Electromechanical Analysis of Piezoelectric Stack Active Member Power Consumption

In this paper, the coupled electromechanical behavior of piezoelectric (PZT) stack active members has been studied to determine power consumption characteristics. The electromechanical admittance of a PZT stack active member has been derived and shown to be dependent on it's structural dynamics as well as on the dynamic characteristics of the host structure, which may be represented as a driving point structural impedance. The derivation of the coupled elec-tromechanical admittance of the device includes detailed modeling of the influences of the actuator housing, fixture, and host structure. These theoretical predictions were tested experimentally and good correlation was found. Additionally, a simple numerical case study was performed to demonstrate the utility of the analysis technique presented in this paper by determining the power consumption of a mechanical system (modeled as a single-degree-of-freedom spring-mass-damper system) driven by the PZT stack active member. The analysis approach presented in this paper is important for the design of active control systems, in particular for the design of energy efficient active control systems for space structures.