liu.seSearch for publications in DiVA
Change search
Refine search result
1 - 17 of 17
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • 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)
  • Disputation date (earliest first)
  • Disputation date (latest 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)
  • Disputation date (earliest first)
  • Disputation date (latest 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.
    Azeez, Ahmed
    et al.
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Faculty of Science & Engineering.
    Eriksson, Robert
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Faculty of Science & Engineering.
    Norman, Viktor
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Leidermark, Daniel
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Faculty of Science & Engineering.
    Moverare, Johan
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    The effect of dwell times and minimum temperature on out-of-phase thermomechanical fatigue crack propagation in a steam turbine steel - Crack closure prediction2022In: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 162, article id 106971Article in journal (Refereed)
    Abstract [en]

    Exploring crack growth behaviour is needed to establish accurate fatigue life predictions. Cracked specimens were tested under strain-controlled out-of-phase thermomechanical fatigue conditions. The tests included dwell times and three different minimum temperatures. Higher minimum temperature gave faster crack growth rates while the additions of dwell times showed no effects. Crack closure was observed in all the tests where the addition of dwell times and change in minimum temperature displayed little to no effect on crack closure stresses. Finite element models with a sharp stationary crack and material parameters switching provided acceptable predictions for the maximum, minimum, and crack closure stresses.

    Download full text (pdf)
    fulltext
  • 2.
    Azeez, Ahmed
    et al.
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Faculty of Science & Engineering.
    Norman, Viktor
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Eriksson, Robert
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Faculty of Science & Engineering.
    Leidermark, Daniel
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Faculty of Science & Engineering.
    Moverare, Johan
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Out-of-phase thermomechanical fatigue crack propagation in a steam turbine steel — modelling of crack closure2021In: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 149, article id 106251Article in journal (Refereed)
    Abstract [en]

    Understanding of crack growth behaviour is necessary to predict accurate fatigue lives. Out-of-phase thermomechanical fatigue crack propagation tests were performed on FB2 steel used in high-temperature steam turbine sections. Testing results showed crack closure where the compressive part of the fatigue cycle affected crack growth rate. Crack closing stress was observed to be different, and had more influence on the growth rate, than crack opening stress. Crack growth rate was largely controlled by the minimum temperature of the cycle, which agreed with an isothermal crack propagation test. Finite element models with stationary sharp cracks captured the crack closure behaviour.

    Download full text (pdf)
    fulltext
  • 3.
    Ge, Zhicheng
    et al.
    School of Materials Science and Engineering, University of Science and Technology of China, Hefei, China; Superalloys Division, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, China.
    Xie, Guang
    Superalloys Division, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, China.
    Segersäll, Mikael
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Norman, Viktor
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Chen, Zhe
    Siemens Energy AB, Finspång, Sweden.
    Moverare, Johan
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Lou, Langhong
    Superalloys Division, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, China.
    Zhang, Jian
    Superalloys Division, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, China.
    Influence of Ru on the thermomechanical fatigue deformation behavior of a single crystal superalloy2022In: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 156, article id 106634Article in journal (Refereed)
    Abstract [en]

    The deformation mechanisms of a single crystal nickel-base superalloy with and without Ru-doped have been investigated under out-of-phase thermomechanical fatigue. The Ru-doped alloy exhibits a thermomechanical fatigue life more than twice as high compared to the Ru-free alloy and a difference in thermomechanical fatigue behavior is also displayed. Microstructure studies by scanning electron microscopy and transmission electron microscopy revealed that the deformation mechanism of the Ru-free alloy in the initial stage is the movement of dislocations in the γ matrix. In the later stage of the thermomechanical fatigue test, large amounts of twins are formed in the material, and a large number of stacking faults and dislocations are sheared into the γ' precipitates. By comparing with the Ru-free alloy, the Ru-doped alloy has a higher matrix strength due to the solid solution strengthening effect of Ru, and is also prone to different deformation mechanisms. For example, the stacking faults are formed in the initial thermomechanical fatigue cycles and remain in the matrix throughout the entire thermomechanical fatigue process. The formation of twins, on the other hand, is suppressed by Ru addition. Such effects are believed to extend the thermomechanical fatigue life effectively.

