design for increasing the operating efficiency of industrial processes involving granular material flow is huge. In the present study, a numerical tool for modelling dense transient granular material flow is presented and validated against experiments. The granular materials are modelled as continuous materials using two different constitutive models. The choice of constitutive models is made with the aim to predict the mechanical behaviour of a granular material during the transition from stationary to flowing and back to stationary state. The particle finite element method (PFEM) is employed as a numerical tool to simulate the transient granular material flow. Use of the PFEM enables a robust treatment of large deformations and free surfaces. The fundamental problem of collapsing rectangular columns of granular material is studied experimentally employing a novel approach for in-plane velocity measurements by digital image correlation. The proposed numerical model is used to simulate the experimentally studied column collapses. The model prediction of the in-plane velocity field during the collapse agrees well with experiments.

Place, publisher, year, edition, pages
Springer, 2021
Keywords
Particle finite element method, Transient granular material flow, Constitutive modelling, Strain-rate-dependent strength, Digital image correlation
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-73197 (URN)10.1007/s40571-020-00317-6 (DOI)000515975800001 ()2-s2.0-85079217630 (Scopus ID)
Funder
EU, Horizon 2020, 636520
Note

Validerad;2021;Nivå 2;2021-01-22 (alebob);

Finansiär: KIC RawMaterials (17152)

Available from: 2019-03-14 Created: 2019-03-14 Last updated: 2023-09-05Bibliographically approved
Ramanenka, D., Gustafsson, G. & Jonsén, P. (2019). Influence of heating and cooling rate on the stress state of the brick lining in a rotary kiln using finite element simulations. Engineering Failure Analysis, 105, 98-109
Open this publication in new window or tab >>Influence of heating and cooling rate on the stress state of the brick lining in a rotary kiln using finite element simulations
2019 (English)In: Engineering Failure Analysis, ISSN 1350-6307, E-ISSN 1873-1961, Vol. 105, p. 98-109Article in journal (Refereed) Published
Abstract [en]

Rotary kilns for iron-ore pellets production are highly dependent on a well-functioned refractory brick lining. To improve the long-term capability of the lining, in-situ observations of the bricks' performance are desired, however, the harsh environment inside the rotary kiln makes it difficult or nearly impossible to study the lining during operation. By using numerical simulations as a tool, some of the problems encountered by the brick lining can be studied without limitation of the extreme conditions.

In this work, stress state of the lining was studied under the influence of different heating and cooling rates, and different brick compaction cases. A finite element model was created for conducting the numerical simulations. The numerical model was calibrated for transient heat transfer. Temperature dependent material properties of the bricks and casing were used as input. The heating and cooling was controlled by temperature prescription on the boundary of the brick lining, while brick lining compaction by defining relative position of the bricks in axial and radial directions.

The conducted numerical simulations showed that considerable tensile stress may appear in a large area of the brick during initial heating stage. The large tensile area corresponds well with the typical circumferential cracks experienced by the bricks. It was demonstrated that the compressive stresses counteract the development of tensile stresses. However, the compressive stresses may become very large in the initial stage of heating. The positive effect of lower heating rate was considerable on the tensile stresses, while influence on the compressive stresses was almost unnoticed. The hypothetical cooling rates showed that very high tensile stresses may occur on the surface of the bricks, potentially leading to surface spalling. Furthermore, it was demonstrated that axial compaction is highly important on the stress development in the lining, which, may not always be followed in practice. As a general conclusion, it is recommended to always achieve a tight compaction of the brick lining and to take measures for lowering the heating and cooling rates.

