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Masatoshi Tsuda - One of the best experts on this subject based on the ideXlab platform.

  • duplex model for homogenized elastic viscoplastic behavior of Plate fin structures at high temperatures
    International Journal of Plasticity, 2011
    Co-Authors: Masatoshi Tsuda
    Abstract:

    Abstract In this study, a duplex model is developed as a constitutive model for the homogenized elastic–viscoplastic behavior of a class of Plate–fin structures operating at high temperatures. This model consists of Plate and fin layers, which are individually ruled by different macro-constitutive models. An anisotropic, compressible power-law equation that was derived in a recent study by the present authors is used to describe the homogenized viscoplastic behavior of the fin layer. On the other hand, an isotropic, incompressible power-law equation is used as the macro-constitutive equation of the Plate layer. The duplex model developed is applied to an ultra-Fine Plate–fin structure made of Hastelloy X. It is shown that the duplex model is more successful under multiaxial loading than the corresponding simplex model in which Plates and fins are non-separately homogenized.

  • homogenized elastic viscoplastic behavior of Plate fin structures at high temperatures numerical analysis and macroscopic constitutive modeling
    International Journal of Mechanical Sciences, 2010
    Co-Authors: Masatoshi Tsuda, T. Asada, Eri Takemura, T. Igari
    Abstract:

    Abstract In this study, homogenized elastic–viscoplastic behavior of an ultra-Fine Plate-fin structure fabricated for compact heat exchangers is investigated. First, the homogenized behavior is numerically analyzed using a fully implicit mathematical homogenization scheme of periodic elastic–inelastic solids. A power-law creep relation is assumed to represent the viscoplasticity of base metals at high temperatures. The Plate-fin structure is thus shown to exhibit significant anisotropy as well as noticeable compressibility in both the elastic and viscoplastic ranges of the homogenized behavior. Second, a non-linear rate-dependent macroscopic constitutive model is developed using the quadratic yield function proposed for anisotropic compressible plasticity. The resulting constitutive model is shown to be successful for simulating the anisotropy, compressibility, and rate dependency in the homogenized behavior in multi-axial stress states.

T. Igari - One of the best experts on this subject based on the ideXlab platform.

  • homogenized elastic viscoplastic behavior of Plate fin structures at high temperatures numerical analysis and macroscopic constitutive modeling
    International Journal of Mechanical Sciences, 2010
    Co-Authors: Masatoshi Tsuda, T. Asada, Eri Takemura, T. Igari
    Abstract:

    Abstract In this study, homogenized elastic–viscoplastic behavior of an ultra-Fine Plate-fin structure fabricated for compact heat exchangers is investigated. First, the homogenized behavior is numerically analyzed using a fully implicit mathematical homogenization scheme of periodic elastic–inelastic solids. A power-law creep relation is assumed to represent the viscoplasticity of base metals at high temperatures. The Plate-fin structure is thus shown to exhibit significant anisotropy as well as noticeable compressibility in both the elastic and viscoplastic ranges of the homogenized behavior. Second, a non-linear rate-dependent macroscopic constitutive model is developed using the quadratic yield function proposed for anisotropic compressible plasticity. The resulting constitutive model is shown to be successful for simulating the anisotropy, compressibility, and rate dependency in the homogenized behavior in multi-axial stress states.

Eri Takemura - One of the best experts on this subject based on the ideXlab platform.

  • homogenized elastic viscoplastic behavior of Plate fin structures at high temperatures numerical analysis and macroscopic constitutive modeling
    International Journal of Mechanical Sciences, 2010
    Co-Authors: Masatoshi Tsuda, T. Asada, Eri Takemura, T. Igari
    Abstract:

    Abstract In this study, homogenized elastic–viscoplastic behavior of an ultra-Fine Plate-fin structure fabricated for compact heat exchangers is investigated. First, the homogenized behavior is numerically analyzed using a fully implicit mathematical homogenization scheme of periodic elastic–inelastic solids. A power-law creep relation is assumed to represent the viscoplasticity of base metals at high temperatures. The Plate-fin structure is thus shown to exhibit significant anisotropy as well as noticeable compressibility in both the elastic and viscoplastic ranges of the homogenized behavior. Second, a non-linear rate-dependent macroscopic constitutive model is developed using the quadratic yield function proposed for anisotropic compressible plasticity. The resulting constitutive model is shown to be successful for simulating the anisotropy, compressibility, and rate dependency in the homogenized behavior in multi-axial stress states.

T. Asada - One of the best experts on this subject based on the ideXlab platform.

  • homogenized elastic viscoplastic behavior of Plate fin structures at high temperatures numerical analysis and macroscopic constitutive modeling
    International Journal of Mechanical Sciences, 2010
    Co-Authors: Masatoshi Tsuda, T. Asada, Eri Takemura, T. Igari
    Abstract:

    Abstract In this study, homogenized elastic–viscoplastic behavior of an ultra-Fine Plate-fin structure fabricated for compact heat exchangers is investigated. First, the homogenized behavior is numerically analyzed using a fully implicit mathematical homogenization scheme of periodic elastic–inelastic solids. A power-law creep relation is assumed to represent the viscoplasticity of base metals at high temperatures. The Plate-fin structure is thus shown to exhibit significant anisotropy as well as noticeable compressibility in both the elastic and viscoplastic ranges of the homogenized behavior. Second, a non-linear rate-dependent macroscopic constitutive model is developed using the quadratic yield function proposed for anisotropic compressible plasticity. The resulting constitutive model is shown to be successful for simulating the anisotropy, compressibility, and rate dependency in the homogenized behavior in multi-axial stress states.

Bo Lv - One of the best experts on this subject based on the ideXlab platform.

  • low temperature bainite in low carbon steel
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2014
    Co-Authors: Xiaoyan Long, J. Kang, Fucheng Zhang, Bo Lv
    Abstract:

    Abstract The microstructures and the mechanical properties of 30MnSiCrAlNiMo low-carbon steel were systematically optimized by a series of heat-treatment processes, and the heat-treatment process of low-temperature bainite in low-carbon steel was explored. Results showed that the microstructure of low-temperature bainite in the low-carbon steel, containing a Fine Plate of carbide-free bainitic ferrite and a thin film of retained austenite, could be produced by continuous cooling transformation around the Ms temperature from Ms+10 °C to Ms−20 °C at a cooling rate of 0.5 °C min −1 . A new model was proposed to evaluate the comprehensive mechanical properties of steel, which found that the low-temperature bainite had the best comprehensive mechanical properties compared to any other microstructures for the low-carbon steel. The higher dislocation density and Finer bainitic ferrite Plate in the low-temperature bainite resulted in the higher yield strength and the higher toughness, but relatively lower ultimate tensile strength owing to the lower work-hardening rate caused by the higher initial dislocation density. There were some very Fine particles in the bainitic ferrite of the steel after isothermal treatment at higher temperature. The ultimate tensile strength and the low-temperature impact toughness of the steel decreased with the volume fraction of the retained austenite increasing, while the elongation initially increased with an increase in the volume fraction of the retained austenite (