<title>Nonlinear finite element analysis of piezoceramic multilayer actuators</title>

Abstract

Piezoelectric multilayer actuators combine the advantages of large deflections, fast response time and, accurate repeatability. By using cofired multilayer structures deflections up to several microns in the case of stacked actuators and several millimeters for transducers operating in bending mode can be achieved. The high driving levels, however, lead to nonlinearities mainly caused by the ferroelectric hysteresis of the piezoceramic material. For an improved design of these complex transducers finite element analysis of the complete system is utilized. We have established a calculation scheme, now allowing full 3D-modeling of a piezoceramic multilayer actuator taking the nonlinear material behavior into account. The hysteretic effects caused by ferroelectricity are modeled using a macroscopic Preisach model describing the actual state of polarization. Furthermore, dependencies of the material parameters on the electric field strength and the mechanical stresses are considered by the implemented constitutive relation. Therewith, the calculation scheme allows the precise numerical analysis of a complex multilayered stack actuator.