The conducted work exemplifies behaviour of the brick lining for realistic heat transfer and material properties. The insight into the behaviour gives possibilities to make adjustments and directed investments for lowering risk of brick lining failure.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
High temperature, Stress state, Refractory brick lining, Rotary kiln, Finite element method
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-68375 (URN)10.1016/j.engfailanal.2019.06.031 (DOI)000496188200009 ()2-s2.0-85068422246 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-07-08 (johcin)

Available from: 2018-04-16 Created: 2018-04-16 Last updated: 2023-09-05Bibliographically approved
Larsson, S., Gustafsson, G., Jonsén, P. & Häggblad, H.-Å. (2018). DEM-CFD Simulation of the Effect of Air on Powder Flow During Die Filling. In: ABSTRACTS: 13th World Congress on Computational Mechanics. Paper presented at 13th World Congress on Computational Mechanics (WCCM XIII), July 22-27, 2018, New York, NY, USA (pp. 1695-1695). IACM
Open this publication in new window or tab >>DEM-CFD Simulation of the Effect of Air on Powder Flow During Die Filling
2018 (English)In: ABSTRACTS: 13th World Congress on Computational Mechanics, IACM , 2018, p. 1695-1695Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

In the field of powder metallurgy (PM), complex components with complicated shapes can be manufactured. One important step in the PM process is the powder pressing process, where powder is consolidated during a forming operation into a desired shape, normally by applying pressure. During powder pressing, the mechanical properties of powder materials change dramatically. PM manufacturers tend to produce components with shapes of increasing complexity, requiring improved pressing equipment and methods. The most crucial aspect is to control the powder flow during die filling and the final powder density distribution after the filling stage, which has been shown to affect the strength of the final component significantly [1].

To investigate the non-homogeneity of the density of PM components, experimental studies combined with numerical simulations of the die filling stage are exploited.

This work covers the numerical modelling and simulation of die filling. The discrete element method (DEM) [2] was used to model the powder, and computational fluid dynamics (CFD) to model the air. To study the effect of air on powder flow, the DEM was coupled to the CFD using a two-way coupling approach. Experimental measurements with digital speckle photography (DSP) from a previous study [3] were used for comparison with the numerical simulations.

The comparison of the DSP measurements and the numerical simulations showed similar macroscopic flow characteristics. Thus, the adequacy of the proposed DEM-CFD model has been demonstrated in a metal powder die filling operation. The DEM-CFD method has been shown to be an effective method for the numerical simulation of the interaction between powder and air.

 

References

[1]   Zenger, D. & Cai, H. (1997). Handbook of the Common Cracks in Green P/M Compacts. Metal Powder Industries Federation, MPIF. Worcester, USA.

[2]   Cundall, P. A., & Strack, O. D. (1979). A discrete numerical model for granular assemblies. geotechnique, 29(1), 47-65.

[3]   Larsson, S., Gustafsson, G., Jonsén, P. & Häggblad, H.-Å. (2016). Study of Powder Filling Using Experimental and Numerical Methods.  In: World PM2016 Congress & Exhibition, Hamburg, October 9-13, 2016.

Place, publisher, year, edition, pages
IACM, 2018
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-71547 (URN)
Conference
13th World Congress on Computational Mechanics (WCCM XIII), July 22-27, 2018, New York, NY, USA
Note

ISBN för värdpublikation: 978-0-578-40837-8

Available from: 2018-11-12 Created: 2018-11-12 Last updated: 2023-09-05Bibliographically approved
Larsson, S., Gustafsson, G., Häggblad, H.-å. & Jonsén, P. (2018). Experimental and numerical study of potassium chloride flow using smoothed particle hydrodynamics. Minerals Engineering, 116, 88-100
Open this publication in new window or tab >>Experimental and numerical study of potassium chloride flow using smoothed particle hydrodynamics
2018 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 116, p. 88-100Article in journal (Refereed) Published
Abstract [en]

