Microstructure-Based Model for Sharp Stress Raiser-Related Fatigue Stage Length Assessment

  • O. M. HerasymchukEmail author
  • A. I. Novikov

A model for evaluating the fatigue life of specimens/structure elements with sharp stress raisers/defects is presented. The model permits of computing the number of cycles to fatigue crack initiation and its growth from a sharp stress raiser to failure at a constant stress span with the only application of characteristics of static strength and microstructure of the initial material. The model can be used to assess the fatigue life of components that contain structural stress raisers and defects stemming from their manufacturing technique (surface roughness, surface cuts, scratches, and microcracks). The model reliability was verified with experimental results taken from the literature, calculations appeared to be in good agreement with experimental data. Fatigue curves to a grain-size crack initiation and to fracture of smooth specimens and those with a chemically-notched blunt raiser that simulates the casting defects in aircraft components were calculated. The two sets of specimens from a Ti–6Al–4V titanium alloy differing in the cross-section (rectangular and cylindrical) and in microstructure (different grain sizes). Smooth specimens exhibited the test surface roughness Rv = 10 and 19 μm (average dent depth), which was assumed to be a sharp raiser for calculations. The model need not long-term and labor-consuming high-cycle fatigue tests to construct the fatigue curve.


high-cycle fatigue stages fatigue life fatigue strength sharp stress raisers/sharp-root notches fatigue crack microstructure 


  1. 1.
    O. M. Herasymchuk, O. V. Kononuchenko, P. E. Markovsky, and V. I. Bondarchuk, “Calculating the fatigue life of smooth specimens of two-phase titanium alloys subject to symmetric uniaxial cyclic load of constant amplitude,” Int. J. Fatigue, 83, 313–322 (2016).CrossRefGoogle Scholar
  2. 2.
    O. M. Herasymchuk, “Nonlinear relationship between the fatigue limit and quantitative parameters of material microstructure,” Int. J. Fatigue, 33, 649–659 (2011).CrossRefGoogle Scholar
  3. 3.
    O. M. Herasymchuk, O. V. Kononuchenko, and V. I. Bondarchuk, “Fatigue life calculation for titanium alloys considering the influence of microstructure and manufacturing defects,” Int. J. Fatigue, 81, 257–264 (2015).CrossRefGoogle Scholar
  4. 4.
    K. S. Chan, “A microstructure-based fatigue-crack-initiation model,” Metall. Mater. Trans. A, 34, 43–58 (2003).CrossRefGoogle Scholar
  5. 5.
    P. Lukáš and M. Klesnil, “Fatigue limit of notched bodies,” Mater. Sci. Eng., 34, 61–66 (1978).CrossRefGoogle Scholar
  6. 6.
    H. Kitagawa and S. Takahashi, “Applicability of fracture mechanics to very small cracks or the cracks in the early stage,” in: Proc. of the Second Int. Conf. of Mechanical Behavior of Materials (August 16–20, 1976, Boston, MA), ASM, Metals Park, OH (1976), pp. 627–631.Google Scholar
  7. 7.
    O. M. Herasymchuk, “Modified KT-diagram for stress raiser-involved fatigue strength assessment,” Strength Mater., 50, No. 4, 608–619 (2018).CrossRefGoogle Scholar
  8. 8.
    M. D. Chapetti, “Fatigue propagation threshold of short cracks under constant amplitude loading,” Int. J. Fatigue, 25, 1319–1326 (2003).CrossRefGoogle Scholar
  9. 9.
    J. Maierhofer, H. P. Gänser, and R. Pippan, “Modified Kitagawa–Takahashi diagram accounting for finite notch depths,” Int. J. Fatigue, 70, 503–509 (2015).CrossRefGoogle Scholar
  10. 10.
    M. H. El Haddad, T. H. Topper, and K. N. Smith, “Prediction of non propagating cracks,” Eng. Fract. Mech., 11, No. 3, 573–584 (1979).CrossRefGoogle Scholar
  11. 11.
    O. M. Herasymchuk, “Relationship between the threshold stress intensity factor ranges of the material and the transition from short to long fatigue crack,” Strength Mater., 46, No. 3, 368–374 (2014).CrossRefGoogle Scholar
  12. 12.
    K. S. Chan, “Variability of large-crack fatigue-crack-growth thresholds in structural alloys,” Metall. Mater. Trans. A, 35, 3721–3735 (2004).CrossRefGoogle Scholar
  13. 13.
    BS 7910:2005. Guide to Methods for Assessing the Acceptability of Flaws in Metallic Structures, British Standard, BSI (2205).Google Scholar
  14. 14.
    R. W. Hertzberg, “A simple calculation of da/dN − ΔK data in the near threshold regime and above,” Int. J. Fracture, 64, R53–R58 (1993).Google Scholar
  15. 15.
    O. M. Herasymchuk, “Microstructurally-dependent model for predicting the kinetics of physically small and long fatigue crack growth,” Int. J. Fatigue, 81, 148–161 (2015).CrossRefGoogle Scholar
  16. 16.
    A. J. McEvily, M. Endo, and Y. Murakami, “On the \( \sqrt{area} \) relationship and the short fatigue threshold,” Fatigue Fract. Eng. Mater. Struct., 26, 269–278 (2003).Google Scholar
  17. 17.
    K. Sadananda, S. Sarkar, D. Kujawski, and A. K. Vasudevan, “A two-parameter analysis of S–N fatigue life using Δσ and σmax,” Int. J. Fatigue, 31, 1648–1659 (2009).Google Scholar
  18. 18.
    C. A. Rodopoulos, J.-H. Choi, E. R. de los Rios, and J. R. Yates, “Stress ratio and the fatigue damage map –Part I: Modelling,” Int. J. Fatigue, 26, 739–746 (2004).CrossRefGoogle Scholar
  19. 19.
    C. A. Rodopoulos, J.-H. Choi, E. R. de los Rios and J. R. Yates, “Stress ratio and the fatigue damage map – Part II: The 2024-T351 aluminium alloy,” Int. J. Fatigue, 26, 747–752 (2004).Google Scholar
  20. 20.
    G. Léopold, Y. Nadot, T. Billaudeau, and J. Mendez, “Influence of artificial and casting defects on fatigue strength of moulded components in Ti-6Al-4V alloy,” Fatigue Fract. Eng. Mater. Struct., 38, 1026–1041 (2015).Google Scholar

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© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Pisarenko Institute of Problems of StrengthNational Academy of Sciences of UkraineKyivUkraine

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