Minimization and Quantification of Error Associated with the K Gradient and the Interval of Crack Length Measurement in Fatigue Crack Growth Testing

    Volume 21, Issue 2 (March 1993)

    ISSN: 0090-3973

    CODEN: JTEOAD

    Page Count: 7


    Oore, M
    IMP AEROSPACE, Halifax, Nova Scotia,

    (Received 27 April 1992; accepted 7 October 1992)

    Abstract

    Analytical method has been developed to minimize and quantify the effect of crack length measurement interval Δa on the error due to the K gradient in the interpretation of da dN derived from crack growth test data using the secant method. The associated error has been quantified in a general form and used to demonstrate the specific errors due to the selection of average crack length a per ASTM E 647-91. Test Method for Measurements of Fatigue Crack Growth Rates. It is shown that the selection of the geometric mean (a¯=a1a2) in the data analysis will reduce the associated error in the crack growth rate interpretation. It is recommended that ASTM E 647-91 be revised accordingly.


    Paper ID: JTE11752J

    DOI: 10.1520/JTE11752J

    ASTM International is a member of CrossRef.

    Author
    Title Minimization and Quantification of Error Associated with the K Gradient and the Interval of Crack Length Measurement in Fatigue Crack Growth Testing
    Symposium , 0000-00-00
    Committee E08