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

## 2pSA8. Reflection of axisymmetric waves from an arbitrary termination of a
fluid-loaded semi-infinite cylindrical shell.

**J. Gregory McDaniel
**

**
P. W. Smith, Jr.
**

**
Kevin D. LePage
**

**
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*Bolt Beranek and Newman, Inc., 70 Fawcett St., Cambridge, MA 02138
*

*
*
This work proposes an approximate theory for the reflection of
axisymmetric waves on a semi-infinite fluid-loaded shell from an arbitrary
termination. The reflected and incident waves are described by wave numbers and
wave shapes derived from the standard thin-shell equations for an infinite
shell with fluid loading. The termination is characterized by an admittance
matrix that relates stress resultants within the shell wall to axial, radial,
and rotational velocities of the midsurface. The admittance matrix is
determined for arbitrary terminations by finite element experiments on a
fluid-loaded finite shell. An example focusing on variations in the axial
admittance shows the effect of added mass at the termination. Results include
the reflection and coupling between surface, longitudinal, and evanescent
waves. [Work supported by ONR.]