Suppression of structural vibrations of an air-inflated membrane dam by its internal pressure

Abstract

The suppression of vibrations in air-inflated membrane dams is considered. The vibrations are assumed to result from disturbances that include unsteady water flow and wind pressure. A mathematical model describing the vibratory motion in the air-inflated membrane and developed in J. C. Hsieh, Free Vibrations of Inflatable Dams, Ph.D. Dissertation, Virginia Polytechnic and State University (1988), is employed for devising a strategy for vibration suppression. The governing equations of motion are discretized to include a finite number of vibrational modes. The proposed suppression strategy is developed with the aid of Lyapunov functions. It has been shown that the suppression of vibrations can be accomplished by properly varying the internal pressure. In other words, the pressure by itself is capable of suppressing the vibrations in the membrane. Possible generalization of the proposed suppression scheme to other systems of relevance is discussed.