Change search
Link to record
Permanent link

Direct link
Publications (10 of 12) Show all publications
Wessling, A. (2024). Heterogeneous Bonded Particle Modelling of Rock Fracture. (Doctoral dissertation). Luleå: Luleå University of Technology
Open this publication in new window or tab >>Heterogeneous Bonded Particle Modelling of Rock Fracture
2024 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The dynamic fracture process of rock materials is of importance for several industries, such as the rock drilling process in geothermal and mining applications. Gaining knowledge and understanding of dynamic rock fracture through numerical simulations can enhance the rock drilling process, for example by optimising the drill bit geometry and drilling parameters. In order for a numerical simulation of rock fracture processes to be accurate, the model needs to be able to capture key aspects of rock materials. Generally, rock materials are said to be britle and heterogeneous. The heterogeneity is partly due to the varying mechanical properties of constituent minerals, and partly due to the varying sizes, shapes, and directions of these minerals. The main objective of this thesis is the development of a heterogeneous rock model to be used for dynamic drilling processes. In the first article in this thesis, a heterogeneous bonded particle model is developed. Here, the heterogeneity is introduced in two steps – a geometrical heterogeneity using statistically distributed grain shapes and sizes, and a mechanical heterogeneity by distributing bonding parameters using a Weibull distribution. The model is applied to the quasi-static Brazilian disc test and a parametric study is conducted on the heterogeneity index and intergranular cement strength. The results show that crack initiation and propagation are highly dependent on the degree of heterogeneity. In general, the model was found to replicate typical phenomena associated with britle heterogeneous materials, for example unpredictability of macroscopic strength and crack properties. In the second paper of this thesis, an extensive dynamic experimental characterization of two igneous rock materials – Kuru grey granite and Kuru black diorite – is conducted. Here, a Split-Hopkinson configuration together with high-speed photography and digital image correlation is utilized to obtain the compressive and indirect tensile behavior of the rock materials. By using a significantly high frame rate of 671,000 fps in the digital image correlation analysis, it is shown that the point in time for crack initiation in the Brazilian disc can be estimated. From this, it is shown that the main splititng crack in the Brazilian disc occurs at 70 and 77 % for the two rock materials. In the third paper of this thesis, the heterogeneous bonded particle model from the first paper is further developed and calibrated using the dynamic experimental data for Kuru black diorite from the second paper. In contrast to the first paper, where one Weibull distribution is used, three Weibull distributions are used here. The first distribution is used for assigning average bonding parameters of the grains, the second for the intragranular bonding parameters and the third for the bonding parameters of the intergranular cementing. First, a homogeneous bonded particle model, i.e., without heterogeneous grains and no statistical distribution of bonding parameters, is calibrated so that the average experimental results are replicated. Then, using this homogeneously calibrated model, the heterogeneous model is activated, and a parametric study is conducted on the heterogeneity index for the average grain properties and the intergranular cement strength. The results show that this modelling approach is able to capture key phenomena of dynamic rock fracture, such as stochastic crack initiation and propagation, as well as peak stress, overloading, strain rate and crack propagation time. In the fourth paper, the proposed heterogeneous bonded particle model from previous papers is validated using a laboratory rock drilling experiment. The rock material is dynamically characterized using the methodology from the second paper and the grain structure is obtained from a scan of the rock surface. Three of the constituent minerals are represented in the model in terms of their size, occurrence, and mechanical properties. Furthermore, the model is calibrated in both compression and tension, where both the peak stress values and fracture behavior are captured. The model is then used to simulate the laboratory rock drilling experiment, where crater depth, load and rock fragment sizes are compared with the experiments. The results show that the simulation is able to capture peak load values and the rock fragment sizes are similar to that of the experiments.

