ASA 127th Meeting M.I.T. 1994 June 6-10

1aSA9. Transmission of energy across a discontinuity by fluid-loading.

Douglas Photiadis

NRL, Code 7131, 4555 Overlook Ave. SW, Washington, DC 20375-5000

The presence of a heavy adjoining fluid is known to play an important role in transporting surface vibrational energy across discontinuities in a thin elastic structure. These effects are particularly important if the discontinuities in the elastic properties of the structure are large and would hence tend to reflect a significant amount of vibration. The main results that have been previously obtained refer to the reflection of a normally incident flexural wave from a line discontinuity: The dependence on the incident angle of the flexural wave relative to the line discontinuity has been only briefly considered. Some simple models to examine this phenomena, fluid-loaded infinite membranes and plates with line discontinuities, have been investigated. It has been found that short-circuiting effects due to the fluid become much weaker as the angle of incidence increases. These results and their phenomenological implications will be discussed.