  • 4.
    Kihlberg, Ebba
    et al.
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Norman, Viktor
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    König, Mathias
    Schmidt, Pål
    Evaluation of the ISO-standards for Graphite Image Analysis of Compacted Graphite Iron2019Conference paper (Refereed)
  • 5.
    Kihlberg, Ebba
    et al.
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Norman, Viktor
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Skoglund, Peter
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Schmidt, Pål
    Moverare, Johan
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Investigation of Microstructure Parameters and Thermo-Mechanical Fatigue Performance of Cast Iron2019Conference paper (Refereed)
  • 6.
    Kihlberg, Ebba
    et al.
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Norman, Viktor
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Skoglund, Peter
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering. Scania, unit 003, Södertälje.
    Schmidt, Pål
    Volvo Group Trucks Technology, Göteborg.
    Moverare, Johan
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    On the Correlation Between Microstructural Parameters and the Thermo-Mechanical Fatigue Performance of Cast Iron2021In: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 145, article id 106112Article in journal (Refereed)
    Abstract [en]

    Strain-controlled out-of-phase thermo-mechanical fatigue tests at 100–500 °C and various strain ranges were conducted on five cast iron grades, including one lamellar, three compacted and one spheroidal graphite iron. Investigations of graphite morphology and matrix characteristics were performed to associate parameters, such as geometrical features of graphite inclusions and the matrix microhardness, to the thermo-mechanical fatigue performance of each grade. From this, thermo-mechanical fatigue life as a function of maximum stress at half-life, is found to decrease consistently with increasing average graphite inclusion length irrespective of the graphite content. In contrast, no evident correlation between the fatigue life and the matrix microhardness is observed.

    Download full text (pdf)
    fulltext
  • 7. Order onlineBuy this publication >>
    Norman, Viktor
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Fatigue of Heavy-Vehicle Engine Materials: Damage Mechanisms, Laboratory Experiments and Life Estimation2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Due to increasing demands on sustainability exerted by end-costumers and policy makers, heavyvehicle manufacturers are urged to increase the engine efficiency in order to reduce the exhaust gas emission. However, increasing the efficiency is also associated with an elevated fatigue rate of the materials constituting the engine parts, which consequently reduces the engine service life. The aim of the present thesis is therefore to confront the expected increase by studying the fatigue behaviour and damage mechanisms of the materials typically employed in heavy-vehicle diesel engines. With this knowledge, this work seeks to guide the development of new heavy-vehicle engine materials, as well as to develop improved life estimation methods designated to assist the mechanical design of durable heavy-vehicle engines.

    In essence, a large set of thermo-mechanical fatigue (TMF) and combined thermomechanical and high-cycle fatigue (TMF-HCF) tests is conducted at engine load conditions on laboratory specimens of lamellar, compacted and spheroidal graphite iron. In this way, the fatigue performance and associated damage mechanisms are investigated. In particular, a new fatigue property is identified, the TMF-HCF threshold, which quantifies how resistant a material is to superimposed high-cycle fatigue.

    The damage mechanism at low temperatures (≲500°C) is confirmed to consist of the initiation, propagation and coalescence of numerous microcracks. Based on this, a successful fatigue life estimation model is formulated, allowing accurate estimations of TMF and TMF-HCF tests on smooth specimens, and TMF tests on notched specimens. In the latter case, the microcrack growth behaviour in non-uniform cyclic stress fields and its implications for life estimation are clarified. At elevated temperatures (≳500°C), surface oxidation is shown to govern the fatigue performance of cast iron grades intended for exhaust manifolds. It is observed that oxide intrusions are induced, from which surface fatigue cracks are initiated. Consequently, an optimal material at these conditions should have a low oxide growth rate and few casting defects at the surface, as these factors are found to stimulate the growth of intrusion.  

