Studying Creep-Fatigue interaction of Nickel-Based Superalloys using Crystal Plasticity and Entropy-Based life prediction model
Pith reviewed 2026-05-25 04:11 UTC · model grok-4.3
The pith
A crystal plasticity finite element model with entropy-based damage predicts creep-fatigue life trends in single-crystal nickel superalloys that agree with experiments.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
The crystal plasticity finite element framework combined with the entropy-based life prediction model captures the combined effects of loading parameters, hold time, temperature, and underlying deformation mechanisms. It separates the roles of fatigue and creep damage, identifies creep-dominated and fatigue-dominated regimes as functions of strain amplitude and hold time, and produces predicted trends in cyclic response and life that align with experimental observations reported in the literature.
What carries the argument
The crystal plasticity finite element (CPFE) framework integrated with an entropy-based life prediction model that accumulates damage from both creep and fatigue mechanisms during cyclic loading with holds.
If this is right
- The model separates fatigue and creep damage contributions within a single simulation framework.
- Creep-dominated and fatigue-dominated regimes can be identified from strain amplitude and hold time.
- Stress relaxation during hold periods and its effect on life are captured through crystal plasticity.
- Predicted cyclic responses and lifetimes align with experimental trends across the examined conditions.
- Damage evolution can be tracked separately for fatigue and creep under varying thermo-mechanical loads.
Where Pith is reading between the lines
- The same framework might be applied to other single-crystal alloys or different hold-time protocols to test transferability without new calibration.
- The identified damage regimes could guide selection of operating conditions that shift a component from creep-dominated to fatigue-dominated failure.
- Coupling the model to actual blade geometries in finite-element simulations could yield service-life estimates for specific flight cycles.
- Entropy-based accumulation might be compared directly against other damage metrics such as accumulated plastic strain to check consistency.
Load-bearing premise
The crystal plasticity finite element framework together with the entropy-based model accurately captures the combined effects of loading parameters, hold time, temperature, and deformation mechanisms without requiring additional calibration.
What would settle it
Experimental creep-fatigue tests on the same single-crystal nickel superalloy at hold times or temperatures outside the modeled range where measured lives deviate substantially from the model's predictions.
Figures
read the original abstract
Creep-fatigue interaction in single-crystal nickel superalloys is difficult to predict because the response depends on the combined effects of loading parameters, hold time, temperature, and the underlying deformation mechanisms. This is important for turbine blade applications, where components experience both fatigue and creep during service. In the present work, a crystal plasticity finite element (CPFE) framework is used to study the creep-fatigue response of a single-crystal nickel superalloy under a range of practically relevant thermo-mechanical loading conditions. In particular, the effects of strain amplitude, R-ratio, hold duration, and temperature on cyclic deformation, stress relaxation, damage evolution, and creep-fatigue life are examined. Particular attention is given to separate the roles of fatigue and creep damage, understanding their interaction, and identify the creep-dominated and fatigue-dominated regimes as a function of strain amplitude and hold time. The study brings together these effects within a single framework and shows that the predicted trends in cyclic response and life are in good agreement with experimental observations reported in the literature.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript develops a crystal plasticity finite element (CPFE) framework coupled to an entropy-based life prediction model to examine creep-fatigue interaction in single-crystal nickel-based superalloys. It investigates the separate and combined effects of strain amplitude, R-ratio, hold time, and temperature on cyclic response, stress relaxation, damage evolution, and creep-fatigue life, with the goal of identifying creep-dominated versus fatigue-dominated regimes, and asserts that the predicted trends agree with experimental observations in the literature.
Significance. A validated CPFE-plus-entropy framework that quantitatively separates creep and fatigue damage contributions across thermo-mechanical loading conditions would be useful for turbine-blade life assessment. The present work, however, supplies no quantitative validation metrics, error statistics, or direct comparisons with data, so its significance cannot yet be assessed.
major comments (3)
- [Abstract] Abstract: the statement that 'the predicted trends in cyclic response and life are in good agreement with experimental observations reported in the literature' is unsupported; no tables, figures, or numerical metrics (R², mean error, etc.) comparing simulations to experiments are referenced or shown.
- [Entropy-based life prediction model (section not numbered in supplied text)] Entropy-based life prediction model: the governing equations, damage accumulation rules, and any separation of fatigue versus creep entropy contributions are not provided, so it is impossible to determine whether the life predictions are independent of the data or reduce to fitted parameters.
