Change search
Refine search result
1 - 20 of 20
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the 'Create feeds' function.
  • 1.
    Ghasemi, Rohollah
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Olofsson, Jakob
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Jarfors, Anders E. W.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Svensson, Ingvar L.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Modelling and simulation of local mechanical properties of high silicon solution-strengthened ferritic CGI materialsManuscript (preprint) (Other academic)
  • 2.
    Ghasemi, Rohollah
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Olofsson, Jakob
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Jarfors, Anders E. W.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Svensson, Ingvar L.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Modelling and simulation of local mechanical properties of high silicon solution-strengthened ferritic compacted graphite iron2017In: International Journal of Cast Metals Research, ISSN 1364-0461, E-ISSN 1743-1336, Vol. 30, no 3, 125-132 p.Article in journal (Refereed)
    Abstract [en]

    This study focuses on the modelling and simulation of local mechanical properties of compacted graphite iron cast at different section thicknesses and three different levels of silicon, ranging from about 3.6% up to 4.6%. The relationship between tensile properties and microstructure is investigated using microstructural analysis and statistical evaluation. Models are generated using response surface methodology, which reveal that silicon level and nodularity mainly affect tensile strength and 0.2% offset yield strength, while Young′s modulus is primarily affected by nodularity. Increase in Si content improves both the yield and tensile strength, while reduces elongation to failure. Furthermore, mechanical properties enhance substantially in thinner section due to the high nodularity. The obtained models have been implemented into a casting process simulation, which enables prediction of local mechanical properties of castings with complex geometries. Very good agreement is observed between the measured and predicted microstructures and mechanical properties, particularly for thinner sections.

  • 3.
    Jarfors, Anders
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Seifeddine, Salem
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Olofsson, Jakob
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Svensson, Ingvar L.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Critical Description of Defects and Mechanical Behaviour in Casting Process Modelling of Light Metals for Automotive Use2013In: Proceedings of the Twenty Second International Conference on Processing and Fabrication of Advanced Materials (PFAM-XXII), Singapore, 18-20 December, 2013, 2013Conference paper (Refereed)
  • 4.
    Kasvayee, Keivan Amiri
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Ghassemali, Ehsan
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting. Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Svensson, Ingvar L.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Olofsson, Jakob
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Jarfors, Anders E.W.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting. Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Characterization and modeling of the mechanical behavior of high silicon ductile iron2017In: Materials Science & Engineering: A, ISSN 0921-5093, E-ISSN 1873-4936, Vol. 708, 159-170 p.Article in journal (Refereed)
    Abstract [en]

    This paper investigates the effect of the solidification conditions and silicon content on the mechanical properties of ductile iron and presents empirical models for predicting the tensile behavior based on the microstructural characterizations. Two ductile iron grades of GJS-500-7 and GJS-500-14 were cast with silicon content of 2.36% and 3.71%, respectively. The cast geometry consisted of six plates with different thicknesses that provided different cooling rates during the solidification. Microstructure analysis, tensile and hardness tests were performed on the as-cast material. Tensile behavior was characterized by the Ludwigson equation. The tensile fracture surfaces were analyzed to quantify the fraction of porosity. The results showed that graphite content, graphite nodule count, ferrite fraction and yield strength were increased by increasing the silicon content. A higher silicon content resulted in lower work hardening exponent and strength coefficient on the Ludwigson equation. The results for 0.2% offset yield and the Ludwigson equation parameters were modeled based on microstructural characteristics, with influence of silicon content as the main contributing factor. The models were implemented into a casting process simulation to enable prediction of microstructure-based tensile behavior. A good agreement was obtained between measured and simulated tensile behavior, validating the predictions of simulation in cast components with similar microstructural characteristics.

    The full text will be freely available from 2019-09-28 00:00
  • 5.
    Malakizadi, Amir
    et al.
    Chalmers Institute of Technology, Gothenburg, Sweden.
    Ghasemi, Rohollah
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Behring, Carsten
    Chalmers Institute of Technology, Gothenburg, Sweden.
    Olofsson, Jakob
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Jarfors, Anders E. W.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Nyborg, Lars
    Chalmers Institute of Technology, Gothenburg, Sweden.
    Machinability of solid solution-strengthened compacted graphite iron: Influence of the microstructure, mechanical properties and cutting conditions on tool wear responseManuscript (preprint) (Other academic)
  • 6.
    Olofsson, Jakob
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Microstructure-based Mechanical Behaviour in Structural Analyses of Cast Components2012Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    In the process of developing cast iron and cast aluminium components, the co-operation between product development and production is important. On the engineering level, this co-operation is limited already in the product development phase e.g. by the lack of established methods to consider the mechanical behaviour of the completed component.

