| Popis: |
A study of the stress wave propagation around localized crack tip regions in engineering materials is presented. The principal tool of this initial investigation is dynamic moire interferometry. Dynamic moire interferometry 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 microns. However, the displacement sensitivity can be as sensitive as 0.2 microns. The spatial resolution developed is below a millimeter. After briefly reviewing the applied optics of dynamic moire interferometry, this paper reviews the case of a longitudinal pulse interacting with an artificial crack in a finite steel bar. The equations for the near tip elastic dynamic crack displacements are re-examined to extract localized elastic dynamic stress intensity factors in light of the capabilities of dynamic moire interferometry. 34 refs., 20 figs. |