    List of papers
    1. Damage evolution in compacted graphite iron during thermomechanical fatigue testing
    Open this publication in new window or tab >>Damage evolution in compacted graphite iron during thermomechanical fatigue testing
    2016 (English)In: International Journal of Cast Metals Research, ISSN 1364-0461, E-ISSN 1743-1336, Vol. 29, no 1-2, p. 26-33Article in journal (Refereed) Published
    Abstract [en]

    Thermomechanical fatigue properties of a compacted graphite iron in an out of phase configuration are investigated for different maximum temperatures and mechanical strain ranges. Furthermore, the stressï¿œstrain hysteresis loops are analysed, and, in particular, the unloading modulus, i.e. the elastic modulus measured during specimen unloading, is obtained from each cycle. This material parameter has earlier been explicitly related to the amount of microcracking in cast irons. The results show that the unloading modulus linearly declines with the numbers of cycles in all tests performed. In addition, the rate of change of the unloading modulus is closely related to the number of cycles to failure. Accordingly, it is concluded that microcracks are independently propagated by fatigue until a point of rapid crack linking resulting in ultimate failure. This is supported by microstructural analyses consisting of optical microscope images taken at different stages throughout the life of a specimen.

    Place, publisher, year, edition, pages
    Taylor & Francis, 2016
    Keywords
    Thermomechanical fatigue, Out-of-phase loading, Compacted graphite iron, Microcracking
    National Category
    Other Materials Engineering
    Identifiers
    urn:nbn:se:liu:diva-121028 (URN)10.1179/1743133615Y.0000000019 (DOI)000377468800005 ()
    Funder
    VINNOVA, FFI-2012-03625Swedish Foundation for Strategic Research , SM12-0014
    Note

    Funding agencies: Scania CV AB; Strategic Faculty Grant AFM (SFO-MAT-LiU) at Linkoping University [2009-00971]

    Available from: 2015-09-03 Created: 2015-09-03 Last updated: 2018-02-13Bibliographically approved
    2. Thermo-mechanical and superimposed high-cycle fatigue interactions in compacted graphite iron
    Open this publication in new window or tab >>Thermo-mechanical and superimposed high-cycle fatigue interactions in compacted graphite iron
    2015 (English)In: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 80, p. 381-390Article in journal (Refereed) Published
    Abstract [en]

    The effect of adding a superimposed high-frequent strain load, denoted as a high-cycle fatigue strain component, upon a strain-controlled thermo-mechanical fatigue test has been studied on a compacted graphite iron EN-GJV-400 for different thermo-mechanical fatigue cycles and high-cycle fatigue strain ranges. It is demonstrated that the successive application of an high-cycle fatigue load has a consistent effect on the fatigue life, namely the existence of a constant high-cycle fatigue strain range threshold below which the fatigue life is unaffected but severely reduced when above. This effect on the fatigue life is predicted assuming that microstructurally small cracks are propagated and accelerated according to a Paris law incorporating an experimentally estimated crack opening level.

    Place, publisher, year, edition, pages
    Elsevier, 2015
    Keywords
    Cast iron, Thermo-mechanical fatigue, High-cycle fatigue, Fatigue crack growth, Life prediction
    National Category
    Other Engineering and Technologies Mechanical Engineering
    Identifiers
    urn:nbn:se:liu:diva-121029 (URN)10.1016/j.ijfatigue.2015.06.005 (DOI)000360596500040 ()
    Available from: 2015-09-03 Created: 2015-09-03 Last updated: 2018-02-13Bibliographically approved
    3. The effect of superimposed high-cycle fatigue on thermo-mechanical fatigue in cast iron
    Open this publication in new window or tab >>The effect of superimposed high-cycle fatigue on thermo-mechanical fatigue in cast iron
    2016 (English)In: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 88, p. 121-131Article in journal (Refereed) Published
    Abstract [en]

    The eect of superimposing a high-cycle fatigue strain load on an out-ofphase thermo-mechanical fatigue test of a lamellar, compacted and spheroidal graphite iron, has been investigated. In particular, dierent total mechanical strain ranges, maximum temperatures and high-cycle fatigue strain ranges have been studied. From this, a new property has been identied, measured and compared, namely the thermo-mechanical and high-cycle fatigue threshold, dened as the high-cycle fatigue strain range at which the life is reduced to half. Using a model developed earlier, the lifetimes and the threshold have been successfully estimated for the lamellar and compacted graphite iron, however underestimated for the spheroidal graphite iron. Nevertheless, an expression of the threshold was deduced from the model, which possibly can estimate its value in other cast irons and its high-cycle fatigue frequency dependence.

