The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform

H. Yuan - One of the best experts on this subject based on the ideXlab platform.

  • Investigation of Thermal Gradient Mechanical Fatigue Test Methods for Nickel-based Superalloys
    Experimental Mechanics, 2021
    Co-Authors: J. Sun, H. Yuan
    Abstract:

    Temperature gradients significantly affect the material Fatigue process. A reliable and robust test procedure is needed for quantifying the effects of temperature gradients on the evolution of Fatigue damage in nickel-based superalloys. The present study aims to develop a radiation heating system for universal material testing machine for simulating thermal gradient Mechanical Fatigue in turbines. The developed heating system mainly consists of halogen lamps, reflectors, cooling subsystems, and control units. Based on extensive experimental and computational investigations, a thermal model is developed for accurate thermo-Mechanical Fatigue testing under given temperature gradients in the heating system, and it is applied to variable temperature Fatigue tests. The detail procedure for determining heat transfer coefficients is presented based on experimental and computational results. TGMF tests are successfully performed with the developed radiation heating system. The temperature gradients are found to reduce the TGMF life significantly in comparison to that of the TMF life. It is confirmed that the developed thermal gradient Mechanical Fatigue methodology can be applied to different thermo-Mechanical Fatigue tests with various temperature gradients.

  • Assessment of thermo-Mechanical Fatigue in a nickel-based single-crystal superalloy CMSX-4 accounting for temperature gradient effects
    Materials Science and Engineering: A, 2021
    Co-Authors: J. Sun, Shun Yang, H. Yuan
    Abstract:

    Abstract Turbine blades are working under complex thermal gradient Mechanical loading conditions. In the present study, a nickel-based single-crystal superalloy CMSX-4 is experimentally and computationally investigated under the thermo-Mechanical Fatigue (TMF) and thermal gradient Mechanical Fatigue (TGMF) loading conditions of the in-phase and out-of-phase thermal-Mechanical angel. The Fatigue life of TGMF with and without the thermal barrier coating was studied. It was confirmed that the lifetime of TGMF is affected by the temperature gradient significantly and substantially differs from conventional isothermal high temperature Fatigue and thermo-Mechanical Fatigue. Since conventional Fatigue models fail to characterize the TGMF, a modified model considers temperature gradient effects and thermal-Mechanical phase angle and can describe the TGMF lifetime of the single-crystal superalloy reasonably.

  • Thermal gradient Mechanical Fatigue assessment of a nickel-based superalloy
    International Journal of Fatigue, 2020
    Co-Authors: J. Sun, H. Yuan, Michael Vormwald
    Abstract:

    Abstract In the present work, a radiation heating system was developed to simulate thermal gradient Mechanical Fatigue (TGMF) loads in turbines. The specimen is externally heated by radiation and internally cooled by compressed air. Experiments showed that the TGMF life of the nickel-based superalloy is significantly shorter than that of the thermo-Mechanical and the isothermal Fatigue, although the thermal stress is small. It was confirmed that the conventional Fatigue models generated seriously deviations and could not catch effects of the thermal gradients. The modified TGMF model introduced a correction term of the temperature gradient effects and can describe the TGMF lifetime of Inconel 718 reasonably. The new model provides a uniform description of isothermal and complex thermo-Mechanical Fatigue.

Johan Moverare - One of the best experts on this subject based on the ideXlab platform.

Thomas Lenoir - One of the best experts on this subject based on the ideXlab platform.

  • Mechanical Fatigue behavior in treated stabilized soils subjected to a uniaxial flexural test
    International Journal of Fatigue, 2015
    Co-Authors: Mathieu Preteseille, Thomas Lenoir
    Abstract:

    The use of in situ fine-grained soils treated with lime and/or hydraulic binders as subgrade in common civil engineering infrastructures is a sustainable upgrading process for natural materials with low Mechanical performances. In the case of land transport projects, the lack of knowledge on Mechanical Fatigue behavior in these materials leads either to empirical oversized design of the layers made with these materials or to their rejection. However, the development of a relevant test now enables us to accurately measure the Mechanical Fatigue performances of treated soils. First, sample preparation appears to explain most Fatigue performances, not sample mineralogy. Second, based on original results on three treated soils and previous results from the literature, it seems that a behavior law governs these performances. Finally, a simple classification tool shows that these materials can be considered within the entirety of transport infrastructures from subgrade layers to subbase layers.

  • Mechanical Fatigue behavior in treated/stabilized soils subjected to a uniaxial flexural test
    International Journal of Fatigue, 2015
    Co-Authors: Mathieu Preteseille, Thomas Lenoir
    Abstract:

    The use of in situ fine-grained soils treated with lime and/or hydraulic binders as subgrade in common civil engineering infrastructures is a sustainable upgrading process for natural materials with low Mechanical performances. In the case of land transport projects, the lack of knowledge on Mechanical Fatigue behavior in these materials leads either to empirical oversized design of the layers made with these materials or to their rejection. However, the development of a relevant test now enables us to accurately measure the Mechanical Fatigue performances of treated soils. First, sample preparation appears to explain most Fatigue performances, not sample mineralogy. Second, based on original results on three treated soils and previous results from the literature, it seems that a behavior law governs these performances. Finally, a simple classification tool shows that these materials can be considered within the entirety of transport infrastructures from subgrade layers to subbase layers.

