Improvement of Creep Behavior Prediction Using Threshold Stress and Tensile Properties: Introduction of the TTC Relations

Zhao, Xu; Niu, Xuming; Song, Yingdong; Sun, Zhonghua

doi:10.1007/s11661-022-06759-2

Cited by 5 publications

(10 citation statements)

References 73 publications

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“…According to the threshold stress theory, however, the minimum creep rate is close to zero as stress tends to threshold stress rather than zero stress. Therefore, the intrinsic relations between threshold stress, tensile properties, and creep behavior were established 25 . These relations, called TTC relations, can be expressed as

\frac{σ - σ_{th}}{σ_{b} - σ} goodbreak= A_{1} {[{\overset{ε}{true}}_{m} \exp (Q_{N}^{*} / RT)]}^{n_{1}}

\frac{σ - σ_{th}}{σ_{b} - σ} goodbreak= A_{2} {[t_{f} \exp (- Q_{N}^{*} / RT)]}^{n_{2}}

where

A_{1}

A_{2}

n_{1}

, and

n_{2}

are constants,

σ_{th}

is the threshold stress, and

Q_{N}^{*}

is the apparent activation energy of TTC relations which can be calculated at constant

((), σ - σ_{th}) / ((), σ_{b} - σ)

.…”

Section: A Novel Damage Constitutive Model Based On Ttc Relationsmentioning

confidence: 99%

A novel damage constitutive model for creep deformation and damage evolution prediction

Zhao

Niu

Song

et al. 2022

Fatigue Fract Eng Mat Struct

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In order to accurately predict creep deformation and damage evolution of nickel-based superalloy GH4169, a novel damage constitutive model, that is, TTC CDM-based model, was proposed based on TTC relations and continuum damage mechanics (CDM). This model combined the best features of the TTC relations and CDM. The recently developed TTC relations were intrinsic relations between threshold stress, tensile properties, and creep behavior and exhibited better prediction ability than Wilshire equations. It was determined that the model accurately predicted the minimum creep rate, rupture time, creep deformation, and damage evolution process of GH4169. Microstructural study has revealed that the creep fracture mode gradually converts from intergranular brittle fracture to transgranular ductile fracture as the stress decreases. Furthermore, the nonlinear creep damage accumulation effect was also revealed by the novel model.

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\frac{σ - σ_{th}}{σ_{b} - σ} goodbreak= A_{1} {[{\overset{ε}{true}}_{m} \exp (Q_{N}^{*} / RT)]}^{n_{1}}

\frac{σ - σ_{th}}{σ_{b} - σ} goodbreak= A_{2} {[t_{f} \exp (- Q_{N}^{*} / RT)]}^{n_{2}}

where

A_{1}

A_{2}

n_{1}

, and

n_{2}

are constants,

σ_{th}

is the threshold stress, and

Q_{N}^{*}

is the apparent activation energy of TTC relations which can be calculated at constant

((), σ - σ_{th}) / ((), σ_{b} - σ)

.…”

Section: A Novel Damage Constitutive Model Based On Ttc Relationsmentioning

confidence: 99%

A novel damage constitutive model for creep deformation and damage evolution prediction

Zhao

Niu

Song

et al. 2022

Fatigue Fract Eng Mat Struct

Self Cite

View full text Add to dashboard Cite

show abstract

“…In recent investigation 28 , the intrinsic relations between threshold stress, tensile properties, and creep behavior were established. These relations, called TTC relations, can be expressed as where , , and are constants, is the threshold stress, is the ultimate tensile strength, is the minimum creep rate, is the gas constant (), is rupture time, and is the apparent activation energy of TTC relations which can be calculated at constant .…”

Section: A Novel Damage Constitutive Model Based On Ttc Relationsmentioning

confidence: 99%

“…In order to determine the threshold stress, a standard linear extrapolation method was introduced by Mishra 38,39 , Huang 40 and Langdon 45 et al And this method has been successfully used to determine the threshold stress of Grade 91 steel 46,47 , ferritic-martensitic steel 48 , Fe-Cr-Ni alloy 44 , Grade 92 steel 49 , nickelbased superalloy 50 , etc. Using the same method, the threshold stresses at 600 and 650 were determined to be 593 MPa and 309 MPa in recent study 28 , respectively. It should be pointed out that the threshold stress is closely related to microstructural evolution and stability.…”

Section: Andmentioning

confidence: 99%

“…Therefore, constants , and , are the slope and y-intercept in the -and -diagrams, respectively. Full details are given in reference [28].…”

Section: Andmentioning

confidence: 99%

“…Our latest research results 28 showed that intrinsic relations exist between threshold stress, tensile properties and creep behavior, and the TTC relations were proposed, which were better at predicting the creep behavior than Wilshire equations. Therefore, to ensure the accuracy of extrapolation of long-term creep behavior, a novel damage constitutive model was derived which combines the TTC relations with continuum damage mechanics.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Modeling the creep deformation and damage evolution of superalloy GH4169: Application of a novel damage constitutive model based on continuum damage mechanics

Zhao

Niu

Song

et al. 2022

Preprint

Self Cite

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In order to accurately predict creep deformation and damage evolution of nickel-based superalloy GH4169, a novel damage constitutive model, which can be called TTC CDM-based model, was proposed based on TTC relations and continuum damage mechanics (CDM). The stress and temperature dependence of constants were all determined in the novel model, which overcame the weakness of the traditional CDM-based model and made the model have the satisfactory abilities of interpolation and extrapolation. Microstructural study has revealed that the creep fracture mode gradually converts from intergranular brittle fracture to transgranular ductile fracture as the stress decreases. And the critical conditions were identified. It was determined that the novel model accurately predicted the minimum creep rate, rupture time, creep deformation and damage evolution process of GH4169. Furthermore, the nonlinear creep damage accumulation effect was also revealed by the novel model, i.e. the total creep life of GH4169 will be reduced if high stress or high temperature condition was applied first, which was consistent with previous experimental results of variable creep load.

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Micromechanical mechanism of creep secondary crack propagation behavior for superalloy

Zhao,

Song

et al. 2024

Journal of Alloys and Compounds

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Improvement of Creep Behavior Prediction Using Threshold Stress and Tensile Properties: Introduction of the TTC Relations

Cited by 5 publications

References 73 publications

A novel damage constitutive model for creep deformation and damage evolution prediction

A novel damage constitutive model for creep deformation and damage evolution prediction

Modeling the creep deformation and damage evolution of superalloy GH4169: Application of a novel damage constitutive model based on continuum damage mechanics

Micromechanical mechanism of creep secondary crack propagation behavior for superalloy

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