STP1253: Life Prediction for Bridged Fatigue Cracks

    Cox, BN
    Manager, Rockwell Science Center, Thousand Oaks, CA

    Pages: 21    Published: Jan 1996


    Abstract

    The growth rates of matrix fatigue cracks bridged by sliding fibers are now commonly predicted by models based on the micromechanics of frictional interfaces. However, there exist many reasons, both theoretical and experimental, for suspecting that the most popular micromechanical models are probably wrong in detail in the context of fatigue cracks. Furthermore, a review of crack growth data reveals that the validity of the micromechanics-based predictive model has never been tested and may never be tested. In this paper, two alternative approaches are suggested to the engineering problem of predicting the growth rates of bridged cracks without explicit recourse to micromechanics. Instead, it is shown that the material properties required to analyze bridging effects can be deduced directly from crack growth data. Some experiments are proposed to test the validity of the approach.

    Keywords:

    titanium, titanium matrix composites, titanium alloys, life prediction, fatigue (materials), modeling, cracks, crack growth, bridging effects


    Paper ID: STP18241S

    Committee/Subcommittee: D30.04

    DOI: 10.1520/STP18241S


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