Vibration Control of Composite Beams with Piezoelectric Sensors and Actuators
| Autor: | Lin Shiaw Jer, 林孝哲 |
|---|---|
| Rok vydání: | 1993 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 81 Although many researches had been done on the vibration control of elastic beams using piezoelectric sensors and actuators, in most of these works either Bernoulli-Euler or Timoshenko beam theory is adopted. As a result, the emphasis is on the suppression of the bending vibration, leaving out the important issue of the control of the torsional vibration. The main goal of this thesis is to develop methods of controlling the bending and torsional vibration of composite beam simultaneously with piezoelectric sensors and actuators. Toward this end, first, an improved beam theory incorporating both bending and torsional deformation effects is employed. Next, the Hamilton principle and finite element method are used to derive the equations of sensor and of motion of beams containing driving source from the piezoelectric actuator. These equations are then transformed into state-space form convenient for control design. Linear quadratic Gaussian (LQG) technique is applied to design the controller for vibration suppression. It is shown that through the design of the observer or by choosing appropriate sensor's locations, the performance of the controller can be improved significantly. As for the control of the torsional vibration, two schemes are proposed. One approach is making use of the mechanical deformation coupling effect existing in the composite materials. Since if there exists a coupling between the bending and torsional vibration, the torsional vibration can be suppressed through the control of the bending vibration. The other approach is to arrange the piezoelectric material in such a way that its principal material direction form an angle (often called skew angle) with beam axis. Then if, furthermore, the dielectric constants d31 and d32 are not equal, the piezoelectric sensors and actuators are able to sense and control both bending and torsional motion. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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