Effects of stress ratio on fatigue crack propagation in Q1N (HY80) pressure vessel steel

https://doi.org/10.1016/0142-1123(90)90005-YGet rights and content

Abstract

The effects of the stress ratio on fatigue crack propagation under plane strain conditions are evaluated by load-shedding tests and closure measurements for stress ratios (R = KminKmax) of 0.2, 0.35, 0.5 and 0.7. The changes in fracture surface morphology associated with crack closure and mechanisms are explained, and the trends in the crack closure data with increasing stress ratio and stress intensity are explained by considering the effects of the increase in crack opening displacement with increasing stress ratio and stress intensity.

References (22)

  • W. Elber

    The significance of fatigue crack closure

  • Cited by (29)

    • Fatigue of Single/Multiple Semi-Elliptical Cracks

      2023, Comprehensive Structural Integrity
    • Fatigue of Thermostructural Alloys

      2023, Comprehensive Structural Integrity
    • Effect of load ratio on fatigue crack growth in the near-threshold regime: A literature review, and a combined crack closure and driving force approach

      2015, Engineering Fracture Mechanics
      Citation Excerpt :

      Whereas in the unstable regime where extensive yielding presented at the crack tip, crack closure load was decreased with the extension of crack length until little or no closure occurred [121]. Soboyejo and Knott [122] explained the different crack closure level among various R by considering the increase of crack opening displacement with the increase of R and ΔK in the near-threshold regime. Dubey et al. [15] developed a three-parameter multiple regression model to describe FCG rate as a function of R, crack closure and ΔK for Ti–6Al–4V.

    View all citing articles on Scopus

    W.O. Soboyejo was a graduate student at the Department of Materials Sciences & Metallurgy and is now a research scientist with the McDonnell Douglas Research Laboratories in St Louis.

    ∗∗

    Dr. J.F. Knott was a Reader with the Materials Science and Metallurgy Department at Cambridge University and is now Head of the Department of Physical Metallurgy at the University of Birmingham.

    View full text