    Place, publisher, year, edition, pages
    Elsevier, 2016
    Keywords
    Cast iron, Thermo-mechanical fatigue, High-cycle fatigue, Fatigue crack growth, Life prediction
    National Category
    Mechanical Engineering Other Engineering and Technologies
    Identifiers
    urn:nbn:se:liu:diva-121030 (URN)10.1016/j.ijfatigue.2016.03.020 (DOI)000375817000013 ()
    Note

    Funding agencies: Scania CV AB; Swedish Governmental Agency for Innovation Systems [FFI - 2012 - 03625]; Swedish Foundation for Strategic Research [SM12 - 0014]; Linkoping University [2009 - 00971]

    Vid tiden för disputation förelåg publikationen endast som manuskript

    Available from: 2015-09-03 Created: 2015-09-03 Last updated: 2018-02-13Bibliographically approved
    4. Damage Mechanisms in Silicon-Molybdenum Cast Irons Subjected to Thermo-mechanical Fatigue
    Open this publication in new window or tab >>Damage Mechanisms in Silicon-Molybdenum Cast Irons Subjected to Thermo-mechanical Fatigue
    2017 (English)In: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 99, no 2, p. 258-265Article in journal (Refereed) Published
    Abstract [en]

    The damage mechanisms active in silicon-molybdenum cast irons, namely EN-GJS-SiMo5-1 and SiMo1000, under thermo-mechanical fatigue and combined thermo-mechanical and high-cycle fatigue conditions have been investigated. The studied load conditions are those experienced at critical locations in exhaust manifolds of heavy-vehicle diesel engines, namely a temperature cycle of 300–750 °C with varied total mechanical and high-cycle fatigue strain ranges. It is established that oxide intrusions are formed in the early life from which macroscopic fatigue cracks are initiated close to the end-of-life. However, when high-cycle fatigue loading is superimposed, small cracks are preferentially initiated at graphite nodules within the bulk. In addition, it is found that both the oxidation growth rate and casting defects located near the surface affect the intrusion growth.

    Place, publisher, year, edition, pages
    Elsevier, 2017
    Keywords
    Cast iron, Thermo-mechanical fatigue, High-cycle fatigue, Enviromental assisted fatigue, Fatigue crack growth
    National Category
    Materials Engineering
    Identifiers
    urn:nbn:se:liu:diva-137287 (URN)10.1016/j.ijfatigue.2017.01.014 (DOI)000400718300007 ()2-s2.0-85017123996 (Scopus ID)
    Note

    Funding agencies: Scania CV AB; Swedish Governmental Agency for Innovation Systems [FFI-2012-03625]; Swedish Foundation for Strategic Research [SM12-0014]; Strategic Faculty Grant AFM (SFO-MAT-LiU) at Linkoping University [2009-00971]

    Available from: 2017-05-10 Created: 2017-05-10 Last updated: 2018-02-13Bibliographically approved
    5. The Transition from Micro- to Macrocrack Growth in Compacted Graphite Iron Subjected to Thermo-Mechanical Fatigue
    Open this publication in new window or tab >>The Transition from Micro- to Macrocrack Growth in Compacted Graphite Iron Subjected to Thermo-Mechanical Fatigue
    2017 (English)In: Engineering Fracture Mechanics, ISSN 0013-7944, E-ISSN 1873-7315, no 186, p. 268-282Article in journal (Refereed) Published
    Abstract [en]

    The complete fatigue process involving the growth of microstructurally small fatigue cracks prior to macrocrack initiation and the subsequent large crack propagation in notched compacted graphite iron, EN-GJV-400, specimens subjected to thermo-mechanical fatigue has been investigated. It is shown that microcracks are initiated at graphite tips within an extended volume at the notch which eventually leads to an abrupt microcrack coalescence event. As a macrocrack is generated in this way, the crack growth switches to conventional characteristics which is assessed in terms of elasto-plastic fracture mechanics parameters. Consequently, two important implications regarding lifetime assessment are identified; possible underestimation due to (i) how the stress is evaluated in view of the spacial distribution of microcracking and (ii) the crack retardation effect associated with the crack growth transition.