Place, publisher, year, edition, pages
Luleå: Luleå University of Technology, 2024
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
Keywords
Rock, DEM, BPM, fracture, drilling, dynamic
National Category
Other Civil Engineering
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-104684 (URN)978-91-8048-505-0 (ISBN)978-91-8048-506-7 (ISBN)
Public defence
2024-05-16, E632, Luleå University of Technology, Luleå, 09:00 (English)
Opponent
Supervisors
Available from: 2024-03-21 Created: 2024-03-19 Last updated: 2024-04-25Bibliographically approved
Wessling, A., Larsson, S. & Kajberg, J. (2023). A statistical bonded particle model study on the effects of rock heterogeneity and cement strength on dynamic rock fracture. Computational Particle Mechanics
Open this publication in new window or tab >>A statistical bonded particle model study on the effects of rock heterogeneity and cement strength on dynamic rock fracture
2023 (English)In: Computational Particle Mechanics, ISSN 2196-4378Article in journal (Refereed) Epub ahead of print
Abstract [en]

Numerical modelling and simulation can be used to gain insight about rock excavation processes such as rock drilling. Since rock materials are heterogeneous by nature due to varying mechanical and geometrical properties of constituent minerals, laboratory observations exhibit a certain degree of unpredictability, e.g. with regard to measured strength and crack propagation. In this work, a recently published heterogeneous bonded particle model is further developed and used to investigate dynamic rock fracture in a Brazilian disc test. The rock heterogeneities are introduced in two steps—a geometrical heterogeneity due to statistically distributed grain sizes and shapes, and a mechanical heterogeneity by distributing mechanical properties using three Weibull distributions. The first distribution is used for assigning average bond properties of the grains, the second one for the intragranular bond properties and the third one for the bond properties of the intergranular cementing. The model is calibrated for Kuru black diorite using previously published experimental data from high-deformation rate tests of Brazilian discs in a split-Hopkinson pressure bar device, where high-speed imaging was used to detect initiations of cracks and their growth. A parametric study is conducted on the Weibull heterogeneity index of the average bond properties and the grain cement strength and evaluated in terms of crack initiation and propagation, indirect tensile stress, strain and strain rate. The results show that this modelling approach is able to reproduce key phenomena of the dynamic rock fracture, such as stochastic crack initiation and propagation, as well as the magnitude and variations of measured quantities. Furthermore, the cement strength is found to be a key parameter for crack propagation path and time, overloading magnitudes and indirect tensile strain rate.

Place, publisher, year, edition, pages
Springer Nature, 2023
Keywords
DEM, Heterogeneous, Rock, Split-Hopkinson pressure bar
National Category
Other Civil Engineering
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-103013 (URN)10.1007/s40571-023-00688-6 (DOI)001103979400001 ()2-s2.0-85176935312 (Scopus ID)
Projects
DigiRock
Funder
Vinnova, 2021-04695
Note

Full text license: CC BY

Available from: 2023-11-27 Created: 2023-11-27 Last updated: 2024-03-19
Wessling, A., Larsson, S., Jonsén, P. & Kajberg, J. (2022). A Brittle and Heterogeneous Bonded Discrete Element Model of Wide Applicability. In: Pär Jonsén; Lars-Göran Westerberg; Simon Larsson; Erik Olsson (Ed.), Svenska Mekanikdagar 2022: . Paper presented at Svenska Mekanikdagarnam2022, Luleå, Sweden, June 15-16, 2022. Luleå tekniska universitet
Open this publication in new window or tab >>A Brittle and Heterogeneous Bonded Discrete Element Model of Wide Applicability
2022 (English)In: Svenska Mekanikdagar 2022 / [ed] Pär Jonsén; Lars-Göran Westerberg; Simon Larsson; Erik Olsson, Luleå tekniska universitet, 2022Conference paper, Oral presentation with published abstract (Refereed)
Place, publisher, year, edition, pages
Luleå tekniska universitet, 2022
National Category
Other Materials Engineering
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-92496 (URN)
Conference
Svenska Mekanikdagarnam2022, Luleå, Sweden, June 15-16, 2022
Available from: 2022-08-16 Created: 2022-08-16 Last updated: 2023-09-05Bibliographically approved
Wessling, A., Larsson, S., Jonsén, P. & Kajberg, J. (2022). A statistical DEM approach for modelling heterogeneous brittle materials. Computational Particle Mechanics, 9(4), 615-631
Open this publication in new window or tab >>A statistical DEM approach for modelling heterogeneous brittle materials
2022 (English)In: Computational Particle Mechanics, ISSN 2196-4378, Vol. 9, no 4, p. 615-631Article in journal (Refereed) Published
Abstract [en]

