Effects of lateral stress on the electromechanical response of ferroelectric ceramics: Experiments versus model

Mechanical depolarization is an important cause of failure in piezoelectric actuators and sensors. In this paper, the effects of one-dimensional lateral pressure on the linear and nonlinear behavior of PZT ceramics were experimentally studied. The experimental results show that the lateral pressure can change the crystal symmetry of the ceramic from infinity mm to mm2. A domain-switching model dividing each 180 degrees switching to two successive 90 degrees switching is proposed to explain the experimental results. Finally, based on the experimental results, a simple design is proposed to prevent piezoelectric sensors from mechanical depolarization. Meanwhile, the simple design is apt to increase the hydrostatic piezoelectric constant of the piezoelectric marine sensors, thus enhancing their sensitivity.