Variable Amplitude Fatigue Crack Growth Using Digital Signal Processing Technology

    Volume 1, Issue 9 (October 2004)

    ISSN: 1546-962X

    CODEN: JAIOAD

    Published Online: 4 October 2004

    Page Count: 14


    Donald, JK
    Research Engineers, Fracture Technology Associates, Bethlehem, PA

    George, K
    Research Engineers, Fracture Technology Associates, Bethlehem, PA

    (Received 29 May 2002; accepted 11 November 2003)

    Abstract

    An automated variable amplitude fatigue crack growth system has been developed using digital signal processing (DSP) technology to provide waveform generation, command-feedback verification, and crack growth monitoring. The system is designed to interface with existing analog or digital closed-loop servo-hydraulic mechanical test systems. An important parameter in the control of variable amplitude testing is the effect of loading errors on the fatigue crack growth rate response. A damage parameter (Γ) has been incorporated to quantify the magnitude and effect of loading errors. In this paper, a FALSTAFF, Mini-TWIST, and truncated Mini-TWIST aircraft spectrum were applied to an M(T) crack growth sample to demonstrate the correlation between the damage parameter and fatigue life.


    Paper ID: JAI19043

    DOI: 10.1520/JAI19043

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    Author
    Title Variable Amplitude Fatigue Crack Growth Using Digital Signal Processing Technology
    Symposium Fatigue Testing and Analysis Under Variable Amplitude Loading Conditions, 2002-05-31
    Committee E08