    Place, publisher, year, edition, pages
    Elsevier, 2017
    Keywords
    Cast iron, notches, delta J, crack tip opening displacement
    National Category
    Materials Engineering
    Identifiers
    urn:nbn:se:liu:diva-143691 (URN)10.1016/j.engfracmech.2017.10.017 (DOI)000418056700017 ()
    Available from: 2017-12-14 Created: 2017-12-14 Last updated: 2018-05-04
    Download full text (pdf)
    Fatigue of Heavy-Vehicle Engine Materials: Damage Mechanisms, Laboratory Experiments and Life Estimation
    Download (pdf)
    omslag
    Download (png)
    presentationsbild
  • 8. Order onlineBuy this publication >>
    Norman, Viktor
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Fatigue of Heavy-Vehicle Engine Materials: Experimental Analysis and Life Estimation2015Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The heavy-vehicle automotive industry is constantly subjected to higher demands. In particular, new European emission standards are formulated with the intention of improving the environmental friendliness of newly-produced vehicles through reduced exhaust emission. In one way or another, this implies a successive improvement of the engine efficiency, which in turn, inevitably will require a higher combustion pressure and temperature. This is a respectable challenge for future engine constructions, but also for the engineering materials used to embody them. As higher thermal and mechanical loads must be sustained, there is a higher rate of wear, and consequently, a negative effect on the extent of the engine lifetime.

    The aim of the present thesis is to confront the expected increase in rate of wear, henceforth referred to as fatigue, by studying the effect on materials typically employed in heavy-vehicle engines, namely cast irons. Foremost, the intention has been to improve the understanding of the physical mechanisms of fatigue in these materials, in order to develop a lifetime estimation method designated to assist the mechanical design of heavy-vehicle engines.

    In essence, a large set of thermo-mechanical fatigue (TMF) and combined thermo-mechanical and high-cycle fatigue (TMF-HCF) tests has been conducted at engine load conditions on laboratory specimens of lamellar, compacted and spheroidal graphite irons. In this way, these three different material groups have been experimentally compared and the associated fatigue mechanism has been studied. In particular, a new property related to TMF-HCF conditions has been identified and measured, . Regarding the fatigue mechanism, it has been affirmed to consist of the initiation, propagation and coalescence of numerous microcracks. Based on this, a successful lifetime assessment model was formulated, allowing good estimations of the fatigue life of laboratory specimens subjected to both TMF and TMF-HCF conditions.

    List of papers
    1. Damage evolution in compacted graphite iron during thermomechanical fatigue testing
    Open this publication in new window or tab >>Damage evolution in compacted graphite iron during thermomechanical fatigue testing
    2016 (English)In: International Journal of Cast Metals Research, ISSN 1364-0461, E-ISSN 1743-1336, Vol. 29, no 1-2, p. 26-33Article in journal (Refereed) Published
    Abstract [en]

    Thermomechanical fatigue properties of a compacted graphite iron in an out of phase configuration are investigated for different maximum temperatures and mechanical strain ranges. Furthermore, the stressï¿œstrain hysteresis loops are analysed, and, in particular, the unloading modulus, i.e. the elastic modulus measured during specimen unloading, is obtained from each cycle. This material parameter has earlier been explicitly related to the amount of microcracking in cast irons. The results show that the unloading modulus linearly declines with the numbers of cycles in all tests performed. In addition, the rate of change of the unloading modulus is closely related to the number of cycles to failure. Accordingly, it is concluded that microcracks are independently propagated by fatigue until a point of rapid crack linking resulting in ultimate failure. This is supported by microstructural analyses consisting of optical microscope images taken at different stages throughout the life of a specimen.