Materials in granular form are widely used in industry and in the society as a whole. Granular materials can have various behaviours and properties. An accurate prediction of their flow behaviour is important to avoid handling and transportation issues. In this study, the flow behaviour of dry potassium chloride (KCl) in granular form was investigated experimentally and simulated numerically. The aim was to develop numerical tools to predict the flow of KCl in transportation and handling systems and granular material flow in various industrial applications. Two experimental setups were used to quantify the flow of KCl. In the first setup, the collapse of an axisymmetric granular column was investigated. In the second setup, digital image correlation was used to obtain velocity field measurements of KCl during the discharge of a flat-bottomed silo. The two experiments were represented numerically using two-dimensional computational domains. The smoothed particle hydrodynamics method was used for the simulations, and a pressure-dependent, elastic-plastic constitutive model was used to describe the granular materials. The numerical results were compared to the experimental observations, and an adequate qualitative and quantitative agreement was found for the granular column collapse and the silo discharge. Overall, the simulated flow patterns showed adequate agreement with the experimental results obtained in this study and with the observations reported in the literature. The experimental measurements, in combination with the numerical simulations, presented in this study adds to the knowledge of granular material flow prediction. The results of this study highlights the potential of numerical simulation as a powerful tool to increase the knowledge of granular material handling operations.

Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-62669 (URN)10.1016/j.mineng.2017.11.003 (DOI)000424172900012 ()2-s2.0-85033796028 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-01-25 (andbra)

Available from: 2017-03-24 Created: 2017-03-24 Last updated: 2023-09-05Bibliographically approved
Larsson, S., Nishida, M., Kurano, S., Moroe, T., Gustafsson, G., Häggblad, H.-Å. & Jonsén, P. (2018). Modelling and characterisation of the high-rate behaviour of rock material. In: EPJ Web of Conferences: DYMAT 2018 - 12th International Conference on the Mechanical and Physical Behaviour of Materials under Dynamic Loading. Paper presented at DYMAT 2018 - 12th International Conference on the Mechanical and Physical Behaviour of Materials under Dynamic Loading, September 9-14, 2018, Arcachon, France. , 183, Article ID 01040.
Open this publication in new window or tab >>Modelling and characterisation of the high-rate behaviour of rock material
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2018 (English)In: EPJ Web of Conferences: DYMAT 2018 - 12th International Conference on the Mechanical and Physical Behaviour of Materials under Dynamic Loading, 2018, Vol. 183, article id 01040Conference paper, Published paper (Refereed)
Abstract [en]

For future reliable numerical simulations of impact wear on steel structures caused by rock material, knowledge about the dynamic mechanical properties of rock material is required. This paper describes the experimental and numerical work to investigate the dynamic mechanical properties of diabase (dolerite), a subvolcanic rock material. In this study, diabase from southern Sweden was used. The impact compressive strength of diabase with a density of 2.63 g/cm3 was examined by using the split-Hopkinson pressure bar (Kolsky bar) method. Cylindrical specimens were used, with a diameter of 8.9 mm and a length of 14 mm. To characterise the rock material, uniaxial compression tests were performed, at high strain rates (150 s-1). Using an inverse modelling approach, material parameters for an elastic constitutive model, with a stress-based fracture criterion were determined. The constitutive model was used in a finite element simulation of a high strain rate uniaxial compression test. Results obtained from the numerical model were in line with the experimental results.

National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-71544 (URN)10.1051/epjconf/201818301040 (DOI)000570191100038 ()2-s2.0-85053691363 (Scopus ID)
Conference
DYMAT 2018 - 12th International Conference on the Mechanical and Physical Behaviour of Materials under Dynamic Loading, September 9-14, 2018, Arcachon, France
Available from: 2018-11-12 Created: 2018-11-12 Last updated: 2023-09-05Bibliographically approved
Gustafsson, G. & Larsson, S. (2018). Numerical modelling, simulation and validation of icing on a wind turbine blade. In: : . Paper presented at 13th World Congress on Computational Mechanics (WCCM XIII), July 22-27, 2018, New York, NY, USA (pp. 1069-1069). IACM
Open this publication in new window or tab >>Numerical modelling, simulation and validation of icing on a wind turbine blade
2018 (English)Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Today there is a strong development of wind power in northern Sweden, where risk for icing conditions is present. Icing of the blades leads to changing load conditions, production loss and risk of overloading the machine components. When the ice loose from the blades, the ice throw can lead to both physical damage and personal injury. Uncertainties around these issues threaten the planned expansion in the northernmost regions. Prediction of loads and production losses are of great importance for the durability and economy of wind power plants [[i]]. A thrust worthy numerical model of ice loads on wind turbines will be a valuable tool for minimizing the costs due to damage and production losses caused by icing.