    This thesis aims to increase the possibilities for co-operation in the product realisation process between product development and production by enabling the use of predicted local mechanical behaviour in structural analyses of cast components. A literature review on existing simulation methods and a work on characterization of mechanical behaviour from microstructural features are performed to identify important knowledge gaps. A simulation strategy is formulated that is able to predict local mechanical behaviour throughout the entire component and incorporate the behaviour into a Finite Element Method (FEM) simulation of the structural behaviour of the component. In the simulation strategy, the component specific microstructure-based mechanical behaviour is predicted using a casting process simulation. A computer program is developed to create FEM material definitions that capture the local variations in mechanical behaviour throughout the component.

    The relevance of the simulation strategy is demonstrated for a ductile iron component. It is found that the local variations in mechanical behaviour result in a stress-strain distribution in the component that a homogeneous material description fails to express. Residual stresses affect the mechanical behaviour at low loads. At higher loads, however, the accuracy of the simulation is determined by the local variations in mechanical behaviour. Using a material reduction technique, the local mechanical behaviour can be incorporated without increasing the FEM simulation time. 

  • 7.
    Olofsson, Jakob
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Simulation of mechanical behaviour of cast aluminium components2012In: International Journal of Cast Metals Research, ISSN 1364-0461, Vol. 25, no 6, 319-327 p.Article, review/survey (Refereed)
    Abstract [en]

    A literature review on methods to consider the mechanical behaviour of cast aluminium alloys in finite element method (FEM) simulations of cast aluminium components has been performed. The mechanical behaviour is related to several microstructural parameters achieved during the casting process. Three different methods to consider these microstructural parameters are introduced. One method predicts the mechanical behaviour of the component using casting process simulation software. The other two methods implement numerical models for the mechanical behaviour of cast aluminium into the FEM simulation. Applications of the methods are shown, including combinations with statistical methods and geometry optimisation methods. The methods are compared, and their different strengths and drawbacks are discussed.

  • 8.
    Olofsson, Jakob
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Simulation of Microstructure-based Mechanical Behaviour of Cast Components2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In the process of developing cast iron and cast aluminium components, a high level of co-operation between product development and production is of great importance. From an engineering standpoint, this co-operation is limited early in the product development phase by e.g. a lack of established methods for the consideration of local variations in the mechanical behaviour of a finished component.

    This thesis aims to increase the possibilities for co-operation between product development and production during the product realisation process by introducing and studying the use of predicted local mechanical behaviour in structural analyses of cast components. A literature review of existing simulation methods and a work on characterisation of mechanical behaviour from microstructural features have been performed to identify important knowledge gaps. A simulation strategy has been formulated which is able to predict local mechanical behaviour throughout the entire component, and to incorporate this into a Finite Element Method (FEM) simulation of the structural behaviour of the component. In the simulation strategy, componentspecific microstructure-based mechanical behaviour is predicted using a casting process simulation. A computer program was developed to create FEM material definitions which capture the local variations in mechanical behaviour throughout the component. Using a material reduction technique, the local mechanical behaviour can be incorporated without increasing the FEM simulation time.

    The relevance of the simulation strategy was experimentally verified on cast aluminium samples, where the strain field was observed using Digital Image Correlation (DIC). It was found that the local variations in mechanical behaviour cause a stress-strain distribution that deviates from that predicted by a homogeneous material description, indicating the importance of calculating with and including such variations in material behaviour in FEM simulations. Numerical investigations demonstrate the strategy’s relevance for predicting the behaviour of cast aluminium and ductile iron components.

