STP1159: The Development of a Fretting Fatigue Experiment with Well-Defined Characteristics

    Hills, DA
    Lecturer, University of Oxford, Oxford,

    Nowell, D
    Lecturer, University of Oxford, Oxford,

    Pages: 16    Published: Jan 1992


    Abstract

    It is shown that many of the unknowns present in a rotating-bending fretting fatigue experiment, fitted with a clamped bridge arrangement, may be avoided by moving to an entirely different geometry, based on a standard uniaxial tensile test specimen. A pair of cylinders is pressed against this specimen, producing a Hertzian contact, and a shear force is developed by impeding axial displacement. The apparatus is run in the partial-slip regime so that the relative displacement within the contact may be calculated.

    The well-defined geometry permits a rigorous analysis of contact pressure, shear traction distribution, interior stress fields, and crack tip stress intensity factors for any cracks present. Explicit equations for these quantities are developed which enable the physical parameters responsible for crack initiation, development, and early propagation to be readily obtained. Refinements to the classical contact calculations include analysis of the effects of using elastically dissimilar contacting elements, the influence of the thickness of the specimen, and the effect of surface roughness on the contact pressure and the interior stress field. A size effect discovered using this apparatus described is also reported.

    Keywords:

    fretting fatigue, Hertzian contact, stress intensity factors


    Paper ID: STP25818S

    Committee/Subcommittee: E08.03

    DOI: 10.1520/STP25818S


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