Accession Number : ADP004728

Title :   Distributed Piezoelectric-Polymer Active Vibration Control of a Cantilever Beam,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Bailey,T. ; Hubbard,J. E. , Jr

Report Date : NOV 1984

Pagination or Media Count : 23

Abstract : An active vibration damper for a cantilever beam was designed using a distributed-parameter actuator and distributed-parameter control theory. The distributed-parameter actuator was a piezoelectric polymer, poly(vinylidene fluoride). Lyapunov's second method for distributed-parameter systems was used to design a control algorithm for the damper. If the angular velocity of the tip of the beam is known, all modes of the beam can be controlled simultaneously. Preliminary testing of the damper was performed on the first mode of the cantilever beam. A linear, constant-gain controller and a nonlinear constant-amplitude controller were compared. The baseline damping of the first mode was eta = 0.003 for large amplitude vibrations (+ or - 2 cm tip displacement) decreasing to eta = 0.001 for small vibrations (+ or - 0.5 mm tip displacement). The constant-gain controller provided more than a factor of 2 increase in the modal damping with a feedback voltage limit of 200 VRMS. With the same voltage limit, the constant-amplitude controller achieved the damping same damping as the constant-gain controller for large vibrations, but increased the damping by a factor of 40 to at least eta = 0.040 for small vibration levels. (Author)

Descriptors :   *DAMPING, *CANTILEVER BEAMS, MATHEMATICAL MODELS, AEROSPACE CRAFT, POLYMERS, PIEZOELECTRIC MATERIALS, CONTROL THEORY, ACTUATORS

Distribution Statement : APPROVED FOR PUBLIC RELEASE