Method for Assessing Applicability of an Artificial Flaw as a Small Initial Crack for Fatigue Limit Evaluation and Its Application to a Drill Hole and an FIB Processed Sharp Notch in Annealed 0.45% Carbon Steel

    Volume 41, Issue 2 (March 2013)

    ISSN: 0090-3973

    CODEN: JTEOAD

    Published Online: 22 January 2013

    Page Count: 6


    Sakamoto, Junji
    Dept. of Mechanical Engineering Science, Graduate School of Engineering, Kyushu Univ., Nishi-ku, Fukuoka

    Takahashi, Yoshimasa
    Dept. of Mechanical Engineering, Kansai Univ., Suita-shi, Osaka

    Aono, Yuuta
    Dept. of Mechanical Engineering, Faculty of Engineering, Kyushu Univ., Nishi-ku, Fukuoka

    Noguchi, Hiroshi
    Dept. of Mechanical Engineering, Faculty of Engineering, Kyushu Univ., Nishi-ku, Fukuoka

    (Received 19 May 2012; accepted 22 August 2012)

    Abstract

    In this study, we propose a method for assessing the applicability of an artificial flaw as a small initial crack for fatigue limit evaluation. The proposed method is applied to drill holes and sharp notches introduced using a focused ion beam (FIB) technique in annealed 0.45% carbon steel. It is found that under rotating bending fatigue, an FIB notch can be used as a small initial crack for fatigue limit evaluation, whereas a drill hole cannot, for √area of ∼50 μm. Here, √area is the square root of the area obtained by projecting the defect onto a plane perpendicular to the load axial direction. The results indicate that an FIB notch can be used as a small initial crack for fatigue limit evaluation in a greater number of materials than those in which a drill hole can be used.


    Paper ID: JTE20120176

    DOI: 10.1520/JTE20120176

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    Title Method for Assessing Applicability of an Artificial Flaw as a Small Initial Crack for Fatigue Limit Evaluation and Its Application to a Drill Hole and an FIB Processed Sharp Notch in Annealed 0.45% Carbon Steel
    Symposium , 0000-00-00
    Committee E08