STP527: Measuring KR-Curves for Thin Sheets

    Ripling, EJ
    Director of research and research engineer, respectively, Materials Research Laboratory, Inc., Glenwood, Ill.

    Falkenstein, E
    Director of research and research engineer, respectively, Materials Research Laboratory, Inc., Glenwood, Ill.

    Pages: 12    Published: Jan 1973


    Abstract

    A modification of the tapered double cantilever beam specimen for measuring KR-curves of thin sheets is described. The modification consists of adhering properly contoured cover plates to the sheet to form a composite zero K-gradient (ZKG) specimen.

    This testing procedure has a number of advantages over those presently used for plane stress testing:

    1. K is proportional to the applied load and independent of crack length. Consequently, the specimen is stable, allowing for the collection of the complete KR-curve.

    2. The testing procedure is simplified, and the instrumentation required to collect data, even at high rates, is relatively simple, since only load need be monitored.

    3. Buckling is eliminated without the need of constraining members near the crack.

    4. Cracking rate is related linearly to displacement rate.

    Keywords:

    fracture toughness, crack propagation, plane stress, brasses, aluminum alloys, double cantilever beam specimen, strains, stresses, loads (forces), measurement, evaluation, tests


    Paper ID: STP34706S

    Committee/Subcommittee: E08.08

    DOI: 10.1520/STP34706S


    CrossRef ASTM International is a member of CrossRef.