STP942: Fatigue Life Estimations for Cast Steels Using Low Cycle Fatigue Behavior

    SG, Lee
    Senior Researcher, DaeJeon Machine Depot, DaeJeon,

    RI, Stephens
    Professor, The University of Iowa, Iowa City, IA

    Pages: 19    Published: Jan 1988


    Abstract

    Fatigue notch factors for compact keyhole specimens of five common cast steels were estimated using an elastic stress distribution around the notches and the fatigue tests of simple specimens. The values were used with modified Neuber's rule to calculate the stress and strain at an equivalent characteristic length under variable loadings. Another method, which uses the load-strain relation obtained from elastic-plastic finite element method (FEM) analysis, was also used to calculate the strain at the equivalent characteristic length. Both methods were used to calculate the fatigue damage at the keyhole notch using the Palmgren-Miner linear damage rule and low cycle fatigue properties obtained from smooth specimens. The results showed that both methods could be used for the crack initiation calculation within a reasonable accuracy.

    Keywords:

    fatigue, life calculations, notch strain analysis, Neuber's rule, notches, spectrum loading, elastic/plastic, finite element methods, characteristic length, cumulative damage, cast steels


    Paper ID: STP24544S

    Committee/Subcommittee: E08.05

    DOI: 10.1520/STP24544S


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