Abstract
Piezoceramics are presently being used increasingly as sensors and actuators in a wide variety of electromechanical applications, for instance, piezoelectric fuel injectors in common rail diesel and gasoline engines. We will introduce the basic mesoscopic domain mechanisms typical of these materials and their relation to macroscopic hysteresis phenomena and piezoelectric properties. In the attempt to improve the performance and especially the reliability of the components, considerable efforts have been made in the development of predictive constitutive models for the coupled and nonβlinear electromechanical behaviour of piezoceramics. The success of such constitutive models depends strongly on the availability of suitable measurements. Supported by DFG, fruitful experimental work has been carried out for a commercial soft PZT polycrystalline material (PIC151, PI Ceramic) under coβaxial, coupled electromechanical loading at room temperature. Furthermore, we will discuss a micromechanical finite element simulation of a ferroelectric volume element, where each grain exhibits single crystal behaviour for the switching of its domains. Next, we will turn to macroscopic constitutive modeling. We will present a phenomenological as well as a micromechanically based model. We will present the application of these models to the analysis of poling processes of piezoceramic devices. The main purpose of this publication is to give a summary and to guide the reader to original papers for detailed reports. (Β© 2008 WILEYβVCH Verlag GmbH & Co. KGaA, Weinheim)