By utilizing numerical models and simulation, insights about the fracture process of brittle heterogeneous materials can be gained without the need for expensive, difficult, or even impossible, experiments. Brittle and heterogeneous materials like rocks usually exhibit a large spread of experimental data and there is a need for a stochastic model that can mimic this behaviour. In this work, a new numerical approach, based on the Bonded Discrete Element Method, for modelling of heterogeneous brittle materials is proposed and evaluated. The material properties are introduced into the model via two main inputs. Firstly, the grains are constructed as ellipsoidal subsets of spherical discrete elements. The sizes and shapes of these ellipsoidal subsets are randomized, which introduces a grain shape heterogeneity Secondly, the micromechanical parameters of the constituent particles of the grains are given by the Weibull distribution. The model was applied to the Brazilian Disc Test, where the crack initiation, propagation, coalescence and branching could be investigated for different sets of grain cement strengths and sample heterogeneities. The crack initiation and propagation was found to be highly dependent on the level of heterogeneity and cement strength. Specifically, the amount of cracks initiating from the loading contact was found to be more prevalent for cases with higher cement strength and lower heterogeneity, while a more severe zigzag shaped crack pattern was found for the cases with lower cement strength and higher heterogeneity. Generally, the proposed model was found to be able to capture typical phenomena associated with brittle heterogeneous materials, e.g. the unpredictability of the strength in tension and crack properties.

Place, publisher, year, edition, pages
Springer Nature, 2022
Keywords
Bonded DEM, Heterogeneous brittle materials, Fracture, Brazilian disc, Weibull
National Category
Other Mechanical Engineering Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-83907 (URN)10.1007/s40571-021-00434-w (DOI)000692075800001 ()2-s2.0-85114114019 (Scopus ID)
Projects
GEOFIT
Funder
EU, Horizon 2020, 792210
Note

Validerad;2022;Nivå 2;2022-07-26 (hanlid)

Available from: 2021-04-23 Created: 2021-04-23 Last updated: 2024-03-19Bibliographically approved
Wessling, A., Kajberg, J., Larsson, S., Jonsén, P., Ramírez Sandoval, G. & Vilaseca Llosada, M. (2022). Discrete Element Modelling of Rock Drilling. In: European Geothermal Congress 2022: . Paper presented at European Geothermal Congress 2022, October 17-21, 2022, Berlin, Germany. , Article ID 272.
Open this publication in new window or tab >>Discrete Element Modelling of Rock Drilling
Show others...
2022 (English)In: European Geothermal Congress 2022, 2022, article id 272Conference paper, Published paper (Refereed)
Abstract [en]

Percussive rotary drilling is recognized as the mostefficient method for hard rock drilling. Despite clearadvantages over conventional rotary methods, there arestill some uncertainties associated with percussivedrilling. For geothermal applications, drilling accountsfor a large portion of the total cost. Specifically, thewear of drill bits when drilling in hard rock is apredominant cost factor and drilling parameters areoften based on the experience of the field operator.Within the framework of the H2020 project GEOFIT,numerical simulations of percussive drilling areperformed in order to evaluate the rock drilling processand gain insight about the trade-off between wear andRate of Penetration (ROP). In the simulations, the rockmaterial was represented by the Bonded DiscreteElement Method (BDEM), the drill bit by the FiniteElement Method (FEM), the drilling fluid by theParticle Finite Element Method (PFEM) and theabrasive wear on the surface of the drill bit wasrepresented by Archard’s wear law. The drillingsimulations were conducted for two rock materials; asedimentary rock material corresponding to what wasfound when drilling at the GEOFIT pilot site in AranIslands, Ireland, and a harder reference rock similar togranite. The results show that, at a drill bit impact forceof 10 kN, the ROP in the sedimentary rock was 6.3times faster than for granite. When increasing theimpact force to 40 and 50 kN, however, the ROP for thesedimentary rock is only 1.9 and 1.6 times faster,respectively. Furthermore, the wear rate decreased withincreased impact force when drilling in the granite rock.For the sedimentary rock, however, the loadingresulting in the best trade-off between abrasive wearand ROP was the second highest loading of 40 kN,which suggests that an increase in impact energy mayincrease the rate of penetration but may not beeconomically motivated.