  • 9.
    Olofsson, Jakob
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Cenni, Riccardo
    Università degli Studi di Modena e Reggio Emilia, Italy.
    Cova, Matteo
    Università degli Studi di Modena e Reggio Emilia, Italy.
    Bertuzzi, Giacomo
    Zanardi Fonderie, Italy.
    Salomonsson, Kent
    Jönköping University, School of Engineering, JTH, Product Development.
    Johansson, Joel
    Jönköping University, School of Engineering, JTH, Product Development.
    Multidisciplinary shape optimization of ductile iron castings byconsidering local microstructure and material behaviour2017In: WCSMO12, 12th World Congress of Structural and Multidisciplinary Optimisation: Book of Abstracts / [ed] Kai-Uwe Bletzinger, Sierk Fiebig, Kurt Maute, Axel Schumacher, Thomas Vietor, Technische Universität , 2017, 82- p.Conference paper (Refereed)
    Abstract [en]

    During the casting process and solidification of ductile iron castings, a heterogeneous microstructure is formed throughout the casting. This distribution is highly controlled by process related factors, as chemical composition, local solidification conditions, and the geometry of the casting. Geometrical changes to the geometry of the casting thus alters the local mechanical behaviour, as well as the distribution of stresses and strains when the casting is subjected to load. In order to find an optimal geometry, e.g. with reduced weight and increased load-bearing capacity, this interdependency between geometry and local material behaviour needs to be considered and integrated into the optimization method. In this contribution, recent developments in the multidisciplinary integration of casting process simulation, solidification and microstructure modelling, microstructure-based material characterization, Finite Element Analyses (FEA) with local material behaviour and structural optimization techniques are presented and discussed. The effect and relevance of considering the local material behaviour in shape optimization of ductile iron castings is discussed and evidenced by an industrial application. It is shown that by adopting a multidisciplinary optimization approach by integration of casting simulation and local material behaviour into shape optimization, the potential of the casting process to obtain components with high performance and reliability can be enabled and utilized.

  • 10.
    Olofsson, Jakob
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Larsson, Dan
    Vestascastings Guldsmedshyttan AB.
    Svensson, Ingvar L.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Effect of Austempering on Plastic Behavior of Some Austempered Ductile Iron Alloys2011In: Metallurgical and Materials Transactions. A, ISSN 1073-5623, E-ISSN 1543-1940, Vol. 42, no 13, 3999-4007 p.Article in journal (Refereed)
    Abstract [en]

    A numerical description relating microstructure to elastic and plastic deformation behavior would make it possible to simulate the mechanical behavior of complex cast components with tailored material properties. Limited work and data have however been published regarding the connection between microstructure and plastic behavior of austempered ductile irons (ADI). In the current work the effects of austempering temperature and austempering time on the strength coefficient and the strain hardening exponent of the Hollomon equation have been investigated for two ADI alloys. The results show that the plastic behavior is highly dependent on the combination of austempering temperature and austempering time. It was found that as the austempering temperature increases both the strength coefficient and the strain hardening exponent initially decrease, but after reaching a minimum at the critical austempering temperature they show a plateau or an increase. The effect of the austempering time on the plastic behavior depends on the austempering temperature. At low austempering temperatures the strength coefficient and the strain hardening exponent decrease with increased austempering time, whereas at higher austempering temperatures they show little time dependence. These relations are explained by the microstructural transformations that take place during the austempering heat treatment.

  • 11.
    Olofsson, Jakob
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Salomonsson, Kent
    Jönköping University, School of Engineering, JTH, Product Development. Jönköping University, School of Engineering, JTH. Research area Product Development - Simulation and Optimization.
    Johansson, Joel
    Jönköping University, School of Engineering, JTH, Product Development. Jönköping University, School of Engineering, JTH. Research area Product Development - Computer supported engineering design.
    Amouzgar, Kaveh
    University of Skövde, Sweden.
    A methodology for microstructure-based structural optimization of cast and injection moulded parts using knowledge-based design automation2017In: Advances in Engineering Software, ISSN 0965-9978, E-ISSN 1873-5339, Vol. 109, 44-52 p.Article in journal (Refereed)
    Abstract [en]

    The local material behaviour of cast metal and injection moulded parts is highly related to the geometrical design of the part as well as to a large number of process parameters. In order to use structural optimization methods to find the geometry that gives the best possible performance, both the geometry and the effect of the production process on the local material behaviour thus has to be considered.

    In this work, a multidisciplinary methodology to consider local microstructure-based material behaviour in optimizations of the design of engineering structures is presented. By adopting a knowledge-based industrial product realisation perspective combined with a previously presented simulation strategy for microstructure-based material behaviour in Finite Element Analyses (FEA), the methodology integrates Computer Aided Design (CAD), casting and injection moulding simulations, FEA, design automation and a multi-objective optimization scheme into a novel structural optimization method for cast metal and injection moulded polymeric parts. The different concepts and modules in the methodology are described, their implementation into a prototype software is outlined, and the application and relevance of the methodology is discussed.