    Place, publisher, year, edition, pages
    Taylor & Francis, 2016
    Keywords
    Thermomechanical fatigue, Out-of-phase loading, Compacted graphite iron, Microcracking
    National Category
    Other Materials Engineering
    Identifiers
    urn:nbn:se:liu:diva-121028 (URN)10.1179/1743133615Y.0000000019 (DOI)000377468800005 ()
    Funder
    VINNOVA, FFI-2012-03625Swedish Foundation for Strategic Research , SM12-0014
    Note

    Funding agencies: Scania CV AB; Strategic Faculty Grant AFM (SFO-MAT-LiU) at Linkoping University [2009-00971]

    Available from: 2015-09-03 Created: 2015-09-03 Last updated: 2018-02-13Bibliographically approved
    2. Thermo-mechanical and superimposed high-cycle fatigue interactions in compacted graphite iron
    Open this publication in new window or tab >>Thermo-mechanical and superimposed high-cycle fatigue interactions in compacted graphite iron
    2015 (English)In: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 80, p. 381-390Article in journal (Refereed) Published
    Abstract [en]

    The effect of adding a superimposed high-frequent strain load, denoted as a high-cycle fatigue strain component, upon a strain-controlled thermo-mechanical fatigue test has been studied on a compacted graphite iron EN-GJV-400 for different thermo-mechanical fatigue cycles and high-cycle fatigue strain ranges. It is demonstrated that the successive application of an high-cycle fatigue load has a consistent effect on the fatigue life, namely the existence of a constant high-cycle fatigue strain range threshold below which the fatigue life is unaffected but severely reduced when above. This effect on the fatigue life is predicted assuming that microstructurally small cracks are propagated and accelerated according to a Paris law incorporating an experimentally estimated crack opening level.

    Place, publisher, year, edition, pages
    Elsevier, 2015
    Keywords
    Cast iron, Thermo-mechanical fatigue, High-cycle fatigue, Fatigue crack growth, Life prediction
    National Category
    Other Engineering and Technologies Mechanical Engineering
    Identifiers
    urn:nbn:se:liu:diva-121029 (URN)10.1016/j.ijfatigue.2015.06.005 (DOI)000360596500040 ()
    Available from: 2015-09-03 Created: 2015-09-03 Last updated: 2018-02-13Bibliographically approved
    3. The effect of superimposed high-cycle fatigue on thermo-mechanical fatigue in cast iron
    Open this publication in new window or tab >>The effect of superimposed high-cycle fatigue on thermo-mechanical fatigue in cast iron
    2016 (English)In: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 88, p. 121-131Article in journal (Refereed) Published
    Abstract [en]

    The eect of superimposing a high-cycle fatigue strain load on an out-ofphase thermo-mechanical fatigue test of a lamellar, compacted and spheroidal graphite iron, has been investigated. In particular, dierent total mechanical strain ranges, maximum temperatures and high-cycle fatigue strain ranges have been studied. From this, a new property has been identied, measured and compared, namely the thermo-mechanical and high-cycle fatigue threshold, dened as the high-cycle fatigue strain range at which the life is reduced to half. Using a model developed earlier, the lifetimes and the threshold have been successfully estimated for the lamellar and compacted graphite iron, however underestimated for the spheroidal graphite iron. Nevertheless, an expression of the threshold was deduced from the model, which possibly can estimate its value in other cast irons and its high-cycle fatigue frequency dependence.

    Place, publisher, year, edition, pages
    Elsevier, 2016
    Keywords
    Cast iron, Thermo-mechanical fatigue, High-cycle fatigue, Fatigue crack growth, Life prediction
    National Category
    Mechanical Engineering Other Engineering and Technologies
    Identifiers
    urn:nbn:se:liu:diva-121030 (URN)10.1016/j.ijfatigue.2016.03.020 (DOI)000375817000013 ()
    Note

    Funding agencies: Scania CV AB; Swedish Governmental Agency for Innovation Systems [FFI - 2012 - 03625]; Swedish Foundation for Strategic Research [SM12 - 0014]; Linkoping University [2009 - 00971]

    Vid tiden för disputation förelåg publikationen endast som manuskript

    Available from: 2015-09-03 Created: 2015-09-03 Last updated: 2018-02-13Bibliographically approved
    Download full text (pdf)
    fulltext
    Download (pdf)
    omslag
    Download (jpg)
    presentationsbild
  • 9.
    Norman, Viktor
    et al.
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Calmunger, Mattias
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    An Accelerated Creep Assessment Method Based on Inelastic Strain Partitioning and Slow Strain Rate Testing2021In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Materials & Design, Vol. 205, article id 109697Article in journal (Refereed)
    Abstract [en]