National Category
Other Civil Engineering
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-96967 (URN)978-2-9601946-2-3 (ISBN)
Conference
European Geothermal Congress 2022, October 17-21, 2022, Berlin, Germany
Projects
GEOFIT
Available from: 2023-05-02 Created: 2023-05-02 Last updated: 2023-09-05Bibliographically approved
Wessling, A. & Kajberg, J. (2022). Dynamic Compressive and Tensile Characterisation of Igneous Rocks Using Split-Hopkinson Pressure Bar and Digital Image Correlation. Materials, 15(22), Article ID 8264.
Open this publication in new window or tab >>Dynamic Compressive and Tensile Characterisation of Igneous Rocks Using Split-Hopkinson Pressure Bar and Digital Image Correlation
2022 (English)In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 15, no 22, article id 8264Article in journal (Refereed) Published
Abstract [en]

The dynamic fracture process of rock materials is of importance for several industrial applications, such as drilling for geothermal installation. Numerical simulation can aid in increasing the understanding about rock fracture; however, it requires precise knowledge about the dynamical mechanical properties alongside information about the initiation and propagation of cracks in the material. This work covers the detailed dynamic mechanical characterisation of two rock materials—Kuru grey granite and Kuru black diorite—using a Split-Hopkinson Pressure Bar complemented with high-speed imaging. The rock materials were characterised using the Brazilian disc and uniaxial compression tests. From the high-speed images, the instant of fracture initiation was estimated for both tests, and a Digital Image Correlation analysis was conducted for the Brazilian disc test. The nearly constant tensile strain in the centre was obtained by selecting a rectangular sensing region, sufficiently large to avoid complicated local strain distributions appearing between grains and at voids. With a significantly high camera frame rate of 671,000 fps, the indirect tensile strain and strain rates on the surface of the disc could be evaluated. Furthermore, the overloading effect in the Brazilian disc test is evaluated using a novel methodology consisting of high-speed images and Digital Image Correlation analysis. From this, the overloading effects were found to be 30 and 23%. The high-speed images of the compression tests indicated fracture initiation at 93 to 95% of the peak dynamic strength for granite and diorite, respectively. However, fracture initiation most likely occurred before this in a non-observed part of the sample. It is concluded that the indirect tensile strain obtained by selecting a proper size of the sensing region combined with the high temporal resolution result in a reliable estimate of crack formation and subsequent propagation.

Place, publisher, year, edition, pages
MDPI, 2022
Keywords
rock, dynamic mechanical properties, fracture, high-speed imaging, digital image correlation, Split-Hopkinson pressure bar
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-94378 (URN)10.3390/ma15228264 (DOI)000887520400001 ()36431749 (PubMedID)2-s2.0-85142756512 (Scopus ID)
Funder
EU, Horizon 2020, 792210
Note

Validerad;2022;Nivå 2;2022-11-30 (joosat);