J. Sun - One of the best experts on this subject based on the ideXlab platform.

  • Investigation of Thermal Gradient Mechanical Fatigue Test Methods for Nickel-based Superalloys
    Experimental Mechanics, 2021
    Co-Authors: J. Sun, H. Yuan
    Abstract:

    Temperature gradients significantly affect the material Fatigue process. A reliable and robust test procedure is needed for quantifying the effects of temperature gradients on the evolution of Fatigue damage in nickel-based superalloys. The present study aims to develop a radiation heating system for universal material testing machine for simulating thermal gradient Mechanical Fatigue in turbines. The developed heating system mainly consists of halogen lamps, reflectors, cooling subsystems, and control units. Based on extensive experimental and computational investigations, a thermal model is developed for accurate thermo-Mechanical Fatigue testing under given temperature gradients in the heating system, and it is applied to variable temperature Fatigue tests. The detail procedure for determining heat transfer coefficients is presented based on experimental and computational results. TGMF tests are successfully performed with the developed radiation heating system. The temperature gradients are found to reduce the TGMF life significantly in comparison to that of the TMF life. It is confirmed that the developed thermal gradient Mechanical Fatigue methodology can be applied to different thermo-Mechanical Fatigue tests with various temperature gradients.

  • Assessment of thermo-Mechanical Fatigue in a nickel-based single-crystal superalloy CMSX-4 accounting for temperature gradient effects
    Materials Science and Engineering: A, 2021
    Co-Authors: J. Sun, Shun Yang, H. Yuan
    Abstract:

    Abstract Turbine blades are working under complex thermal gradient Mechanical loading conditions. In the present study, a nickel-based single-crystal superalloy CMSX-4 is experimentally and computationally investigated under the thermo-Mechanical Fatigue (TMF) and thermal gradient Mechanical Fatigue (TGMF) loading conditions of the in-phase and out-of-phase thermal-Mechanical angel. The Fatigue life of TGMF with and without the thermal barrier coating was studied. It was confirmed that the lifetime of TGMF is affected by the temperature gradient significantly and substantially differs from conventional isothermal high temperature Fatigue and thermo-Mechanical Fatigue. Since conventional Fatigue models fail to characterize the TGMF, a modified model considers temperature gradient effects and thermal-Mechanical phase angle and can describe the TGMF lifetime of the single-crystal superalloy reasonably.

  • Thermal gradient Mechanical Fatigue assessment of a nickel-based superalloy
    International Journal of Fatigue, 2020
    Co-Authors: J. Sun, H. Yuan, Michael Vormwald
    Abstract:

    Abstract In the present work, a radiation heating system was developed to simulate thermal gradient Mechanical Fatigue (TGMF) loads in turbines. The specimen is externally heated by radiation and internally cooled by compressed air. Experiments showed that the TGMF life of the nickel-based superalloy is significantly shorter than that of the thermo-Mechanical and the isothermal Fatigue, although the thermal stress is small. It was confirmed that the conventional Fatigue models generated seriously deviations and could not catch effects of the thermal gradients. The modified TGMF model introduced a correction term of the temperature gradient effects and can describe the TGMF lifetime of Inconel 718 reasonably. The new model provides a uniform description of isothermal and complex thermo-Mechanical Fatigue.

Mathieu Preteseille - One of the best experts on this subject based on the ideXlab platform.

  • Mechanical Fatigue behavior in treated stabilized soils subjected to a uniaxial flexural test
    International Journal of Fatigue, 2015
    Co-Authors: Mathieu Preteseille, Thomas Lenoir
    Abstract:

    The use of in situ fine-grained soils treated with lime and/or hydraulic binders as subgrade in common civil engineering infrastructures is a sustainable upgrading process for natural materials with low Mechanical performances. In the case of land transport projects, the lack of knowledge on Mechanical Fatigue behavior in these materials leads either to empirical oversized design of the layers made with these materials or to their rejection. However, the development of a relevant test now enables us to accurately measure the Mechanical Fatigue performances of treated soils. First, sample preparation appears to explain most Fatigue performances, not sample mineralogy. Second, based on original results on three treated soils and previous results from the literature, it seems that a behavior law governs these performances. Finally, a simple classification tool shows that these materials can be considered within the entirety of transport infrastructures from subgrade layers to subbase layers.

  • Mechanical Fatigue behavior in treated/stabilized soils subjected to a uniaxial flexural test
    International Journal of Fatigue, 2015
    Co-Authors: Mathieu Preteseille, Thomas Lenoir
    Abstract:

    The use of in situ fine-grained soils treated with lime and/or hydraulic binders as subgrade in common civil engineering infrastructures is a sustainable upgrading process for natural materials with low Mechanical performances. In the case of land transport projects, the lack of knowledge on Mechanical Fatigue behavior in these materials leads either to empirical oversized design of the layers made with these materials or to their rejection. However, the development of a relevant test now enables us to accurately measure the Mechanical Fatigue performances of treated soils. First, sample preparation appears to explain most Fatigue performances, not sample mineralogy. Second, based on original results on three treated soils and previous results from the literature, it seems that a behavior law governs these performances. Finally, a simple classification tool shows that these materials can be considered within the entirety of transport infrastructures from subgrade layers to subbase layers.