Homogenization and characterization of piezoelectric stack actuators by means of the inverse method

Numerical simulations of piezoelectric stack actuators are suitable to predict the mechanical and electrical performance in actuator applications in advance. The major conditions for reliable numerical simulations are a detailed knowledge regarding internal structure of the actuators as well as precise material parameters of all involved materials. Complex actuator structures and a composition of various materials, however, lead to challenging preparatory work and elaborate numerical simulations. In this contribution, we present an innovative and novel top-down approach, which simplifies the actuator structure by means of a homogenized, uniform model for only one fictive piezoelectric material with effective material parameters. These material parameters are determined through the inverse method, a simulation-based approach for identifying all small signal parameters of piezoelectric materials. In doing so, frequencyresolved electrical impedance and mechanical displacement measurements of the piezoelectric stack actuator serve as input quantities. Thus, all small signal parameters of the fictive material are determined in a very efficient way, which leads to excellent numerical simulation results with minimal effort.