Numerical simulation of fatigue crack initiation in thin-walled high strength steel as modeled by voronoi-polygons

Shunsuke Toyoda, Hideto Kimura, Yoshikazu Kawabata, Shota Hashimoto, Naotake Yoshihara, JuN'Ichi Sakai

    Research output: Contribution to journalArticle

    2 Citations (Scopus)

    Abstract

    The fatigue endurance of TS 590 MPa grade low-alloy precipitation strengthened steel was numerically and experimentally examined. The microstructure was modeled using two-dimensional Voronoi polygons. Heterogeneous stress distributions were calculated using the finite element method, taking elastic anisotropy into consideration. The number of cycles before crack initiation was estimated based on the Tanaka-Mura model. By taking into account the effects of the cyclic strain of the preceding cracks, a definable macroscopic crack initiation cycle was obtained. An actual tensile and compression fatigue test was conducted on the same steel. The stress amplitude decreased as the cycle number increased. Distinct dislocation cell structure was not observed by TEM analysis. The experimental strain fatigue limit was, to some extent, lower than that of the simulation. Surface effects, specimen homogeneity, selection of slip system, and dislocation reversibility are mentioned as the probable causes for the difference.

    Original languageEnglish
    Pages (from-to)1695-1701
    Number of pages7
    JournalISIJ International
    Volume50
    Issue number11
    DOIs
    Publication statusPublished - 2010

    Keywords

    • Crack initiation
    • Cyclic deformation
    • Fatigue life
    • High strength steel
    • Microstructure
    • Precipitation hardening
    • Simulation

    ASJC Scopus subject areas

    • Mechanical Engineering
    • Mechanics of Materials
    • Materials Chemistry
    • Metals and Alloys

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