Piezoelectric modal sensor/actuator pairs for critical active damping vibration control

Incorporating the piezoelectric effect into classical laminate plate theory, distributed sensors and actuators capable of sensing and controlling the modal vibration of a one-dimensional cantilever plate are derived theoretically and verified experimentally. It is shown that critical damping of a particular mode can be achieved using such a modal sensor/actuator combination as long as the vibrational amplitude of the controlled structure does not saturate the modal actuator. Since the sensor signal is proportional to the modal coordinate time derivative, velocity feedback control can be employed without using any element tuned to the resonant frequency in the feedback controller. Therefore, the sensitivity of the closed-loop performance and stability to resonant frequency variations is minimized. By eliminating electromagnetic interference and ground loop noise, critical damping is experimentally demonstrated for the first mode of a one-dimensional cantilever plate using PVF2as the sensor/actuator material. © 1991, Acoustical Society of America. All rights reserved.