Vibration Control of a Beam with Piezoelectric Film Sensors/Actuators.

Vibration control of a flexible beam with piezoelectric film sonsors/actuators is investigated. Triangular-shaped piezoelectric films are bonded on the both surfaces of a flexible beam, and are treated as collocated sensor/actuator pairs. Equations of motions of the beam and sensor output are derived for two boundary conditions: 1) fixed-free, 2) both ends simply supported. Direct velocity feedback (DVFB) control law is employed, and closed-loop stability is analytically checked using Lyapunov's direct method. Forced vibration responses of the beams are calucutated under the condition that the system is harmonically excited. Analytical results show that first several bending modes can be controlled with reasonable feedback gains. In the simply supported case, anti-symmet-rical modes (even modes) are also efficiently controlled, and thus it is shown that the proposed control scheme is valid for multi-mode vibration control' of flexible beams.