Piezoelectric ring-stack actuator characterization and modeling for high-bandwidth application

Abstract

Piezoelectric materials are excellent actuator candidates due to their high frequency bandwidth. However, hysteresis and nonlinear material effects can reduce their overall performance, particularly when driven at high amplitudes and high frequencies. Of interest here is an application for high-frequency actuation. The demand for actuation authority requires careful characterization and accurate modeling of the piezoelectric actuator dynamics to ensure the intended performance. This paper presents such a characterization of a ring-shaped piezoelectric stack actuator. A series of experiments is presented to explore the ring stack actuator's response both under free boundary conditions and with spring-applied preloads. Fixed voltage tests conducted confirm the expected quasi-static response, while oscillatory tests exhibit dynamics that impact response at higher frequencies. Preload stiffnesses appear to minimally change the nominal displacement observed compared to the baseline, no-load case. While the preloads were small, the actuator showed qualitatively similar performance for the unloaded and several loaded cases.