    The full text will be freely available from 2019-03-25 08:00
  • 12.
    Olofsson, Jakob
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Salomonsson, Kent
    Jönköping University, School of Engineering, JTH, Product Development. Jönköping University, School of Engineering, JTH. Research area Product Development - Simulation and Optimization.
    Svensson, Ingvar L.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Modelling and simulations of ductile iron solidification-induced variations in mechanical behaviour on component and microstructural level2015In: IOP Conference Series: Materials Science and Engineering, Volume 84: MCWASP XIV: International Conference on Modeling of Casting, Welding and Advanced Solidification Processes / [ed] Hideyuki Yasuda, Kyoto University, Japan, London: Institute of Physics Publishing (IOPP), 2015, Vol. 84, 1-8 p.Conference paper (Refereed)
    Abstract [en]

    The mechanical behaviour and performance of a ductile iron component is highly dependent on the local variations in solidification conditions during the casting process. Here we show a framework which combine a previously developed closed chain of simulations for cast components with a micro-scale Finite Element Method (FEM) simulation of the behaviour and performance of the microstructure. A casting process simulation, including modelling of solidification and mechanical material characterization, provides the basis for a macro-scale FEM analysis of the component. A critical region is identified to which the micro-scale FEM simulation of a representative microstructure, generated using X-ray tomography, is applied. The mechanical behaviour of the different microstructural phases are determined using a surrogate model based optimisation routine and experimental data. It is discussed that the approach enables a link between solidification- and microstructure-models and simulations of as well component as microstructural behaviour, and can contribute with new understanding regarding the behaviour and performance of different microstructural phases and morphologies in industrial ductile iron components in service.

  • 13.
    Olofsson, Jakob
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Salomonsson, Kent
    Jönköping University, School of Engineering, JTH, Product Development. Jönköping University, School of Engineering, JTH. Research area Product Development - Simulation and Optimization.
    Svensson, Ingvar L.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    The multi-scale closed chain of simulations – incorporating local variations in microstructure into finite element simulations2015In: TMS2015, 144th Annual Meeting and Exhibition, Orlando, FL, USA, March 15-19, 2015, 2015Conference paper (Refereed)
    Abstract [en]

    Numerical simulations of component behavior and performance is critical to develop optimized and robust load-bearing components. The reliability of these simulations depend on the description of the components material behavior, which for e.g. cast and polymeric materials exhibit component specific local variations depending on geometry and manufacturing parameters. Here an extension of a previously presented strategy, the closed chain of simulations for cast components, to predict and incorporate local material data into Finite Element Method (FEM) simulations on multiple scales is shown. Manufacturing process simulation, solidification modelling, material characterization and representative volume elements (RVE) provides the basis for a microstructure-based FEM analysis of component behavior and a simulation of the mechanical behavior of the local microstructure in a critical region. It is discussed that the strategy is applicable not only to cast materials but also to injection molded polymeric materials, and enables a common integrated computational microstructure-based approach to optimized components.

  • 14.
    Olofsson, Jakob
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Svensson, Ingvar L.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Casting and stress-strain simulations of a cast ductile iron component using microstructure based mechanical behavior2012In: IOP Conference Series: Materials Science and Engineering, Volume 33: MCWASP XIII: International Conference on Modeling of Casting, Welding and Advanced Solidification Processes / [ed] Andreas Ludwig, Menghuai Wu and Abdellah Kharicha, London: IOP Publishing , 2012Conference paper (Refereed)
    Abstract [en]

    The industrial demand for increased component performance with concurrent reductions in component weight, development times and verifications using physical prototypes drives the need to use the full potential of casting and Finite Element Method (FEM) simulations to correctly predict the mechanical behavior of cast components in service. The mechanical behavior of the component is determined by the casting process, and factors as component geometry and casting process parameters are known to affect solidification and microstructure formation throughout the component and cause local variations in mechanical behavior as well as residual stresses. Though residual stresses are known to be an important factor in the mechanical behavior of the component, the importance of local mechanical behavior is not well established and the material is typically considered homogeneous throughout the component. This paper deals with the influence of solidification and solid state transformation on microstructure formation and the effect of local microstructure variations on the mechanical behavior of the cast component in service. The current work aims to investigate the coupling between simulation of solidification, microstructure and local variations in mechanical behavior and stress-strain simulation. This is done by performing several simulations of a ductile iron component using a recently developed simulation strategy, a closed chain of simulations for cast components, able to predict and describe the local variations in not only elastic but also plastic behavior throughout the component by using microstructural parameters determined by simulations of microstructural evolution in the component during the casting process. In addition the residual stresses are considered. The results show that the FEM simulation results are significantly affected by including microstructure based mechanical behavior. When the applied load is low and the component is subjected to stress levels well below the yield strength of the material, the residual stresses highly affects the simulation results while the effect of local material behavior is low. As the applied load increases and the stress level in the component approaches and passes the yield strength, the effect of residual stresses diminishes while the effect of local mechanical behavior increases. In particular the predicted strain level is heavily affected by the use of local mechanical behavior. It is proposed that it is important to include both local mechanical behavior and residual stresses in stress-strain simulations to predict the true mechanical behavior of the component.

