
Accession Number : ADP004728
Title : Distributed PiezoelectricPolymer 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 distributedparameter actuator and distributedparameter control theory. The distributedparameter actuator was a piezoelectric polymer, poly(vinylidene fluoride). Lyapunov's second method for distributedparameter 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, constantgain controller and a nonlinear constantamplitude 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 constantgain 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 constantamplitude controller achieved the damping same damping as the constantgain 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