Available from: 2022-11-30 Created: 2022-11-30 Last updated: 2024-03-19Bibliographically approved
Wessling, A., Larsson, S., Jonsén, P. & Kajberg, J. (2022). Modelling Rock Fracture using the Stochastic Bonded Discrete Element Method. In: Book of Abstracts: WCCM-APCOM 2022: 15th World Congress on Computational Mechanics & 8th Asian Pacific Congress on Computational Mechanics, Yokohama, Japan Virtual. Paper presented at 15th World Congress in Computational Mechanics (WCCM XV) and 8th Asia Pacific Congress on Computational Mechanics (APCOM VIII), Yokohama, Japan [Virtual], July 31-August 5, 2022 (pp. 390-390). Barcelona: International Center for Numerical Methods in Engineering (CIMNE)
Open this publication in new window or tab >>Modelling Rock Fracture using the Stochastic Bonded Discrete Element Method
2022 (English)In: Book of Abstracts: WCCM-APCOM 2022: 15th World Congress on Computational Mechanics & 8th Asian Pacific Congress on Computational Mechanics, Yokohama, Japan Virtual, Barcelona: International Center for Numerical Methods in Engineering (CIMNE), 2022, p. 390-390Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Numerical modelling of the fracture of heterogeneous brittle materials is of interest for several industries, such as rock excavation and comminution applications. A numerical model of brittle materials needs to be able to capture the unpredictable results, e.g. with regards to measured strength and fracture pattern, as observed experimentally. In a previous work [1], the Bonded Discrete Element Method [2] was combined with statistical methods in order to generate heterogeneous rock bodies. Grains of random sizes and shapes, consisting of multiple bonded discrete elements, were generated in the body and the micromechanical parameters of these grains were governed by the Weibull distribution [3]. In this work, this modelling approach was used to evaluate the fracture behaviour of experiments commonly found within the field of rock mechanics - the unconfined and confined axial compression test, Brazilian disc test and the three point bend test. For each test, a large set of numerical samples were generated and simulated. The fracture behaviour, e.g. initiation, propagation and coalescence of cracks, were investigated for different levels of heterogeneity and grain cement strengths. The results show that a variety of different fracture modes can be obtained with this modelling approach. Further, the results suggests that the statistical methods employed in this work improves the versatility of the Bonded Discrete Element Method for rock modelling.

Place, publisher, year, edition, pages
Barcelona: International Center for Numerical Methods in Engineering (CIMNE), 2022
Keywords
Bonded Discrete Element Method, Rock Fracture, Heterogeneous
National Category
Other Mechanical Engineering
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-92497 (URN)
Conference
15th World Congress in Computational Mechanics (WCCM XV) and 8th Asia Pacific Congress on Computational Mechanics (APCOM VIII), Yokohama, Japan [Virtual], July 31-August 5, 2022
Note

ISBN för värdpublikation: 978-84-123222-8-6

Available from: 2022-08-16 Created: 2022-08-16 Last updated: 2023-09-05Bibliographically approved
Wessling, A., Larsson, S., Jonsén, P. & Kajberg, J. (2021). A Statistical Bonded Discrete Element Model for heterogeneous brittle materials. In: : . Paper presented at VII International Conference on Particle-based Methods (Particles 2021), Hamburg, Germany [Online], October 4-6, 2021.
Open this publication in new window or tab >>A Statistical Bonded Discrete Element Model for heterogeneous brittle materials
2021 (English)Conference paper, Oral presentation with published abstract (Other academic)
Abstract [en]

Numerical modelling of the fracture of heterogeneous brittle materials is of interest for several industries,such as rock excavation and comminution applications. A numerical model of brittle materials needs tobe able to capture the unpredictable results, e.g. with regards to measured strength and fracture pattern,as observed experimentally. In this study a new approach, based on the Parallel Bond Model (PBM) [1] and theWeibull distribution, for modelling brittle heterogeneous materials in 3D is proposed and appliedto the Brazilian Disc Test (BDT) [2]. The PBM is used to generate irregular grains with varying bondstrengths and stiffnesses. For the grain generation, a parent particle is chosen at random in the rockbody and a randomized ellipsoid is generated around the particle. The mean grain bond stiffnesses andstrengths are associated with the grain and all particles within the ellipsoid surface are bonded togetherwithin +/- 10 % of these mean values. Further, the bond parameters of the cement between a grain andits neighbours is scaled based on the mean grain properties. An example of a generated sample is shownin Figure 1 a). In order to evaluate the model, a series of simulations of the BDT were conducted.The effects of the Weibull heterogeneity index and cement strengths on the predicted tensile strengthand crack pattern were evaluated. Specifically, the initiation, propagation, coalescence and branching ofcracks were examined in detail. Apart from demonstrating challenges with the BDT, the results also showthat the proposed model is able to capture key phenomena related to brittle heterogeneous materials, suchas unpredictable fracture pattern and a large variation in tensile strength, see Figure 1 b-c).