This work presents a numerical model for simulating ice accretion on a wind turbine blade in lab-scale. It is a multi-physic model with interaction of three phases: the air, the water droplets and the wind turbine blade. The air flow is modelled with incompressible fluid dynamics (ICFD), the water droplets in the air is modelled with the discrete element method (DEM) and the wind turbine blade is modelled with the finite element method (FEM). A two way coupling is used for the interaction between the air and the water droplets and between the air and the wind turbine blade. A freezing condition controls the ice accretion when the water droplets hits the wing profile. The simulation is compared with a lab-scale experiment of ice accretion of a wind turbine profile in a wind tunnel found in literature [[ii]]. The experiment is well documented with well defined parameters such as: temperature, wind velocity, water content in the air, size of the water droplets, wing profile and angle of attack. Two simulations were done for two different angles of attack and validated by comparing ice profiles on the blades numerically and experimentally for the two cases. Similar ice profiles were found numerically and experimentally.

[[i]]             IEA Wind Recommended Practice 13: Wind Energy in Cold Climates, 2012.

 

[[ii]]                         C. Hochart et. al., “Wind Turbine Performance under Icing Conditions”, Wind Energy, 11, 319-333 (2008)

 

Place, publisher, year, edition, pages
IACM, 2018
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-71528 (URN)
Conference
13th World Congress on Computational Mechanics (WCCM XIII), July 22-27, 2018, New York, NY, USA
Note

ISBN för värdpublikation: 978-0-578-40837-8

Available from: 2018-11-09 Created: 2018-11-09 Last updated: 2020-08-21Bibliographically approved
Ramanenka, D., Antti, M.-L., Gustafsson, G. & Jonsén, P. (2017). Characterization of high-alumina refractory bricks and modelling of hot rotary kiln behaviour. Engineering Failure Analysis, 79, 852-864
Open this publication in new window or tab >>Characterization of high-alumina refractory bricks and modelling of hot rotary kiln behaviour
2017 (English)In: Engineering Failure Analysis, ISSN 1350-6307, E-ISSN 1873-1961, Vol. 79, p. 852-864Article in journal (Refereed) Published
Abstract [en]

Rotary kilns for iron-ore pellets production are highly dependent on a well-functioning refractory brick lining. To improve the long-term capability of the lining, in-situ observations of the bricks' performance are desired, however, the high process temperatures and the size of the kiln make it difficult to study the lining during operation. By using numerical simulations as a tool, some of the problems encountered by the brick lining can be studied. Knowing material properties of the refractory bricks as input in a numerical model is therefore necessary. However, material properties are poorly documented for this type of materials, especially, at elevated temperatures. In this work three commercial aluminasilicate bricks were tested in compression until failure for a temperature range of 25–1300 °C. The purpose was to evaluate compression strength and Young's modulus in compression of the fully burned bricks at a wide range of temperatures. The data was later used for modelling of a hot rotary kiln lined with bricks by using the finite element method, whereupon load state of the lining was evaluated at steady state after the expansion of the system. The objective of the numerical modelling was to investigate trustworthiness of the model and to give insight into the stress levels that can potentially arise. It was found that for all of the investigated brick types the compression strength increased with increased temperature, having a peak in the vicinity of 1000 °C. The maximum increase was between 50 and 150 % for the different brick types. After passing 1100 °C the compression strength rapidly and considerably decreased below its as-received compression strength. Young's modulus was measured to vary between 2 and 10 GPa in the range of up to 1000 °C. The numerical results indicate that severe boundary conditions (expansion of the lining is highly restricted) can potentially lead to compression stress of up to 34 MPa in the brick lining at steady state. However, at these boundary conditions the present tensile stress was only 0.5 MPa, while tensile stresses of close to 3 MPa could be observed in the lining with mild boundary conditions. The authors conclude that the created model is trustworthy and that it has high potential for being used as a tool in further investigations of the lining in hot state.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Applied Mechanics Other Materials Engineering
Research subject
Solid Mechanics; Engineering Materials
Identifiers
urn:nbn:se:ltu:diva-63536 (URN)10.1016/j.engfailanal.2017.04.038 (DOI)000405538800068 ()2-s2.0-85020181003 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-06-14 (rokbeg)