    A new accelerated creep assessment method to evaluate the creep performance of metals and alloys from high-temperature tensile tests, i.e. slow-strain-rate testing (SSRT), is proposed and evaluated. The method consists of decomposing the inelastic strain into a plastic and creep component by adopting general assumptions on the inelastic strain behaviour of materials, formulated using a state variable formalism and verified by tensile tests with intermediate dwell times at constant stress. Either, the plastic and creep strain components are considered non-interacting and additive, as observed in the stainless steel AISI 316L at 600 °C. Or, as in the case of the ductile cast iron EN-GJS-SiMo5-1 at 500 °C and the nickel-base superalloy Hastelloy X at 800 °C, the components are considered unified, meaning that the effect of inelastic straining is the same irrespective of whether it is caused through creep at constant stress or by plastic deformation due to an instantaneous stress increase. Based on these assumptions, the proposed method is used to assess the creep strain from SSRT in good agreement with conventional creep test results.

    Download full text (pdf)
    fulltext
  • 10.
    Norman, Viktor
    et al.
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Skoglund, Peter
    Scania CV AB, Materials Technology, Södertälje.
    Leidermark, Daniel
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Faculty of Science & Engineering.
    Moverare, Johan
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Damage Mechanisms in Silicon-Molybdenum Cast Irons Subjected to Thermo-mechanical Fatigue2017In: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 99, no 2, p. 258-265Article in journal (Refereed)
    Abstract [en]

    The damage mechanisms active in silicon-molybdenum cast irons, namely EN-GJS-SiMo5-1 and SiMo1000, under thermo-mechanical fatigue and combined thermo-mechanical and high-cycle fatigue conditions have been investigated. The studied load conditions are those experienced at critical locations in exhaust manifolds of heavy-vehicle diesel engines, namely a temperature cycle of 300–750 °C with varied total mechanical and high-cycle fatigue strain ranges. It is established that oxide intrusions are formed in the early life from which macroscopic fatigue cracks are initiated close to the end-of-life. However, when high-cycle fatigue loading is superimposed, small cracks are preferentially initiated at graphite nodules within the bulk. In addition, it is found that both the oxidation growth rate and casting defects located near the surface affect the intrusion growth.

    Download full text (pdf)
    fulltext
  • 11.
    Norman, Viktor
    et al.
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Skoglund, Peter
    Scania CV AB, Materials Technology, Södertälje, Sweden.
    Leidermark, Daniel
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Faculty of Science & Engineering.
    Moverare, Johan
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    The effect of superimposed high-cycle fatigue on thermo-mechanical fatigue in cast iron2016In: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 88, p. 121-131Article in journal (Refereed)
    Abstract [en]

    The eect of superimposing a high-cycle fatigue strain load on an out-ofphase thermo-mechanical fatigue test of a lamellar, compacted and spheroidal graphite iron, has been investigated. In particular, dierent total mechanical strain ranges, maximum temperatures and high-cycle fatigue strain ranges have been studied. From this, a new property has been identied, measured and compared, namely the thermo-mechanical and high-cycle fatigue threshold, dened as the high-cycle fatigue strain range at which the life is reduced to half. Using a model developed earlier, the lifetimes and the threshold have been successfully estimated for the lamellar and compacted graphite iron, however underestimated for the spheroidal graphite iron. Nevertheless, an expression of the threshold was deduced from the model, which possibly can estimate its value in other cast irons and its high-cycle fatigue frequency dependence.

    Download full text (pdf)
    fulltext
  • 12.
    Norman, Viktor
    et al.
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Skoglund, Peter
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering. Scania CV AB, Materials Technology, Södertälje, Sweden.
    Leidermark, Daniel
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Faculty of Science & Engineering.
    Moverare, Johan
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Thermo-mechanical and superimposed high-cycle fatigue interactions in compacted graphite iron2015In: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 80, p. 381-390Article in journal (Refereed)
    Abstract [en]

    The effect of adding a superimposed high-frequent strain load, denoted as a high-cycle fatigue strain component, upon a strain-controlled thermo-mechanical fatigue test has been studied on a compacted graphite iron EN-GJV-400 for different thermo-mechanical fatigue cycles and high-cycle fatigue strain ranges. It is demonstrated that the successive application of an high-cycle fatigue load has a consistent effect on the fatigue life, namely the existence of a constant high-cycle fatigue strain range threshold below which the fatigue life is unaffected but severely reduced when above. This effect on the fatigue life is predicted assuming that microstructurally small cracks are propagated and accelerated according to a Paris law incorporating an experimentally estimated crack opening level.

