STP868: J-R Curve Determination Using Precracked Charpy Specimens and the Load-Drop Method for Crack Growth Measurements

    Kapp, JA
    U.S. Army Armament, Munitions, and Chemical Command, Armament Research and Development Center, Large Caliber Weapon Systems Laboratory, Benet Weapons Laboratory, Watervliet, NY

    Pages: 12    Published: Jan 1985


    J-R curves for two aluminum alloys, a titanium alloy, and a high strength, low alloy steel at two different strength levels were determined using precracked Charpy specimens. Three methods were used to measure crack growth: (1) multi-specimen, (2) compliance unloading, and (3) the “load-drop” method. The “load-drop” method assumes that crack growth occurs only after peak load has been attained and the amount which the load decreases after peak load is related to the size of the uncracked ligament. Comparisons between the three methods for all the materials show remarkably similar J-R curves. Also, using these curves to determine a JIc indicates very little difference between the “load-drop” method and the others in the measurement of toughness.


    fracture, test methods, J-R, curves, toughness, precracked Charpy specimens

    Paper ID: STP34258S

    Committee/Subcommittee: E08.06

    DOI: 10.1520/STP34258S

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