### ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

## 2aSA1. Application of Skudrzyk's ``mean-value theory'' to fluid-loaded
plates.

**Rendell R. Torres
**

**
Victor W. Sparrow
**

**
Alan D. Stuart
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**
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*Grad. Prog. in Acoust., Penn State Univ., P.O. Box 30, State College, PA
16804
*

*
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The geometric-mean drive-point admittance of a complex structure can be
found by examining the admittance of the corresponding infinite structure (i.e.,
``characteristic admittance,'' Y[inf c]) [Skudrzyk, J. Acoust. Soc. Am. 67,
1105--1135 (1980)]. The frequency response of an infinite plate, for example,
coincides with the geometric-mean response of a finite plate, i.e., the response
equidistant from the resonance maxima and antiresonance minima, plotted on a
logarithmic scale. Skudrzyk's ``mean-value theorem'' was derived (and
experimentally verified) without consideration of fluid coupling, which
introduces a reactive effect that physically resembles a mass loading. The
purpose of this research is to find whether the response of the fluid-loaded
infinite plate still corresponds to the geometric-mean response of the
fluid-loaded finite plate. Numerical results indicate that, in the presence of
fluid loading and at low frequencies (below critical), the mean-line drive-point
admittance of the finite plate still corresponds to the infinite-plate
drive-point admittance that has been derived analytically [Crighton, J. Sound
Vib. 54, 389--391 (1977)]. [Work supported by the Applied Research Laboratory.]