A study of piezoelectric actuators for active noise and vibration control
Abstract
A generalized investigation of piezo-actuator for active control of structural noise and vibration is performed to provide a foundation for general design guidelines of piezo-actuators. A set of Love equations of motion for a composite shell with piezoelectric layers is developed to represent the electromechanical coupling behavior of piezoelectric actuators. The effects of piezo-actuator thickness on the active control of structural vibration are investigated. It is demonstrated that there exists an optimal thickness which maximizes the piezo-actuator/substructure coupling. The optimal thickness is primarily influenced by the piezo-actuator/substructure stiffness ratio and mass density ratio, becoming thinner with stiffer and heavier piezo-actuators. The equivalent forces generated by various shaped (triangular, rectangular, rhombus, circular and elliptic) piezo-actuators are discussed. The effects of piezo-actuator number, size and location are investigated. It is shown that the optimal size of piezo-actuator is the node-to-node length of the mode to be controlled. It is also demonstrated that the optimal location of piezo-actuator is centered at the anti-node of the mode to be controlled. The effects of delamination of the piezo-actuators on the performance of active vibration control systems are studied to identify the potential problems associated with the delaminations in the practical application of piezo-actuators. Two types of delamination are considered: an edge delamination and an inner delamination. It is shown that the edge delamination brings detrimental effects on the performance of the piezo-actuator whereas the inner delamination brings little detrimental effects. It is also demonstrated that the edge delamination brings more significant variation of the dynamic characteristics of the composite beam. A new and novel 'semi-active (or passive adaptive)' control strategy is also investigated to study the influence of the in-plane loads generated by the piezo-actuators on the dynamic characteristics of an elastic system. It is shown that the applied in-plane load due to the piezo-actuator can significantly influence the dynamic characteristics of a composite beam.
Degree
Ph.D.
Advisors
Jones, Purdue University.
Subject Area
Mechanical engineering
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