## 5aSA7. Stability of clamped rectangular plates in uniform subsonic flow.

### Session: Friday Morning, May 17

### Time: 10:50

**Author: Jinshuo Zhu**

**Location: Perstorp Components, 47785 W. Anchor Ct., Plymouth, MI 48170**

**Author: Sean F. Wu**

**Location: Wayne State Univ., Detroit, MI 48202**

**Abstract:**

This paper depicts the stability charts of rectangular plates clamped to an
infinite, rigid baffle in uniform subsonic flow. The correlations among the
critical flow speeds and the plate aspect ratio, plate thickness/length ratio,
and plate/fluid density ratio are exhibited. Results show that when the flow
speed exceeds a critical value, the plate may vibrate around an equilibrium
position other than its undeformed one. When the flow speed exceeds all the
critical values, the plate may be locally unstable at all equilibrium positions.
In particular, it may jump from one equilibrium position to another in a random
fashion. These local instabilities are controlled by structural nonlinearities.
Without the inclusion of structural nonlinearities, the plate may have only one
equilibrium position, namely, its undeformed one. The amplitude of plate
vibration would then grow unboundedly when the flow speed exceeds the critical
value, known as absolute instability. With the inclusion of structural
nonlinearities, the plate may have more than one equilibrium position when the
flow speed exceeds the critical values. Under this condition, plate vibration
may seem chaotic, the overall amplitude of flexural vibration is nevertheless
bounded.

from ASA 131st Meeting, Indianapolis, May 1996