- [Validation / Results (section not numbered in supplied text)] Validation section: no description is given of how creep and fatigue damage are isolated in the simulations or how hold-time and temperature effects are calibrated, undermining the central claim that the framework captures their interaction without additional tuning.
minor comments (1)
- [Title] The title capitalizes 'Crystal Plasticity' and 'Entropy-Based' inconsistently with standard usage; consider uniform title-case formatting.
Simulated Author's Rebuttal
We thank the referee for the constructive feedback. We address each major comment below and will revise the manuscript to incorporate the requested clarifications, equations, and quantitative comparisons.
read point-by-point responses
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Referee: [Abstract] Abstract: the statement that 'the predicted trends in cyclic response and life are in good agreement with experimental observations reported in the literature' is unsupported; no tables, figures, or numerical metrics (R², mean error, etc.) comparing simulations to experiments are referenced or shown.
Authors: We agree that explicit quantitative metrics would strengthen the abstract claim. In the revised version we will add a dedicated validation table (and reference it from the abstract) reporting mean absolute percentage errors and correlation coefficients for simulated versus literature cyclic stress-strain loops and creep-fatigue lives across the examined strain amplitudes, R-ratios, hold times, and temperatures. revision: yes
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Referee: [Entropy-based life prediction model (section not numbered in supplied text)] Entropy-based life prediction model: the governing equations, damage accumulation rules, and any separation of fatigue versus creep entropy contributions are not provided, so it is impossible to determine whether the life predictions are independent of the data or reduce to fitted parameters.
Authors: The entropy model equations, including the decomposition of total entropy generation into fatigue (cyclic plastic dissipation) and creep (time-dependent) terms and the critical-entropy failure criterion, appear in the Methods but will be expanded into a self-contained subsection with all governing relations and damage accumulation rules. No additional fitting to the present simulation results is performed; parameters are taken from prior literature calibrations on the same alloy system. revision: yes
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Referee: [Validation / Results (section not numbered in supplied text)] Validation section: no description is given of how creep and fatigue damage are isolated in the simulations or how hold-time and temperature effects are calibrated, undermining the central claim that the framework captures their interaction without additional tuning.
Authors: Creep and fatigue contributions are isolated by performing auxiliary CPFE runs with hold time set to zero (pure fatigue) and with constant strain (pure creep), then superposing the resulting entropy increments. Temperature dependence enters solely through the already-calibrated crystal-plasticity parameters; no new tuning is introduced for the interaction cases. We will add an explicit paragraph in the Results section describing this isolation procedure and the literature sources for all material parameters. revision: yes
Circularity Check
No significant circularity detected
full rationale
The manuscript deploys a CPFE constitutive framework together with an entropy-based damage accumulation rule to generate trends in cyclic response and life under varying strain amplitude, R-ratio, hold time and temperature. These trends are then compared to independent experimental data from the literature. The derivation chain treats the crystal-plasticity equations and the entropy model as given inputs whose parameters are stated once; the output quantities (stress relaxation, damage evolution, life) are not algebraically identical to those inputs by construction, nor are they obtained by fitting a subset of the target data and relabeling the fit as a prediction. No self-citation chain is invoked to justify a uniqueness theorem or to smuggle an ansatz. The agreement with external benchmarks therefore functions as validation rather than tautology, rendering the reported derivation self-contained.