Keywords
DEM, rock, fracture
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-89932 (URN)
Conference
VII International Conference on Particle-based Methods (Particles 2021), Hamburg, Germany [Online], October 4-6, 2021
Projects
GEOFIT
Funder
EU, Horizon 2020, 792210
Available from: 2022-03-29 Created: 2022-03-29 Last updated: 2023-09-05Bibliographically approved
Wessling, A. (2021). Towards Discrete Element Modelling of Rock Drilling. (Licentiate dissertation). Luleå: Luleå University of Technology
Open this publication in new window or tab >>Towards Discrete Element Modelling of Rock Drilling
2021 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

The method of percussive rotary drilling is recognized as the most efficient method for hard rock drilling. Despite the clear advantages over conventional rotary meth-ods, there are still uncertainties associated with percussive rotary drilling. For geothermal applications, it is estimated that 50 % of the total cost per installed megawatt of energy is associated with drilling and well construction, with drill bit wear being a predominant cost factor. Numerical modelling and simulation of rock drilling, calibrated and validated towards rigorous experiments, can give insight into the rock drilling process. This thesis is focused on the prerequisites of numer-ical simulations of rock drilling, i.e. the development of a numerical model and experimental characterization of rock materials. A new approach for modelling brittle heterogeneous materials was developed in this work. The model is based on the Bonded Particle Method (BPM) for the Discrete Element Method (DEM), where heterogeneity is introduced in two ways. Firstly, the material grains are rep-resented by random, irregular ellipsoids that are distributed throughout the body. Secondly, these grains are constructed using the BPM-DEM approach with mi-cromechanical parameters governed by the Weibull distribution. The model was applied to the Brazilian Disc Test (BDT), where crack initiation, propagation, coalescence and branching could be investigated for different levels of heterogene-ity and intergranular cement strengths. The initiation and propagation of the cracks were found to be highly dependent on the level of heterogeneity and cement strengths. In the experimental study, the static and dynamic properties of two rock materials - Kuru grey granite and Kuru black diorite - were obtained from uniaxial compression and indirect tension tests. A Split-Hopkinson Pressure Bar was used to obtain the dynamic properties. Using high-speed photography with frame rate 663,000 fps, the crack initiation and propagation could be studied in de-tail, and the full-field exterior deformation fields of the samples were evaluated by using digital image correlation. From the high-speed images, the onset of unstable crack growth was detected. The crack-damage stresses, associated with unstable crack growth, was approx. 90 % of the peak strength in the dynamic compression tests, whereas the tensile crack-damage stress was approx 70 % of the tensile peak strength.

Place, publisher, year, edition, pages
Luleå: Luleå University of Technology, 2021
Series
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757
Keywords
DEM Rock Dynamic Drilling
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-83911 (URN)978-91-7790-836-4 (ISBN)978-91-7790-837-1 (ISBN)
Presentation
2021-06-18, E632, 09:00 (English)
Opponent
Supervisors
Available from: 2021-04-23 Created: 2021-04-23 Last updated: 2023-09-05Bibliographically approved
Wessling, A., Jonsén, P. & Kajberg, J. (2019). Towards the Discrete Element Modeling of Rock Drilling. In: : . Paper presented at Svenska mekanikdagar 2019, 11-12 juni, 2019, Stockholm, Sverige (pp. 98-98). Stockholm: Svenska Nationalkommitén för Mekanik
Open this publication in new window or tab >>Towards the Discrete Element Modeling of Rock Drilling
2019 (English)Conference paper, Oral presentation with published abstract (Refereed)
Place, publisher, year, edition, pages
Stockholm: Svenska Nationalkommitén för Mekanik, 2019
Keywords
Discrete Element Method, Rock Drilling, Wear, Percussive
National Category
Applied Mechanics
Research subject
Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-78047 (URN)
Conference
Svenska mekanikdagar 2019, 11-12 juni, 2019, Stockholm, Sverige
Available from: 2020-03-13 Created: 2020-03-13 Last updated: 2023-09-05Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-1345-0740

Search in DiVA

Show all publications