  • 15.
    Olofsson, Jakob
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Svensson, Ingvar L.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Closed chain simulations of a cast aluminium component - Incorporating casting process simulation and local material characterization into stress-strain simulations2014In: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 54, no 2, 259-265 p.Article in journal (Refereed)
    Abstract [en]

    The coupling between simulations of solidification, microstructure and local mechanical behaviour and simulation of stress-strain behaviour is studied by applying a recently developed simulation strategy to a high pressure die cast aluminium component. In the simulation strategy, named a closed chain of simulations for cast components, the mechanical behaviour throughout the component is determined locally by a casting process simulation. The entire casting process, including mould filling and solidification, is simulated to predict the formation of microstructure and residual stresses throughout the component, and material characterization models are applied to relate microstructural features to local elastic and plastic mechanical material behaviour. The local material behaviour is incorporated into a finite element method (FEM) stress-strain simulation of a realistic load case of the component in service.

    In the current contribution the influences of local variations in mechanical behaviour and residual stresses on the component behaviour are investigated. The simulation results for local microstructure and mechanical behaviour are compared to experimental results, and the predicted local mechanical behaviour is incorporated on an element level into the FEM simulation. The numerical effect of the variations in mechanical behaviour is quantified by comparing the results achieved using local behaviour and homogeneous behaviour. The influence of residual stresses predicted by the casting process simulation on the component behaviour is also studied.

    The casting process simulation is found to accurately predict the local variations in microstructure throughout the component, and the local variations in mechanical behaviour are well described. The numerical results show that casting process simulation and modelling of microstructure formation, material behaviour and residual stresses are important contributions to correctly predict the behaviour of a cast aluminium component in service. This motivates the use of the proposed simulation strategy, and show the importance of incorporating materials science and casting process simulations into structural analyses of cast components. It is discussed that integration of these areas, e.g. using the closed chain of simulations, is important in order to increase the accuracy of FEM simulations and the product development efficiency in the future.

  • 16.
    Olofsson, Jakob
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Svensson, Ingvar L.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Incorporating predicted local mechanical behaviour of cast components into finite element simulations2012In: Materials & Design, ISSN 0261-3069, Vol. 34, 494-500 p.Article in journal (Refereed)
    Abstract [en]

    A software which enables the incorporation of local variations in both elastic and plastic mechanical behaviour predicted by a casting process simulation into a Finite Element Method (FEM) simulation is presented. The software uses a piecewise linearization of the Hollomon or the Ludwigson equation to characterise plastic mechanical behaviour of the material on an element level throughout a component. The accuracy obtained in the linearization is investigated, and the performance of the software is studied using different input parameters. The applicability of the software is verified and demonstrated on a ductile iron component, and a simulation strategy for cast components denoted a closed chain of simulations for cast components is discussed.

  • 17.
    Olofsson, Jakob
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Svensson, Ingvar L.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    The effects of local variations in mechanical behaviour – Numerical investigation of a ductile iron component2012In: Materials & design, ISSN 0264-1275, Vol. 43, 264-271 p.Article in journal (Refereed)
    Abstract [en]

    The effects of incorporating local mechanical behaviour into a structural analysis of a cast ductile iron component are investigated. A recently presented simulation strategy, the closed chain of simulations for cast components, is applied to incorporate local behaviour predicted by a casting process simulation into a Finite Element Method (FEM) structural analysis, and the effects of the strategy on predicted component behaviour and simulation time are evaluated. The results are compared to using a homogeneous material description. A material reduction method is investigated, and the effects of material reduction and number of linearization points are evaluated.