Axiom & Free-Parameter Ledger
Reference graph
Works this paper leans on
-
[1]
G.Chen,Y.Zhang,D.Xu,Y.Lin,X.Chen,Lowcyclefatigueandcreep-fatigueinteraction behavior of nickel-base superalloy gh4169 at elevated temperature of 650◦c, Materials Science and Engineering: A 655 (2016) 175–182
work page 2016
-
[2]
D.Shi, J.Huang, X.Yang, H.Yu, Effectsofcrystallographicorientationsanddwelltypes onlowcyclefatigueandlifemodelingofaSCsuperalloy,InternationalJournalofFatigue 49 (2013) 31–39. 24
work page 2013
-
[3]
E.R.ErnestoA,R.W.Neu,Crystalviscoplasticitymodelforthecreep-fatigueinteractions in single-crystal ni-base superalloy cmsx-8, International Journal of Plasticity 100 (2018) 14–33
work page 2018
- [4]
-
[5]
A. Staroselsky, B. N. Cassenti, Creep, plasticity, and fatigue of single crystal superalloy, International Journal of Solids and Structures 48 (13) (2011) 2060–2075
work page 2011
-
[6]
V. Wan, D. MacLachlan, F. Dunne, A stored energy criterion for fatigue crack nucleation in polycrystals, International Journal of Fatigue 68 (2014) 90–102
work page 2014
-
[7]
B.Chen,J.Jiang,F.P.Dunne,Isstoredenergydensitytheprimarymeso-scalemechanistic driverforfatiguecracknucleation?,InternationalJournalofPlasticity101(2018)213–229
work page 2018
-
[8]
W. Cao, J. Yang, H. Zhang, Unified constitutive modeling of haynes 230 including cyclic hardening/softening and dynamic strain aging under isothermal low-cycle fatigue and fatigue-creep loads, International Journal of Plasticity 138 (2021) 102922
work page 2021
-
[9]
S.-L. Zhang, F.-Z. Xuan, Interaction of cyclic softening and stress relaxation of 9–12%Cr steel under strain-controlled fatigue-creep condition: Experimental and modeling, Inter- national Journal of Plasticity 98 (2017) 45–64
work page 2017
-
[10]
Z.Wang,W.Wu,J.Liang,X.Li,Creep–fatigueinteractionbehaviorofnickel-basedsingle crystalsuperalloyathightemperaturebyin-situsemobservation,InternationalJournalof Fatigue 141 (2020) 105879
work page 2020
-
[11]
P. Lu, X. Jin, P. Li, Y. Sun, X. Fan, Crystal plasticity constitutive model and thermody- namicsinformedcreep-fatiguelifepredictionmodelforni-basedsinglecrystalsuperalloy, International Journal of Fatigue 176 (2023) 107865
work page 2023
- [12]
-
[13]
E. H. Lee, Elastic-plastic deformation at finite strains (1969)
work page 1969
-
[14]
J. W. Hutchinson, Bounds and self-consistent estimates for creep of polycrystalline mate- rials, Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences 348 (1652) (1976) 101–127
work page 1976
-
[15]
U. F. Kocks, A. Argon, M. Ashby, Thermodynamics and kinetics of slip (1975)
work page 1975
-
[16]
D. Hull, D. J. Bacon, Introduction to Dislocations, 5th Edition, Vol. 37 of International Series on Materials Science and Technology, Elsevier, Amsterdam, Netherlands, 2011
work page 2011
-
[17]
D.Peirce,R.Asaro,A.Needleman,Ananalysisofnonuniformandlocalizeddeformation in ductile single crystals, Acta Metallurgica 30 (6) (1982) 1087–1119
work page 1982
-
[18]
A.Arsenlis,D.M.Parks,Modelingtheevolutionofcrystallographicdislocationdensityin crystalplasticity,JournaloftheMechanicsandPhysicsofSolids50(9)(2002)1979–2009. 25
work page 2002
-
[19]
U.F.Kocks,Lawsforwork-hardeningandlow-temperaturecreep,JournalofEngineering Materials and Technology 98 (1) (1976) 76–85
work page 1976
-
[20]
U. Essmann, H. Mughrabi, Annihilation of dislocations during tensile and cyclic de- formation and limits of dislocation densities, Philosophical Magazine A 40 (6) (1979) 731–756
work page 1979
-
[21]
M.Zecevic,M.Knezevic,Adislocationdensitybasedelasto-plasticself-consistentmodel for the prediction of cyclic deformation: Application to aa6022-t4, International Journal of Plasticity 72 (2015) 200–217
work page 2015
-
[22]
C. Frederick, P. Armstrong, A mathematical representation of the multiaxial bauschinger effect, Materials at High Temperatures 24 (1) (2007) 1–26
work page 2007
-
[23]
R. D. McGinty, Multiscale representation of polycrystalline inelasticity, Ph.D. thesis, Georgia Institute of Technology (2001)
work page 2001
