Vibration control of cylindrical shells using distributed piezoelectric sensors and actuators

Summary form only given. A hybrid control method which is a combination of active control and disturbance cancellation method is proposed and used in the vibration control of a piezoelectric cylindrical shell. The active controller and disturbance cancellation controller are designed independently. The H/sup /spl infin// control and m-synthesis theory are used in the design of the active controller. The active control input calculated from the feedback signal and the disturbance cancellation input calculated from the disturbance signal are added together and the sum is used as the input of hybrid control. The electrodes on the surfaces of piezoelectric films are divided into several parts so that independent PVDF patches can be obtained. When the PVDF patches are applied with voltages, they will output distributed forces or moments so that they can be used as actuators. When the PVDF patches deform during vibration, they will output voltage so that they can be used as sensors. Two types of actuator models can be established for multimode piezoelectric actuators. When 180 out-of-phase voltages are applied to the inside and outside piezoelectric films in the same patch, the patch generates distributed bending moments and can he used as a bending moment actuator. When in-phase voltages are applied to the inside and outside piezoelectric films in the same patch, the patch generates distributed in-plane forces and can be used as an in-plane force actuator. In this study, two parts of the piezoelectric films were used as in-plane force actuators and one part as a sensor.