Nonlinear electric-mechanical behavior of a soft PZT-51 ferroelectric ceramic

In this investigation, the electric-mechanical response of a PZT ferroelect ric ceramic subjected to the combined electric-mechanical loads was experim entally observed. The effect of different compressive stress levels on the electromechanical response was examined. The stress-strain relationship was also measured. The ceramic sample was isolated from the test frame and the high voltage arcing were prevented effectively in the setup which promotes the precise measurement and makes the systemic experimental results availa ble. With a high voltage amplifier and a servo-hydraulic test frame, the bu tterfly shaped strain vs. electric field curves and the electric displaceme nt vs. electric field hysteresis loops of a soft PZT ceramic at different c ompressive stress levels were measured. The results show that the electric- mechanical coupled properties of the PZT ceramic are the function of the co mpressive stress. The switching criteria are given to account for the exper imental results and to analyze the nonlinear electric-mechanical behavior r elative to the domain switching process in this paper. (C) 1999 Kluwer Acad emic Publishers.