STP645: Use of Microfractography in the Study of Fatigue Crack Propagation under Spectrum Loading

    Abelkis, PR
    Senior engineer/scientist, Douglas Aircraft Company, McDonnell Douglas Corporation, Long Beach, Calif.

    Pages: 22    Published: Jan 1978


    Use of electron microscope fractography in the study of fatigue crack propagation under spectrum loadings is based on the evaluation of 7075-T651 aluminum alloy specimens from an experimental program. Microscopically established crack propagation data by striation spacing measurements are shown to provide cycle-to-cycle evidence of crack propagation behavior under spectrum loading that normally cannot be established under macroscopic observation. Crack propagation rate retardation and acceleration is illustrated through fractographic striation measurements. Contribution and interaction of various loads of a transport wing loads spectrum are illustrated fractographically from the test program.


    fractography, electron microscopes, spectrum loading, aluminum alloys, crack propagation, fatigue (materials)

    Paper ID: STP38093S

    Committee/Subcommittee: E08.03

    DOI: 10.1520/STP38093S

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