    The results show that local mechanical behaviour may significantly affect the predicted behaviour of the component, and a homogeneous material description fails to express the stress-strain distribution caused by the local variations in mechanical behaviour in the component. The material reduction method is able to accurately describe this effect while only slightly increasing the simulation time. It is proposed that local variations in mechanical behaviour are important to consider in structural analyses of the mechanical behaviour of ductile iron components.

  • 18.
    Olofsson, Jakob
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Svensson, Ingvar L.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Lava, Pascal
    Department MTM, KU Leuven, Belgium.
    Debruyne, Dimitri
    Department MTM, KU Leuven, Belgium.
    Characterisation and investigation of local variations in mechanical behaviour in cast aluminium using gradient solidification, Digital Image Correlation and finite element simulation2014In: Materials & Design, ISSN 0261-3069, Vol. 56, 755-762 p.Article in journal (Refereed)
    Abstract [en]

    Due to design and process-related factors, there are local variations in the microstructure and mechanical behaviour of cast components. This work establishes a Digital Image Correlation (DIC) based method for characterisation and investigation of the effects of such local variations on the behaviour of a high pressure, die cast (HPDC) aluminium alloy. Plastic behaviour is studied using gradient solidified samples and characterisation models for the parameters of the Hollomon equation are developed, based on microstructural refinement. Samples with controlled microstructural variations are produced and the observed DIC strain field is compared with Finite Element Method (FEM) simulation results. The results show that the DIC based method can be applied to characterise local mechanical behaviour with high accuracy. The microstructural variations are observed to cause a redistribution of strain during tensile loading. This redistribution of strain can be predicted in the FEM simulation by incorporating local mechanical behaviour using the developed characterization model. A homogeneous FEM simulation is unable to predict the observed behaviour. The results motivate the application of a previously proposed simulation strategy, which is able to predict and incorporate local variations in mechanical behaviour into FEM simulations already in the design process for cast components.

  • 19.
    Svensson, Ingvar L.
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Olofsson, Jakob
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    On microstructure-based mechanical behaviour of a ductile iron component2014In: 10th International Symposium on the Science and Processing of Cast Iron - SPCI10, Mar del Plata, 10-13 November 2014, 2014Conference paper (Refereed)
    Abstract [en]

    Castings are produced by a manufacturing method which gives the components properties that are depending on design, metallurgy and casting method. The aim is to explore and model the local properties in a cast iron component where the properties can vary in the casting volume, which makes it difficult to optimize the castings with good accuracy.

    This paper presents modelling and simulation of local microstructure-based mechanical behaviour. The mechanical behaviour can be shown as stress-strain curves at different locations of the cast iron component. A careful evaluation of tensile tests are made of three industrial components to characterize the stress – strain curves for regions holding different microstructures. This data will be used to determine the local properties and how they will influence the component behaviour at service.

  • 20.
    Svensson, Ingvar L.
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Olofsson, Jakob
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Understanding cast iron materials and components - a never ending story2015In: TMS2015, 144th Annual Meeting and Exhibition, Orlando, FL, USA, March 15-19, 2015, 2015, 2015Conference paper (Refereed)
    Abstract [en]

    How can an in principal binary alloy of iron and carbon show so many fascinating phenomena and still today give surprises to users, foundrymen and researchers? This paper points out some critical steps in the understanding of the whole chain, from the melt to a cast iron product in service. The understanding of the material is gradually improved, assisted by the advances of other fields, e.g. analyzing methods and computational techniques. The heart in cast iron is the graphite, which is a highly difficult phase to understand but gives the material its unique properties. The linkage between understanding and modelling is necessary to calculate/simulate the processes occurring, where the precipitation, nucleation and growth of the different phases are the keys. Proper nucleation and growth models have been introduced to predict e.g. primary precipitation of austenite and graphite, eutectic growth of different morphologies of graphite or cementite and austenite, solid state transformation of austenite into ferrite and pearlite in both grey and ductile irons, and now gives realistic microstructures and solidification curves for most practical cases. The microstructure formation models gives input to shrinkage and volume calculations to predict porosities, and to predictions of mechanical properties. By linking microstructure formation models, characterization models for mechanical properties and Finite Element Analysis (FEA) it is today possible to use local properties in simulations of the behavior of cast iron components.  

    Many phenomena in cast iron, however, still remain unexplained. As one student labelled one of his experimental files on ductile iron, cast iron materials and simulations are indeed a never ending story, with a bright future in industrial applications.

1 - 20 of 20
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf