STP743: A Simple Crack Closure Model for Prediction of Fatigue Crack Growth Rates Under Variable-Amplitude Loading

    de Koning, AU
    Research engineer, Structures and Materials Division, National Aerospace Laboratory, NLR,

    Pages: 23    Published: Jan 1981


    Abstract

    A model for the prediction of growth rates of fatigue cracks in aluminium alloys is presented. The model is based on an approximate description of the crack closure behavior and can be used to predict effects of crack growth acceleration and retardation observed experimentally under variable-amplitude loading.

    A computer program was developed for analysis of fatigue crack growth. It was used to analyze the effect of certain parameter variations in a flight simulation load spectrum on the crack growth rate. For 7075-T6 thin sheet material the results are compared with experimental data.

    Keywords:

    fatigue crack growth, flight simulation loading, TWIST, variable-amplitude loading, delay effects, crack growth model, crack closure, crack opening, delay switcher, plane-strain/plane-stress transition


    Paper ID: STP28791S

    Committee/Subcommittee: E08.06

    DOI: 10.1520/STP28791S


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