Use of the stretch zone for the characterization of ductile fracture

https://doi.org/10.1016/0924-0136(95)01928-6Get rights and content

Abstract

There is an increasing effort to use the stretch zone ahead of a fatigue crack as a measure of the fracture toughness of ductile materials, particularly in cases where alternative means of measuring the toughness are not possible, e.g. at high strain rates. The stretch zone (SZ) is hence related to parameters such as the J-integral. It was, however, found that the relationship between (SZ) and JIC is affected by other factors including fatigue pre-straining of the material. In this study, the effect of initial pre-straining on the evolution of the stretch zone in a number of ductile steels was investigated. Actual measurements of the deformation of the stretch zone as it is loaded were undertaken using electron microscopy. It is shown that both prior pre-straining and fatigue pre-cracking have a significant work-hardening effect, which controls the width of the stretch zone and hence the measured fracture toughness.

References (19)

  • K.F. Amouzouvi et al.

    Mats. Sci. Eng.

    (1982)
  • K.F. Amouzouvi et al.

    Mats. Sci. Eng.

    (1982)
  • J.A. Begley et al.
  • J.D. Landes et al.
  • G.A. Griffis et al.

    Met. Trans.

    (1970)
  • D. Brock

    Int. J. Fracture Mech.

    (1968)
  • A. Spitzig

    Trans. Am. Soc. Met.

    (1968)
  • D. Brock

    Eng. Fracture Mech.

    (1974)
  • J.D. Landes et al.
There are more references available in the full text version of this article.

Cited by (20)

  • Long term ageing effect on fracture toughness of the GTAW welded joints for nuclear power main pipelines

    2020, International Journal of Pressure Vessels and Piping
    Citation Excerpt :

    Besides, according to Fig. 7, it seems that the crack growth mode is mainly not affected by the thermal ageing significantly. SZW is considered as an essential parameter for the fracture toughness characterization [26,37,38]. Generally, stretch zone forms at the beginning stage of the loading process.

  • Evaluating the effect of side grooving parameters on critical SZW

    2016, Engineering Fracture Mechanics
    Citation Excerpt :

    Several attempts have been made to understand the effect of SG on the evaluated initiation fracture toughness. The magnitude of SZW variation across the fracture specimen thickness has been experimentally studied by Bassim [5]. A uniform magnitude of stretch zone is observed [5] in thin fracture specimen.

  • Acoustic emission during fracture toughness tests of SA333 Gr.6 steel

    2012, Engineering Fracture Mechanics
    Citation Excerpt :

    The measure of this stretch zone is an estimation of crack tip opening prior to tearing. Use of stretch zone size as a measure of ductile fracture toughness was reported [5]. Acoustic emission technique (AET) is an advanced non-destructive evaluation (NDE) tool that possesses the ability for understanding deformation and fracture behavior of materials.

  • Numerical evaluation of geometric independent stretch zone width value for assessing valid J <inf>SZW</inf>

    2012, Nuclear Engineering and Design
    Citation Excerpt :

    Several attempts (Landes and Begley, 1971, 1974; Paranjpe and Banerjee, 1979; Mills, 1981; Amouzouvi and Bassim, 1982; Yin et al., 1983; Doig et al., 1984; Kobayashi et al., 1985a,b; Bassim et al., 1992; Bassim, 1995; Smith et al., 1995; Tai, 1996; Ebrahimi and Seo, 1996; Wang and Hwang, 1996; Tarafder et al., 2004) were made to understand the process of crack initiation and demonstrated the fracture toughness evaluation procedure in ductile materials.

  • Determination of stretch zone width using fem

    2009, Engineering Fracture Mechanics
    Citation Excerpt :

    Kobayashi et al. [12] compared the standard procedure of determining the fracture toughness to the one based on SZW. Bassim [13] and Smith et al. [14] discussed SZW for fracture toughness measurement. Tai [15] employed FEM route to study the damage ahead of the crack tip.

View all citing articles on Scopus
View full text