Investigation of two-parameter approach to assessment of defects in residual stress fields

Jack Beswick, Andrey P Jivkov, Peter M James, Andrew Sherry

    Research output: Chapter in Book/Conference proceedingConference contributionpeer-review

    111 Downloads (Pure)

    Abstract

    Current structural integrity assessment procedures, R6 for example, provide advice on the inclusion of residual stresses and the effect of plasticity on such stresses via specific corrections to the proximity to fracture parameter, Kr. These approaches are conservative, as there are no established methods to accurately assess the interaction of residual stress and inelastic strains at a defect. Low-constraint geometries introduce substantial crack-tip plasticity, the effect of which on existing residual stresses needs to be understood better for reducing conservatism. The advice in R6 for less conservative assessment of low-constraint crack geometries is to use two-parameter approaches: defect assessments are carried out in the J-Q space, where J is the usual crack driving force and Q is used to quantify constraint. This paper reports results from ongoing work investigating the applicability of two-parameter approaches to structural integrity assessments of low-constraint crack geometries in the presence of residual stresses. Specifically, numerical results showing the behaviour of SENB specimens are presented within the J-Q space. These are derived for different defect depths in various stress fields, including local residual stress, global equivalent plastic strains, and a combination of the two. A collation of previously published J-Q results, both numerical and experimental, are presented and compared to the relevant outcomes of the work. This work provides a basis for an experimental programme for determining fracture toughness loci in the two-parameter J-Q space. A brief description of this testing programme is also provided.
    Original languageEnglish
    Title of host publicationProveeding of SMiRT23
    Place of PublicationManchester
    PublisherInternational Association for Structural Mechanics in Reactor Technology (IASMiRT)
    Publication statusPublished - 10 Aug 2015
    EventSMiRT23 - Manchester
    Duration: 9 Aug 201514 Aug 2015

    Conference

    ConferenceSMiRT23
    CityManchester
    Period9/08/1514/08/15

    Fingerprint

    Dive into the research topics of 'Investigation of two-parameter approach to assessment of defects in residual stress fields'. Together they form a unique fingerprint.

    Cite this