Available from: 2017-05-26 Created: 2017-05-26 Last updated: 2023-09-05Bibliographically approved
Larsson, S., Gustafsson, G., Jonsén, P. & Häggblad, H.-Å. (2017). Experimental and numerical study of granular flow using particle methods: application in handling of potassium chloride. In: : . Paper presented at Computational Modelling '17, Falmouth, Cornwall, UK, June 13-14, 2017.
Open this publication in new window or tab >>Experimental and numerical study of granular flow using particle methods: application in handling of potassium chloride
2017 (English)Conference paper, Oral presentation only (Refereed)
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-74073 (URN)
Conference
Computational Modelling '17, Falmouth, Cornwall, UK, June 13-14, 2017
Available from: 2019-05-28 Created: 2019-05-28 Last updated: 2023-09-05Bibliographically approved
Gustafsson, G., Häggblad, H.-å., Nishida, M., Larsson, S. & Jonsén, P. (2017). Fracture probability modelling of impact-loaded iron ore pellets. International Journal of Impact Engineering, 102, 180-186
Open this publication in new window or tab >>Fracture probability modelling of impact-loaded iron ore pellets
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2017 (English)In: International Journal of Impact Engineering, ISSN 0734-743X, E-ISSN 1879-3509, Vol. 102, p. 180-186Article in journal (Refereed) Published
Abstract [en]

Blast furnace iron ore pellets are sintered, centimetre-sized ore spheres with a high iron content. Together with carbonized coal, iron ore pellets are used in the production of steel. In transporting pellets from pelletizing plants to customers, iron ore pellets are exposed to different static and dynamic loading situations, resulting in strength degradation and, in some cases, fragmentation. This can lead to a reduced gas flow in the blast furnace, which causes reduced quality in steel production. Reliable numerical simulations that can predict the ability of the pellets to endure their handling are important tools for optimizing the design of equipment for iron ore handling. This paper describes the experimental and numerical work performed to investigate the impact fracture behaviour of iron ore pellets at different strain rates. A number of split Hopkinson pressure bar tests with different striker velocities are carried out and analysed to investigate the strain rate dependency of the fracture strength of iron ore pellets. Fracture data for iron ore pellets are derived and expressed in terms of statistical means and standard deviations. A stress based, strain-rate dependent fracture model that takes triaxiality into account is suggested. The fracture model is used and validated with impact tests of iron ore pellets. In the validation experiment, iron ore pellets are fired against a steel plate, and the percentage of fractured pellets at different impact velocities are measured. Finite element simulations of the experiment are carried out and the probability of pellets fracturing during impact are calculated and compared with the experimental results. The agreement between the experiments and numerical simulations shows the validity of the model.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-61326 (URN)10.1016/j.ijimpeng.2016.12.014 (DOI)000393001400017 ()2-s2.0-85008350828 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-01-09 (andbra)

Available from: 2017-01-09 Created: 2017-01-09 Last updated: 2023-09-05Bibliographically approved
Ramanenka, D., Gustafsson, G. & Jonsén, P. (2017). Modelling of Hot Rotary Kiln. In: : . Paper presented at 11th European LS-DYNA Conference, Salzburg, Austria, 9-11 May 2017.
Open this publication in new window or tab >>Modelling of Hot Rotary Kiln
2017 (English)Conference paper, Published paper (Refereed)
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-63626 (URN)
Conference
11th European LS-DYNA Conference, Salzburg, Austria, 9-11 May 2017
Available from: 2017-05-31 Created: 2017-05-31 Last updated: 2023-09-05Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-3907-0802

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