STP856: A Sensitivity Study of the Unloading Compliance Single-Specimen J-Test Technique

    Futato, RJ
    Research engineer and technical advisor, Babcock and Wilcox Co., Alliance Research Center, Alliance, OH

    Aadland, JD
    Engineer and advisory engineer, Babcock and Wilcox Co., Lynchburg, VA

    Van Der Sluys, WA
    Research engineer and technical advisor, Babcock and Wilcox Co., Alliance Research Center, Alliance, OH

    Lowe, AL
    Engineer and advisory engineer, Babcock and Wilcox Co., Lynchburg, VA

    Pages: 20    Published: Jan 1985


    Abstract

    A sensitivity analysis of the unloading compliance single-specimen J-test technique was performed to determine the effect of errors in test parameters on calculated ductile fracture toughness JIc values and the shape of the J-R curve. Systematic errors in measured specimen dimensions, material properties, and load and displacement transducer calibration were considered. In addition, the effect of extensometer nonlinearity on the test results was modeled. The results of the study indicate that the shape of the J-R curve and the calculated JIc value are relatively insensitive to errors in parameters in the magnitudes allowed by the ASTM Test Method for JIc, a Measure of Fracture Toughness E 813 and the Tentative Procedure for Determining the Plane Strain J1-R curve. However, the JIc calculation appears to be quite sensitive to the location and spacing of Ja data points along the J-R curve. Means for desensitizing the JIc calculation to the manner in which the test is run are discussed.

    Keywords:

    unloading, sensitivity, errors, unloading compliance, J, -integral test


    Paper ID: STP34519S

    Committee/Subcommittee: E08.08

    DOI: 10.1520/STP34519S


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