Power Flow and Consumption in Piezoelectrically Actuated Structures

摘要

In a piezoelectric (PZT) actuator-driven adaptive structure, the electromechanical power consumption and power flow of the system are dominated by the complex electromechanical impedance of the system. The entire actuator/substrate system can essentially be represented by a coupled electromechanical system model. This paper presents such a system model to quantitatively determine where the energy goes and how the power is consumed in an active structure. The formulation of a coupled electromechanical admittance for a generic PZT actuator-driven two-dimensional structure was developed. The model was then used to predict the power factor, the power dissipation, and the power requirement of the system. As a numerical example, the modeling approach was applied to a simply supported thin plate excited by a pair of PZT path actuators in pure bending mode. A parametric study was performed to examine the nature and components of electromechanical power flow and consumption in the active structure. An experiment was conducted to directly measure the complex electromechanical admittance of an integrated PZT/plate system to verify the theoretical model.