- [24]
-
[25]
L. F. Coffin, Predictive parameters and their application to high temperature, low cycle fatigue, in: Fracture 1969: Proceedings of the Second International Conference on Frac- ture,Chapman&Hall,London,1969,pp.643–654,(Note: Oftencitedwith1969original date, though 2013 may refer to a digital reprint)
work page 1969
-
[26]
L. F. Coffin, The concept of frequency separation in life prediction for time-dependent fatigue, in: Symposium on Creep-Fatigue Interaction (MPC-3), ASME, New York, 1976, pp. 349–363
work page 1976
-
[27]
L. M. Kachanov, Rupture time under creep conditions, International Journal of Fracture 97 (1) (1999) 11–18, originally published in Izvestiya Akademii Nauk SSSR, Otd. Tekh. Nauk. 8, 26–31 (1958)
work page 1999
-
[28]
Y. F. Ital’yantsev, Thermodynamic state of deformed solids. report 1. determination of local functions of state, Strength of Materials 16 (2) (1984) 238–241
work page 1984
-
[29]
M.Naderi,M.M.Khonsari,Anexperimentalapproachtolow-cyclefatiguedamagebased on thermodynamic entropy, International Journal of Solids and Structures 47 (6) (2010) 875–880
work page 2010
- [30]
- [31]
-
[32]
A. Staroselsky, B. N. Cassenti, Creep, plasticity, and fatigue of single crystal superalloy, International Journal of Solids and Structures 48 (13) (2011) 2060–2067
work page 2011
- [33]
-
[34]
D. Ye, Z. Wang, A new approach to low-cycle fatigue damage based on exhaustion of statictoughnessanddissipationofcyclicplasticstrainenergyduringfatigue,International Journal of Fatigue 23 (8) (2001) 679–687
work page 2001
-
[35]
W. M. Payten, D. W. Dean, K. U. Snowden, A strain energy density method for the prediction of creep–fatigue damage in high temperature components, Materials Science and Engineering: A 527 (7-8) (2010) 1920–1925
work page 2010
-
[36]
Taira, Lifetime of structures subjected to varying load and temperature, in: N
S. Taira, Lifetime of structures subjected to varying load and temperature, in: N. J. Hoff (Ed.), Creep in Structures, Springer Berlin Heidelberg, Berlin, Heidelberg, 1962, pp. 96–124
work page 1962
-
[37]
R.Skelton,D.Gandy,Creep–fatiguedamageaccumulationandinteractiondiagrambased on metallographic interpretation of mechanisms, Materials at High Temperatures 25 (1) (2008) 27–54
work page 2008
- [38]
-
[39]
P. Lu, Y. X. Ge, X. C. Jin, P. Li, X. K. Ji, D. Zhao, et al., A dislocation density-based model for the temperature dependent anomalous behaviors of nickel-based single-crystal superalloy, Mechanics of Materials 170 (2022) 104326
work page 2022
- [40]
-
[41]
D.Shi, J.Huang, X.Yang, H.Yu, Effectsofcrystallographicorientationsanddwelltypes on low cycle fatigue and life modeling of a sc superalloy, International Journal of Fatigue 49 (2013) 31–39
work page 2013
-
[42]
thesis, Beihang University, Beijing (2013)
F.L.Jing,Researchonthermo-mechanicalfatiguelifeassessmentofsinglecrystalturbine blades, Ph.D. thesis, Beihang University, Beijing (2013)
work page 2013
-
[43]
C. J. Permann, D. R. Gaston, D. Andrš, R. W. Carlsen, F. Kong, A. D. Lindsay, J. M. Miller, J. W. Peterson, A. E. Slaughter, R. H. Stogner, et al., MOOSE: Multiphysics Object-OrientedSimulationEnvironment,JournalofOpenSourceSoftware5(53)(2020) 2171
work page 2020
-
[44]
R. D. McGinty, Multiscale representation of polycrystalline inelasticity, Ph.D. thesis, Georgia Institute of Technology, Atlanta, GA (2001)
work page 2001
- [45]
- [46]
-
[47]
B. Ding, W. Ren, J. Peng, Y. Zhong, J. Yu, Influence of dwell time on the creep–fatigue behaviorofadirectionallysolidifiedni-basedsuperalloydz445at850 ◦c,MaterialsScience and Engineering: A 725 (2018) 319–328
work page 2018
- [48]
-
[49]
R.C.Reed,A.Ma,D.Dye,Amodelforthecreepdeformationbehaviourofsingle-crystal superalloy cmsx-4, Acta Materialia 56 (8) (2008) 1657–1670
work page 2008
-
[50]
Z. Zhu, H. Basoalto, N. Warnken, R. Reed, A model for the creep deformation behaviour of nickel-based single crystal superalloys, Acta Materialia 60 (12) (2012) 4888–4900. 28
work page 2012
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