STP1092: A Semiautomated Computer-Interactive Dynamic Impact Testing System

    Alexander, DJ
    Metallurgist, group leader, and program manager, Oak Ridge National Laboratory, Oak Ridge, TN

    Nanstad, RK
    Metallurgist, group leader, and program manager, Oak Ridge National Laboratory, Oak Ridge, TN

    Corwin, WR
    Metallurgist, group leader, and program manager, Oak Ridge National Laboratory, Oak Ridge, TN

    Hutton, JT
    Development engineer, Oak Ridge National Laboratory, Oak Ridge, TN

    Pages: 12    Published: Jan 1990


    Abstract

    A computer-assisted semiautomated system has been developed for testing a variety of specimen types under dynamic impact conditions. The primary use of this system is for the testing of Charpy specimens. Full-, half-, and third-size specimens have been tested, both in the laboratory and remotely in a hot cell for irradiated specimens. Specimens are loaded into a transfer device that moves the specimen into a chamber, where a hot air gun is used to heat the specimen, or cold nitrogen gas is used for cooling, as required. The specimen is then quickly transferred from the furnace to the anvils and then broken. This system incorporates an instrumented tup to determine the change in voltage during the fracture process. These data are analyzed by the computer system after the test is complete. The voltage-time trace is recorded with a digital oscilloscope, transferred to the computer, and analyzed. The analysis program incorporates several unique features. It interacts with the operator and identifies the maximum voltage during the test, the amount of rapid fracture during the test (if any), and the end of the fracture process. The program then calculates the area to maximum voltage and the total area under the voltage-time curve. The data acquisition and analysis part of the system can be also used to conduct other dynamic testing. Dynamic tear and precracked specimens can be tested with an instrumented tup and analyzed in a similar manner.

    Keywords:

    Charpy specimens, semiautomated systems, dynamic testing, toughness, fracture testing, fatigue testing, automation, irradiated materials, computer programs, fracture


    Paper ID: STP25032S

    Committee/Subcommittee: E08.03

    DOI: 10.1520/STP25032S


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