STP1360: Fracture Toughness Testing with Notched Round Bars

    Wilson, CD
    Assistant professor, Tennessee Technological University, Cookeville, TN

    Landes, JD
    Professor, The University of Tennessee, Knoxville, TN

    Pages: 14    Published: Jan 2000


    Abstract

    A method to simplify fracture toughness testing and reduce testing costs is discussed. An alternative specimen geometry, the notched round bar (NRB), has been combined with a simpler testing methodology. A multispecimen technique using notched round bars with finite notch root radii ρ was applied to 2024-T351 and overaged 2024 aluminum alloy. No fatigue precracking was used. A graph of apparent fracture toughness versus the square root of notch root radius √ρ was extrapolated to ρ = 0, corresponding to a fatigue precracked configuration. The resulting fracture toughness values were the same as those obtained from ASTM E 399 tests. Apparent fracture toughness , determined from NRB J-R curves for overaged 2024, was graphed versus notch root radius ρ. The extrapolated value of fracture toughness was the same as that obtained from ASTM E 813 and E 1152 tests.

    Keywords:

    apparent fracture toughness, J, -integral, notched round bar (NRB), finite radii notches


    Paper ID: STP13396S

    Committee/Subcommittee: E08.03

    DOI: 10.1520/STP13396S


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