    Download full text (pdf)
    fulltext
  • 13.
    Norman, Viktor
    et al.
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, The Institute of Technology.
    Skoglund, Peter
    Moverare, Johan
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, The Institute of Technology.
    Damage Evolution in Compacted Graphite Iron during Thermo-Mechaical Fatigue Testing2014Conference paper (Refereed)
  • 14.
    Norman, Viktor
    et al.
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Skoglund, Peter
    Scania CV AB, Materials Technology, Södertälje, Sweden.
    Moverare, Johan
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Damage evolution in compacted graphite iron during thermomechanical fatigue testing2016In: International Journal of Cast Metals Research, ISSN 1364-0461, E-ISSN 1743-1336, Vol. 29, no 1-2, p. 26-33Article in journal (Refereed)
    Abstract [en]

    Thermomechanical fatigue properties of a compacted graphite iron in an out of phase configuration are investigated for different maximum temperatures and mechanical strain ranges. Furthermore, the stressï¿œstrain hysteresis loops are analysed, and, in particular, the unloading modulus, i.e. the elastic modulus measured during specimen unloading, is obtained from each cycle. This material parameter has earlier been explicitly related to the amount of microcracking in cast irons. The results show that the unloading modulus linearly declines with the numbers of cycles in all tests performed. In addition, the rate of change of the unloading modulus is closely related to the number of cycles to failure. Accordingly, it is concluded that microcracks are independently propagated by fatigue until a point of rapid crack linking resulting in ultimate failure. This is supported by microstructural analyses consisting of optical microscope images taken at different stages throughout the life of a specimen.

    Download full text (pdf)
    fulltext
  • 15.
    Norman, Viktor
    et al.
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Stekovic, Svjetlana
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Jones, J
    Swansea University, Swansea, UK.
    Whittaker, M
    Swansea University, Swansea, UK.
    Grant, B
    Rolls-Royce plc, Derby, UK.
    On the Mechanistic Difference Between In-phase and Out-of-phase Thermo-Mechanical Fatigue Crack Growth2020In: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 135, p. 1-11, article id 105528Article in journal (Refereed)
    Abstract [en]

    The crack driving mechanisms in a coarse grained nickel-base superalloy RR1000 when subjected to in- and out of phase thermo mechanical fatigue are investigated. It is found that the difference in fatigue crack growth rate between these two load conditions is accounted for by the different mechanical conditions at the crack tip region, rather than oxidation effects. This is based on digital image correlation and finite element analyses of the mechanical strain field at the crack tip, which demonstrate that in phase leads to larger crack tip deformation and crack opening. Notably, it is demonstrated that in- and out of phase crack growth rates coincide when correlated to the crack tip opening displacement.

    Download full text (pdf)
    fulltext
  • 16.
    Norman, Viktor
    et al.
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Stekovic, Svjetlana
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, Faculty of Science & Engineering.
    Leidermark, Daniel
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, Faculty of Science & Engineering.
    Engel, Benedikt
    The University of Nottingham, Nottingham, England.
    Rouse, James
    The University of Nottingham, Nottingham, England.
    Chris, Hyde
    The University of Nottingham, Nottingham, England.
    Grant, Ben
    Rolls-Royce plc.
    Crack initiation in notched coarse- grained RR1000 specimens subjected to in-phase thermo-mechanical fatigue2020In: 4th workshop on thermo-mechanical fatigue / [ed] Hellmuth Klingelhöffer, Berlin, 2020Conference paper (Other academic)
  • 17.
    Segersäll, Mikael
    et al.
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, The Institute of Technology.
    Calmunger, Mattias
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, The Institute of Technology.
    Norman, Viktor
    Linköping University, Department of Management and Engineering, Engineering Materials. Linköping University, The Institute of Technology.
    Fredriksson, Claes
    Student Reactions to CES EduPack in an Undergraduate Materials Selection Course2015Conference paper (Refereed)
1 - 17 of 17
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • 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