ACTIVE VIBRATION CONTROL OF A HANGED RECTANGULAR PLATE PARTIALLY SUBMERGED INTO FLUID BY USING PIEZOELECTRIC SENSORS AND ACTUATORS

This paper is concerned with the active vibration control of a hanged rectangular plate partially submerged into a fluid by using piezoelectric sensors and actuators bonded to the plate. A dynamic model for the plate is derived by using the Rayleigh-Ritz method and the fluid effect is modeled by the virtual mass increase that is obtained by solving the Laplace equation. The natural vibration characteristics of the plate in air obtained theoretically are in good agreement with the experimental results. The changes in natural frequencies due to the presence of fluid were measured and compared to the theoretical predictions. Experimental results show that the theoretical predictions are in good agreement with the experimental results. The natural vibration characteristics of the plate both in air and in water are used for the active vibration control design. In this study, the multi-input and multi-output positive position feedback controller was designed based on the natural vibration characteristics and implemented by using a digital controller. Experimental results show that the vibration of the hanged rectangular plate both in air and partially submerged into a fluid can be successfully suppressed by using piezoelectric sensors and actuators.