STP969: Dynamic Moiré Interferometry Studies of Stress Wave and Crack-Tip Diffraction Events in 1018 Steel

    Epstein, JS
    Engineering specialist and principal engineer, Materials Science Div., Idaho National Engineering Laboratory, Idaho Falls, ID

    Deason, VA
    Senior scientist, Sensors and Diagnostics Div., Idaho National Engineering Laboratory, Idaho Falls, ID

    Reuter, WG
    Engineering specialist and principal engineer, Materials Science Div., Idaho National Engineering Laboratory, Idaho Falls, ID

    Pages: 22    Published: Jan 1988


    Abstract

    A study of stress wave propagation around localized crack-tip regions in engineering materials is presented. The principal tool of this initial investigation is dynamic moiré interferometry, which yields full-field continuum boundary conditions of surface displacement in a real-time optical processing manner. The displacement sensitivity employed for this study is 3.3 μm; however, the displacement sensitivity can be as high as 0.2 μm. The spatial resolution developed is less than 1 mm. After a brief review of the technique of dynamic moiré interferometry, the study of a longitudinal pulse, interacting with an artificial crack in a finite steel bar, is presented. Equations for the near-tip elastic dynamic crack displacements will be reexamined to extract localized elastic dynamic stress-intensity factors in light of the capabilities of dynamic moiré interferometry.

    Keywords:

    dynamic moiré interferometry, dynamic fracture mechanics, experimental mechanics, stress wave diffraction, fracture mechanics


    Paper ID: STP33090S

    Committee/Subcommittee: E08.08

    DOI: 10.1520/STP33090S


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