STP924: Unified Treatment of Deep and Shallow Notches in Rotating Bending Fatigue

    Nisitani, H
    Professor, Faculty of Engineering, Kyushu University, Fukuoka,

    Endo, M
    Associate Professor, Fukuoka University, Fukuoka,

    Pages: 18    Published: Jan 1988


    Abstract

    As a concept useful for evaluating the strength of notched members, “linear notch mechanics” is proposed. It is explained by this concept that the elastic-plastic behavior near the root of a notch under the condition of small-scale yielding is controlled by the maximum elastic stress σmax and the notch root radius ρ alone, independently of the other notch geometries. In order to confirm the effectiveness of “linear notch mechanics” in fatigue problems, rotating bending fatigue tests are carried out on notched steel specimens having widely varying notch geometries. Moreover, the fatigue notch effects of extremely shallow notches, whose depths are of the order of the grain size, are also discussed.

    Summarizing the present studies, a unifying treatment of fatigue notch effects is presented.

    Keywords:

    fatigue (materials), notch effects, fatigue limit, fracture, steels, crack initiation, crack propagation, maximum elastic stress, notch root radius, stress concentration factors, stress-intensity factors, plastic zone sizes, nonpropagating crack, linear fracture mechanics, linear notch mechanics


    Paper ID: STP23214S

    Committee/Subcommittee: E08.08

    DOI: 10.1520/STP23214S


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